From 61cf45d0199041df1a8ba334b6bf4a3a13b7f904 Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Wed, 14 Sep 2011 15:06:00 -0400 Subject: encrypted-keys: create encrypted-keys directory Move all files associated with encrypted keys to keys/encrypted-keys. Signed-off-by: Mimi Zohar --- security/keys/Makefile | 2 +- security/keys/ecryptfs_format.c | 81 -- security/keys/ecryptfs_format.h | 30 - security/keys/encrypted-keys/Makefile | 5 + security/keys/encrypted-keys/ecryptfs_format.c | 81 ++ security/keys/encrypted-keys/ecryptfs_format.h | 30 + security/keys/encrypted-keys/encrypted.c | 1049 ++++++++++++++++++++++++ security/keys/encrypted-keys/encrypted.h | 54 ++ security/keys/encrypted.c | 1049 ------------------------ security/keys/encrypted.h | 54 -- 10 files changed, 1220 insertions(+), 1215 deletions(-) delete mode 100644 security/keys/ecryptfs_format.c delete mode 100644 security/keys/ecryptfs_format.h create mode 100644 security/keys/encrypted-keys/Makefile create mode 100644 security/keys/encrypted-keys/ecryptfs_format.c create mode 100644 security/keys/encrypted-keys/ecryptfs_format.h create mode 100644 security/keys/encrypted-keys/encrypted.c create mode 100644 security/keys/encrypted-keys/encrypted.h delete mode 100644 security/keys/encrypted.c delete mode 100644 security/keys/encrypted.h (limited to 'security') diff --git a/security/keys/Makefile b/security/keys/Makefile index b34cc6ee690..a56f1ffdc64 100644 --- a/security/keys/Makefile +++ b/security/keys/Makefile @@ -14,7 +14,7 @@ obj-y := \ user_defined.o obj-$(CONFIG_TRUSTED_KEYS) += trusted.o -obj-$(CONFIG_ENCRYPTED_KEYS) += ecryptfs_format.o encrypted.o +obj-$(CONFIG_ENCRYPTED_KEYS) += encrypted-keys/ obj-$(CONFIG_KEYS_COMPAT) += compat.o obj-$(CONFIG_PROC_FS) += proc.o obj-$(CONFIG_SYSCTL) += sysctl.o diff --git a/security/keys/ecryptfs_format.c b/security/keys/ecryptfs_format.c deleted file mode 100644 index 6daa3b6ff9e..00000000000 --- a/security/keys/ecryptfs_format.c +++ /dev/null @@ -1,81 +0,0 @@ -/* - * ecryptfs_format.c: helper functions for the encrypted key type - * - * Copyright (C) 2006 International Business Machines Corp. - * Copyright (C) 2010 Politecnico di Torino, Italy - * TORSEC group -- http://security.polito.it - * - * Authors: - * Michael A. Halcrow - * Tyler Hicks - * Roberto Sassu - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation, version 2 of the License. - */ - -#include -#include "ecryptfs_format.h" - -u8 *ecryptfs_get_auth_tok_key(struct ecryptfs_auth_tok *auth_tok) -{ - return auth_tok->token.password.session_key_encryption_key; -} -EXPORT_SYMBOL(ecryptfs_get_auth_tok_key); - -/* - * ecryptfs_get_versions() - * - * Source code taken from the software 'ecryptfs-utils' version 83. - * - */ -void ecryptfs_get_versions(int *major, int *minor, int *file_version) -{ - *major = ECRYPTFS_VERSION_MAJOR; - *minor = ECRYPTFS_VERSION_MINOR; - if (file_version) - *file_version = ECRYPTFS_SUPPORTED_FILE_VERSION; -} -EXPORT_SYMBOL(ecryptfs_get_versions); - -/* - * ecryptfs_fill_auth_tok - fill the ecryptfs_auth_tok structure - * - * Fill the ecryptfs_auth_tok structure with required ecryptfs data. - * The source code is inspired to the original function generate_payload() - * shipped with the software 'ecryptfs-utils' version 83. - * - */ -int ecryptfs_fill_auth_tok(struct ecryptfs_auth_tok *auth_tok, - const char *key_desc) -{ - int major, minor; - - ecryptfs_get_versions(&major, &minor, NULL); - auth_tok->version = (((uint16_t)(major << 8) & 0xFF00) - | ((uint16_t)minor & 0x00FF)); - auth_tok->token_type = ECRYPTFS_PASSWORD; - strncpy((char *)auth_tok->token.password.signature, key_desc, - ECRYPTFS_PASSWORD_SIG_SIZE); - auth_tok->token.password.session_key_encryption_key_bytes = - ECRYPTFS_MAX_KEY_BYTES; - /* - * Removed auth_tok->token.password.salt and - * auth_tok->token.password.session_key_encryption_key - * initialization from the original code - */ - /* TODO: Make the hash parameterizable via policy */ - auth_tok->token.password.flags |= - ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET; - /* The kernel code will encrypt the session key. */ - auth_tok->session_key.encrypted_key[0] = 0; - auth_tok->session_key.encrypted_key_size = 0; - /* Default; subject to change by kernel eCryptfs */ - auth_tok->token.password.hash_algo = PGP_DIGEST_ALGO_SHA512; - auth_tok->token.password.flags &= ~(ECRYPTFS_PERSISTENT_PASSWORD); - return 0; -} -EXPORT_SYMBOL(ecryptfs_fill_auth_tok); - -MODULE_LICENSE("GPL"); diff --git a/security/keys/ecryptfs_format.h b/security/keys/ecryptfs_format.h deleted file mode 100644 index 40294de238b..00000000000 --- a/security/keys/ecryptfs_format.h +++ /dev/null @@ -1,30 +0,0 @@ -/* - * ecryptfs_format.h: helper functions for the encrypted key type - * - * Copyright (C) 2006 International Business Machines Corp. - * Copyright (C) 2010 Politecnico di Torino, Italy - * TORSEC group -- http://security.polito.it - * - * Authors: - * Michael A. Halcrow - * Tyler Hicks - * Roberto Sassu - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation, version 2 of the License. - */ - -#ifndef __KEYS_ECRYPTFS_H -#define __KEYS_ECRYPTFS_H - -#include - -#define PGP_DIGEST_ALGO_SHA512 10 - -u8 *ecryptfs_get_auth_tok_key(struct ecryptfs_auth_tok *auth_tok); -void ecryptfs_get_versions(int *major, int *minor, int *file_version); -int ecryptfs_fill_auth_tok(struct ecryptfs_auth_tok *auth_tok, - const char *key_desc); - -#endif /* __KEYS_ECRYPTFS_H */ diff --git a/security/keys/encrypted-keys/Makefile b/security/keys/encrypted-keys/Makefile new file mode 100644 index 00000000000..cbd3f8de37b --- /dev/null +++ b/security/keys/encrypted-keys/Makefile @@ -0,0 +1,5 @@ +# +# Makefile for encrypted keys +# + +obj-$(CONFIG_ENCRYPTED_KEYS) += encrypted.o ecryptfs_format.o diff --git a/security/keys/encrypted-keys/ecryptfs_format.c b/security/keys/encrypted-keys/ecryptfs_format.c new file mode 100644 index 00000000000..6daa3b6ff9e --- /dev/null +++ b/security/keys/encrypted-keys/ecryptfs_format.c @@ -0,0 +1,81 @@ +/* + * ecryptfs_format.c: helper functions for the encrypted key type + * + * Copyright (C) 2006 International Business Machines Corp. + * Copyright (C) 2010 Politecnico di Torino, Italy + * TORSEC group -- http://security.polito.it + * + * Authors: + * Michael A. Halcrow + * Tyler Hicks + * Roberto Sassu + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, version 2 of the License. + */ + +#include +#include "ecryptfs_format.h" + +u8 *ecryptfs_get_auth_tok_key(struct ecryptfs_auth_tok *auth_tok) +{ + return auth_tok->token.password.session_key_encryption_key; +} +EXPORT_SYMBOL(ecryptfs_get_auth_tok_key); + +/* + * ecryptfs_get_versions() + * + * Source code taken from the software 'ecryptfs-utils' version 83. + * + */ +void ecryptfs_get_versions(int *major, int *minor, int *file_version) +{ + *major = ECRYPTFS_VERSION_MAJOR; + *minor = ECRYPTFS_VERSION_MINOR; + if (file_version) + *file_version = ECRYPTFS_SUPPORTED_FILE_VERSION; +} +EXPORT_SYMBOL(ecryptfs_get_versions); + +/* + * ecryptfs_fill_auth_tok - fill the ecryptfs_auth_tok structure + * + * Fill the ecryptfs_auth_tok structure with required ecryptfs data. + * The source code is inspired to the original function generate_payload() + * shipped with the software 'ecryptfs-utils' version 83. + * + */ +int ecryptfs_fill_auth_tok(struct ecryptfs_auth_tok *auth_tok, + const char *key_desc) +{ + int major, minor; + + ecryptfs_get_versions(&major, &minor, NULL); + auth_tok->version = (((uint16_t)(major << 8) & 0xFF00) + | ((uint16_t)minor & 0x00FF)); + auth_tok->token_type = ECRYPTFS_PASSWORD; + strncpy((char *)auth_tok->token.password.signature, key_desc, + ECRYPTFS_PASSWORD_SIG_SIZE); + auth_tok->token.password.session_key_encryption_key_bytes = + ECRYPTFS_MAX_KEY_BYTES; + /* + * Removed auth_tok->token.password.salt and + * auth_tok->token.password.session_key_encryption_key + * initialization from the original code + */ + /* TODO: Make the hash parameterizable via policy */ + auth_tok->token.password.flags |= + ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET; + /* The kernel code will encrypt the session key. */ + auth_tok->session_key.encrypted_key[0] = 0; + auth_tok->session_key.encrypted_key_size = 0; + /* Default; subject to change by kernel eCryptfs */ + auth_tok->token.password.hash_algo = PGP_DIGEST_ALGO_SHA512; + auth_tok->token.password.flags &= ~(ECRYPTFS_PERSISTENT_PASSWORD); + return 0; +} +EXPORT_SYMBOL(ecryptfs_fill_auth_tok); + +MODULE_LICENSE("GPL"); diff --git a/security/keys/encrypted-keys/ecryptfs_format.h b/security/keys/encrypted-keys/ecryptfs_format.h new file mode 100644 index 00000000000..40294de238b --- /dev/null +++ b/security/keys/encrypted-keys/ecryptfs_format.h @@ -0,0 +1,30 @@ +/* + * ecryptfs_format.h: helper functions for the encrypted key type + * + * Copyright (C) 2006 International Business Machines Corp. + * Copyright (C) 2010 Politecnico di Torino, Italy + * TORSEC group -- http://security.polito.it + * + * Authors: + * Michael A. Halcrow + * Tyler Hicks + * Roberto Sassu + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, version 2 of the License. + */ + +#ifndef __KEYS_ECRYPTFS_H +#define __KEYS_ECRYPTFS_H + +#include + +#define PGP_DIGEST_ALGO_SHA512 10 + +u8 *ecryptfs_get_auth_tok_key(struct ecryptfs_auth_tok *auth_tok); +void ecryptfs_get_versions(int *major, int *minor, int *file_version); +int ecryptfs_fill_auth_tok(struct ecryptfs_auth_tok *auth_tok, + const char *key_desc); + +#endif /* __KEYS_ECRYPTFS_H */ diff --git a/security/keys/encrypted-keys/encrypted.c b/security/keys/encrypted-keys/encrypted.c new file mode 100644 index 00000000000..e7eca9ec4c6 --- /dev/null +++ b/security/keys/encrypted-keys/encrypted.c @@ -0,0 +1,1049 @@ +/* + * Copyright (C) 2010 IBM Corporation + * Copyright (C) 2010 Politecnico di Torino, Italy + * TORSEC group -- http://security.polito.it + * + * Authors: + * Mimi Zohar + * Roberto Sassu + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, version 2 of the License. + * + * See Documentation/security/keys-trusted-encrypted.txt + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "encrypted.h" +#include "ecryptfs_format.h" + +static const char KEY_TRUSTED_PREFIX[] = "trusted:"; +static const char KEY_USER_PREFIX[] = "user:"; +static const char hash_alg[] = "sha256"; +static const char hmac_alg[] = "hmac(sha256)"; +static const char blkcipher_alg[] = "cbc(aes)"; +static const char key_format_default[] = "default"; +static const char key_format_ecryptfs[] = "ecryptfs"; +static unsigned int ivsize; +static int blksize; + +#define KEY_TRUSTED_PREFIX_LEN (sizeof (KEY_TRUSTED_PREFIX) - 1) +#define KEY_USER_PREFIX_LEN (sizeof (KEY_USER_PREFIX) - 1) +#define KEY_ECRYPTFS_DESC_LEN 16 +#define HASH_SIZE SHA256_DIGEST_SIZE +#define MAX_DATA_SIZE 4096 +#define MIN_DATA_SIZE 20 + +struct sdesc { + struct shash_desc shash; + char ctx[]; +}; + +static