1 files changed, 342 insertions, 184 deletions

diff --git a/drivers/target/iscsi/iscsi_target_auth.c b/drivers/target/iscsi/iscsi_target_auth.c
index cee17543278c..c8a248bd11be 100644
--- a/drivers/target/iscsi/iscsi_target_auth.c
+++ b/drivers/target/iscsi/iscsi_target_auth.c
@@ -1,68 +1,61 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*******************************************************************************
  * This file houses the main functions for the iSCSI CHAP support
  *
- * \u00a9 Copyright 2007-2011 RisingTide Systems LLC.
- *
- * Licensed to the Linux Foundation under the General Public License (GPL) version 2.
+ * (c) Copyright 2007-2013 Datera, Inc.
  *
  * Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
  *
- * 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; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
  ******************************************************************************/
 
+#include <crypto/hash.h>
 #include <linux/kernel.h>
 #include <linux/string.h>
-#include <linux/crypto.h>
 #include <linux/err.h>
+#include <linux/random.h>
 #include <linux/scatterlist.h>
-
-#include "iscsi_target_core.h"
+#include <target/iscsi/iscsi_target_core.h>
 #include "iscsi_target_nego.h"
 #include "iscsi_target_auth.h"
 
-static int chap_string_to_hex(unsigned char *dst, unsigned char *src, int len)
-{
-	int j = DIV_ROUND_UP(len, 2), rc;
-
-	rc = hex2bin(dst, src, j);
-	if (rc < 0)
-		pr_debug("CHAP string contains non hex digit symbols\n");
-
-	dst[j] = '\0';
-	return j;
-}
-
-static void chap_binaryhex_to_asciihex(char *dst, char *src, int src_len)
+static char *chap_get_digest_name(const int digest_type)
 {
-	int i;
-
-	for (i = 0; i < src_len; i++) {
-		sprintf(&dst[i*2], "%02x", (int) src[i] & 0xff);
+	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 void chap_gen_challenge(
-	struct iscsi_conn *conn,
+static int chap_gen_challenge(
+	struct iscsit_conn *conn,
 	int caller,
 	char *c_str,
 	unsigned int *c_len)
 {
-	unsigned char challenge_asciihex[CHAP_CHALLENGE_LENGTH * 2 + 1];
+	int ret;
+	unsigned char *challenge_asciihex;
 	struct iscsi_chap *chap = conn->auth_protocol;
 
-	memset(challenge_asciihex, 0, CHAP_CHALLENGE_LENGTH * 2 + 1);
+	challenge_asciihex = kzalloc(chap->challenge_len * 2 + 1, GFP_KERNEL);
+	if (!challenge_asciihex)
+		return -ENOMEM;
 
-	get_random_bytes(chap->challenge, CHAP_CHALLENGE_LENGTH);
-	chap_binaryhex_to_asciihex(challenge_asciihex, chap->challenge,
-				CHAP_CHALLENGE_LENGTH);
+	memset(chap->challenge, 0, MAX_CHAP_CHALLENGE_LEN);
+
+	ret = get_random_bytes_wait(chap->challenge, chap->challenge_len);
+	if (unlikely(ret))
+		goto out;
+
+	bin2hex(challenge_asciihex, chap->challenge,
+				chap->challenge_len);
 	/*
 	 * Set CHAP_C, and copy the generated challenge into c_str.
 	 */
@@ -71,16 +64,84 @@ static void chap_gen_challenge(
 
 	pr_debug("[%s] Sending CHAP_C=0x%s\n\n", (caller) ? "server" : "client",
 			challenge_asciihex);
+
+out:
+	kfree(challenge_asciihex);
+	return ret;
 }
 
+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, *digest_name;
+	long digest_type;
+	int r = CHAP_DIGEST_UNKNOWN;
+
+	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 (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 r;
+}
+
+static void chap_close(struct iscsit_conn *conn)
+{
+	kfree(conn->auth_protocol);
+	conn->auth_protocol = NULL;
+}
 
 static struct iscsi_chap *chap_server_open(
-	struct iscsi_conn *conn,
+	struct iscsit_conn *conn,
 	struct iscsi_node_auth *auth,
 	const char *a_str,
 	char *aic_str,
 	unsigned int *aic_len)
 {
+	int digest_type;
 	struct iscsi_chap *chap;
 
