[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / target / iscsi / iscsi_target_auth.c

/*******************************************************************************
 * 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.
 *
 * 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 <linux/kernel.h>
#include <linux/string.h>
#include <linux/crypto.h>
#include <linux/err.h>
#include <linux/scatterlist.h>

#include "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)
{
	int i;

	for (i = 0; i < src_len; i++) {
		sprintf(&dst[i*2], "%02x", (int) src[i] & 0xff);
	}
}

static void chap_gen_challenge(
	struct iscsi_conn *conn,
	int caller,
	char *c_str,
	unsigned int *c_len)
{
	unsigned char challenge_asciihex[CHAP_CHALLENGE_LENGTH * 2 + 1];
	struct iscsi_chap *chap = conn->auth_protocol;

	memset(challenge_asciihex, 0, CHAP_CHALLENGE_LENGTH * 2 + 1);

	get_random_bytes(chap->challenge, CHAP_CHALLENGE_LENGTH);
	chap_binaryhex_to_asciihex(challenge_asciihex, chap->challenge,
				CHAP_CHALLENGE_LENGTH);
	/*
	 * Set CHAP_C, and copy the generated challenge into c_str.
	 */
	*c_len += sprintf(c_str + *c_len, "CHAP_C=0x%s", challenge_asciihex);
	*c_len += 1;

	pr_debug("[%s] Sending CHAP_C=0x%s\n\n", (caller) ? "server" : "client",
			challenge_asciihex);
}


static struct iscsi_chap *chap_server_open(
	struct iscsi_conn *conn,
	struct iscsi_node_auth *auth,
	const char *a_str,
	char *aic_str,
	unsigned int *aic_len)
{
	struct iscsi_chap *chap;

	if (!(auth->naf_flags & NAF_USERID_SET) ||
	    !(auth->naf_flags & NAF_PASSWORD_SET)) {
		pr_err("CHAP user or password not set for"
				" Initiator ACL\n");
		return NULL;
	}

	conn->auth_protocol = kzalloc(sizeof(struct iscsi_chap), GFP_KERNEL);
	if (!conn->auth_protocol)
		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");
		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.
	 */
	chap->id = ISCSI_TPG_C(conn)->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);

	return chap;
}

static void chap_close(struct iscsi_conn *conn)
{
	kfree(conn->auth_protocol);
	conn->auth_protocol = NULL;
}

static int chap_server_compute_md5(
	struct iscsi_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 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;

	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) {
		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");
		goto out;
	}
	/*
	 * Extract CHAP_N.
	 */
	if (extract_param(nr_in_ptr, "CHAP_N", MAX_CHAP_N_SIZE, chap_n,
				&type) < 0) {
		pr_err("Could not find CHAP_N.\n");
		goto out;
	}
	if (type == HEX) {
		pr_err("Could not find CHAP_N.\n");
		goto out;
	}

	/* 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;
	}
	pr_debug("[server] Got CHAP_N=%s\n", chap_n);
	/*
	 * Extract CHAP_R.
	 */
	if (extract_param(nr_in_ptr, "CHAP_R", MAX_RESPONSE_LENGTH, chap_r,
				&type) < 0) {
		pr_err("Could not find CHAP_R.\n");
		goto out;
	}
	if (type != HEX) {
		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);
	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);
	if (ret < 0) {
		pr_err("crypto_hash_init() failed\n");
		crypto_free_hash(tfm);
		goto out;
	}

	sg_init_one(&sg, &chap->id, 1);
	ret = crypto_hash_update(&desc, &sg, 1);
	if (ret < 0) {
		pr_err("crypto_hash_update() failed for id\n");
		crypto_free_hash(tfm);
		goto out;
	}

	sg_init_one(&sg, &auth->password, strlen(auth->password));
	ret = crypto_hash_update(&desc, &sg, strlen(auth->password));
	if (ret < 0) {
		pr_err("crypto_hash_update() failed for password\n");
		crypto_free_hash(tfm);
		goto out;
	}

	sg_init_one(&sg, chap->challenge, CHAP_CHALLENGE_LENGTH);
	ret = crypto_hash_update(&desc, &sg, CHAP_CHALLENGE_LENGTH);
	if (ret < 0) {
		pr_err("crypto_hash_update() failed for challenge\n");
		crypto_free_hash(tfm);
		goto out;
	}

	ret = crypto_hash_final(&desc, server_digest);
	if (ret < 0) {
		pr_err("crypto_hash_final() failed for server digest\n");
		crypto_free_hash(tfm);
		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);