struct crypto_shash *hashalg; +static struct crypto_shash *hmacalg; + +enum { + Opt_err = -1, Opt_new, Opt_load, Opt_update +}; + +enum { + Opt_error = -1, Opt_default, Opt_ecryptfs +}; + +static const match_table_t key_format_tokens = { + {Opt_default, "default"}, + {Opt_ecryptfs, "ecryptfs"}, + {Opt_error, NULL} +}; + +static const match_table_t key_tokens = { + {Opt_new, "new"}, + {Opt_load, "load"}, + {Opt_update, "update"}, + {Opt_err, NULL} +}; + +static int aes_get_sizes(void) +{ + struct crypto_blkcipher *tfm; + + tfm = crypto_alloc_blkcipher(blkcipher_alg, 0, CRYPTO_ALG_ASYNC); + if (IS_ERR(tfm)) { + pr_err("encrypted_key: failed to alloc_cipher (%ld)\n", + PTR_ERR(tfm)); + return PTR_ERR(tfm); + } + ivsize = crypto_blkcipher_ivsize(tfm); + blksize = crypto_blkcipher_blocksize(tfm); + crypto_free_blkcipher(tfm); + return 0; +} + +/* + * valid_ecryptfs_desc - verify the description of a new/loaded encrypted key + * + * The description of a encrypted key with format 'ecryptfs' must contain + * exactly 16 hexadecimal characters. + * + */ +static int valid_ecryptfs_desc(const char *ecryptfs_desc) +{ + int i; + + if (strlen(ecryptfs_desc) != KEY_ECRYPTFS_DESC_LEN) { + pr_err("encrypted_key: key description must be %d hexadecimal " + "characters long\n", KEY_ECRYPTFS_DESC_LEN); + return -EINVAL; + } + + for (i = 0; i < KEY_ECRYPTFS_DESC_LEN; i++) { + if (!isxdigit(ecryptfs_desc[i])) { + pr_err("encrypted_key: key description must contain " + "only hexadecimal characters\n"); + return -EINVAL; + } + } + + return 0; +} + +/* + * valid_master_desc - verify the 'key-type:desc' of a new/updated master-key + * + * key-type:= "trusted:" | "user:" + * desc:= master-key description + * + * Verify that 'key-type' is valid and that 'desc' exists. On key update, + * only the master key description is permitted to change, not the key-type. + * The key-type remains constant. + * + * On success returns 0, otherwise -EINVAL. + */ +static int valid_master_desc(const char *new_desc, const char *orig_desc) +{ + if (!memcmp(new_desc, KEY_TRUSTED_PREFIX, KEY_TRUSTED_PREFIX_LEN)) { + if (strlen(new_desc) == KEY_TRUSTED_PREFIX_LEN) + goto out; + if (orig_desc) + if (memcmp(new_desc, orig_desc, KEY_TRUSTED_PREFIX_LEN)) + goto out; + } else if (!memcmp(new_desc, KEY_USER_PREFIX, KEY_USER_PREFIX_LEN)) { + if (strlen(new_desc) == KEY_USER_PREFIX_LEN) + goto out; + if (orig_desc) + if (memcmp(new_desc, orig_desc, KEY_USER_PREFIX_LEN)) + goto out; + } else + goto out; + return 0; +out: + return -EINVAL; +} + +/* + * datablob_parse - parse the keyctl data + * + * datablob format: + * new [] + * load [] + * + * update + * + * Tokenizes a copy of the keyctl data, returning a pointer to each token, + * which is null terminated. + * + * On success returns 0, otherwise -EINVAL. + */ +static int datablob_parse(char *datablob, const char **format, + char **master_desc, char **decrypted_datalen, + char **hex_encoded_iv) +{ + substring_t args[MAX_OPT_ARGS]; + int ret = -EINVAL; + int key_cmd; + int key_format; + char *p, *keyword; + + keyword = strsep(&datablob, " \t"); + if (!keyword) { + pr_info("encrypted_key: insufficient parameters specified\n"); + return ret; + } + key_cmd = match_token(keyword, key_tokens, args); + + /* Get optional format: default | ecryptfs */ + p = strsep(&datablob, " \t"); + if (!p) { + pr_err("encrypted_key: insufficient parameters specified\n"); + return ret; + } + + key_format = match_token(p, key_format_tokens, args); + switch (key_format) { + case Opt_ecryptfs: + case Opt_default: + *format = p; + *master_desc = strsep(&datablob, " \t"); + break; + case Opt_error: + *master_desc = p; + break; + } + + if (!*master_desc) { + pr_info("encrypted_key: master key parameter is missing\n"); + goto out; + } + + if (valid_master_desc(*master_desc, NULL) < 0) { + pr_info("encrypted_key: master key parameter \'%s\' " + "is invalid\n", *master_desc); + goto out; + } + + if (decrypted_datalen) { + *decrypted_datalen = strsep(&datablob, " \t"); + if (!*decrypted_datalen) { + pr_info("encrypted_key: keylen parameter is missing\n"); + goto out; + } + } + + switch (key_cmd) { + case Opt_new: + if (!decrypted_datalen) { + pr_info("encrypted_key: keyword \'%s\' not allowed " + "when called from .update method\n", keyword); + break; + } + ret = 0; + break; + case Opt_load: + if (!decrypted_datalen) { + pr_info("encrypted_key: keyword \'%s\' not allowed " + "when called from .update method\n", keyword); + break; + } + *hex_encoded_iv = strsep(&datablob, " \t"); + if (!*hex_encoded_iv) { + pr_info("encrypted_key: hex blob is missing\n"); + break; + } + ret = 0; + break; + case Opt_update: + if (decrypted_datalen) { + pr_info("encrypted_key: keyword \'%s\' not allowed " + "when called from .instantiate method\n", + keyword); + break; + } + ret = 0; + break; + case Opt_err: + pr_info("encrypted_key: keyword \'%s\' not recognized\n", + keyword); + break; + } +out: + return ret; +} + +/* + * datablob_format - format as an ascii string, before copying to userspace + */ +static char *datablob_format(struct encrypted_key_payload *epayload, + size_t asciiblob_len) +{ + char *ascii_buf, *bufp; + u8 *iv = epayload->iv; + int len; + int i; + + ascii_buf = kmalloc(asciiblob_len + 1, GFP_KERNEL); + if (!ascii_buf) + goto out; + + ascii_buf[asciiblob_len] = '\0'; + + /* copy datablob master_desc and datalen strings */ + len = sprintf(ascii_buf, "%s %s %s ", epayload->format, + epayload->master_desc, epayload->datalen); + + /* convert the hex encoded iv, encrypted-data and HMAC to ascii */ + bufp = &ascii_buf[len]; + for (i = 0; i < (asciiblob_len - len) / 2; i++) + bufp = pack_hex_byte(bufp, iv[i]); +out: + return ascii_buf; +} + +/* + * request_trusted_key - request the trusted key + * + * Trusted keys are sealed to PCRs and other metadata. Although userspace + * manages both trusted/encrypted key-types, like the encrypted key type + * data, trusted key type data is not visible decrypted from userspace. + */ +static struct key *request_trusted_key(const char *trusted_desc, + u8 **master_key, size_t *master_keylen) +{ + struct trusted_key_payload *tpayload; + struct key *tkey; + + tkey = request_key(&key_type_trusted, trusted_desc, NULL); + if (IS_ERR(tkey)) + goto error; + + down_read(&tkey->sem); + tpayload = rcu_dereference(tkey->payload.data); + *master_key = tpayload->key; + *master_keylen = tpayload->key_len; +error: + return tkey; +} + +/* + * request_user_key - request the user key + * + * Use a user provided key to encrypt/decrypt an encrypted-key. + */ +static struct key *request_user_key(const char *master_desc, u8 **master_key, + size_t *master_keylen) +{ + struct user_key_payload *upayload; + struct key *ukey; + + ukey = request_key(&key_type_user, master_desc, NULL); + if (IS_ERR(ukey)) + goto error; + + down_read(&ukey->sem); + upayload = rcu_dereference(ukey->payload.data); + *master_key = upayload->data; + *master_keylen = upayload->datalen; +error: + return ukey; +} + +static struct sdesc *alloc_sdesc(struct crypto_shash *alg) +{ + struct sdesc *sdesc; + int size; + + size = sizeof(struct shash_desc) + crypto_shash_descsize(alg); + sdesc = kmalloc(size, GFP_KERNEL); + if (!sdesc) + return ERR_PTR(-ENOMEM); + sdesc->shash.tfm = alg; + sdesc->shash.flags = 0x0; + return sdesc; +} + +static int calc_hmac(u8 *digest, const u8 *key, unsigned int keylen, + const u8 *buf, unsigned int buflen) +{ + struct sdesc *sdesc; + int ret; + + sdesc = alloc_sdesc(hmacalg); + if (IS_ERR(sdesc)) { + pr_info("encrypted_key: can't alloc %s\n", hmac_alg); + return PTR_ERR(sdesc); + } + + ret = crypto_shash_setkey(hmacalg, key, keylen); + if (!ret) + ret = crypto_shash_digest(&sdesc->shash, buf, buflen, digest); + kfree(sdesc); + return ret; +} + +static int calc_hash(u8 *digest, const u8 *buf, unsigned int buflen) +{ + struct sdesc *sdesc; + int ret; + + sdesc = alloc_sdesc(hashalg); + if (IS_ERR(sdesc)) { + pr_info("encrypted_key: can't alloc %s\n", hash_alg); + return PTR_ERR(sdesc); + } + + ret = crypto_shash_digest(&sdesc->shash, buf, buflen, digest); + kfree(sdesc); + return ret; +} + +enum derived_key_type { ENC_KEY, AUTH_KEY }; + +/* Derive authentication/encryption key from trusted key */ +static int get_derived_key(u8 *derived_key, enum derived_key_type key_type, + const u8 *master_key, size_t master_keylen) +{ + u8 *derived_buf; + unsigned int derived_buf_len; + int ret; + + derived_buf_len = strlen("AUTH_KEY") + 1 + master_keylen; + if (derived_buf_len < HASH_SIZE) + derived_buf_len = HASH_SIZE; + + derived_buf = kzalloc(derived_buf_len, GFP_KERNEL); + if (!derived_buf) { + pr_err("encrypted_key: out of memory\n"); + return -ENOMEM; + } + if (key_type) + strcpy(derived_buf, "AUTH_KEY"); + else + strcpy(derived_buf, "ENC_KEY"); + + memcpy(derived_buf + strlen(derived_buf) + 1, master_key, + master_keylen); + ret = calc_hash(derived_key, derived_buf, derived_buf_len); + kfree(derived_buf); + return ret; +} + +static int init_blkcipher_desc(struct blkcipher_desc *desc, const u8 *key, + unsigned int key_len, const u8 *iv, + unsigned int ivsize) +{ + int ret; + + desc->tfm = crypto_alloc_blkcipher(blkcipher_alg, 0, CRYPTO_ALG_ASYNC); + if (IS_ERR(desc->tfm)) { + pr_err("encrypted_key: failed to load %s transform (%ld)\n", + blkcipher_alg, PTR_ERR(desc->tfm)); + return PTR_ERR(desc->tfm); + } + desc->flags = 0; + + ret = crypto_blkcipher_setkey(desc->tfm, key, key_len); + if (ret < 0) { + pr_err("encrypted_key: failed to setkey (%d)\n", ret); + crypto_free_blkcipher(desc->tfm); + return ret; + } + crypto_blkcipher_set_iv(desc->tfm, iv, ivsize); + return 0; +} + +static struct key *request_master_key(struct encrypted_key_payload *epayload, + u8 **master_key, size_t *master_keylen) +{ + struct key *mkey = NULL; + + if (!strncmp(epayload->master_desc, KEY_TRUSTED_PREFIX, + KEY_TRUSTED_PREFIX_LEN)) { + mkey = request_trusted_key(epayload->master_desc + + KEY_TRUSTED_PREFIX_LEN, + master_key, master_keylen); + } else if (!strncmp(epayload->master_desc, KEY_USER_PREFIX, + KEY_USER_PREFIX_LEN)) { + mkey = request_user_key(epayload->master_desc + + KEY_USER_PREFIX_LEN, + master_key, master_keylen); + } else + goto out; + + if (IS_ERR(mkey)) { + pr_info("encrypted_key: key %s not found", + epayload->master_desc); + goto out; + } + + dump_master_key(*master_key, *master_keylen); +out: + return mkey; +} + +/* Before returning data to userspace, encrypt decrypted data. */ +static int derived_key_encrypt(struct encrypted_key_payload *epayload, + const u8 *derived_key, + unsigned int derived_keylen) +{ + struct scatterlist sg_in[2]; + struct scatterlist sg_out[1]; + struct blkcipher_desc desc; + unsigned int encrypted_datalen; + unsigned int padlen; + char pad[16]; + int ret; + + encrypted_datalen = roundup(epayload->decrypted_datalen, blksize); + padlen = encrypted_datalen - epayload->decrypted_datalen; + + ret = init_blkcipher_desc(&desc, derived_key, derived_keylen, + epayload->iv, ivsize); + if (ret < 0) + goto out; + dump_decrypted_data(epayload); + + memset(pad, 0, sizeof pad); + sg_init_table(sg_in, 2); + sg_set_buf(&sg_in[0], epayload->decrypted_data, + epayload->decrypted_datalen); + sg_set_buf(&sg_in[1], pad, padlen); + + sg_init_table(sg_out, 1); + sg_set_buf(sg_out, epayload->encrypted_data, encrypted_datalen); + + ret = crypto_blkcipher_encrypt(&desc, sg_out, sg_in, encrypted_datalen); + crypto_free_blkcipher(desc.tfm); + if (ret < 0) + pr_err("encrypted_key: failed to encrypt (%d)\n", ret); + else + dump_encrypted_data(epayload, encrypted_datalen); +out: + return ret; +} + +static int datablob_hmac_append(struct encrypted_key_payload *epayload, + const u8 *master_key, size_t master_keylen) +{ + u8 derived_key[HASH_SIZE]; + u8 *digest; + int ret; + + ret = get_derived_key(derived_key, AUTH_KEY, master_key, master_keylen); + if (ret < 0) + goto out; + + digest = epayload->format + epayload->datablob_len; + ret = calc_hmac(digest, derived_key, sizeof derived_key, + epayload->format, epayload->datablob_len); + if (!ret) + dump_hmac(NULL, digest, HASH_SIZE); +out: + return ret; +} + +/* verify HMAC before decrypting encrypted key */ +static int datablob_hmac_verify(struct encrypted_key_payload *epayload, + const u8 *format, const u8 *master_key, + size_t master_keylen) +{ + u8 derived_key[HASH_SIZE]; + u8 digest[HASH_SIZE]; + int ret; + char *p; + unsigned short len; + + ret = get_derived_key(derived_key, AUTH_KEY, master_key, master_keylen); + if (ret < 0) + goto out; + + len = epayload->datablob_len; + if (!format) { + p = epayload->master_desc; + len -= strlen(epayload->format) + 1; + } else + p = epayload->format; + + ret = calc_hmac(digest, derived_key, sizeof derived_key, p, len); + if (ret < 0) + goto out; + ret = memcmp(digest, epayload->format + epayload->datablob_len, + sizeof digest); + if (ret) { + ret = -EINVAL; + dump_hmac("datablob", + epayload->format + epayload->datablob_len, + HASH_SIZE); + dump_hmac("calc", digest, HASH_SIZE); + } +out: + return ret; +} + +static int derived_key_decrypt(struct encrypted_key_payload *epayload, + const u8 *derived_key, + unsigned int derived_keylen) +{ + struct scatterlist sg_in[1]; + struct scatterlist sg_out[2]; + struct blkcipher_desc desc; + unsigned int encrypted_datalen; + char pad[16]; + int ret; + + encrypted_datalen = roundup(epayload->decrypted_datalen, blksize); + ret = init_blkcipher_desc(&desc, derived_key, derived_keylen, + epayload->iv, ivsize); + if (ret < 0) + goto out; + dump_encrypted_data(epayload, encrypted_datalen); + + memset(pad, 0, sizeof pad); + sg_init_table(sg_in, 1); + sg_init_table(sg_out, 2); + sg_set_buf(sg_in, epayload->encrypted_data, encrypted_datalen); + sg_set_buf(&sg_out[0], epayload->decrypted_data, + epayload->decrypted_datalen); + sg_set_buf(&sg_out[1], pad, sizeof pad); + + ret = crypto_blkcipher_decrypt(&desc, sg_out, sg_in, encrypted_datalen); + crypto_free_blkcipher(desc.tfm); + if (ret < 0) + goto out; + dump_decrypted_data(epayload); +out: + return ret; +} + +/* Allocate memory for decrypted key and datablob. */ +static struct encrypted_key_payload *encrypted_key_alloc(struct key *key, + const char *format, + const char *master_desc, + const char *datalen) +{ + struct encrypted_key_payload *epayload = NULL; + unsigned short datablob_len; + unsigned short decrypted_datalen; + unsigned short payload_datalen; + unsigned int encrypted_datalen; + unsigned int format_len; + long dlen; + int ret; + + ret = strict_strtol(datalen, 10, &dlen); + if (ret < 0 || dlen < MIN_DATA_SIZE || dlen > MAX_DATA_SIZE) + return ERR_PTR(-EINVAL); + + format_len = (!format) ? strlen(key_format_default) : strlen(format); + decrypted_datalen = dlen; + payload_datalen = decrypted_datalen; + if (format && !strcmp(format, key_format_ecryptfs)) { + if (dlen != ECRYPTFS_MAX_KEY_BYTES) { + pr_err("encrypted_key: keylen for the ecryptfs format " + "must be equal to %d bytes\n", + ECRYPTFS_MAX_KEY_BYTES); + return ERR_PTR(-EINVAL); + } + decrypted_datalen = ECRYPTFS_MAX_KEY_BYTES; + payload_datalen = sizeof(struct ecryptfs_auth_tok); + } + + encrypted_datalen = roundup(decrypted_datalen, blksize); + + datablob_len = format_len + 1 + strlen(master_desc) + 1 + + strlen(datalen) + 1 + ivsize + 1 + encrypted_datalen; + + ret = key_payload_reserve(key, payload_datalen + datablob_len + + HASH_SIZE + 1); + if (ret < 0) + return ERR_PTR(ret); + + epayload = kzalloc(sizeof(*epayload) + payload_datalen + + datablob_len + HASH_SIZE + 1, GFP_KERNEL); + if (!epayload) + return ERR_PTR(-ENOMEM); + + epayload->payload_datalen = payload_datalen; + epayload->decrypted_datalen = decrypted_datalen; + epayload->datablob_len = datablob_len; + return epayload; +} + +static int encrypted_key_decrypt(struct encrypted_key_payload *epayload, + const char *format, const char *hex_encoded_iv) +{ + struct key *mkey; + u8 derived_key[HASH_SIZE]; + u8 *master_key; + u8 *hmac; + const char *hex_encoded_data; + unsigned int encrypted_datalen; + size_t master_keylen; + size_t asciilen; + int ret; + + encrypted_datalen = roundup(epayload->decrypted_datalen, blksize); + asciilen = (ivsize + 1 + encrypted_datalen + HASH_SIZE) * 2; + if (strlen(hex_encoded_iv) != asciilen) + return -EINVAL; + + hex_encoded_data = hex_encoded_iv + (2 * ivsize) + 2; + hex2bin(epayload->iv, hex_encoded_iv, ivsize); + hex2bin(epayload->encrypted_data, hex_encoded_data, encrypted_datalen); + + hmac = epayload->format + epayload->datablob_len; + hex2bin(hmac, hex_encoded_data + (encrypted_datalen * 2), HASH_SIZE); + + mkey = request_master_key(epayload, &master_key, &master_keylen); + if (IS_ERR(mkey)) + return PTR_ERR(mkey); + + ret = datablob_hmac_verify(epayload, format, master_key, master_keylen); + if (ret < 0) { + pr_err("encrypted_key: bad hmac (%d)\n", ret); + goto out; + } + + ret = get_derived_key(derived_key, ENC_KEY, master_key, master_keylen); + if (ret < 0) + goto out; + + ret = derived_key_decrypt(epayload, derived_key, sizeof derived_key); + if (ret < 0) + pr_err("encrypted_key: failed to decrypt key (%d)\n", ret); +out: + up_read(&mkey->sem); + key_put(mkey); + return ret; +} + +static void __ekey_init(struct encrypted_key_payload *epayload, + const char *format, const char *master_desc, + const char *datalen) +{ + unsigned int format_len; + + format_len = (!format) ? strlen(key_format_default) : strlen(format); + epayload->format = epayload->payload_data + epayload->payload_datalen; + epayload->master_desc = epayload->format + format_len + 1; + epayload->datalen = epayload->master_desc + strlen(master_desc) + 1; + epayload->iv = epayload->datalen + strlen(datalen) + 1; + epayload->encrypted_data = epayload->iv + ivsize + 1; + epayload->decrypted_data = epayload->payload_data; + + if (!format) + memcpy(epayload->format, key_format_default, format_len); + else { + if (!strcmp(format, key_format_ecryptfs)) + epayload->decrypted_data = + ecryptfs_get_auth_tok_key((struct ecryptfs_auth_tok *)epayload->payload_data); + + memcpy(epayload->format, format, format_len); + } + + memcpy(epayload->master_desc, master_desc, strlen(master_desc)); + memcpy(epayload->datalen, datalen, strlen(datalen)); +} + +/* + * encrypted_init - initialize an encrypted key + * + * For a new key, use a random number for both the iv and data + * itself. For an old key, decrypt the hex encoded data. + */ +static int encrypted_init(struct encrypted_key_payload *epayload, + const char *key_desc, const char *format, + const char *master_desc, const char *datalen, + const char *hex_encoded_iv) +{ + int ret = 0; + + if (format && !strcmp(format, key_format_ecryptfs)) { + ret = valid_ecryptfs_desc(key_desc); + if (ret < 0) + return ret; + + ecryptfs_fill_auth_tok((struct ecryptfs_auth_tok *)epayload->payload_data, + key_desc); + } + + __ekey_init(epayload, format, master_desc, datalen); + if (!hex_encoded_iv) { + get_random_bytes(epayload->iv, ivsize); + + get_random_bytes(epayload->decrypted_data, + epayload->decrypted_datalen); + } else + ret = encrypted_key_decrypt(epayload, format, hex_encoded_iv); + return ret; +} + +/* + * encrypted_instantiate - instantiate an encrypted key + * + * Decrypt an existing encrypted datablob or create a new encrypted key + * based on a kernel random number. + * + * On success, return 0. Otherwise return errno. + */ +static int encrypted_instantiate(struct key *key, const void *data, + size_t datalen) +{ + struct encrypted_key_payload *epayload = NULL; + char *datablob = NULL; + const char *format = NULL; + char *master_desc = NULL; + char *decrypted_datalen = NULL; + char *hex_encoded_iv = NULL; + int ret; + + if (datalen <= 0 || datalen > 32767 || !data) + return -EINVAL; + + datablob = kmalloc(datalen + 1, GFP_KERNEL); + if (!datablob) + return -ENOMEM; + datablob[datalen] = 0; + memcpy(datablob, data, datalen); + ret = datablob_parse(datablob, &format, &master_desc, + &decrypted_datalen, &hex_encoded_iv); + if (ret < 0) + goto out; + + epayload = encrypted_key_alloc(key, format, master_desc, + decrypted_datalen); + if (IS_ERR(epayload)) { + ret = PTR_ERR(epayload); + goto out; + } + ret = encrypted_init(epayload, key->description, format, master_desc, + decrypted_datalen, hex_encoded_iv); + if (ret < 0) { + kfree(epayload); + goto out; + } + + rcu_assign_pointer(key->payload.data, epayload); +out: + kfree(datablob); + return ret; +} + +static void encrypted_rcu_free(struct rcu_head *rcu) +{ + struct encrypted_key_payload *epayload; + + epayload = container_of(rcu, struct encrypted_key_payload, rcu); + memset(epayload->decrypted_data, 0, epayload->decrypted_datalen); + kfree(epayload); +} + +/* + * encrypted_update - update the master key description + * + * Change the master key description for an existing encrypted key. + * The next read will return an encrypted datablob using the new + * master key description. + * + * On success, return 0. Otherwise return errno. + */ +static int encrypted_update(struct key *key, const void *data, size_t datalen) +{ + struct encrypted_key_payload *epayload = key->payload.data; + struct encrypted_key_payload *new_epayload; + char *buf; + char *new_master_desc = NULL; + const char *format = NULL; + int ret = 0; + + if (datalen <= 0 || datalen > 32767 || !data) + return -EINVAL; + + buf = kmalloc(datalen + 1, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + buf[datalen] = 0; + memcpy(buf, data, datalen); + ret = datablob_parse(buf, &format, &new_master_desc, NULL, NULL); + if (ret < 0) + goto out; + + ret = valid_master_desc(new_master_desc, epayload->master_desc); + if (ret < 0) + goto out; + + new_epayload = encrypted_key_alloc(key, epayload->format, + new_master_desc, epayload->datalen); + if (IS_ERR(new_epayload)) { + ret = PTR_ERR(new_epayload); + goto