This patches modifies the chap_server_compute_hash() function
to make it agnostic to the choice of hash algorithm that is used.
It also adds support to two new hash algorithms: SHA1 and SHA3-256
Signed-off-by: Maurizio Lombardi <mlombard@xxxxxxxxxx>
---
drivers/target/iscsi/iscsi_target_auth.c | 135 +++++++++++++++++------
drivers/target/iscsi/iscsi_target_auth.h | 9 +-
2 files changed, 108 insertions(+), 36 deletions(-)
diff --git a/drivers/target/iscsi/iscsi_target_auth.c b/drivers/target/iscsi/iscsi_target_auth.c
index 51ddca2033e0..3d1e94333835 100644
--- a/drivers/target/iscsi/iscsi_target_auth.c
+++ b/drivers/target/iscsi/iscsi_target_auth.c
@@ -46,9 +46,22 @@ static int chap_gen_challenge(
return 0;
}
+static int chap_test_algorithm(const char *name)
+{
+ struct crypto_shash *tfm;
+
+ tfm = crypto_alloc_shash(name, 0, 0);
+ if (IS_ERR(tfm))
+ return -1;
+
+ crypto_free_shash(tfm);
+ return 0;
+}
+
static int chap_check_algorithm(const char *a_str)
{
char *tmp, *orig, *token;
+ int r = CHAP_DIGEST_UNKNOWN;
tmp = kstrdup(a_str, GFP_KERNEL);
if (!tmp) {
@@ -72,13 +85,33 @@ static int chap_check_algorithm(const char *a_str)
if (!strncmp(token, "5", 1)) {
pr_debug("Selected MD5 Algorithm\n");
- kfree(orig);
- return CHAP_DIGEST_MD5;
+ if (chap_test_algorithm("md5") < 0) {
+ pr_err("failed to allocate md5 algo\n");
+ continue;
+ }
+ r = CHAP_DIGEST_MD5;
+ goto out;
+ } else if (!strncmp(token, "6", 1)) {
+ pr_debug("Selected SHA1 Algorithm\n");
+ if (chap_test_algorithm("sha1") < 0) {
+ pr_err("failed to allocate sha1 algo\n");
+ continue;
+ }
+ r = CHAP_DIGEST_SHA;
+ goto out;
+ } else if (!strncmp(token, "7", 1)) {
+ pr_debug("Selected SHA3-256 Algorithm\n");
+ if (chap_test_algorithm("sha3-256") < 0) {
+ pr_err("failed to allocate sha3-256 algo\n");
+ continue;
+ }
+ r = CHAP_DIGEST_SHA3_256;
+ goto out;
}
}
out:
kfree(orig);
- return CHAP_DIGEST_UNKNOWN;
+ return r;
}
static void chap_close(struct iscsi_conn *conn)
@@ -94,7 +127,7 @@ static struct iscsi_chap *chap_server_open(
char *aic_str,
unsigned int *aic_len)
{
- int ret;
+ int digest_type;
struct iscsi_chap *chap;
if (!(auth->naf_flags & NAF_USERID_SET) ||
@@ -109,17 +142,19 @@ static struct iscsi_chap *chap_server_open(
return NULL;
chap = conn->auth_protocol;
- ret = chap_check_algorithm(a_str);
- switch (ret) {
+ digest_type = chap_check_algorithm(a_str);
+ switch (digest_type) {
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);
+ chap->digest_size = MD5_SIGNATURE_SIZE;
+ chap->digest_name = "md5";
+ break;
+ case CHAP_DIGEST_SHA:
+ chap->digest_size = SHA_SIGNATURE_SIZE;
+ chap->digest_name = "sha1";
+ break;
+ case CHAP_DIGEST_SHA3_256:
+ chap->digest_size = SHA3_256_SIGNATURE_SIZE;
+ chap->digest_name = "sha3-256";
break;
case CHAP_DIGEST_UNKNOWN:
default:
@@ -128,6 +163,11 @@ static struct iscsi_chap *chap_server_open(
return NULL;
}
+ pr_debug("[server] Got CHAP_A=%d\n", digest_type);
+ *aic_len = sprintf(aic_str, "CHAP_A=%d", digest_type);
+ *aic_len += 1;
+ pr_debug("[server] Sending CHAP_A=%d\n", digest_type);
+
/*
* Set Identifier.
