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-rw-r--r--security/integrity/Kconfig12
-rw-r--r--security/integrity/Makefile1
-rw-r--r--security/integrity/digsig.c11
-rw-r--r--security/integrity/digsig_asymmetric.c115
-rw-r--r--security/integrity/integrity.h12
5 files changed, 150 insertions, 1 deletions
diff --git a/security/integrity/Kconfig b/security/integrity/Kconfig
index 5bd1cc1b4a5..4bb3a775a99 100644
--- a/security/integrity/Kconfig
+++ b/security/integrity/Kconfig
@@ -17,5 +17,17 @@ config INTEGRITY_SIGNATURE
This is useful for evm and module keyrings, when keys are
usually only added from initramfs.
+config INTEGRITY_ASYMMETRIC_KEYS
+ boolean "Enable asymmetric keys support"
+ depends on INTEGRITY_SIGNATURE
+ default n
+ select ASYMMETRIC_KEY_TYPE
+ select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
+ select PUBLIC_KEY_ALGO_RSA
+ select X509_CERTIFICATE_PARSER
+ help
+ This option enables digital signature verification using
+ asymmetric keys.
+
source security/integrity/ima/Kconfig
source security/integrity/evm/Kconfig
diff --git a/security/integrity/Makefile b/security/integrity/Makefile
index d43799cc14f..ebb6409b3fc 100644
--- a/security/integrity/Makefile
+++ b/security/integrity/Makefile
@@ -4,6 +4,7 @@
obj-$(CONFIG_INTEGRITY) += integrity.o
obj-$(CONFIG_INTEGRITY_SIGNATURE) += digsig.o
+obj-$(CONFIG_INTEGRITY_ASYMMETRIC_KEYS) += digsig_asymmetric.o
integrity-y := iint.o
diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c
index 2dc167d7cde..0b759e17a13 100644
--- a/security/integrity/digsig.c
+++ b/security/integrity/digsig.c
@@ -44,5 +44,14 @@ int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
}
}
- return digsig_verify(keyring[id], sig, siglen, digest, digestlen);
+ switch (sig[0]) {
+ case 1:
+ return digsig_verify(keyring[id], sig, siglen,
+ digest, digestlen);
+ case 2:
+ return asymmetric_verify(keyring[id], sig, siglen,
+ digest, digestlen);
+ }
+
+ return -EOPNOTSUPP;
}
diff --git a/security/integrity/digsig_asymmetric.c b/security/integrity/digsig_asymmetric.c
new file mode 100644
index 00000000000..b4754667659
--- /dev/null
+++ b/security/integrity/digsig_asymmetric.c
@@ -0,0 +1,115 @@
+/*
+ * Copyright (C) 2013 Intel Corporation
+ *
+ * Author:
+ * Dmitry Kasatkin <dmitry.kasatkin@intel.com>
+ *
+ * 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.
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/err.h>
+#include <linux/key-type.h>
+#include <crypto/public_key.h>
+#include <keys/asymmetric-type.h>
+
+#include "integrity.h"
+
+/*
+ * signature format v2 - for using with asymmetric keys
+ */
+struct signature_v2_hdr {
+ uint8_t version; /* signature format version */
+ uint8_t hash_algo; /* Digest algorithm [enum pkey_hash_algo] */
+ uint32_t keyid; /* IMA key identifier - not X509/PGP specific*/
+ uint16_t sig_size; /* signature size */
+ uint8_t sig[0]; /* signature payload */
+} __packed;
+
+/*
+ * Request an asymmetric key.
+ */
+static struct key *request_asymmetric_key(struct key *keyring, uint32_t keyid)
+{
+ struct key *key;
+ char name[12];
+
+ sprintf(name, "id:%x", keyid);
+
+ pr_debug("key search: \"%s\"\n", name);
+
+ if (keyring) {
+ /* search in specific keyring */
+ key_ref_t kref;
+ kref = keyring_search(make_key_ref(keyring, 1),
+ &key_type_asymmetric, name);
+ if (IS_ERR(kref))
+ key = ERR_CAST(kref);
+ else
+ key = key_ref_to_ptr(kref);
+ } else {
+ key = request_key(&key_type_asymmetric, name, NULL);
+ }
+
+ if (IS_ERR(key)) {
+ pr_warn("Request for unknown key '%s' err %ld\n",
+ name, PTR_ERR(key));
+ switch (PTR_ERR(key)) {
+ /* Hide some search errors */
+ case -EACCES:
+ case -ENOTDIR:
+ case -EAGAIN:
+ return ERR_PTR(-ENOKEY);
+ default:
+ return key;
+ }
+ }
+
+ pr_debug("%s() = 0 [%x]\n", __func__, key_serial(key));
+
+ return key;
+}
+
+int asymmetric_verify(struct key *keyring, const char *sig,
+ int siglen, const char *data, int datalen)
+{
+ struct public_key_signature pks;
+ struct signature_v2_hdr *hdr = (struct signature_v2_hdr *)sig;
+ struct key *key;
+ int ret = -ENOMEM;
+
+ if (siglen <= sizeof(*hdr))
+ return -EBADMSG;
+
+ siglen -= sizeof(*hdr);
+
+ if (siglen != __be16_to_cpu(hdr->sig_size))
+ return -EBADMSG;
+
+ if (hdr->hash_algo >= PKEY_HASH__LAST)
+ return -ENOPKG;
+
+ key = request_asymmetric_key(keyring, __be32_to_cpu(hdr->keyid));
+ if (IS_ERR(key))
+ return PTR_ERR(key);
+
+ memset(&pks, 0, sizeof(pks));
+
+ pks.pkey_hash_algo = hdr->hash_algo;
+ pks.digest = (u8 *)data;
+ pks.digest_size = datalen;
+ pks.nr_mpi = 1;
+ pks.rsa.s = mpi_read_raw_data(hdr->sig, siglen);
+
+ if (pks.rsa.s)
+ ret = verify_signature(key, &pks);
+
+ mpi_free(pks.rsa.s);
+ key_put(key);
+ pr_debug("%s() = %d\n", __func__, ret);
+ return ret;
+}
diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h
index 0ae08fc8858..84c37c4db91 100644
--- a/security/integrity/integrity.h
+++ b/security/integrity/integrity.h
@@ -14,6 +14,7 @@
#include <linux/types.h>
#include <linux/integrity.h>
#include <crypto/sha.h>
+#include <linux/key.h>
/* iint action cache flags */
#define IMA_MEASURE 0x00000001
@@ -101,5 +102,16 @@ static inline int integrity_digsig_verify(const unsigned int id,
#endif /* CONFIG_INTEGRITY_SIGNATURE */
+#ifdef CONFIG_INTEGRITY_ASYMMETRIC_KEYS
+int asymmetric_verify(struct key *keyring, const char *sig,
+ int siglen, const char *data, int datalen);
+#else
+static inline int asymmetric_verify(struct key *keyring, const char *sig,
+ int siglen, const char *data, int datalen)
+{
+ return -EOPNOTSUPP;
+}
+#endif
+
/* set during initialization */
extern int iint_initialized;