All of lore.kernel.org
 help / color / mirror / Atom feed
* [PATCH V3 1/3] target-iscsi: CHAP: add support to SHA1, SHA256 and SHA3-256 hash functions
@ 2019-10-28 12:38 Maurizio Lombardi
  0 siblings, 0 replies; only message in thread
From: Maurizio Lombardi @ 2019-10-28 12:38 UTC (permalink / raw)
  To: target-devel

This patch 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 three new hash algorithms: SHA1, SHA256
and SHA3-256.

The chap_got_response() function has been removed because the
digest type validity is already checked by chap_server_open()

Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
---
 drivers/target/iscsi/iscsi_target_auth.c | 169 +++++++++++++++--------
 drivers/target/iscsi/iscsi_target_auth.h |  13 +-
 2 files changed, 120 insertions(+), 62 deletions(-)

diff --git a/drivers/target/iscsi/iscsi_target_auth.c b/drivers/target/iscsi/iscsi_target_auth.c
index 8fe9b12a07a4..b09f20842e40 100644
--- a/drivers/target/iscsi/iscsi_target_auth.c
+++ b/drivers/target/iscsi/iscsi_target_auth.c
@@ -18,6 +18,22 @@
 #include "iscsi_target_nego.h"
 #include "iscsi_target_auth.h"
 
+static char *chap_get_digest_name(const int digest_type)
+{
+	switch (digest_type) {
+	case CHAP_DIGEST_MD5:
+		return "md5";
+	case CHAP_DIGEST_SHA1:
+		return "sha1";
+	case CHAP_DIGEST_SHA256:
+		return "sha256";
+	case CHAP_DIGEST_SHA3_256:
+		return "sha3-256";
+	default:
+		return NULL;
+	}
+}
+
 static int chap_gen_challenge(
 	struct iscsi_conn *conn,
 	int caller,
@@ -46,9 +62,23 @@ 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;
+	char *tmp, *orig, *token, *digest_name;
+	long digest_type;
+	int r = CHAP_DIGEST_UNKNOWN;
 
 	tmp = kstrdup(a_str, GFP_KERNEL);
 	if (!tmp) {
@@ -70,15 +100,24 @@ static int chap_check_algorithm(const char *a_str)
 		if (!token)
 			goto out;
 
-		if (!strcmp(token, "5")) {
-			pr_debug("Selected MD5 Algorithm\n");
-			kfree(orig);
-			return CHAP_DIGEST_MD5;
+		if (kstrtol(token, 10, &digest_type))
+			continue;
+
+		digest_name = chap_get_digest_name(digest_type);
+		if (!digest_name)
+			continue;
+
+		pr_debug("Selected %s Algorithm\n", digest_name);
+		if (chap_test_algorithm(digest_name) < 0) {
+			pr_err("failed to allocate %s algo\n", digest_name);
+		} else {
+			r = digest_type;
+			goto out;
 		}
 	}
 out:
 	kfree(orig);
-	return CHAP_DIGEST_UNKNOWN;
+	return r;
 }
 
 static void chap_close(struct iscsi_conn *conn)
@@ -94,7 +133,7 @@ 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 +148,19 @@ 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;
+		break;
+	case CHAP_DIGEST_SHA1:
+		chap->digest_size = SHA1_SIGNATURE_SIZE;
+		break;
+	case CHAP_DIGEST_SHA256:
+		chap->digest_size = SHA256_SIGNATURE_SIZE;
+		break;
+	case CHAP_DIGEST_SHA3_256:
+		chap->digest_size = SHA3_256_SIGNATURE_SIZE;
 		break;
 	case CHAP_DIGEST_UNKNOWN:
 	default:
@@ -128,6 +169,13 @@ static struct iscsi_chap *chap_server_open(
 		return NULL;
 	}
 
+	chap->digest_name = chap_get_digest_name(digest_type);
+
+	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 +194,7 @@ 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 +203,13 @@ 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 +217,33 @@ 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 +288,18 @@ 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 +340,15 @@ 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 +462,7 @@ 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;
@@ -405,31 +474,13 @@ 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;
 }
 
-static int chap_got_response(
-	struct iscsi_conn *conn,
-	struct iscsi_node_auth *auth,
-	char *nr_in_ptr,
-	char *nr_out_ptr,
-	unsigned int *nr_out_len)
-{
-	struct iscsi_chap *chap = conn->auth_protocol;
-
-	switch (chap->digest_type) {
-	case CHAP_DIGEST_MD5:
-		if (chap_server_compute_md5(conn, auth, nr_in_ptr,
-				nr_out_ptr, nr_out_len) < 0)
-			return -1;
-		return 0;
-	default:
-		pr_err("Unknown CHAP digest type %d!\n",
-				chap->digest_type);
-		return -1;
-	}
-}
-
 u32 chap_main_loop(
 	struct iscsi_conn *conn,
 	struct iscsi_node_auth *auth,
@@ -448,7 +499,7 @@ u32 chap_main_loop(
 		return 0;
 	} else if (chap->chap_state == CHAP_STAGE_SERVER_AIC) {
 		convert_null_to_semi(in_text, *in_len);
-		if (chap_got_response(conn, auth, in_text, out_text,
+		if (chap_server_compute_hash(conn, auth, in_text, out_text,
 				out_len) < 0) {
 			chap_close(conn);
 			return 2;
diff --git a/drivers/target/iscsi/iscsi_target_auth.h b/drivers/target/iscsi/iscsi_target_auth.h
index d5600ac30b53..93db1ab5516c 100644
--- a/drivers/target/iscsi/iscsi_target_auth.h
+++ b/drivers/target/iscsi/iscsi_target_auth.h
@@ -6,14 +6,19 @@
 
 #define CHAP_DIGEST_UNKNOWN	0
 #define CHAP_DIGEST_MD5		5
-#define CHAP_DIGEST_SHA		6
+#define CHAP_DIGEST_SHA1	6
+#define CHAP_DIGEST_SHA256	7
+#define CHAP_DIGEST_SHA3_256	8
 
 #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 SHA1_SIGNATURE_SIZE	20	/* 20 bytes in a SHA1 message digest */
+#define SHA256_SIGNATURE_SIZE	32	/* 32 bytes in a SHA256 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 +33,11 @@ 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

^ permalink raw reply	[flat|nested] only message in thread

only message in thread, other threads:[~2019-10-28 12:38 UTC | newest]

Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-10-28 12:38 [PATCH V3 1/3] target-iscsi: CHAP: add support to SHA1, SHA256 and SHA3-256 hash functions Maurizio Lombardi

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.