 	if (!(auth->naf_flags & NAF_USERID_SET) ||
@@ -95,82 +156,147 @@ 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");
+	digest_type = chap_check_algorithm(a_str);
+	switch (digest_type) {
+	case CHAP_DIGEST_MD5:
+		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:
+		pr_err("Unsupported CHAP_A value\n");
+		chap_close(conn);
 		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");
+
+	chap->digest_name = chap_get_digest_name(digest_type);
+
+	/* Tie the challenge length to the digest size */
+	chap->challenge_len = chap->digest_size;
+
+	pr_debug("[server] Got CHAP_A=%d\n", digest_type);
+	*aic_len = sprintf(aic_str, "CHAP_A=%d", digest_type);
 	*aic_len += 1;
-	chap->digest_type = CHAP_DIGEST_MD5;
-	pr_debug("[server] Sending CHAP_A=%d\n", chap->digest_type);
+	pr_debug("[server] Sending CHAP_A=%d\n", digest_type);
+
 	/*
 	 * Set Identifier.
 	 */
-	chap->id = ISCSI_TPG_C(conn)->tpg_chap_id++;
+	chap->id = conn->tpg->tpg_chap_id++;
 	*aic_len += sprintf(aic_str + *aic_len, "CHAP_I=%d", chap->id);
 	*aic_len += 1;
 	pr_debug("[server] Sending CHAP_I=%d\n", chap->id);
 	/*
 	 * Generate Challenge.
 	 */
-	chap_gen_challenge(conn, 1, aic_str, aic_len);
+	if (chap_gen_challenge(conn, 1, aic_str, aic_len) < 0) {
+		chap_close(conn);
+		return NULL;
+	}
 
 	return chap;
 }
 
-static void chap_close(struct iscsi_conn *conn)
+static const char base64_lookup_table[] =
+	"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+static int chap_base64_decode(u8 *dst, const char *src, size_t len)
 {
-	kfree(conn->auth_protocol);
-	conn->auth_protocol = NULL;
+	int i, bits = 0, ac = 0;
+	const char *p;
+	u8 *cp = dst;
+
+	for (i = 0; i < len; i++) {
+		if (src[i] == '=')
+			return cp - dst;
+
+		p = strchr(base64_lookup_table, src[i]);
+		if (p == NULL || src[i] == 0)
+			return -2;
+
+		ac <<= 6;
+		ac += (p - base64_lookup_table);
+		bits += 6;
+		if (bits >= 8) {
+			*cp++ = (ac >> (bits - 8)) & 0xff;
+			ac &= ~(BIT(16) - BIT(bits - 8));
+			bits -= 8;
+		}
+	}
+	if (ac)
+		return -1;
+
+	return cp - dst;
 }
 
-static int chap_server_compute_md5(
-	struct iscsi_conn *conn,
+static int chap_server_compute_hash(
+	struct iscsit_conn *conn,
 	struct iscsi_node_auth *auth,
 	char *nr_in_ptr,
 	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];
-	unsigned char type, response[MD5_SIGNATURE_SIZE * 2 + 2];
-	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 type;
+	unsigned char identifier[10], *initiatorchg = NULL;
+	unsigned char *initiatorchg_binhex = NULL;
+	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;
-	struct crypto_hash *tfm;
-	struct hash_desc desc;
-	struct scatterlist sg;
-	int auth_ret = -1, ret, challenge_len;
+	struct crypto_shash *tfm = NULL;
+	struct shash_desc *desc = NULL;
+	int auth_ret = -1, ret, initiatorchg_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) {
+	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;
 	}
 	/*
@@ -186,7 +312,9 @@ static int chap_server_compute_md5(
 		goto out;
 	}
 
-	if (memcmp(chap_n, auth->userid, strlen(auth->userid)) != 0) {
+	/* Include the terminating NULL in the compare */
+	compare_len = strlen(auth->userid) + 1;
+	if (strncmp(chap_n, auth->userid, compare_len) != 0) {
 		pr_err("CHAP_N values do not match!\n");
 		goto out;
 	}
@@ -199,91 +327,115 @@ static int chap_server_compute_md5(
 		pr_err("Could not find CHAP_R.\n");
 		goto out;
 	}
-	if (type != HEX) {
-		pr_err("Could not find CHAP_R.\n");
+
+	switch (type) {
+	case HEX:
+		if (strlen(chap_r) != chap->digest_size * 2) {
+			pr_err("Malformed CHAP_R\n");
+			goto out;
+		}
+		if (hex2bin(client_digest, chap_r, chap->digest_size) < 0) {
+			pr_err("Malformed CHAP_R: invalid HEX\n");
+			goto out;
+		}
+		break;
+	case BASE64:
+		if (chap_base64_decode(client_digest, chap_r, strlen(chap_r)) !=
+		    chap->digest_size) {
+			pr_err("Malformed CHAP_R: invalid BASE64\n");
+			goto out;
+		}
+		break;
+	default:
+		pr_err("Could not find CHAP_R\n");
 		goto out;
 	}
 
 	pr_debug("[server] Got CHAP_R=%s\n", chap_r);
-	chap_string_to_hex(client_digest, chap_r, strlen(chap_r));
 