out; + } + + __ekey_init(new_epayload, epayload->format, new_master_desc, + epayload->datalen); + + memcpy(new_epayload->iv, epayload->iv, ivsize); + memcpy(new_epayload->payload_data, epayload->payload_data, + epayload->payload_datalen); + + rcu_assign_pointer(key->payload.data, new_epayload); + call_rcu(&epayload->rcu, encrypted_rcu_free); +out: + kfree(buf); + return ret; +} + +/* + * encrypted_read - format and copy the encrypted data to userspace + * + * The resulting datablob format is: + * + * + * On success, return to userspace the encrypted key datablob size. + */ +static long encrypted_read(const struct key *key, char __user *buffer, + size_t buflen) +{ + struct encrypted_key_payload *epayload; + struct key *mkey; + u8 *master_key; + size_t master_keylen; + char derived_key[HASH_SIZE]; + char *ascii_buf; + size_t asciiblob_len; + int ret; + + epayload = rcu_dereference_key(key); + + /* returns the hex encoded iv, encrypted-data, and hmac as ascii */ + asciiblob_len = epayload->datablob_len + ivsize + 1 + + roundup(epayload->decrypted_datalen, blksize) + + (HASH_SIZE * 2); + + if (!buffer || buflen < asciiblob_len) + return asciiblob_len; + + mkey = request_master_key(epayload, &master_key, &master_keylen); + if (IS_ERR(mkey)) + return PTR_ERR(mkey); + + ret = get_derived_key(derived_key, ENC_KEY, master_key, master_keylen); + if (ret < 0) + goto out; + + ret = derived_key_encrypt(epayload, derived_key, sizeof derived_key); + if (ret < 0) + goto out; + + ret = datablob_hmac_append(epayload, master_key, master_keylen); + if (ret < 0) + goto out; + + ascii_buf = datablob_format(epayload, asciiblob_len); + if (!ascii_buf) { + ret = -ENOMEM; + goto out; + } + + up_read(&mkey->sem); + key_put(mkey); + + if (copy_to_user(buffer, ascii_buf, asciiblob_len) != 0) + ret = -EFAULT; + kfree(ascii_buf); + + return asciiblob_len; +out: + up_read(&mkey->sem); + key_put(mkey); + return ret; +} + +/* + * encrypted_destroy - before freeing the key, clear the decrypted data + * + * Before freeing the key, clear the memory containing the decrypted + * key data. + */ +static void encrypted_destroy(struct key *key) +{ + struct encrypted_key_payload *epayload = key->payload.data; + + if (!epayload) + return; + + memset(epayload->decrypted_data, 0, epayload->decrypted_datalen); + kfree(key->payload.data); +} + +struct key_type key_type_encrypted = { + .name = "encrypted", + .instantiate = encrypted_instantiate, + .update = encrypted_update, + .match = user_match, + .destroy = encrypted_destroy, + .describe = user_describe, + .read = encrypted_read, +}; +EXPORT_SYMBOL_GPL(key_type_encrypted); + +static void encrypted_shash_release(void) +{ + if (hashalg) + crypto_free_shash(hashalg); + if (hmacalg) + crypto_free_shash(hmacalg); +} + +static int __init encrypted_shash_alloc(void) +{ + int ret; + + hmacalg = crypto_alloc_shash(hmac_alg, 0, CRYPTO_ALG_ASYNC); + if (IS_ERR(hmacalg)) { + pr_info("encrypted_key: could not allocate crypto %s\n", + hmac_alg); + return PTR_ERR(hmacalg); + } + + hashalg = crypto_alloc_shash(hash_alg, 0, CRYPTO_ALG_ASYNC); + if (IS_ERR(hashalg)) { + pr_info("encrypted_key: could not allocate crypto %s\n", + hash_alg); + ret = PTR_ERR(hashalg); + goto hashalg_fail; + } + + return 0; + +hashalg_fail: + crypto_free_shash(hmacalg); + return ret; +} + +static int __init init_encrypted(void) +{ + int ret; + + ret = encrypted_shash_alloc(); + if (ret < 0) + return ret; + ret = register_key_type(&key_type_encrypted); + if (ret < 0) + goto out; + return aes_get_sizes(); +out: + encrypted_shash_release(); + return ret; + +} + +static void __exit cleanup_encrypted(void) +{ + encrypted_shash_release(); + unregister_key_type(&key_type_encrypted); +} + +late_initcall(init_encrypted); +module_exit(cleanup_encrypted); + +MODULE_LICENSE("GPL"); diff --git a/security/keys/encrypted-keys/encrypted.h b/security/keys/encrypted-keys/encrypted.h new file mode 100644 index 00000000000..cef5e2f2b7d --- /dev/null +++ b/security/keys/encrypted-keys/encrypted.h @@ -0,0 +1,54 @@ +#ifndef __ENCRYPTED_KEY_H +#define __ENCRYPTED_KEY_H + +#define ENCRYPTED_DEBUG 0 + +#if ENCRYPTED_DEBUG +static inline void dump_master_key(const u8 *master_key, size_t master_keylen) +{ + print_hex_dump(KERN_ERR, "master key: ", DUMP_PREFIX_NONE, 32, 1, + master_key, master_keylen, 0); +} + +static inline void dump_decrypted_data(struct encrypted_key_payload *epayload) +{ + print_hex_dump(KERN_ERR, "decrypted data: ", DUMP_PREFIX_NONE, 32, 1, + epayload->decrypted_data, + epayload->decrypted_datalen, 0); +} + +static inline void dump_encrypted_data(struct encrypted_key_payload *epayload, + unsigned int encrypted_datalen) +{ + print_hex_dump(KERN_ERR, "encrypted data: ", DUMP_PREFIX_NONE, 32, 1, + epayload->encrypted_data, encrypted_datalen, 0); +} + +static inline void dump_hmac(const char *str, const u8 *digest, + unsigned int hmac_size) +{ + if (str) + pr_info("encrypted_key: %s", str); + print_hex_dump(KERN_ERR, "hmac: ", DUMP_PREFIX_NONE, 32, 1, digest, + hmac_size, 0); +} +#else +static inline void dump_master_key(const u8 *master_key, size_t master_keylen) +{ +} + +static inline void dump_decrypted_data(struct encrypted_key_payload *epayload) +{ +} + +static inline void dump_encrypted_data(struct encrypted_key_payload *epayload, + unsigned int encrypted_datalen) +{ +} + +static inline void dump_hmac(const char *str, const u8 *digest, + unsigned int hmac_size) +{ +} +#endif +#endif diff --git a/security/keys/encrypted.c b/security/keys/encrypted.c deleted file mode 100644 index e7eca9ec4c6..00000000000 --- a/security/keys/encrypted.c +++ /dev/null @@ -1,1049 +0,0 @@ -/* - * Copyright (C) 2010 IBM Corporation - * Copyright (C) 2010 Politecnico di Torino, Italy - * TORSEC group -- http://security.polito.it - * - * Authors: - * Mimi Zohar - * Roberto Sassu - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation, version 2 of the License. - * - * See Documentation/security/keys-trusted-encrypted.txt - */ - -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#include "encrypted.h" -#include "ecryptfs_format.h" - -static const char KEY_TRUSTED_PREFIX[] = "trusted:"; -static const char KEY_USER_PREFIX[] = "user:"; -static const char hash_alg[] = "sha256"; -static const char hmac_alg[] = "hmac(sha256)"; -static const char blkcipher_alg[] = "cbc(aes)"; -static const char key_format_default[] = "default"; -static const char key_format_ecryptfs[] = "ecryptfs"; -static unsigned int ivsize; -static int blksize; - -#define KEY_TRUSTED_PREFIX_LEN (sizeof (KEY_TRUSTED_PREFIX) - 1) -#define KEY_USER_PREFIX_LEN (sizeof (KEY_USER_PREFIX) - 1) -#define KEY_ECRYPTFS_DESC_LEN 16 -#define HASH_SIZE SHA256_DIGEST_SIZE -#define MAX_DATA_SIZE 4096 -#define MIN_DATA_SIZE 20 - -struct sdesc { - struct shash_desc shash; - char ctx[]; -}; - -static struct crypto_shash *hashalg; -static struct crypto_shash *hmacalg; - -enum { - Opt_err = -1, Opt_new, Opt_load, Opt_update -}; - -enum { - Opt_error = -1, Opt_default, Opt_ecryptfs -}; - -static const match_table_t key_format_tokens = { - {Opt_default, "default"}, - {Opt_ecryptfs, "ecryptfs"}, - {Opt_error, NULL} -}; - -static const match_table_t key_tokens = { - {Opt_new, "new"}, - {Opt_load, "load"}, - {Opt_update, "update"}, - {Opt_err, NULL} -}; - -static int aes_get_sizes(void) -{ - struct crypto_blkcipher *tfm; - - tfm = crypto_alloc_blkcipher(blkcipher_alg, 0, CRYPTO_ALG_ASYNC); - if (IS_ERR(tfm)) { - pr_err("encrypted_key: failed to alloc_cipher (%ld)\n", - PTR_ERR(tfm)); - return PTR_ERR(tfm); - } - ivsize = crypto_blkcipher_ivsize(tfm); - blksize = crypto_blkcipher_blocksize(tfm); - crypto_free_blkcipher(tfm); - return 0; -} - -/* - * valid_ecryptfs_desc - verify the description of a new/loaded encrypted key - * - * The description of a encrypted key with format 'ecryptfs' must contain - * exactly 16 hexadecimal characters. - * - */ -static int valid_ecryptfs_desc(const char *ecryptfs_desc) -{ - int i; - - if (strlen(ecryptfs_desc) != KEY_ECRYPTFS_DESC_LEN) { - pr_err("encrypted_key: key description must be %d hexadecimal " - "characters long\n", KEY_ECRYPTFS_DESC_LEN); - return -EINVAL; - } - - for (i = 0; i < KEY_ECRYPTFS_DESC_LEN; i++) { - if (!isxdigit(ecryptfs_desc[i])) { - pr_err("encrypted_key: key description must contain " - "only hexadecimal characters\n"); - return -EINVAL; - } - } - - return 0; -} - -/* - * valid_master_desc - verify the 'key-type:desc' of a new/updated master-key - * - * key-type:= "trusted:" | "user:" - * desc:= master-key description - * - * Verify that 'key-type' is valid and that 'desc' exists. On key update, - * only the master key description is permitted to change, not the key-type. - * The key-type remains constant. - * - * On success returns 0, otherwise -EINVAL. - */ -static int valid_master_desc(const char *new_desc, const char *orig_desc) -{ - if (!memcmp(new_desc, KEY_TRUSTED_PREFIX, KEY_TRUSTED_PREFIX_LEN)) { - if (strlen(new_desc) == KEY_TRUSTED_PREFIX_LEN) - goto out; - if (orig_desc) - if (memcmp(new_desc, orig_desc, KEY_TRUSTED_PREFIX_LEN)) - goto out; - } else if (!memcmp(new_desc, KEY_USER_PREFIX, KEY_USER_PREFIX_LEN)) { - if (strlen(new_desc) == KEY_USER_PREFIX_LEN) - goto out; - if (orig_desc) - if (memcmp(new_desc, orig_desc, KEY_USER_PREFIX_LEN)) - goto out; - } else - goto out; - return 0; -out: - return -EINVAL; -} - -/* - * datablob_parse - parse the keyctl data - * - * datablob format: - * new [] - * load [] - * - * update - * - * Tokenizes a copy of the keyctl data, returning a pointer to each token, - * which is null terminated. - * - * On success returns 0, otherwise -EINVAL. - */ -static int datablob_parse(char *datablob, const char **format, - char **master_desc, char **decrypted_datalen, - char **hex_encoded_iv) -{ - substring_t args[MAX_OPT_ARGS]; - int ret = -EINVAL; - int key_cmd; - int key_format; - char *p, *keyword; - - keyword = strsep(&datablob, " \t"); - if (!keyword) { - pr_info("encrypted_key: insufficient parameters specified\n"); - return ret; - } - key_cmd = match_token(keyword, key_tokens, args); - - /* Get optional format: default | ecryptfs */ - p = strsep(&datablob, " \t"); - if (!p) { - pr_err("encrypted_key: insufficient parameters specified\n"); - return ret; - } - - key_format = match_token(p, key_format_tokens, args); - switch (key_format) { - case Opt_ecryptfs: - case Opt_default: - *format = p; - *master_desc = strsep(&datablob, " \t"); - break; - case Opt_error: - *master_desc = p; - break; - } - - if (!*master_desc) { - pr_info("encrypted_key: master key parameter is missing\n"); - goto out; - } - - if (valid_master_desc(*master_desc, NULL) < 0) { - pr_info("encrypted_key: master key parameter \'%s\' " - "is invalid\n", *master_desc); - goto out; - } - - if (decrypted_datalen) { - *decrypted_datalen = strsep(&datablob, " \t"); - if (!