	if (memcmp(server_digest, client_digest, MD5_SIGNATURE_SIZE) != 0) {
		pr_debug("[server] MD5 Digests do not match!\n\n");
		goto out;
	} else
		pr_debug("[server] MD5 Digests match, CHAP connetication"
				" successful.\n\n");
	/*
	 * One way authentication has succeeded, return now if mutual
	 * authentication is not enabled.
	 */
	if (!auth->authenticate_target) {
		kfree(challenge);
		kfree(challenge_binhex);
		return 0;
	}
	/*
	 * Get CHAP_I.
	 */
	if (extract_param(nr_in_ptr, "CHAP_I", 10, identifier, &type) < 0) {
		pr_err("Could not find CHAP_I.\n");
		goto out;
	}

	if (type == HEX)
		id = simple_strtoul(&identifier[2], &endptr, 0);
	else
		id = simple_strtoul(identifier, &endptr, 0);
	if (id > 255) {
		pr_err("chap identifier: %lu greater than 255\n", id);
		goto out;
	}
	/*
	 * RFC 1994 says Identifier is no more than octet (8 bits).
	 */
	pr_debug("[server] Got CHAP_I=%lu\n", id);
	/*
	 * Get CHAP_C.
	 */
	if (extract_param(nr_in_ptr, "CHAP_C", CHAP_CHALLENGE_STR_LEN,
			challenge, &type) < 0) {
		pr_err("Could not find CHAP_C.\n");
		goto out;
	}

	if (type != HEX) {
		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");
		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.
	 */
	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);
	if (ret < 0) {
		pr_err("crypto_hash_init() failed\n");
		crypto_free_hash(tfm);
		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);
	if (ret < 0) {
		pr_err("crypto_hash_update() failed for id\n");
		crypto_free_hash(tfm);
		goto out;
	}

	sg_init_one(&sg, auth->password_mutual,
				strlen(auth->password_mutual));
	ret = crypto_hash_update(&desc, &sg, strlen(auth->password_mutual));
	if (ret < 0) {
		pr_err("crypto_hash_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);
	if (ret < 0) {
		pr_err("crypto_hash_update() failed for ma challenge\n");
		crypto_free_hash(tfm);
		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.
	 */
	*nr_out_len = sprintf(nr_out_ptr, "CHAP_N=%s", auth->userid_mutual);
	*nr_out_len += 1;
	pr_debug("[server] Sending CHAP_N=%s\n", auth->userid_mutual);
	/*
	 * Convert response from binary hex to ascii hext.
	 */
	chap_binaryhex_to_asciihex(response, digest, MD5_SIGNATURE_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);
	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,
	char *in_text,
	char *out_text,
	int *in_len,
	int *out_len)
{
	struct iscsi_chap *chap = conn->auth_protocol;

	if (!chap) {
		chap = chap_server_open(conn, auth, in_text, out_text, out_len);
		if (!chap)
			return 2;
		chap->chap_state = CHAP_STAGE_SERVER_AIC;
		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,
				out_len) < 0) {
			chap_close(conn);
			return 2;
		}
		if (auth->authenticate_target)
			chap->chap_state = CHAP_STAGE_SERVER_NR;
		else
			*out_len = 0;
		chap_close(conn);
		return 1;
	}