*/
@@ -146,7 +186,7 @@ static struct iscsi_chap *chap_server_open(
return chap;
}
-static int chap_server_compute_md5(
+static int chap_server_compute_hash(
struct iscsi_conn *conn,
struct iscsi_node_auth *auth,
char *nr_in_ptr,
@@ -155,12 +195,13 @@ static int chap_server_compute_md5(
{
unsigned long id;
unsigned char id_as_uchar;
- unsigned char digest[MD5_SIGNATURE_SIZE];
- unsigned char type, response[MD5_SIGNATURE_SIZE * 2 + 2];
+ unsigned char type;
unsigned char identifier[10], *challenge = NULL;
unsigned char *challenge_binhex = NULL;
- unsigned char client_digest[MD5_SIGNATURE_SIZE];
- unsigned char server_digest[MD5_SIGNATURE_SIZE];
+ unsigned char *digest = NULL;
+ unsigned char *response = NULL;
+ unsigned char *client_digest = NULL;
+ unsigned char *server_digest = NULL;
unsigned char chap_n[MAX_CHAP_N_SIZE], chap_r[MAX_RESPONSE_LENGTH];
size_t compare_len;
struct iscsi_chap *chap = conn->auth_protocol;
@@ -168,13 +209,33 @@ static int chap_server_compute_md5(
struct shash_desc *desc = NULL;
int auth_ret = -1, ret, challenge_len;
+ digest = kzalloc(chap->digest_size, GFP_KERNEL);
+ if (!digest) {
+ pr_err("Unable to allocate the digest buffer\n");
+ goto out;
+ }
+
+ response = kzalloc(chap->digest_size * 2 + 2, GFP_KERNEL);
+ if (!response) {
+ pr_err("Unable to allocate the response buffer\n");
+ goto out;
+ }
+
+ client_digest = kzalloc(chap->digest_size, GFP_KERNEL);
+ if (!client_digest) {
+ pr_err("Unable to allocate the client_digest buffer\n");
+ goto out;
+ }
+
+ server_digest = kzalloc(chap->digest_size, GFP_KERNEL);
+ if (!server_digest) {
+ pr_err("Unable to allocate the server_digest buffer\n");
+ goto out;
+ }
+
memset(identifier, 0, 10);
memset(chap_n, 0, MAX_CHAP_N_SIZE);
memset(chap_r, 0, MAX_RESPONSE_LENGTH);
- memset(digest, 0, MD5_SIGNATURE_SIZE);
- memset(response, 0, MD5_SIGNATURE_SIZE * 2 + 2);
- memset(client_digest, 0, MD5_SIGNATURE_SIZE);
- memset(server_digest, 0, MD5_SIGNATURE_SIZE);
challenge = kzalloc(CHAP_CHALLENGE_STR_LEN, GFP_KERNEL);
if (!challenge) {
@@ -219,18 +280,18 @@ static int chap_server_compute_md5(
pr_err("Could not find CHAP_R.\n");
goto out;
}
- if (strlen(chap_r) != MD5_SIGNATURE_SIZE * 2) {
+ if (strlen(chap_r) != chap->digest_size * 2) {
pr_err("Malformed CHAP_R\n");
goto out;
}
- if (hex2bin(client_digest, chap_r, MD5_SIGNATURE_SIZE) < 0) {
+ if (hex2bin(client_digest, chap_r, chap->digest_size) < 0) {
pr_err("Malformed CHAP_R\n");
goto out;
}
pr_debug("[server] Got CHAP_R=%s\n", chap_r);
- tfm = crypto_alloc_shash("md5", 0, 0);
+ tfm = crypto_alloc_shash(chap->digest_name, 0, 0);
if (IS_ERR(tfm)) {
tfm = NULL;
pr_err("Unable to allocate struct crypto_shash\n");
@@ -271,15 +332,15 @@ static int chap_server_compute_md5(
goto out;
}
- bin2hex(response, server_digest, MD5_SIGNATURE_SIZE);
- pr_debug("[server] MD5 Server Digest: %s\n", response);
+ bin2hex(response, server_digest, chap->digest_size);
+ pr_debug("[server] %s Server Digest: %s\n", hash_name, response);
- if (memcmp(server_digest, client_digest, MD5_SIGNATURE_SIZE) != 0) {
- pr_debug("[server] MD5 Digests do not match!\n\n");
+ if (memcmp(server_digest, client_digest, chap->digest_size) != 0) {
+ pr_debug("[server] %s Digests do not match!\n\n", hash_name);
goto out;
} else
- pr_debug("[server] MD5 Digests match, CHAP connection"
- " successful.\n\n");
+ pr_debug("[server] %s Digests match, CHAP connection"
+ " successful.\n\n", hash_name);
/*
* One way authentication has succeeded, return now if mutual
* authentication is not enabled.