*decrypted_datalen) { - pr_info("encrypted_key: keylen parameter is missing\n"); - goto out; - } - } - - switch (key_cmd) { - case Opt_new: - if (!decrypted_datalen) { - pr_info("encrypted_key: keyword \'%s\' not allowed " - "when called from .update method\n", keyword); - break; - } - ret = 0; - break; - case Opt_load: - if (!decrypted_datalen) { - pr_info("encrypted_key: keyword \'%s\' not allowed " - "when called from .update method\n", keyword); - break; - } - *hex_encoded_iv = strsep(&datablob, " \t"); - if (!*hex_encoded_iv) { - pr_info("encrypted_key: hex blob is missing\n"); - break; - } - ret = 0; - break; - case Opt_update: - if (decrypted_datalen) { - pr_info("encrypted_key: keyword \'%s\' not allowed " - "when called from .instantiate method\n", - keyword); - break; - } - ret = 0; - break; - case Opt_err: - pr_info("encrypted_key: keyword \'%s\' not recognized\n", - keyword); - break; - } -out: - return ret; -} - -/* - * datablob_format - format as an ascii string, before copying to userspace - */ -static char *datablob_format(struct encrypted_key_payload *epayload, - size_t asciiblob_len) -{ - char *ascii_buf, *bufp; - u8 *iv = epayload->iv; - int len; - int i; - - ascii_buf = kmalloc(asciiblob_len + 1, GFP_KERNEL); - if (!ascii_buf) - goto out; - - ascii_buf[asciiblob_len] = '\0'; - - /* copy datablob master_desc and datalen strings */ - len = sprintf(ascii_buf, "%s %s %s ", epayload->format, - epayload->master_desc, epayload->datalen); - - /* convert the hex encoded iv, encrypted-data and HMAC to ascii */ - bufp = &ascii_buf[len]; - for (i = 0; i < (asciiblob_len - len) / 2; i++) - bufp = pack_hex_byte(bufp, iv[i]); -out: - return ascii_buf; -} - -/* - * request_trusted_key - request the trusted key - * - * Trusted keys are sealed to PCRs and other metadata. Although userspace - * manages both trusted/encrypted key-types, like the encrypted key type - * data, trusted key type data is not visible decrypted from userspace. - */ -static struct key *request_trusted_key(const char *trusted_desc, - u8 **master_key, size_t *master_keylen) -{ - struct trusted_key_payload *tpayload; - struct key *tkey; - - tkey = request_key(&key_type_trusted, trusted_desc, NULL); - if (IS_ERR(tkey)) - goto error; - - down_read(&tkey->sem); - tpayload = rcu_dereference(tkey->payload.data); - *master_key = tpayload->key; - *master_keylen = tpayload->key_len; -error: - return tkey; -} - -/* - * request_user_key - request the user key - * - * Use a user provided key to encrypt/decrypt an encrypted-key. - */ -static struct key *request_user_key(const char *master_desc, u8 **master_key, - size_t *master_keylen) -{ - struct user_key_payload *upayload; - struct key *ukey; - - ukey = request_key(&key_type_user, master_desc, NULL); - if (IS_ERR(ukey)) - goto error; - - down_read(&ukey->sem); - upayload = rcu_dereference(ukey->payload.data); - *master_key = upayload->data; - *master_keylen = upayload->datalen; -error: - return ukey; -} - -static struct sdesc *alloc_sdesc(struct crypto_shash *alg) -{ - struct sdesc *sdesc; - int size; - - size = sizeof(struct shash_desc) + crypto_shash_descsize(alg); - sdesc = kmalloc(size, GFP_KERNEL); - if (!sdesc) - return ERR_PTR(-ENOMEM); - sdesc->shash.tfm = alg; - sdesc->shash.flags = 0x0; - return sdesc; -} - -static int calc_hmac(u8 *digest, const u8 *key, unsigned int keylen, - const u8 *buf, unsigned int buflen) -{ - struct sdesc *sdesc; - int ret; - - sdesc = alloc_sdesc(hmacalg); - if (IS_ERR(sdesc)) { - pr_info("encrypted_key: can't alloc %s\n", hmac_alg); - return PTR_ERR(sdesc); - } - - ret = crypto_shash_setkey(hmacalg, key, keylen); - if (!ret) - ret = crypto_shash_digest(&sdesc->shash, buf, buflen, digest); - kfree(sdesc); - return ret; -} - -static int calc_hash(u8 *digest, const u8 *buf, unsigned int buflen) -{ - struct sdesc *sdesc; - int ret; - - sdesc = alloc_sdesc(hashalg); - if (IS_ERR(sdesc)) { - pr_info("encrypted_key: can't alloc %s\n", hash_alg); - return PTR_ERR(sdesc); - } - - ret = crypto_shash_digest(&sdesc->shash, buf, buflen, digest); - kfree(sdesc); - return ret; -} - -enum derived_key_type { ENC_KEY, AUTH_KEY }; - -/* Derive authentication/encryption key from trusted key */ -static int get_derived_key(u8 *derived_key, enum derived_key_type key_type, - const u8 *master_key, size_t master_keylen) -{ - u8 *derived_buf; - unsigned int derived_buf_len; - int ret; - - derived_buf_len = strlen("AUTH_KEY") + 1 + master_keylen; - if (derived_buf_len < HASH_SIZE) - derived_buf_len = HASH_SIZE; - - derived_buf = kzalloc(derived_buf_len, GFP_KERNEL); - if (!derived_buf) { - pr_err("encrypted_key: out of memory\n"); - return -ENOMEM; - } - if (key_type) - strcpy(derived_buf, "AUTH_KEY"); - else - strcpy(derived_buf, "ENC_KEY"); - - memcpy(derived_buf + strlen(derived_buf) + 1, master_key, - master_keylen); - ret = calc_hash(derived_key, derived_buf, derived_buf_len); - kfree(derived_buf); - return ret; -} - -static int init_blkcipher_desc(struct blkcipher_desc *desc, const u8 *key, - unsigned int key_len, const u8 *iv, - unsigned int ivsize) -{ - int ret; - - desc->tfm = crypto_alloc_blkcipher(blkcipher_alg, 0, CRYPTO_ALG_ASYNC); - if (IS_ERR(desc->tfm)) { - pr_err("encrypted_key: failed to load %s transform (%ld)\n", - blkcipher_alg, PTR_ERR(desc->tfm)); - return PTR_ERR(desc->tfm); - } - desc->flags = 0; - - ret = crypto_blkcipher_setkey(desc->tfm, key, key_len); - if (ret < 0) { - pr_err("encrypted_key: failed to setkey (%d)\n", ret); - crypto_free_blkcipher(desc->tfm); - return ret; - } - crypto_blkcipher_set_iv(desc->tfm, iv, ivsize); - return 0; -} - -static struct key *request_master_key(struct encrypted_key_payload *epayload, - u8 **master_key, size_t *master_keylen) -{ - struct key *mkey = NULL; - - if (!strncmp(epayload->master_desc, KEY_TRUSTED_PREFIX, - KEY_TRUSTED_PREFIX_LEN)) { - mkey = request_trusted_key(epayload->master_desc + - KEY_TRUSTED_PREFIX_LEN, - master_key, master_keylen); - } else if (!strncmp(epayload->master_desc, KEY_USER_PREFIX, - KEY_USER_PREFIX_LEN)) { - mkey = request_user_key(epayload->master_desc + - KEY_USER_PREFIX_LEN, - master_key, master_keylen); - } else - goto out; - - if (IS_ERR(mkey)) { - pr_info("encrypted_key: key %s not found", - epayload->master_desc); - goto out; - } - - dump_master_key(*master_key, *master_keylen); -out: - return mkey; -} - -/* Before returning data to userspace, encrypt decrypted data. */ -static int derived_key_encrypt(struct encrypted_key_payload *epayload, - const u8 *derived_key, - unsigned int derived_keylen) -{ - struct scatterlist sg_in[2]; - struct scatterlist sg_out[1]; - struct blkcipher_desc desc; - unsigned int encrypted_datalen; - unsigned int padlen; - char pad[16]; - int ret; - - encrypted_datalen = roundup(epayload->decrypted_datalen, blksize); - padlen = encrypted_datalen - epayload->decrypted_datalen; - - ret = init_blkcipher_desc(&desc, derived_key, derived_keylen, - epayload->iv, ivsize); - if (ret < 0) - goto out; - dump_decrypted_data(epayload); - - memset(pad, 0, sizeof pad); - sg_init_table(sg_in, 2); - sg_set_buf(&sg_in[0], epayload->decrypted_data, - epayload->decrypted_datalen); - sg_set_buf(&sg_in[1], pad, padlen); - - sg_init_table(sg_out, 1); - sg_set_buf(sg_out, epayload->encrypted_data, encrypted_datalen); - - ret = crypto_blkcipher_encrypt(&desc, sg_out, sg_in, encrypted_datalen); - crypto_free_blkcipher(desc.tfm); - if (ret < 0) - pr_err("encrypted_key: failed to encrypt (%d)\n", ret); - else - dump_encrypted_data(epayload, encrypted_datalen); -out: - return ret; -} - -static int datablob_hmac_append(struct encrypted_key_payload *epayload, - const u8 *master_key, size_t master_keylen) -{ - u8 derived_key[HASH_SIZE]; - u8 *digest; - int ret; - - ret = get_derived_key(derived_key, AUTH_KEY, master_key, master_keylen); - if (ret < 0) - goto out; - - digest = epayload->format + epayload->datablob_len; - ret = calc_hmac(digest, derived_key, sizeof derived_key, - epayload->format, epayload->datablob_len); - if (!ret) - dump_hmac(NULL, digest, HASH_SIZE); -out: - return ret; -} - -/* verify HMAC before decrypting encrypted key */ -static int datablob_hmac_verify(struct encrypted_key_payload *epayload, - const u8 *format, const u8 *master_key, - size_t master_keylen) -{ - u8 derived_key[HASH_SIZE]; - u8 digest[HASH_SIZE]; - int ret; - char *p; - unsigned short len; - - ret = get_derived_key(derived_key, AUTH_KEY, master_key, master_keylen); - if (ret < 0) - goto out; - - len = epayload->datablob_len; - if (!format) { - p = epayload->master_desc; - len -= strlen(epayload->format) + 1; - } else - p = epayload->format; - - ret = calc_hmac(digest, derived_key, sizeof derived_key, p, len); - if (ret < 0) - goto out; - ret = memcmp(digest, epayload->format + epayload->datablob_len, - sizeof digest); - if (ret) { - ret = -EINVAL; - dump_hmac("datablob", - epayload->format + epayload->datablob_len, - HASH_SIZE); - dump_hmac("calc", digest, HASH_SIZE); - } -out: - return ret; -} - -static int derived_key_decrypt(struct encrypted_key_payload *epayload, - const u8 *derived_key, - unsigned int derived_keylen) -{ - struct scatterlist sg_in[1]; - struct scatterlist sg_out[2]; - struct blkcipher_desc desc; - unsigned int encrypted_datalen; - char pad[16]; - int ret; - - encrypted_datalen = roundup(epayload->decrypted_datalen, blksize); - ret = init_blkcipher_desc(&desc, derived_key, derived_keylen, - epayload->iv, ivsize); - if (ret < 0) - goto out; - dump_encrypted_data(epayload, encrypted_datalen); - - memset(pad, 0, sizeof pad); - sg_init_table(sg_in, 1); - sg_init_table(sg_out, 2); - sg_set_buf(sg_in, epayload->encrypted_data, encrypted_datalen); - sg_set_buf(&sg_out[0], epayload->decrypted_data, - epayload->decrypted_datalen); - sg_set_buf(&sg_out[1], pad, sizeof pad); - - ret = crypto_blkcipher_decrypt(&desc, sg_out, sg_in, encrypted_datalen); - crypto_free_blkcipher(desc.tfm); - if (ret < 0) - goto out; - dump_decrypted_data(epayload); -out: - return ret; -} - -/* Allocate memory for decrypted key and datablob. */ -static struct encrypted_key_payload *encrypted_key_alloc(struct key *key, - const char *format, - const char *master_desc, - const char *datalen) -{ - struct encrypted_key_payload *epayload = NULL; - unsigned short datablob_len; - unsigned short decrypted_datalen; - unsigned short payload_datalen; - unsigned int encrypted_datalen; - unsigned int format_len; - long dlen; - int ret; - - ret = strict_strtol(datalen, 10, &dlen); - if (ret < 0 || dlen < MIN_DATA_SIZE || dlen > MAX_DATA_SIZE) - return ERR_PTR(-EINVAL); - - format_len = (!format) ? strlen(key_format_default) : strlen(format); - decrypted_datalen = dlen; - payload_datalen = decrypted_datalen; - if (format && !strcmp(format, key_format_ecryptfs)) { - if (dlen != ECRYPTFS_MAX_KEY_BYTES) { - pr_err("encrypted_key: keylen for the ecryptfs format " - "must be equal to %d bytes\n", - ECRYPTFS_MAX_KEY_BYTES); - return ERR_PTR(-EINVAL); - } - decrypted_datalen = ECRYPTFS_MAX_KEY_BYTES; - payload_datalen = sizeof(struct ecryptfs_auth_tok); - } - - encrypted_datalen = roundup(decrypted_datalen, blksize); - - datablob_len = format_len + 1 + strlen(master_desc) + 1 - + strlen(datalen) + 1 + ivsize + 1 + encrypted_datalen; - - ret = key_payload_reserve(key, payload_datalen + datablob_len - + HASH_SIZE + 1); - if (ret < 0) - return ERR_PTR(ret); - - epayload = kzalloc(sizeof(*epayload) + payload_datalen + - datablob_len + HASH_SIZE + 1, GFP_KERNEL); - if (!epayload) - return ERR_PTR(-ENOMEM); - - epayload->payload_datalen = payload_datalen; - epayload->decrypted_datalen = decrypted_datalen; - epayload->datablob_len = datablob_len; - return epayload; -} - -static int encrypted_key_decrypt(struct encrypted_key_payload *epayload, - const char *format, const char *hex_encoded_iv) -{ - struct key *mkey; - u8 derived_key[HASH_SIZE]; - u8 *master_key; - u8 *hmac; - const char *hex_encoded_data; - unsigned int encrypted_datalen; - size_t master_keylen; - size_t asciilen; - int ret; - - encrypted_datalen = roundup(epayload->decrypted_datalen, blksize); - asciilen = (ivsize + 1 + encrypted_datalen + HASH_SIZE) * 2; - if (strlen(hex_encoded_iv) != asciilen) - return -EINVAL; - - hex_encoded_data = hex_encoded_iv + (2 * ivsize) + 2; - hex2bin(epayload->iv, hex_encoded_iv, ivsize); - hex2bin(epayload->encrypted_data, hex_encoded_data, encrypted_datalen); - - hmac = epayload->format + epayload->datablob_len; - hex2bin(hmac, hex_encoded_data + (encrypted_datalen * 2), HASH_SIZE); - - mkey = request_master_key(epayload, &master_key, &master_keylen); - if (IS_ERR(mkey)) - return PTR_ERR(mkey); - - ret = datablob_hmac_verify(epayload, format, master_key, master_keylen); - if (ret < 0) { - pr_err("encrypted_key: bad hmac (%d)\n", ret); - goto out; - } - - ret = get_derived_key(derived_key, ENC_KEY, master_key, master_keylen); - if (ret < 0) - goto out; - - ret = derived_key_decrypt(epayload, derived_key, sizeof derived_key); - if (ret < 0) - pr_err("encrypted_key: failed to decrypt key (%d)\n", ret); -out: - up_read(&mkey->sem); - key_put(mkey); - return ret; -} - -static void __ekey_init(struct encrypted_key_payload *epayload, - const char *format, const char *master_desc, - const char *datalen) -{ - unsigned int format_len; - - format_len = (!format) ? strlen(key_format_default) : strlen(format); - epayload->format = epayload->payload_data + epayload->payload_datalen; - epayload->master_desc = epayload->format + format_len + 1; - epayload->datalen = epayload->master_desc + strlen(master_desc) + 1; - epayload->iv = epayload->datalen + strlen(datalen) + 1; - epayload->encrypted_data = epayload->iv + ivsize + 1; - epayload->decrypted_data = epayload->payload_data; - - if (!format) - memcpy(epayload->format, key_format_default, format_len); - else { - if (!strcmp(format, key_format_ecryptfs)) - epayload->decrypted_data = - ecryptfs_get_auth_tok_key((struct ecryptfs_auth_tok *)epayload->payload_data); - - memcpy(epayload->format, format, format_len); - } - - memcpy(epayload->master_desc, master_desc, strlen(master_desc)); - memcpy(epayload->datalen, datalen, strlen(datalen)); -} - -/* - * encrypted_init - initialize an encrypted key - * - * For a new key, use a random number for both the iv and data - * itself. For an old key, decrypt the hex encoded data. - */ -static int encrypted_init(struct encrypted_key_payload *epayload, - const char *key_desc, const char *format, - const char *master_desc, const char *datalen, - const char *hex_encoded_iv) -{ - int ret = 0; - - if (format && !strcmp(format, key_format_ecryptfs)) { - ret = valid_ecryptfs_desc(key_desc); - if (ret < 0) - return ret; - - ecryptfs_fill_auth_tok((struct ecryptfs_auth_tok *)epayload->payload_data, - key_desc); - } - - __ekey_init(epayload, format, master_desc, datalen); - if (!hex_encoded_iv) { - get_random_bytes(epayload->iv, ivsize); - - get_random_bytes(epayload->decrypted_data, - epayload->decrypted_datalen); - } else - ret = encrypted_key_decrypt(epayload, format, hex_encoded_iv); - return ret; -} - -/* - * encrypted_instantiate - instantiate an encrypted key - * - * Decrypt an existing encrypted datablob or create a new encrypted key - * based on a kernel random number. - * - * On success, return 0. Otherwise return errno. - */ -static int encrypted_instantiate(struct key *key, const void *data, - size_t datalen) -{ - struct encrypted_key_payload *epayload = NULL; - char *datablob = NULL; - const char *format = NULL; - char *master_desc = NULL; - char *decrypted_datalen = NULL; - char *hex_encoded_iv = NULL; - int ret; - - if (datalen <= 0 || datalen > 32767 || !data) - return -EINVAL; - - datablob = kmalloc(datalen + 1, GFP_KERNEL); - if (!datablob) - return -ENOMEM; - datablob[datalen] = 0; - memcpy(datablob, data, datalen); - ret = datablob_parse(datablob, &format, &master_desc, - &decrypted_datalen, &hex_encoded_iv); - if (ret < 0) - goto out; - - epayload = encrypted_key_alloc(key, format, master_desc, - decrypted_datalen); - if (IS_ERR(epayload)) { - ret = PTR_ERR(epayload); - goto out; - } - ret = encrypted_init(epayload, key->description, format, master_desc, - decrypted_datalen, hex_encoded_iv); - if (ret < 0) { - kfree(epayload); - goto out; - } - - rcu_assign_pointer(key->payload.data, epayload); -out: - kfree(datablob); - return ret; -} - -static void encrypted_rcu_free(struct rcu_head *rcu) -{ - struct encrypted_key_payload *epayload; - - epayload = container_of(rcu, struct encrypted_key_payload, rcu); - memset(epayload->decrypted_data, 0, epayload->decrypted_datalen); - kfree(epayload); -} - -/* - * encrypted_update - update the master key description - * - * Change the master key description for an existing encrypted key. - * The next read will return an encrypted datablob using the new - * master key description. - * - * On success, return 0. Otherwise return errno. - */ -static int encrypted_update(struct key *key, const void *data, size_t datalen) -{ - struct encrypted_key_payload *epayload = key->payload.data; - struct encrypted_key_payload *new_epayload; - char *buf; - char *new_master_desc = NULL; - const char *format = NULL; - int ret = 0; - - if (datalen <= 0 || datalen > 32767 || !data) - return -EINVAL; - - buf = kmalloc(datalen + 1, GFP_KERNEL); - if (!buf) - return -ENOMEM; - - buf[datalen] = 0; - memcpy(buf, data, datalen); - ret = datablob_parse(buf, &format, &new_master_desc, NULL, NULL); - if (ret < 0) - goto out; - - ret = valid_master_desc(new_master_desc, epayload->master_desc); - if (ret < 0) - goto out; - - new_epayload = encrypted_key_alloc(key, epayload->format, - new_master_desc, epayload->datalen); - if (IS_ERR(new_epayload)) { - ret = PTR_ERR(new_epayload); - goto out; - } - - __ekey_init(new_epayload, epayload->format, new_master_desc, - epayload->datalen); - - memcpy(new_epayload->iv, epayload->iv, ivsize); - memcpy(new_epayload->payload_data, epayload->payload_data, - epayload->payload_datalen); - - rcu_assign_pointer(key->payload.data, new_epayload); - call_rcu(&epayload->rcu, encrypted_rcu_free); -out: - kfree(buf); - return ret; -} - -/* - * encrypted_read - format and copy the encrypted data to userspace - * - * The resulting datablob format is: - * - * - * On success, return to userspace the encrypted key datablob size. - */ -static long encrypted_read(const struct key *key, char __user *buffer, - size_t buflen) -{ - struct encrypted_key_payload *epayload; - struct key *mkey; - u8 *master_key; - size_t master_keylen; - char derived_key[HASH_SIZE]; - char *ascii_buf; - size_t asciiblob_len; - int ret; - - epayload = rcu_dereference_key(key); - - /* returns the hex encoded iv, encrypted-data, and hmac as ascii */ - asciiblob_len = epayload->datablob_len + ivsize + 1 - + roundup(epayload->decrypted_datalen, blksize) - + (HASH_SIZE * 2); - - if (!buffer || buflen < asciiblob_len) - return asciiblob_len; - - mkey = request_master_key(epayload, &master_key, &master_keylen); - if (IS_ERR(mkey)) - return PTR_ERR(mkey); - - ret = get_derived_key(derived_key, ENC_KEY, master_key, master_keylen); - if (ret < 0) - goto out; - - ret = derived_key_encrypt(epayload, derived_key, sizeof derived_key); - if (ret < 0) - goto out; - - ret = datablob_hmac_append(epayload, master_key, master_keylen); - if (ret < 0) - goto out; - - ascii_buf = datablob_format(epayload, asciiblob_len); - if (!ascii_buf) { - ret = -ENOMEM; - goto out; - } - - up_read(&mkey->sem); - key_put(mkey); - - if (copy_to_user(buffer, ascii_buf, asciiblob_len) != 0) - ret = -EFAULT; - kfree(ascii_buf); - - return asciiblob_len; -out: - up_read(&mkey->sem); - key_put(mkey); - return ret; -} - -/* - * encrypted_destroy - before freeing the key, clear the decrypted data - * - * Before freeing the key, clear the memory containing the decrypted - * key data. - */ -static void encrypted_destroy(struct key *key) -{ - struct encrypted_key_payload *epayload = key->payload.data; - - if (!epayload) - return; - - memset(epayload->decrypted_data, 0, epayload->decrypted_datalen); - kfree(key->payload.data); -} - -struct key_type key_type_encrypted = { - .name = "encrypted", - .instantiate = encrypted_instantiate, - .update = encrypted_update, - .match = user_match, - .destroy = encrypted_destroy, - .describe = user_describe, - .read = encrypted_read, -}; -EXPORT_SYMBOL_GPL(key_type_encrypted); - -static void encrypted_shash_release(void) -{ - if (hashalg) - crypto_free_shash(hashalg); - if (hmacalg) - crypto_free_shash(hmacalg); -} - -static int __init encrypted_shash_alloc(void) -{ - int ret; - - hmacalg = crypto_alloc_shash(hmac_alg, 0, CRYPTO_ALG_ASYNC); - if (IS_ERR(hmacalg)) { - pr_info("encrypted_key: could not allocate crypto %s\n", - hmac_alg); - return PTR_ERR(hmacalg); - } - - hashalg = crypto_alloc_shash(hash_alg, 0, CRYPTO_ALG_ASYNC); - if (IS_ERR(hashalg)) { - pr_info("encrypted_key: could not allocate crypto %s\n", - hash_alg); - ret = PTR_ERR(hashalg); - goto hashalg_fail; - } - - return 0; - -hashalg_fail: - crypto_free_shash(hmacalg); - return ret; -} - -static int __init init_encrypted(void) -{ - int ret; - - ret = encrypted_shash_alloc(); - if (ret < 0) - return ret; - ret = register_key_type(&key_type_encrypted); - if (ret < 0) - goto out; - return aes_get_sizes(); -out: - encrypted_shash_release(); - return ret; - -} - -static void __exit cleanup_encrypted(void) -{ - encrypted_shash_release(); - unregister_key_type(&key_type_encrypted); -} - -late_initcall(init_encrypted); -module_exit(cleanup_encrypted); - -MODULE_LICENSE("GPL"); diff --git a/security/keys/encrypted.h b/security/keys/encrypted.h deleted file mode 100644 index cef5e2f2b7d..00000000000 --- a/security/keys/encrypted.h +++ /dev/null @@ -1,54 +0,0 @@ -#ifndef __ENCRYPTED_KEY_H -#define __ENCRYPTED_KEY_H - -#define ENCRYPTED_DEBUG 0 - -#if ENCRYPTED_DEBUG -static inline void dump_master_key(const u8 *master_key, size_t master_keylen) -{ - print_hex_dump(KERN_ERR, "master key: ", DUMP_PREFIX_NONE, 32, 1, - master_key, master_keylen, 