-	tfm = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC);
+	tfm = crypto_alloc_shash(chap->digest_name, 0, 0);
 	if (IS_ERR(tfm)) {
-		pr_err("Unable to allocate struct crypto_hash\n");
+		tfm = NULL;
+		pr_err("Unable to allocate struct crypto_shash\n");
 		goto out;
 	}
-	desc.tfm = tfm;
-	desc.flags = 0;
 
-	ret = crypto_hash_init(&desc);
-	if (ret < 0) {
-		pr_err("crypto_hash_init() failed\n");
-		crypto_free_hash(tfm);
+	desc = kmalloc(sizeof(*desc) + crypto_shash_descsize(tfm), GFP_KERNEL);
+	if (!desc) {
+		pr_err("Unable to allocate struct shash_desc\n");
 		goto out;
 	}
 
-	sg_init_one(&sg, &chap->id, 1);
-	ret = crypto_hash_update(&desc, &sg, 1);
+	desc->tfm = tfm;
+
+	ret = crypto_shash_init(desc);
 	if (ret < 0) {
-		pr_err("crypto_hash_update() failed for id\n");
-		crypto_free_hash(tfm);
+		pr_err("crypto_shash_init() failed\n");
 		goto out;
 	}
 
-	sg_init_one(&sg, &auth->password, strlen(auth->password));
-	ret = crypto_hash_update(&desc, &sg, strlen(auth->password));
+	ret = crypto_shash_update(desc, &chap->id, 1);
 	if (ret < 0) {
-		pr_err("crypto_hash_update() failed for password\n");
-		crypto_free_hash(tfm);
+		pr_err("crypto_shash_update() failed for id\n");
 		goto out;
 	}
 
-	sg_init_one(&sg, chap->challenge, CHAP_CHALLENGE_LENGTH);
-	ret = crypto_hash_update(&desc, &sg, CHAP_CHALLENGE_LENGTH);
+	ret = crypto_shash_update(desc, (char *)&auth->password,
+				  strlen(auth->password));
 	if (ret < 0) {
-		pr_err("crypto_hash_update() failed for challenge\n");
-		crypto_free_hash(tfm);
+		pr_err("crypto_shash_update() failed for password\n");
 		goto out;
 	}
 
-	ret = crypto_hash_final(&desc, server_digest);
+	ret = crypto_shash_finup(desc, chap->challenge,
+				 chap->challenge_len, server_digest);
 	if (ret < 0) {
-		pr_err("crypto_hash_final() failed for server digest\n");
-		crypto_free_hash(tfm);
+		pr_err("crypto_shash_finup() failed for challenge\n");
 		goto out;
 	}
-	crypto_free_hash(tfm);
 
-	chap_binaryhex_to_asciihex(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",
+		chap->digest_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",
+			chap->digest_name);
 		goto out;
 	} else
-		pr_debug("[server] MD5 Digests match, CHAP connetication"
-				" successful.\n\n");
+		pr_debug("[server] %s Digests match, CHAP connection"
+				" successful.\n\n", chap->digest_name);
 	/*
 	 * One way authentication has succeeded, return now if mutual
 	 * authentication is not enabled.
 	 */
 	if (!auth->authenticate_target) {
-		kfree(challenge);
-		kfree(challenge_binhex);
-		return 0;
+		auth_ret = 0;
+		goto out;
 	}
 	/*
 	 * Get CHAP_I.
 	 */
-	if (extract_param(nr_in_ptr, "CHAP_I", 10, identifier, &type) < 0) {
+	ret = extract_param(nr_in_ptr, "CHAP_I", 10, identifier, &type);
+	if (ret == -ENOENT) {
+		pr_debug("Could not find CHAP_I. Initiator uses One way authentication.\n");
+		auth_ret = 0;
+		goto out;
+	}
+	if (ret < 0) {
 		pr_err("Could not find CHAP_I.\n");
 		goto out;
 	}
 
 	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;
@@ -296,77 +448,98 @@ static int chap_server_compute_md5(
 	 * 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;
 	}
 