@@ -393,7 +454,7 @@ static int chap_server_compute_md5(
/*
* Convert response from binary hex to ascii hext.
*/
- bin2hex(response, digest, MD5_SIGNATURE_SIZE);
+ bin2hex(response, digest, chap->digest_size);
*nr_out_len += sprintf(nr_out_ptr + *nr_out_len, "CHAP_R=0x%s",
response);
*nr_out_len += 1;
@@ -405,6 +466,10 @@ static int chap_server_compute_md5(
crypto_free_shash(tfm);
kfree(challenge);
kfree(challenge_binhex);
+ kfree(digest);
+ kfree(response);
+ kfree(server_digest);
+ kfree(client_digest);
return auth_ret;
}
@@ -419,7 +484,9 @@ static int chap_got_response(
switch (chap->digest_type) {
case CHAP_DIGEST_MD5:
- if (chap_server_compute_md5(conn, auth, nr_in_ptr,
+ case CHAP_DIGEST_SHA:
+ case CHAP_DIGEST_SHA3_256:
+ if (chap_server_compute_hash(conn, auth, nr_in_ptr,
nr_out_ptr, nr_out_len) < 0)
return -1;
return 0;
diff --git a/drivers/target/iscsi/iscsi_target_auth.h b/drivers/target/iscsi/iscsi_target_auth.h
index d5600ac30b53..8b10f935675a 100644
--- a/drivers/target/iscsi/iscsi_target_auth.h
+++ b/drivers/target/iscsi/iscsi_target_auth.h
@@ -7,13 +7,16 @@
#define CHAP_DIGEST_UNKNOWN 0
#define CHAP_DIGEST_MD5 5
#define CHAP_DIGEST_SHA 6
+#define CHAP_DIGEST_SHA3_256 7
#define CHAP_CHALLENGE_LENGTH 16
#define CHAP_CHALLENGE_STR_LEN 4096
-#define MAX_RESPONSE_LENGTH 64 /* sufficient for MD5 */
+#define MAX_RESPONSE_LENGTH 128 /* sufficient for SHA3 256 */
#define MAX_CHAP_N_SIZE 512
#define MD5_SIGNATURE_SIZE 16 /* 16 bytes in a MD5 message digest */
+#define SHA_SIGNATURE_SIZE 20 /* 20 bytes in a SHA1 message digest */
+#define SHA3_256_SIGNATURE_SIZE 32 /* 32 bytes in a SHA3 256 message digest */
#define CHAP_STAGE_CLIENT_A 1
#define CHAP_STAGE_SERVER_AIC 2
@@ -28,9 +31,11 @@ extern u32 chap_main_loop(struct iscsi_conn *, struct iscsi_node_auth *, char *,
int *, int *);
struct iscsi_chap {
- unsigned char digest_type;
unsigned char id;
unsigned char challenge[CHAP_CHALLENGE_LENGTH];
+ unsigned int challenge_len;
+ unsigned char *digest_name;
+ unsigned int digest_size;
unsigned int authenticate_target;
unsigned int chap_state;
} ____cacheline_aligned;
--
Maurizio Lombardi