0); -} - -static inline void dump_decrypted_data(struct encrypted_key_payload *epayload) -{ - print_hex_dump(KERN_ERR, "decrypted data: ", DUMP_PREFIX_NONE, 32, 1, - epayload->decrypted_data, - epayload->decrypted_datalen, 0); -} - -static inline void dump_encrypted_data(struct encrypted_key_payload *epayload, - unsigned int encrypted_datalen) -{ - print_hex_dump(KERN_ERR, "encrypted data: ", DUMP_PREFIX_NONE, 32, 1, - epayload->encrypted_data, encrypted_datalen, 0); -} - -static inline void dump_hmac(const char *str, const u8 *digest, - unsigned int hmac_size) -{ - if (str) - pr_info("encrypted_key: %s", str); - print_hex_dump(KERN_ERR, "hmac: ", DUMP_PREFIX_NONE, 32, 1, digest, - hmac_size, 0); -} -#else -static inline void dump_master_key(const u8 *master_key, size_t master_keylen) -{ -} - -static inline void dump_decrypted_data(struct encrypted_key_payload *epayload) -{ -} - -static inline void dump_encrypted_data(struct encrypted_key_payload *epayload, - unsigned int encrypted_datalen) -{ -} - -static inline void dump_hmac(const char *str, const u8 *digest, - unsigned int hmac_size) -{ -} -#endif -#endif -- cgit v1.2.3-70-g09d2 From 982e617a313b57abee3bcfa53381c356d00fd64a Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Sat, 27 Aug 2011 22:21:26 -0400 Subject: encrypted-keys: remove trusted-keys dependency Encrypted keys are decrypted/encrypted using either a trusted-key or, for those systems without a TPM, a user-defined key. This patch removes the trusted-keys and TCG_TPM dependencies. Signed-off-by: Mimi Zohar --- security/Kconfig | 4 ++- security/keys/encrypted-keys/Makefile | 1 + security/keys/encrypted-keys/encrypted.c | 35 +++++-------------- security/keys/encrypted-keys/encrypted.h | 11 ++++++ security/keys/encrypted-keys/masterkey_trusted.c | 44 ++++++++++++++++++++++++ 5 files changed, 67 insertions(+), 28 deletions(-) create mode 100644 security/keys/encrypted-keys/masterkey_trusted.c (limited to 'security') diff --git a/security/Kconfig b/security/Kconfig index 22847a88908..51bd5a0b69a 100644 --- a/security/Kconfig +++ b/security/Kconfig @@ -38,7 +38,9 @@ config TRUSTED_KEYS config ENCRYPTED_KEYS tristate "ENCRYPTED KEYS" - depends on KEYS && TRUSTED_KEYS + depends on KEYS + select CRYPTO + select CRYPTO_HMAC select CRYPTO_AES select CRYPTO_CBC select CRYPTO_SHA256 diff --git a/security/keys/encrypted-keys/Makefile b/security/keys/encrypted-keys/Makefile index cbd3f8de37b..6bc7a86d102 100644 --- a/security/keys/encrypted-keys/Makefile +++ b/security/keys/encrypted-keys/Makefile @@ -3,3 +3,4 @@ # obj-$(CONFIG_ENCRYPTED_KEYS) += encrypted.o ecryptfs_format.o +obj-$(CONFIG_TRUSTED_KEYS) += masterkey_trusted.o diff --git a/security/keys/encrypted-keys/encrypted.c b/security/keys/encrypted-keys/encrypted.c index e7eca9ec4c6..3f577954b85 100644 --- a/security/keys/encrypted-keys/encrypted.c +++ b/security/keys/encrypted-keys/encrypted.c @@ -298,31 +298,6 @@ out: return ascii_buf; } -/* - * request_trusted_key - request the trusted key - * - * Trusted keys are sealed to PCRs and other metadata. Although userspace - * manages both trusted/encrypted key-types, like the encrypted key type - * data, trusted key type data is not visible decrypted from userspace. - */ -static struct key *request_trusted_key(const char *trusted_desc, - u8 **master_key, size_t *master_keylen) -{ - struct trusted_key_payload *tpayload; - struct key *tkey; - - tkey = request_key(&key_type_trusted, trusted_desc, NULL); - if (IS_ERR(tkey)) - goto error; - - down_read(&tkey->sem); - tpayload = rcu_dereference(tkey->payload.data); - *master_key = tpayload->key; - *master_keylen = tpayload->key_len; -error: - return tkey; -} - /* * request_user_key - request the user key * @@ -469,8 +444,14 @@ static struct key *request_master_key(struct encrypted_key_payload *epayload, goto out; if (IS_ERR(mkey)) { - pr_info("encrypted_key: key %s not found", - epayload->master_desc); + int ret = PTR_ERR(epayload); + + if (ret == -ENOTSUPP) + pr_info("encrypted_key: key %s not supported", + epayload->master_desc); + else + pr_info("encrypted_key: key %s not found", + epayload->master_desc); goto out; } diff --git a/security/keys/encrypted-keys/encrypted.h b/security/keys/encrypted-keys/encrypted.h index cef5e2f2b7d..b6ade894525 100644 --- a/security/keys/encrypted-keys/encrypted.h +++ b/security/keys/encrypted-keys/encrypted.h @@ -2,6 +2,17 @@ #define __ENCRYPTED_KEY_H #define ENCRYPTED_DEBUG 0 +#ifdef CONFIG_TRUSTED_KEYS +extern struct key *request_trusted_key(const char *trusted_desc, + u8 **master_key, size_t *master_keylen); +#else +static inline struct key *request_trusted_key(const char *trusted_desc, + u8 **master_key, + size_t *master_keylen) +{ + return ERR_PTR(-EOPNOTSUPP); +} +#endif #if ENCRYPTED_DEBUG static inline void dump_master_key(const u8 *master_key, size_t master_keylen) diff --git a/security/keys/encrypted-keys/masterkey_trusted.c b/security/keys/encrypted-keys/masterkey_trusted.c new file mode 100644 index 00000000000..a5da5128891 --- /dev/null +++ b/security/keys/encrypted-keys/masterkey_trusted.c @@ -0,0 +1,44 @@ +/* + * Copyright (C) 2010 IBM Corporation + * Copyright (C) 2010 Politecnico di Torino, Italy + * TORSEC group -- http://security.polito.it + * + * Authors: + * Mimi Zohar + * Roberto Sassu + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, version 2 of the License. + * + * See Documentation/security/keys-trusted-encrypted.txt + */ + +#include +#include +#include + +/* + * request_trusted_key - request the trusted key + * + * Trusted keys are sealed to PCRs and other metadata. Although userspace + * manages both trusted/encrypted key-types, like the encrypted key type + * data, trusted key type data is not visible decrypted from userspace. + */ +struct key *request_trusted_key(const char *trusted_desc, + u8 **master_key, size_t *master_keylen) +{ + struct trusted_key_payload *tpayload; + struct key *tkey; + + tkey = request_key(&key_type_trusted, trusted_desc, NULL); + if (IS_ERR(tkey)) + goto error; + + down_read(&tkey->sem); + tpayload = rcu_dereference(tkey->payload.data); + *master_key = tpayload->key; + *master_keylen = tpayload->key_len; +error: + return tkey; +} -- cgit v1.2.3-70-g09d2 From 1d714057ef8f6348eba7b28ace6d307513e57cef Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Sun, 28 Aug 2011 08:57:11 -0400 Subject: evm: remove TCG_TPM dependency All tristates selected by EVM(boolean) are forced to be builtin, except in the TCG_TPM(tristate) dependency case. Arnaud Lacombe summarizes the Kconfig bug as, "So it would seem direct dependency state influence the state of reverse dependencies.." For a detailed explanation, refer to Arnaud Lacombe's posting http://lkml.org/lkml/2011/8/23/498. With the "encrypted-keys: remove trusted-keys dependency" patch, EVM can now be built without a dependency on TCG_TPM. The trusted-keys dependency requires trusted-keys to either be builtin or not selected. This dependency will prevent the boolean/tristate mismatch from occuring. Reported-by: Stephen Rothwell , Randy Dunlap Signed-off-by: Mimi Zohar --- security/integrity/evm/Kconfig | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'security') diff --git a/security/integrity/evm/Kconfig b/security/integrity/evm/Kconfig index 884617d4aad..afbb59dd262 100644 --- a/security/integrity/evm/Kconfig +++ b/security/integrity/evm/Kconfig @@ -1,11 +1,10 @@ config EVM boolean "EVM support" - depends on SECURITY && KEYS && TCG_TPM + depends on SECURITY && KEYS && (TRUSTED_KEYS=y || TRUSTED_KEYS=n) select CRYPTO_HMAC select CRYPTO_MD5 select CRYPTO_SHA1 select ENCRYPTED_KEYS - select TRUSTED_KEYS default n help EVM protects a file's security extended attributes against -- cgit v1.2.3-70-g09d2 From fb88c2b6cbb1265a8bef60694699b37f5cd4ba76 Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Mon, 15 Aug 2011 10:13:18 -0400 Subject: evm: fix security/security_old_init_security return code security_inode_init_security previously returned -EOPNOTSUPP, for S_PRIVATE inodes, and relied on the callers to change it to 0. As the callers do not change the return code anymore, return 0, intead of -EOPNOTSUPP. Signed-off-by: Mimi Zohar --- security/security.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'security') diff --git a/security/security.c b/security/security.c index 9ebda054a33..c1d69875db6 100644 --- a/security/security.c +++ b/security/security.c @@ -348,7 +348,7 @@ int security_inode_init_security(struct inode *inode, struct inode *dir, int ret; if (unlikely(IS_PRIVATE(inode))) - return -EOPNOTSUPP; + return 0; memset(new_xattrs, 0, sizeof new_xattrs); if (!initxattrs) @@ -381,7 +381,7 @@ int security_old_inode_init_security(struct inode *inode, struct inode *dir, void **value, size_t *len) { if (unlikely(IS_PRIVATE(inode))) - return -EOPNOTSUPP; + return 0; return security_ops->inode_init_security(inode, dir, qstr, name, value, len); } -- cgit v1.2.3-70-g09d2 From a924ce0b35875ef9512135b46a32f4150fd700b2 Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Thu, 11 Aug 2011 01:22:30 -0400 Subject: evm: limit verifying current security.evm integrity evm_protect_xattr unnecessarily validates the current security.evm integrity, before updating non-evm protected extended attributes and other file metadata. This patch limits validating the current security.evm integrity to evm protected metadata. Signed-off-by: Mimi Zohar --- security/integrity/evm/evm_main.c | 58 ++++++++++++++++----------------------- 1 file changed, 24 insertions(+), 34 deletions(-) (limited to 'security') diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c index f0127e536f8..7d4247535f9 100644 --- a/security/integrity/evm/evm_main.c +++ b/security/integrity/evm/evm_main.c @@ -158,21 +158,6 @@ enum integrity_status evm_verifyxattr(struct dentry *dentry, } EXPORT_SYMBOL_GPL(evm_verifyxattr); -/* - * evm_protect_xattr - protect the EVM extended attribute - * - * Prevent security.evm from being modified or removed. - */ -static int evm_protect_xattr(struct dentry *dentry, const char *xattr_name, - const void *xattr_value, size_t xattr_value_len) -{ - if (strcmp(xattr_name, XATTR_NAME_EVM) == 0) { - if (!capable(CAP_SYS_ADMIN)) - return -EPERM; - } - return 0; -} - /* * evm_verify_current_integrity - verify the dentry's metadata integrity * @dentry: pointer to the affected dentry @@ -189,6 +174,26 @@ static enum integrity_status evm_verify_current_integrity(struct dentry *dentry) return evm_verify_hmac(dentry, NULL, NULL, 0, NULL); } +/* + * evm_protect_xattr - protect the EVM extended attribute + * + * Prevent security.evm from being modified or removed. + */ +static int evm_protect_xattr(struct dentry *dentry, const char *xattr_name, + const void *xattr_value, size_t xattr_value_len) +{ + enum integrity_status evm_status; + + if (strcmp(xattr_name, XATTR_NAME_EVM) == 0) { + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + } else if (!evm_protected_xattr(xattr_name)) + return 0; + + evm_status = evm_verify_current_integrity(dentry); + return evm_status == INTEGRITY_PASS ? 