scsi: target: iscsi: rename some variables to avoid confusion.

This patch renames some variables in chap_server_compute_hash() to make it
harder to confuse the initiator's challenge with the target's challenge
when the mutual chap authentication is used.

Link: https://lore.kernel.org/r/20191017131037.9903-4-mlombard@redhat.comSigned-off-by: Maurizio Lombardi <mlombard@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/target/iscsi/iscsi_target_auth.c

@@ -215,8 +215,8 @@ static int chap_server_compute_hash(
 	unsigned long id;
 	unsigned char id_as_uchar;
 	unsigned char type;
-	unsigned char identifier[10], *challenge = NULL;
-	unsigned char *challenge_binhex = NULL;
+	unsigned char identifier[10], *initiatorchg = NULL;
+	unsigned char *initiatorchg_binhex = NULL;
 	unsigned char *digest = NULL;
 	unsigned char *response = NULL;
 	unsigned char *client_digest = NULL;
@@ -226,7 +226,7 @@ static int chap_server_compute_hash(
 	struct iscsi_chap *chap = conn->auth_protocol;
 	struct crypto_shash *tfm = NULL;
 	struct shash_desc *desc = NULL;
-	int auth_ret = -1, ret, challenge_len;
+	int auth_ret = -1, ret, initiatorchg_len;
 
 	digest = kzalloc(chap->digest_size, GFP_KERNEL);
 	if (!digest) {
@@ -256,15 +256,15 @@ static int chap_server_compute_hash(
 	memset(chap_n, 0, MAX_CHAP_N_SIZE);
 	memset(chap_r, 0, MAX_RESPONSE_LENGTH);
 
-	challenge = kzalloc(CHAP_CHALLENGE_STR_LEN, GFP_KERNEL);
-	if (!challenge) {
+	initiatorchg = kzalloc(CHAP_CHALLENGE_STR_LEN, GFP_KERNEL);
+	if (!initiatorchg) {
 		pr_err("Unable to allocate challenge buffer\n");
 		goto out;
 	}
 
-	challenge_binhex = kzalloc(CHAP_CHALLENGE_STR_LEN, GFP_KERNEL);
-	if (!challenge_binhex) {
-		pr_err("Unable to allocate challenge_binhex buffer\n");
+	initiatorchg_binhex = kzalloc(CHAP_CHALLENGE_STR_LEN, GFP_KERNEL);
+	if (!initiatorchg_binhex) {
+		pr_err("Unable to allocate initiatorchg_binhex buffer\n");
 		goto out;
 	}
 	/*
@@ -399,7 +399,7 @@ static int chap_server_compute_hash(
 	 * Get CHAP_C.
 	 */
 	if (extract_param(nr_in_ptr, "CHAP_C", CHAP_CHALLENGE_STR_LEN,
-			challenge, &type) < 0) {
+			initiatorchg, &type) < 0) {
 		pr_err("Could not find CHAP_C.\n");
 		goto out;
 	}
@@ -408,28 +408,28 @@ static int chap_server_compute_hash(
 		pr_err("Could not find CHAP_C.\n");
 		goto out;
 	}
-	challenge_len = DIV_ROUND_UP(strlen(challenge), 2);
-	if (!challenge_len) {
+	initiatorchg_len = DIV_ROUND_UP(strlen(initiatorchg), 2);
+	if (!initiatorchg_len) {
 		pr_err("Unable to convert incoming challenge\n");
 		goto out;
 	}
-	if (challenge_len > 1024) {
+	if (initiatorchg_len > 1024) {
 		pr_err("CHAP_C exceeds maximum binary size of 1024 bytes\n");
 		goto out;
 	}
-	if (hex2bin(challenge_binhex, challenge, challenge_len) < 0) {
+	if (hex2bin(initiatorchg_binhex, initiatorchg, initiatorchg_len) < 0) {
 		pr_err("Malformed CHAP_C\n");
 		goto out;
 	}
-	pr_debug("[server] Got CHAP_C=%s\n", challenge);
+	pr_debug("[server] Got CHAP_C=%s\n", initiatorchg);
 	/*
 	 * During mutual authentication, the CHAP_C generated by the
 	 * initiator must not match the original CHAP_C generated by
 	 * the target.
 	 */
-	if (challenge_len == chap->challenge_len &&
-				!memcmp(challenge_binhex, chap->challenge,
-				challenge_len)) {
+	if (initiatorchg_len == chap->challenge_len &&
+				!memcmp(initiatorchg_binhex, chap->challenge,
+				initiatorchg_len)) {
 		pr_err("initiator CHAP_C matches target CHAP_C, failing"
 		       " login attempt\n");
 		goto out;
@@ -461,7 +461,7 @@ static int chap_server_compute_hash(
 	/*
 	 * Convert received challenge to binary hex.
 	 */
-	ret = crypto_shash_finup(desc, challenge_binhex, challenge_len,
+	ret = crypto_shash_finup(desc, initiatorchg_binhex, initiatorchg_len,
 				 digest);
 	if (ret < 0) {
 		pr_err("crypto_shash_finup() failed for ma challenge\n");
@@ -487,8 +487,8 @@ static int chap_server_compute_hash(
 	kzfree(desc);
 	if (tfm)
 		crypto_free_shash(tfm);
-	kfree(challenge);
-	kfree(challenge_binhex);
+	kfree(initiatorchg);
+	kfree(initiatorchg_binhex);
 	kfree(digest);
 	kfree(response);
 	kfree(server_digest);