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scsi: target: iscsi: CHAP: add support for SHA1, SHA256 and SHA3-256

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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()

Link: https://lore.kernel.org/r/20191028123822.5864-2-mlombard@redhat.com
Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Tested-by: Chris Leech <cleech@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Maurizio Lombardi
2019-10-28 13:38:20 +01:00
committed by Martin K. Petersen
parent f6b8540f40
commit a572d24af4
2 changed files with 120 additions and 62 deletions
Download Patch File Download Diff File Expand all files Collapse all files

169
drivers/target/iscsi/iscsi_target_auth.c
View File

@ -18,6 +18,22 @@
#include "iscsi_target_nego.h" #include "iscsi_target_nego.h"
#include "iscsi_target_auth.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( static int chap_gen_challenge(
struct iscsi_conn *conn, struct iscsi_conn *conn,
int caller, int caller,
@ -46,9 +62,23 @@ static int chap_gen_challenge(
return 0; 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) 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); tmp = kstrdup(a_str, GFP_KERNEL);
if (!tmp) { if (!tmp) {
@ -70,15 +100,24 @@ static int chap_check_algorithm(const char *a_str)
if (!token) if (!token)
goto out; goto out;
if (!strcmp(token, "5")) { if (kstrtol(token, 10, &digest_type))
pr_debug("Selected MD5 Algorithm\n"); continue;
kfree(orig);
return CHAP_DIGEST_MD5; 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: out:
kfree(orig); kfree(orig);
return CHAP_DIGEST_UNKNOWN; return r;
} }
static void chap_close(struct iscsi_conn *conn) static void chap_close(struct iscsi_conn *conn)
@ -94,7 +133,7 @@ static struct iscsi_chap *chap_server_open(
char *aic_str, char *aic_str,
unsigned int *aic_len) unsigned int *aic_len)
{ {
int ret; int digest_type;
struct iscsi_chap *chap; struct iscsi_chap *chap;
if (!(auth->naf_flags & NAF_USERID_SET) || if (!(auth->naf_flags & NAF_USERID_SET) ||
@ -109,17 +148,19 @@ static struct iscsi_chap *chap_server_open(
return NULL; return NULL;
chap = conn->auth_protocol; chap = conn->auth_protocol;
ret = chap_check_algorithm(a_str); digest_type = chap_check_algorithm(a_str);
switch (ret) { switch (digest_type) {
case CHAP_DIGEST_MD5: case CHAP_DIGEST_MD5:
pr_debug("[server] Got CHAP_A=5\n"); chap->digest_size = MD5_SIGNATURE_SIZE;
/* break;
* Send back CHAP_A set to MD5. case CHAP_DIGEST_SHA1:
*/ chap->digest_size = SHA1_SIGNATURE_SIZE;
*aic_len = sprintf(aic_str, "CHAP_A=5"); break;
*aic_len += 1; case CHAP_DIGEST_SHA256:
chap->digest_type = CHAP_DIGEST_MD5; chap->digest_size = SHA256_SIGNATURE_SIZE;
pr_debug("[server] Sending CHAP_A=%d\n", chap->digest_type); break;
case CHAP_DIGEST_SHA3_256:
chap->digest_size = SHA3_256_SIGNATURE_SIZE;
break; break;
case CHAP_DIGEST_UNKNOWN: case CHAP_DIGEST_UNKNOWN:
default: default:
@ -128,6 +169,13 @@ static struct iscsi_chap *chap_server_open(
return NULL; 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. * Set Identifier.
*/ */
@ -146,7 +194,7 @@ static struct iscsi_chap *chap_server_open(
return chap; return chap;
} }
static int chap_server_compute_md5( static int chap_server_compute_hash(
struct iscsi_conn *conn, struct iscsi_conn *conn,
struct iscsi_node_auth *auth, struct iscsi_node_auth *auth,
char *nr_in_ptr, char *nr_in_ptr,
@ -155,12 +203,13 @@ static int chap_server_compute_md5(
{ {
unsigned long id; unsigned long id;
unsigned char id_as_uchar; unsigned char id_as_uchar;
unsigned char digest[MD5_SIGNATURE_SIZE]; unsigned char type;
unsigned char type, response[MD5_SIGNATURE_SIZE * 2 + 2];
unsigned char identifier[10], *challenge = NULL; unsigned char identifier[10], *challenge = NULL;
unsigned char *challenge_binhex = NULL; unsigned char *challenge_binhex = NULL;
unsigned char client_digest[MD5_SIGNATURE_SIZE]; unsigned char *digest = NULL;
unsigned char server_digest[MD5_SIGNATURE_SIZE]; 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]; unsigned char chap_n[MAX_CHAP_N_SIZE], chap_r[MAX_RESPONSE_LENGTH];
size_t compare_len; size_t compare_len;
struct iscsi_chap *chap = conn->auth_protocol; struct iscsi_chap *chap = conn->auth_protocol;