0 : -EPERM; +} + /** * evm_inode_setxattr - protect the EVM extended attribute * @dentry: pointer to the affected dentry @@ -202,16 +207,8 @@ static enum integrity_status evm_verify_current_integrity(struct dentry *dentry) int evm_inode_setxattr(struct dentry *dentry, const char *xattr_name, const void *xattr_value, size_t xattr_value_len) { - - enum integrity_status evm_status; - int ret; - - ret = evm_protect_xattr(dentry, xattr_name, xattr_value, - xattr_value_len); - if (ret) - return ret; - evm_status = evm_verify_current_integrity(dentry); - return evm_status == INTEGRITY_PASS ? 0 : -EPERM; + return evm_protect_xattr(dentry, xattr_name, xattr_value, + xattr_value_len); } /** @@ -224,14 +221,7 @@ int evm_inode_setxattr(struct dentry *dentry, const char *xattr_name, */ int evm_inode_removexattr(struct dentry *dentry, const char *xattr_name) { - enum integrity_status evm_status; - int ret; - - ret = evm_protect_xattr(dentry, xattr_name, NULL, 0); - if (ret) - return ret; - evm_status = evm_verify_current_integrity(dentry); - return evm_status == INTEGRITY_PASS ? 0 : -EPERM; + return evm_protect_xattr(dentry, xattr_name, NULL, 0); } /** @@ -286,7 +276,7 @@ int evm_inode_setattr(struct dentry *dentry, struct iattr *attr) unsigned int ia_valid = attr->ia_valid; enum integrity_status evm_status; - if (ia_valid & ~(ATTR_MODE | ATTR_UID | ATTR_GID)) + if (!(ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID))) return 0; evm_status = evm_verify_current_integrity(dentry); return evm_status == INTEGRITY_PASS ? 0 : -EPERM; -- cgit v1.2.3-70-g09d2 From bf6d0f5dcda17df3cc5577e203d0f8ea1c2ad6aa Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Thu, 18 Aug 2011 18:07:44 -0400 Subject: evm: posix acls modify i_mode The posix xattr acls are 'system' prefixed, which normally would not affect security.evm. An interesting side affect of writing posix xattr acls is their modifying of the i_mode, which is included in security.evm. This patch updates security.evm when posix xattr acls are written. Signed-off-by: Mimi Zohar --- include/linux/evm.h | 8 ++++++++ include/linux/xattr.h | 5 +++++ security/integrity/evm/Makefile | 1 + security/integrity/evm/evm_main.c | 24 +++++++++++++++++++----- security/integrity/evm/evm_posix_acl.c | 26 ++++++++++++++++++++++++++ 5 files changed, 59 insertions(+), 5 deletions(-) create mode 100644 security/integrity/evm/evm_posix_acl.c (limited to 'security') diff --git a/include/linux/evm.h b/include/linux/evm.h index ea603c9e775..9fc13a76092 100644 --- a/include/linux/evm.h +++ b/include/linux/evm.h @@ -33,6 +33,14 @@ extern void evm_inode_post_removexattr(struct dentry *dentry, extern int evm_inode_init_security(struct inode *inode, const struct xattr *xattr_array, struct xattr *evm); +#ifdef CONFIG_FS_POSIX_ACL +extern int posix_xattr_acl(const char *xattrname); +#else +static inline int posix_xattr_acl(const char *xattrname) +{ + return 0; +} +#endif #else #ifdef CONFIG_INTEGRITY static inline enum integrity_status evm_verifyxattr(struct dentry *dentry, diff --git a/include/linux/xattr.h b/include/linux/xattr.h index b20cb965c32..e5d12203154 100644 --- a/include/linux/xattr.h +++ b/include/linux/xattr.h @@ -52,6 +52,11 @@ #define XATTR_CAPS_SUFFIX "capability" #define XATTR_NAME_CAPS XATTR_SECURITY_PREFIX XATTR_CAPS_SUFFIX +#define XATTR_POSIX_ACL_ACCESS "posix_acl_access" +#define XATTR_NAME_POSIX_ACL_ACCESS XATTR_SYSTEM_PREFIX XATTR_POSIX_ACL_ACCESS +#define XATTR_POSIX_ACL_DEFAULT "posix_acl_default" +#define XATTR_NAME_POSIX_ACL_DEFAULT XATTR_SYSTEM_PREFIX XATTR_POSIX_ACL_DEFAULT + #ifdef __KERNEL__ #include diff --git a/security/integrity/evm/Makefile b/security/integrity/evm/Makefile index 0787d262b9e..7393c415a06 100644 --- a/security/integrity/evm/Makefile +++ b/security/integrity/evm/Makefile @@ -4,3 +4,4 @@ obj-$(CONFIG_EVM) += evm.o evm-y := evm_main.o evm_crypto.o evm_secfs.o +evm-$(CONFIG_FS_POSIX_ACL) += evm_posix_acl.o diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c index 7d4247535f9..73c008d047c 100644 --- a/security/integrity/evm/evm_main.c +++ b/security/integrity/evm/evm_main.c @@ -177,7 +177,14 @@ static enum integrity_status evm_verify_current_integrity(struct dentry *dentry) /* * evm_protect_xattr - protect the EVM extended attribute * - * Prevent security.evm from being modified or removed. + * Prevent security.evm from being modified or removed without the + * necessary permissions or when the existing value is invalid. + * + * The posix xattr acls are 'system' prefixed, which normally would not + * affect security.evm. An interesting side affect of writing posix xattr + * acls is their modifying of the i_mode, which is included in security.evm. + * For posix xattr acls only, permit security.evm, even if it currently + * doesn't exist, to be updated. */ static int evm_protect_xattr(struct dentry *dentry, const char *xattr_name, const void *xattr_value, size_t xattr_value_len) @@ -187,9 +194,15 @@ static int evm_protect_xattr(struct dentry *dentry, const char *xattr_name, if (strcmp(xattr_name, XATTR_NAME_EVM) == 0) { if (!capable(CAP_SYS_ADMIN)) return -EPERM; - } else if (!evm_protected_xattr(xattr_name)) - return 0; - + } else if (!evm_protected_xattr(xattr_name)) { + if (!posix_xattr_acl(xattr_name)) + return 0; + evm_status = evm_verify_current_integrity(dentry); + if ((evm_status == INTEGRITY_PASS) || + (evm_status == INTEGRITY_NOLABEL)) + return 0; + return -EPERM; + } evm_status = evm_verify_current_integrity(dentry); return evm_status == INTEGRITY_PASS ? 0 : -EPERM; } @@ -240,7 +253,8 @@ int evm_inode_removexattr(struct dentry *dentry, const char *xattr_name) void evm_inode_post_setxattr(struct dentry *dentry, const char *xattr_name, const void *xattr_value, size_t xattr_value_len) { - if (!evm_initialized || !evm_protected_xattr(xattr_name)) + if (!evm_initialized || (!evm_protected_xattr(xattr_name) + && !posix_xattr_acl(xattr_name))) return; evm_update_evmxattr(dentry, xattr_name, xattr_value, xattr_value_len); diff --git a/security/integrity/evm/evm_posix_acl.c b/security/integrity/evm/evm_posix_acl.c new file mode 100644 index 00000000000..b1753e98bf9 --- /dev/null +++ b/security/integrity/evm/evm_posix_acl.c @@ -0,0 +1,26 @@ +/* + * Copyright (C) 2011 IBM Corporation + * + * Author: + * Mimi Zohar + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, version 2 of the License. + */ + +#include +#include + +int posix_xattr_acl(char *xattr) +{ + int xattr_len = strlen(xattr); + + if ((strlen(XATTR_NAME_POSIX_ACL_ACCESS) == xattr_len) + && (strncmp(XATTR_NAME_POSIX_ACL_ACCESS, xattr, xattr_len) == 0)) + return 1; + if ((strlen(XATTR_NAME_POSIX_ACL_DEFAULT) == xattr_len) + && (strncmp(XATTR_NAME_POSIX_ACL_DEFAULT, xattr, xattr_len) == 0)) + return 1; + return 0; +} -- cgit v1.2.3-70-g09d2 From 566be59ab86c0e030b980645a580d683a015a483 Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Mon, 22 Aug 2011 09:14:18 -0400 Subject: evm: permit mode bits to be updated Before permitting 'security.evm' to be updated, 'security.evm' must exist and be valid. In the case that there are no existing EVM protected xattrs, it is safe for posix acls to update the mode bits. To differentiate between no 'security.evm' xattr and no xattrs used to calculate 'security.evm', this patch defines INTEGRITY_NOXATTR. Signed-off-by: Mimi Zohar --- include/linux/integrity.h | 1 + security/integrity/evm/evm_main.c | 30 +++++++++++++----------------- 2 files changed, 14 insertions(+), 17 deletions(-) (limited to 'security') diff --git a/include/linux/integrity.h b/include/linux/integrity.h index 96844338567..a0c41256cb9 100644 --- a/include/linux/integrity.h +++ b/include/linux/integrity.h @@ -16,6 +16,7 @@ enum integrity_status { INTEGRITY_PASS = 0, INTEGRITY_FAIL, INTEGRITY_NOLABEL, + INTEGRITY_NOXATTRS, INTEGRITY_UNKNOWN, }; diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c index 73c008d047c..92d3d99a9f7 100644 --- a/security/integrity/evm/evm_main.c +++ b/security/integrity/evm/evm_main.c @@ -66,7 +66,7 @@ static enum integrity_status evm_verify_hmac(struct dentry *dentry, struct integrity_iint_cache *iint) { struct evm_ima_xattr_data xattr_data; - enum integrity_status evm_status; + enum integrity_status evm_status = INTEGRITY_PASS; int rc; if (iint && iint->evm_status == INTEGRITY_PASS) @@ -76,25 +76,18 @@ static enum integrity_status evm_verify_hmac(struct dentry *dentry, rc = evm_calc_hmac(dentry, xattr_name, xattr_value, xattr_value_len, xattr_data.digest); - if (rc < 0) - goto err_out; + if (rc < 0) { + evm_status = (rc == -ENODATA) + ? INTEGRITY_NOXATTRS : INTEGRITY_FAIL; + goto out; + } xattr_data.type = EVM_XATTR_HMAC; rc = vfs_xattr_cmp(dentry, XATTR_NAME_EVM, (u8 *)&xattr_data, sizeof xattr_data, GFP_NOFS); if (rc < 0) - goto err_out; - evm_status = INTEGRITY_PASS; - goto out; - -err_out: - switch (rc) { - case -ENODATA: /* file not labelled */ - evm_status = INTEGRITY_NOLABEL; - break; - default: - evm_status = INTEGRITY_FAIL; - } + evm_status = (rc == -ENODATA) + ? INTEGRITY_NOLABEL : INTEGRITY_FAIL; out: if (iint) iint->evm_status = evm_status; @@ -199,7 +192,7 @@ static int evm_protect_xattr(struct dentry *dentry, const char *xattr_name, return 0; evm_status = evm_verify_current_integrity(dentry); if ((evm_status == INTEGRITY_PASS) || - (evm_status == INTEGRITY_NOLABEL)) + (evm_status == INTEGRITY_NOXATTRS)) return 0; return -EPERM; } @@ -293,7 +286,10 @@ int evm_inode_setattr(struct dentry *dentry, struct iattr *attr) if (!(ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID))) return 0; evm_status = evm_verify_current_integrity(dentry); - return evm_status == INTEGRITY_PASS ? 0 : -EPERM; + if ((evm_status == INTEGRITY_PASS) || + (evm_status == INTEGRITY_NOXATTRS)) + return 0; + return -EPERM; } /** -- cgit v1.2.3-70-g09d2 From fb788d8b981fa55603873416882f8dcf835e7924 Mon Sep 17 00:00:00 2001 From: Dmitry Kasatkin Date: Mon, 15 Aug 2011 15:30:11 +0300 Subject: evm: clean verification status When allocating from slab, initialization is done the first time in init_once() and subsequently on free. Because evm_status was not re-initialized on free, evm_verify_hmac() skipped verifications. This patch re-initializes evm_status. Signed-off-by: Dmitry Kasatkin Signed-off-by: Mimi Zohar --- security/integrity/iint.c | 1 + 1 file changed, 1 insertion(+) (limited to 'security') diff --git a/security/integrity/iint.c b/security/integrity/iint.c index 0a23e075e1d..399641c3e84 100644 --- a/security/integrity/iint.c +++ b/security/integrity/iint.c @@ -74,6 +74,7 @@ static void iint_free(struct integrity_iint_cache *iint) { iint->version = 0; iint->flags = 0UL; + iint->evm_status = INTEGRITY_UNKNOWN; kmem_cache_free(iint_cache, iint); } -- cgit v1.2.3-70-g09d2