diff options
Diffstat (limited to 'drivers/target/iscsi/iscsi_target_auth.c')
| -rw-r--r-- | drivers/target/iscsi/iscsi_target_auth.c | 88 |
1 files changed, 72 insertions, 16 deletions
diff --git a/drivers/target/iscsi/iscsi_target_auth.c b/drivers/target/iscsi/iscsi_target_auth.c index de77d9aa22c..ab4915c0d93 100644 --- a/drivers/target/iscsi/iscsi_target_auth.c +++ b/drivers/target/iscsi/iscsi_target_auth.c @@ -71,6 +71,40 @@ static void chap_gen_challenge( challenge_asciihex); } +static int chap_check_algorithm(const char *a_str) +{ + char *tmp, *orig, *token; + + tmp = kstrdup(a_str, GFP_KERNEL); + if (!tmp) { + pr_err("Memory allocation failed for CHAP_A temporary buffer\n"); + return CHAP_DIGEST_UNKNOWN; + } + orig = tmp; + + token = strsep(&tmp, "="); + if (!token) + goto out; + + if (strcmp(token, "CHAP_A")) { + pr_err("Unable to locate CHAP_A key\n"); + goto out; + } + while (token) { + token = strsep(&tmp, ","); + if (!token) + goto out; + + if (!strncmp(token, "5", 1)) { + pr_debug("Selected MD5 Algorithm\n"); + kfree(orig); + return CHAP_DIGEST_MD5; + } + } +out: + kfree(orig); + return CHAP_DIGEST_UNKNOWN; +} static struct iscsi_chap *chap_server_open( struct iscsi_conn *conn, @@ -79,6 +113,7 @@ static struct iscsi_chap *chap_server_open( char *aic_str, unsigned int *aic_len) { + int ret; struct iscsi_chap *chap; if (!(auth->naf_flags & NAF_USERID_SET) || @@ -93,21 +128,24 @@ static struct iscsi_chap *chap_server_open( return NULL; chap = conn->auth_protocol; - /* - * We only support MD5 MDA presently. - */ - if (strncmp(a_str, "CHAP_A=5", 8)) { - pr_err("CHAP_A is not MD5.\n"); + ret = chap_check_algorithm(a_str); + switch (ret) { + case CHAP_DIGEST_MD5: + pr_debug("[server] Got CHAP_A=5\n"); + /* + * Send back CHAP_A set to MD5. + */ + *aic_len = sprintf(aic_str, "CHAP_A=5"); + *aic_len += 1; + chap->digest_type = CHAP_DIGEST_MD5; + pr_debug("[server] Sending CHAP_A=%d\n", chap->digest_type); + break; + case CHAP_DIGEST_UNKNOWN: + default: + pr_err("Unsupported CHAP_A value\n"); return NULL; } - pr_debug("[server] Got CHAP_A=5\n"); - /* - * Send back CHAP_A set to MD5. - */ - *aic_len = sprintf(aic_str, "CHAP_A=5"); - *aic_len += 1; - chap->digest_type = CHAP_DIGEST_MD5; - pr_debug("[server] Sending CHAP_A=%d\n", chap->digest_type); + /* * Set Identifier. */ @@ -136,7 +174,6 @@ static int chap_server_compute_md5( char *nr_out_ptr, unsigned int *nr_out_len) { - char *endptr; unsigned long id; unsigned char id_as_uchar; unsigned char digest[MD5_SIGNATURE_SIZE]; @@ -282,9 +319,14 @@ static int chap_server_compute_md5( } if (type == HEX) - id = simple_strtoul(&identifier[2], &endptr, 0); + ret = kstrtoul(&identifier[2], 0, &id); else - id = simple_strtoul(identifier, &endptr, 0); + ret = kstrtoul(identifier, 0, &id); + + if (ret < 0) { + pr_err("kstrtoul() failed for CHAP identifier: %d\n", ret); + goto out; + } if (id > 255) { pr_err("chap identifier: %lu greater than 255\n", id); goto out; @@ -313,6 +355,20 @@ static int chap_server_compute_md5( pr_err("Unable to convert incoming challenge\n"); goto out; } + if (challenge_len > 1024) { + pr_err("CHAP_C exceeds maximum binary size of 1024 bytes\n"); + goto out; + } + /* + * During mutual authentication, the CHAP_C generated by the + * initiator must not match the original CHAP_C generated by + * the target. + */ + if (!memcmp(challenge_binhex, chap->challenge, CHAP_CHALLENGE_LENGTH)) { + pr_err("initiator CHAP_C matches target CHAP_C, failing" + " login attempt\n"); + goto out; + } /* * Generate CHAP_N and CHAP_R for mutual authentication. */ |