	return 2;
}
Commit	Line	Data
e48354ce NB	1	/*******************************************************************************
	2	* This file houses the main functions for the iSCSI CHAP support
	3	*
	4	* \u00a9 Copyright 2007-2011 RisingTide Systems LLC.
	5	*
	6	* Licensed to the Linux Foundation under the General Public License (GPL) version 2.
	7	*
	8	* Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
	9	*
	10	* This program is free software; you can redistribute it and/or modify
	11	* it under the terms of the GNU General Public License as published by
	12	* the Free Software Foundation; either version 2 of the License, or
	13	* (at your option) any later version.
	14	*
	15	* This program is distributed in the hope that it will be useful,
	16	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	17	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	18	* GNU General Public License for more details.
	19	******************************************************************************/
	20
f2b56afd	21	#include <linux/kernel.h>
e48354ce NB	22	#include <linux/string.h>
	23	#include <linux/crypto.h>
	24	#include <linux/err.h>
	25	#include <linux/scatterlist.h>
	26
	27	#include "iscsi_target_core.h"
	28	#include "iscsi_target_nego.h"
	29	#include "iscsi_target_auth.h"
	30
e48354ce NB	31	static int chap_string_to_hex(unsigned char dst, unsigned char src, int len)
e48354ce NB	32	{
ddca8f3e	33	int j = DIV_ROUND_UP(len, 2), rc;
e48354ce	34
ddca8f3e NB	35	rc = hex2bin(dst, src, j);
	36	if (rc < 0)
	37	pr_debug("CHAP string contains non hex digit symbols\n");
e48354ce NB	38
	39	dst[j] = '\0';
	40	return j;
	41	}
	42
	43	static void chap_binaryhex_to_asciihex(char dst, char src, int src_len)
	44	{
	45	int i;
	46
	47	for (i = 0; i < src_len; i++) {
	48	sprintf(&dst[i*2], "%02x", (int) src[i] & 0xff);
	49	}
	50	}
	51
e48354ce NB	52	static void chap_gen_challenge(
	53	struct iscsi_conn *conn,
	54	int caller,
	55	char *c_str,
	56	unsigned int *c_len)
	57	{
	58	unsigned char challenge_asciihex[CHAP_CHALLENGE_LENGTH * 2 + 1];
8359cf43	59	struct iscsi_chap *chap = conn->auth_protocol;
e48354ce NB	60
	61	memset(challenge_asciihex, 0, CHAP_CHALLENGE_LENGTH * 2 + 1);
	62
98e2eeb3	63	get_random_bytes(chap->challenge, CHAP_CHALLENGE_LENGTH);
e48354ce NB	64	chap_binaryhex_to_asciihex(challenge_asciihex, chap->challenge,
	65	CHAP_CHALLENGE_LENGTH);
	66	/*
	67	* Set CHAP_C, and copy the generated challenge into c_str.
	68	*/
	69	c_len += sprintf(c_str + c_len, "CHAP_C=0x%s", challenge_asciihex);
	70	*c_len += 1;
	71
	72	pr_debug("[%s] Sending CHAP_C=0x%s\n\n", (caller) ? "server" : "client",
	73	challenge_asciihex);
	74	}
	75
	76
	77	static struct iscsi_chap *chap_server_open(
	78	struct iscsi_conn *conn,
	79	struct iscsi_node_auth *auth,
	80	const char *a_str,
	81	char *aic_str,
	82	unsigned int *aic_len)
	83	{
	84	struct iscsi_chap *chap;
	85
	86	if (!(auth->naf_flags & NAF_USERID_SET) \|\|
	87	!(auth->naf_flags & NAF_PASSWORD_SET)) {
	88	pr_err("CHAP user or password not set for"
	89	" Initiator ACL\n");
	90	return NULL;
	91	}
	92
	93	conn->auth_protocol = kzalloc(sizeof(struct iscsi_chap), GFP_KERNEL);
	94	if (!conn->auth_protocol)
	95	return NULL;
	96
8359cf43	97	chap = conn->auth_protocol;
e48354ce NB	98	/*
	99	* We only support MD5 MDA presently.
	100	*/
	101	if (strncmp(a_str, "CHAP_A=5", 8)) {
	102	pr_err("CHAP_A is not MD5.\n");
	103	return NULL;
	104	}
	105	pr_debug("[server] Got CHAP_A=5\n");
	106	/*
	107	* Send back CHAP_A set to MD5.