-	if (type != HEX) {
+	switch (type) {
+	case HEX:
+		initiatorchg_len = DIV_ROUND_UP(strlen(initiatorchg), 2);
+		if (!initiatorchg_len) {
+			pr_err("Unable to convert incoming challenge\n");
+			goto out;
+		}
+		if (initiatorchg_len > 1024) {
+			pr_err("CHAP_C exceeds maximum binary size of 1024 bytes\n");
+			goto out;
+		}
+
+		if (hex2bin(initiatorchg_binhex, initiatorchg,
+			    initiatorchg_len) < 0) {
+			pr_err("Malformed CHAP_C: invalid HEX\n");
+			goto out;
+		}
+		break;
+	case BASE64:
+		initiatorchg_len = chap_base64_decode(initiatorchg_binhex,
+						      initiatorchg,
+						      strlen(initiatorchg));
+		if (initiatorchg_len < 0) {
+			pr_err("Malformed CHAP_C: invalid BASE64\n");
+			goto out;
+		}
+		if (!initiatorchg_len) {
+			pr_err("Unable to convert incoming challenge\n");
+			goto out;
+		}
+		if (initiatorchg_len > 1024) {
+			pr_err("CHAP_C exceeds maximum binary size of 1024 bytes\n");
+			goto out;
+		}
+		break;
+	default:
 		pr_err("Could not find CHAP_C.\n");
 		goto out;
 	}
-	pr_debug("[server] Got CHAP_C=%s\n", challenge);
-	challenge_len = chap_string_to_hex(challenge_binhex, challenge,
-				strlen(challenge));
-	if (!challenge_len) {
-		pr_err("Unable to convert incoming challenge\n");
+
+	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 (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;
 	}
 	/*
 	 * Generate CHAP_N and CHAP_R for mutual authentication.
 	 */
-	tfm = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC);
-	if (IS_ERR(tfm)) {
-		pr_err("Unable to allocate struct crypto_hash\n");
-		goto out;
-	}
-	desc.tfm = tfm;
-	desc.flags = 0;
-
-	ret = crypto_hash_init(&desc);
+	ret = crypto_shash_init(desc);
 	if (ret < 0) {
-		pr_err("crypto_hash_init() failed\n");
-		crypto_free_hash(tfm);
+		pr_err("crypto_shash_init() failed\n");
 		goto out;
 	}
 
 	/* To handle both endiannesses */
 	id_as_uchar = id;
-	sg_init_one(&sg, &id_as_uchar, 1);
-	ret = crypto_hash_update(&desc, &sg, 1);
+	ret = crypto_shash_update(desc, &id_as_uchar, 1);
 	if (ret < 0) {
-		pr_err("crypto_hash_update() failed for id\n");
-		crypto_free_hash(tfm);
+		pr_err("crypto_shash_update() failed for id\n");
 		goto out;
 	}
 
-	sg_init_one(&sg, auth->password_mutual,
-				strlen(auth->password_mutual));
-	ret = crypto_hash_update(&desc, &sg, strlen(auth->password_mutual));
+	ret = crypto_shash_update(desc, auth->password_mutual,
+				  strlen(auth->password_mutual));
 	if (ret < 0) {
-		pr_err("crypto_hash_update() failed for"
+		pr_err("crypto_shash_update() failed for"
 				" password_mutual\n");
-		crypto_free_hash(tfm);
 		goto out;
 	}
 	/*
 	 * Convert received challenge to binary hex.
 	 */
-	sg_init_one(&sg, challenge_binhex, challenge_len);
-	ret = crypto_hash_update(&desc, &sg, challenge_len);
+	ret = crypto_shash_finup(desc, initiatorchg_binhex, initiatorchg_len,
+				 digest);
 	if (ret < 0) {
-		pr_err("crypto_hash_update() failed for ma challenge\n");
-		crypto_free_hash(tfm);
+		pr_err("crypto_shash_finup() failed for ma challenge\n");
 		goto out;
 	}
 
-	ret = crypto_hash_final(&desc, digest);
-	if (ret < 0) {
-		pr_err("crypto_hash_final() failed for ma digest\n");
-		crypto_free_hash(tfm);
-		goto out;
-	}
-	crypto_free_hash(tfm);
 	/*
 	 * Generate CHAP_N and CHAP_R.
 	 */
@@ -376,42 +549,27 @@ static int chap_server_compute_md5(
 	/*
 	 * Convert response from binary hex to ascii hext.
 	 */
-	chap_binaryhex_to_asciihex(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;
 	pr_debug("[server] Sending CHAP_R=0x%s\n", response);
 	auth_ret = 0;
 out:
-	kfree(challenge);
-	kfree(challenge_binhex);
+	kfree_sensitive(desc);
+	if (tfm)
+		crypto_free_shash(tfm);
+	kfree(initiatorchg);
+	kfree(initiatorchg_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 iscsit_conn *conn,
 	struct iscsi_node_auth *auth,
 	char *in_text,
 	char *out_text,
@@ -428,7 +586,7 @@ 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;