Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0-or-later
/*******************************************************************************
 * This file houses the main functions for the iSCSI CHAP support
 *
 * (c) Copyright 2007-2013 Datera, Inc.
 *
 * Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
 *
 ******************************************************************************/
 
#include <crypto/hash.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/err.h>
#include <linux/random.h>
#include <linux/scatterlist.h>
#include <target/iscsi/iscsi_target_core.h>
#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,
<------>char *c_str,
<------>unsigned int *c_len)
{
<------>int ret;
<------>unsigned char *challenge_asciihex;
<------>struct iscsi_chap *chap = conn->auth_protocol;
 
<------>challenge_asciihex = kzalloc(chap->challenge_len * 2 + 1, GFP_KERNEL);
<------>if (!challenge_asciihex)
<------><------>return -ENOMEM;
 
<------>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.
<------> */
<------>*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);
 
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 iscsi_conn *conn)
{
<------>kfree(conn->auth_protocol);
<------>conn->auth_protocol = NULL;
}
 
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)
{
<------>int digest_type;
<------>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;
<------>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;
<------>}
 
<------>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;
<------>pr_debug("[server] Sending CHAP_A=%d\n", digest_type);
 
<------>/*
<------> * Set Identifier.
<------> */
<------>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.
<------> */
<------>if (chap_gen_challenge(conn, 1, aic_str, aic_len) < 0) {
<------><------>chap_close(conn);
<------><------>return NULL;
<------>}
 
<------>return chap;
}
 
static int chap_server_compute_hash(
<------>struct iscsi_conn *conn,
<------>struct iscsi_node_auth *auth,
<------>char *nr_in_ptr,
<------>char *nr_out_ptr,
<------>unsigned int *nr_out_len)
{
<------>unsigned long id;
<------>unsigned char id_as_uchar;
<------>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_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);
 
<------>initiatorchg = kzalloc(CHAP_CHALLENGE_STR_LEN, GFP_KERNEL);
<------>if (!initiatorchg) {
<------><------>pr_err("Unable to allocate challenge buffer\n");
<------><------>goto out;
<------>}
 
<------>initiatorchg_binhex = kzalloc(CHAP_CHALLENGE_STR_LEN, GFP_KERNEL);
<------>if (!initiatorchg_binhex) {
<------><------>pr_err("Unable to allocate initiatorchg_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;
<------>}
<------>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\n");
<------><------>goto out;
<------>}
 
<------>pr_debug("[server] Got CHAP_R=%s\n", chap_r);
 
<------>tfm = crypto_alloc_shash(chap->digest_name, 0, 0);
<------>if (IS_ERR(tfm)) {
<------><------>tfm = NULL;
<------><------>pr_err("Unable to allocate struct crypto_shash\n");
<------><------>goto out;
<------>}
 
<------>desc = kmalloc(sizeof(*desc) + crypto_shash_descsize(tfm), GFP_KERNEL);
<------>if (!desc) {
<------><------>pr_err("Unable to allocate struct shash_desc\n");
<------><------>goto out;
<------>}
 
<------>desc->tfm = tfm;
 
<------>ret = crypto_shash_init(desc);
<------>if (ret < 0) {
<------><------>pr_err("crypto_shash_init() failed\n");
<------><------>goto out;
<------>}
 
<------>ret = crypto_shash_update(desc, &chap->id, 1);
<------>if (ret < 0) {
<------><------>pr_err("crypto_shash_update() failed for id\n");
<------><------>goto out;
<------>}
 
<------>ret = crypto_shash_update(desc, (char *)&auth->password,
<------><------><------><------>  strlen(auth->password));
<------>if (ret < 0) {
<------><------>pr_err("crypto_shash_update() failed for password\n");
<------><------>goto out;
<------>}
 
<------>ret = crypto_shash_finup(desc, chap->challenge,
<------><------><------><------> chap->challenge_len, server_digest);
<------>if (ret < 0) {
<------><------>pr_err("crypto_shash_finup() failed for challenge\n");
<------><------>goto out;
<------>}
 
<------>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, chap->digest_size) != 0) {
<------><------>pr_debug("[server] %s Digests do not match!\n\n",
<------><------><------>chap->digest_name);
<------><------>goto out;
<------>} else
<------><------>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) {
<------><------>auth_ret = 0;
<------><------>goto out;
<------>}
<------>/*
<------> * 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)
<------><------>ret = kstrtoul(&identifier[2], 0, &id);
<------>else
<------><------>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;
<------>}
<------>/*
<------> * 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,
<------><------><------>initiatorchg, &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;
<------>}
<------>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\n");
<------><------>goto out;
<------>}
<------>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.
<------> */
<------>ret = crypto_shash_init(desc);
<------>if (ret < 0) {
<------><------>pr_err("crypto_shash_init() failed\n");
<------><------>goto out;
<------>}
 
<------>/* To handle both endiannesses */
<------>id_as_uchar = id;
<------>ret = crypto_shash_update(desc, &id_as_uchar, 1);
<------>if (ret < 0) {
<------><------>pr_err("crypto_shash_update() failed for id\n");
<------><------>goto out;
<------>}
 
<------>ret = crypto_shash_update(desc, auth->password_mutual,
<------><------><------><------>  strlen(auth->password_mutual));
<------>if (ret < 0) {
<------><------>pr_err("crypto_shash_update() failed for"
<------><------><------><------>" password_mutual\n");
<------><------>goto out;
<------>}
<------>/*
<------> * Convert received challenge to binary hex.
<------> */
<------>ret = crypto_shash_finup(desc, initiatorchg_binhex, initiatorchg_len,
<------><------><------><------> digest);
<------>if (ret < 0) {
<------><------>pr_err("crypto_shash_finup() failed for ma challenge\n");
<------><------>goto out;
<------>}
 
<------>/*
<------> * 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.
<------> */
<------>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_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;
}
 
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_server_compute_hash(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;
}