	108	*/
	109	*aic_len = sprintf(aic_str, "CHAP_A=5");
	110	*aic_len += 1;
	111	chap->digest_type = CHAP_DIGEST_MD5;
	112	pr_debug("[server] Sending CHAP_A=%d\n", chap->digest_type);
	113	/*
	114	* Set Identifier.
	115	*/
	116	chap->id = ISCSI_TPG_C(conn)->tpg_chap_id++;
	117	aic_len += sprintf(aic_str + aic_len, "CHAP_I=%d", chap->id);
	118	*aic_len += 1;
	119	pr_debug("[server] Sending CHAP_I=%d\n", chap->id);
	120	/*
	121	* Generate Challenge.
	122	*/
	123	chap_gen_challenge(conn, 1, aic_str, aic_len);
	124
	125	return chap;
	126	}
	127
	128	static void chap_close(struct iscsi_conn *conn)
	129	{
	130	kfree(conn->auth_protocol);
	131	conn->auth_protocol = NULL;
	132	}
	133
	134	static int chap_server_compute_md5(
	135	struct iscsi_conn *conn,
	136	struct iscsi_node_auth *auth,
	137	char *nr_in_ptr,
	138	char *nr_out_ptr,
	139	unsigned int *nr_out_len)
	140	{
	141	char *endptr;
bc704fb5	142	unsigned long id;
7ac9ad11	143	unsigned char id_as_uchar;
bc704fb5	144	unsigned char digest[MD5_SIGNATURE_SIZE];
e48354ce NB	145	unsigned char type, response[MD5_SIGNATURE_SIZE * 2 + 2];
	146	unsigned char identifier[10], *challenge = NULL;
	147	unsigned char *challenge_binhex = NULL;
	148	unsigned char client_digest[MD5_SIGNATURE_SIZE];
	149	unsigned char server_digest[MD5_SIGNATURE_SIZE];
	150	unsigned char chap_n[MAX_CHAP_N_SIZE], chap_r[MAX_RESPONSE_LENGTH];
6aec95b4	151	size_t compare_len;
8359cf43	152	struct iscsi_chap *chap = conn->auth_protocol;
e48354ce NB	153	struct crypto_hash *tfm;
	154	struct hash_desc desc;
	155	struct scatterlist sg;
	156	int auth_ret = -1, ret, challenge_len;
	157
	158	memset(identifier, 0, 10);
	159	memset(chap_n, 0, MAX_CHAP_N_SIZE);
	160	memset(chap_r, 0, MAX_RESPONSE_LENGTH);
	161	memset(digest, 0, MD5_SIGNATURE_SIZE);
	162	memset(response, 0, MD5_SIGNATURE_SIZE * 2 + 2);
	163	memset(client_digest, 0, MD5_SIGNATURE_SIZE);
	164	memset(server_digest, 0, MD5_SIGNATURE_SIZE);
	165
	166	challenge = kzalloc(CHAP_CHALLENGE_STR_LEN, GFP_KERNEL);
	167	if (!challenge) {
	168	pr_err("Unable to allocate challenge buffer\n");
	169	goto out;
	170	}
	171
	172	challenge_binhex = kzalloc(CHAP_CHALLENGE_STR_LEN, GFP_KERNEL);
	173	if (!challenge_binhex) {
	174	pr_err("Unable to allocate challenge_binhex buffer\n");
	175	goto out;
	176	}
	177	/*
	178	* Extract CHAP_N.
	179	*/
	180	if (extract_param(nr_in_ptr, "CHAP_N", MAX_CHAP_N_SIZE, chap_n,
	181	&type) < 0) {
	182	pr_err("Could not find CHAP_N.\n");
	183	goto out;
	184	}
	185	if (type == HEX) {
	186	pr_err("Could not find CHAP_N.\n");
	187	goto out;
	188	}
	189
6aec95b4 ES	190	/* Include the terminating NULL in the compare */
	191	compare_len = strlen(auth->userid) + 1;
	192	if (strncmp(chap_n, auth->userid, compare_len) != 0) {
e48354ce NB	193	pr_err("CHAP_N values do not match!\n");
	194	goto out;
	195	}
	196	pr_debug("[server] Got CHAP_N=%s\n", chap_n);
	197	/*
	198	* Extract CHAP_R.
	199	*/
	200	if (extract_param(nr_in_ptr, "CHAP_R", MAX_RESPONSE_LENGTH, chap_r,
	201	&type) < 0) {
	202	pr_err("Could not find CHAP_R.\n");
	203	goto out;
	204	}
	205	if (type != HEX) {
	206	pr_err("Could not find CHAP_R.\n");
	207	goto out;
	208	}
	209
	210	pr_debug("[server] Got CHAP_R=%s\n", chap_r);
	211	chap_string_to_hex(client_digest, chap_r, strlen(chap_r));
	212
	213	tfm = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC);
	214	if (IS_ERR(tfm)) {
	215	pr_err("Unable to allocate struct crypto_hash\n");
	216	goto out;
	217	}
	218	desc.tfm = tfm;
	219	desc.flags = 0;