@ -168,13 +217,33 @@ static int chap_server_compute_md5(
struct shash_desc *desc = NULL; struct shash_desc *desc = NULL;
int auth_ret = -1, ret, challenge_len; 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(identifier, 0, 10);
memset(chap_n, 0, MAX_CHAP_N_SIZE); memset(chap_n, 0, MAX_CHAP_N_SIZE);
memset(chap_r, 0, MAX_RESPONSE_LENGTH); 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); challenge = kzalloc(CHAP_CHALLENGE_STR_LEN, GFP_KERNEL);
if (!challenge) { if (!challenge) {
@ -219,18 +288,18 @@ static int chap_server_compute_md5(
pr_err("Could not find CHAP_R.\n"); pr_err("Could not find CHAP_R.\n");
goto out; goto out;
} }
if (strlen(chap_r) != MD5_SIGNATURE_SIZE * 2) { if (strlen(chap_r) != chap->digest_size * 2) {
pr_err("Malformed CHAP_R\n"); pr_err("Malformed CHAP_R\n");
goto out; 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"); pr_err("Malformed CHAP_R\n");
goto out; goto out;
} }
pr_debug("[server] Got CHAP_R=%s\n", chap_r); 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)) { if (IS_ERR(tfm)) {
tfm = NULL; tfm = NULL;
pr_err("Unable to allocate struct crypto_shash\n"); pr_err("Unable to allocate struct crypto_shash\n");
@ -271,15 +340,15 @@ static int chap_server_compute_md5(
goto out; goto out;
} }
bin2hex(response, server_digest, MD5_SIGNATURE_SIZE); bin2hex(response, server_digest, chap->digest_size);
pr_debug("[server] MD5 Server Digest: %s\n", response); pr_debug("[server] %s Server Digest: %s\n", hash_name, response);
if (memcmp(server_digest, client_digest, MD5_SIGNATURE_SIZE) != 0) { if (memcmp(server_digest, client_digest, chap->digest_size) != 0) {
pr_debug("[server] MD5 Digests do not match!\n\n"); pr_debug("[server] %s Digests do not match!\n\n", hash_name);
goto out; goto out;
} else } else
pr_debug("[server] MD5 Digests match, CHAP connection" pr_debug("[server] %s Digests match, CHAP connection"
" successful.\n\n"); " successful.\n\n", hash_name);
/* /*
* One way authentication has succeeded, return now if mutual * One way authentication has succeeded, return now if mutual
* authentication is not enabled. * authentication is not enabled.
@ -393,7 +462,7 @@ static int chap_server_compute_md5(
/* /*
* Convert response from binary hex to ascii hext. * 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", *nr_out_len += sprintf(nr_out_ptr + *nr_out_len, "CHAP_R=0x%s",
response); response);
*nr_out_len += 1; *nr_out_len += 1;
@ -405,31 +474,13 @@ out:
crypto_free_shash(tfm); crypto_free_shash(tfm);
kfree(challenge); kfree(challenge);
kfree(challenge_binhex); kfree(challenge_binhex);
kfree(digest);
kfree(response);
kfree(server_digest);
kfree(client_digest);
return auth_ret; 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( u32 chap_main_loop(
struct iscsi_conn *conn, struct iscsi_conn *conn,
struct iscsi_node_auth *auth, struct iscsi_node_auth *auth,
@ -448,7 +499,7 @@ u32 chap_main_loop(
return 0; return 0;
} else if (chap->chap_state == CHAP_STAGE_SERVER_AIC) { } else if (chap->chap_state == CHAP_STAGE_SERVER_AIC) {
convert_null_to_semi(in_text, *in_len); 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) { out_len) < 0) {
chap_close(conn); chap_close(conn);
return 2; return 2;

13
drivers/target/iscsi/iscsi_target_auth.h
View File

@ -6,14 +6,19 @@
#define CHAP_DIGEST_UNKNOWN 0 #define CHAP_DIGEST_UNKNOWN 0
#define CHAP_DIGEST_MD5 5 #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_LENGTH 16
#define CHAP_CHALLENGE_STR_LEN 4096 #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 MAX_CHAP_N_SIZE 512
#define MD5_SIGNATURE_SIZE 16 /* 16 bytes in a MD5 message digest */ #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_CLIENT_A 1
#define CHAP_STAGE_SERVER_AIC 2 #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 *); int *, int *);
struct iscsi_chap { struct iscsi_chap {
unsigned char digest_type;
unsigned char id; unsigned char id;
unsigned char challenge[CHAP_CHALLENGE_LENGTH]; unsigned char challenge[CHAP_CHALLENGE_LENGTH];
unsigned int challenge_len;
unsigned char *digest_name;
unsigned int digest_size;
unsigned int authenticate_target; unsigned int authenticate_target;
unsigned int chap_state; unsigned int chap_state;
} ____cacheline_aligned; } ____cacheline_aligned;