	220
	221	ret = crypto_hash_init(&desc);
	222	if (ret < 0) {
	223	pr_err("crypto_hash_init() failed\n");
	224	crypto_free_hash(tfm);
	225	goto out;
	226	}
	227
8359cf43	228	sg_init_one(&sg, &chap->id, 1);
e48354ce NB	229	ret = crypto_hash_update(&desc, &sg, 1);
	230	if (ret < 0) {
	231	pr_err("crypto_hash_update() failed for id\n");
	232	crypto_free_hash(tfm);
	233	goto out;
	234	}
	235
8359cf43	236	sg_init_one(&sg, &auth->password, strlen(auth->password));
e48354ce NB	237	ret = crypto_hash_update(&desc, &sg, strlen(auth->password));
	238	if (ret < 0) {
	239	pr_err("crypto_hash_update() failed for password\n");
	240	crypto_free_hash(tfm);
	241	goto out;
	242	}
	243
8359cf43	244	sg_init_one(&sg, chap->challenge, CHAP_CHALLENGE_LENGTH);
e48354ce NB	245	ret = crypto_hash_update(&desc, &sg, CHAP_CHALLENGE_LENGTH);
	246	if (ret < 0) {
	247	pr_err("crypto_hash_update() failed for challenge\n");
	248	crypto_free_hash(tfm);
	249	goto out;
	250	}
	251
	252	ret = crypto_hash_final(&desc, server_digest);
	253	if (ret < 0) {
	254	pr_err("crypto_hash_final() failed for server digest\n");
	255	crypto_free_hash(tfm);
	256	goto out;
	257	}
	258	crypto_free_hash(tfm);
	259
	260	chap_binaryhex_to_asciihex(response, server_digest, MD5_SIGNATURE_SIZE);
	261	pr_debug("[server] MD5 Server Digest: %s\n", response);
	262
	263	if (memcmp(server_digest, client_digest, MD5_SIGNATURE_SIZE) != 0) {
	264	pr_debug("[server] MD5 Digests do not match!\n\n");
	265	goto out;
	266	} else
	267	pr_debug("[server] MD5 Digests match, CHAP connetication"
	268	" successful.\n\n");
	269	/*
	270	* One way authentication has succeeded, return now if mutual
	271	* authentication is not enabled.
	272	*/
	273	if (!auth->authenticate_target) {
	274	kfree(challenge);
	275	kfree(challenge_binhex);
	276	return 0;
	277	}
	278	/*
	279	* Get CHAP_I.
	280	*/
	281	if (extract_param(nr_in_ptr, "CHAP_I", 10, identifier, &type) < 0) {
	282	pr_err("Could not find CHAP_I.\n");
	283	goto out;
	284	}
	285
	286	if (type == HEX)
8359cf43	287	id = simple_strtoul(&identifier[2], &endptr, 0);
e48354ce	288	else
8359cf43	289	id = simple_strtoul(identifier, &endptr, 0);
bc704fb5 NB	290	if (id > 255) {
	291	pr_err("chap identifier: %lu greater than 255\n", id);
	292	goto out;
	293	}
e48354ce NB	294	/*
	295	* RFC 1994 says Identifier is no more than octet (8 bits).
	296	*/
bc704fb5	297	pr_debug("[server] Got CHAP_I=%lu\n", id);
e48354ce NB	298	/*
	299	* Get CHAP_C.
	300	*/
	301	if (extract_param(nr_in_ptr, "CHAP_C", CHAP_CHALLENGE_STR_LEN,
	302	challenge, &type) < 0) {
	303	pr_err("Could not find CHAP_C.\n");
	304	goto out;
	305	}
	306
	307	if (type != HEX) {
	308	pr_err("Could not find CHAP_C.\n");
	309	goto out;
	310	}
	311	pr_debug("[server] Got CHAP_C=%s\n", challenge);
	312	challenge_len = chap_string_to_hex(challenge_binhex, challenge,
	313	strlen(challenge));
	314	if (!challenge_len) {
	315	pr_err("Unable to convert incoming challenge\n");
	316	goto out;
	317	}
63afedf4 NB	318	/*
	319	* During mutual authentication, the CHAP_C generated by the
	320	* initiator must not match the original CHAP_C generated by
	321	* the target.
	322	*/
	323	if (!memcmp(challenge_binhex, chap->challenge, CHAP_CHALLENGE_LENGTH)) {
	324	pr_err("initiator CHAP_C matches target CHAP_C, failing"
	325	" login attempt\n");
	326	goto out;
	327	}
e48354ce NB	328	/*
	329	* Generate CHAP_N and CHAP_R for mutual authentication.
	330	*/
	331	tfm = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC);
	332	if (IS_ERR(tfm)) {
	333	pr_err("Unable to allocate struct crypto_hash\n");
	334	goto out;
	335	}
	336	desc.tfm = tfm;
	337	desc.flags = 0;
	338
	339	ret = crypto_hash_init(&desc);
	340	if (ret < 0) {
	341	pr_err("crypto_hash_init() failed\n");
	342	crypto_free_hash(tfm);
	343	goto out;
	344	}
	345
7ac9ad11 AG	346	/* To handle both endiannesses */
	347	id_as_uchar = id;
	348	sg_init_one(&sg, &id_as_uchar, 1);
e48354ce NB	349	ret = crypto_hash_update(&desc, &sg, 1);
	350	if (ret < 0) {
	351	pr_err("crypto_hash_update() failed for id\n");
	352	crypto_free_hash(tfm);
	353	goto out;
	354	}
	355
8359cf43	356	sg_init_one(&sg, auth->password_mutual,
e48354ce NB	357	strlen(auth->password_mutual));
	358	ret = crypto_hash_update(&desc, &sg, strlen(auth->password_mutual));
	359	if (ret < 0) {
	360	pr_err("crypto_hash_update() failed for"
	361	" password_mutual\n");
	362	crypto_free_hash(tfm);
	363	goto out;
	364	}
	365	/*
	366	* Convert received challenge to binary hex.
	367	*/
8359cf43	368	sg_init_one(&sg, challenge_binhex, challenge_len);
e48354ce NB	369	ret = crypto_hash_update(&desc, &sg, challenge_len);
	370	if (ret < 0) {
	371	pr_err("crypto_hash_update() failed for ma challenge\n");
	372	crypto_free_hash(tfm);
	373	goto out;
	374	}
	375
	376	ret = crypto_hash_final(&desc, digest);
	377	if (ret < 0) {
	378	pr_err("crypto_hash_final() failed for ma digest\n");
	379	crypto_free_hash(tfm);
	380	goto out;
	381	}
	382	crypto_free_hash(tfm);
	383	/*
	384	* Generate CHAP_N and CHAP_R.
	385	*/
	386	*nr_out_len = sprintf(nr_out_ptr, "CHAP_N=%s", auth->userid_mutual);
	387	*nr_out_len += 1;
	388	pr_debug("[server] Sending CHAP_N=%s\n", auth->userid_mutual);
	389	/*
	390	* Convert response from binary hex to ascii hext.
	391	*/
	392	chap_binaryhex_to_asciihex(response, digest, MD5_SIGNATURE_SIZE);
	393	nr_out_len += sprintf(nr_out_ptr + nr_out_len, "CHAP_R=0x%s",
	394	response);
	395	*nr_out_len += 1;
	396	pr_debug("[server] Sending CHAP_R=0x%s\n", response);
	397	auth_ret = 0;
	398	out:
	399	kfree(challenge);
	400	kfree(challenge_binhex);
	401	return auth_ret;
	402	}
	403
	404	static int chap_got_response(
	405	struct iscsi_conn *conn,
	406	struct iscsi_node_auth *auth,
	407	char *nr_in_ptr,
	408	char *nr_out_ptr,
	409	unsigned int *nr_out_len)
	410	{
8359cf43	411	struct iscsi_chap *chap = conn->auth_protocol;
e48354ce NB	412
	413	switch (chap->digest_type) {
	414	case CHAP_DIGEST_MD5:
	415	if (chap_server_compute_md5(conn, auth, nr_in_ptr,
	416	nr_out_ptr, nr_out_len) < 0)
	417	return -1;
	418	return 0;
	419	default:
	420	pr_err("Unknown CHAP digest type %d!\n",
	421	chap->digest_type);
	422	return -1;
	423	}
	424	}
	425
	426	u32 chap_main_loop(
	427	struct iscsi_conn *conn,
	428	struct iscsi_node_auth *auth,
	429	char *in_text,
	430	char *out_text,
	431	int *in_len,
	432	int *out_len)
	433	{
8359cf43	434	struct iscsi_chap *chap = conn->auth_protocol;
e48354ce NB	435
	436	if (!chap) {
	437	chap = chap_server_open(conn, auth, in_text, out_text, out_len);
	438	if (!chap)
	439	return 2;
	440	chap->chap_state = CHAP_STAGE_SERVER_AIC;
	441	return 0;
	442	} else if (chap->chap_state == CHAP_STAGE_SERVER_AIC) {
	443	convert_null_to_semi(in_text, *in_len);
	444	if (chap_got_response(conn, auth, in_text, out_text,
	445	out_len) < 0) {
	446	chap_close(conn);
	447	return 2;
	448	}
	449	if (auth->authenticate_target)
	450	chap->chap_state = CHAP_STAGE_SERVER_NR;
	451	else
	452	*out_len = 0;
	453	chap_close(conn);
	454	return 1;
	455	}
	456
	457	return 2;
	458	}