github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-05-31 18:43:33 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

smb: client: Use HMAC-SHA256 library for key generation

Browse Source 
Convert generate_key() to use the HMAC-SHA256 library instead of a
"hmac(sha256)" crypto_shash.  This is simpler and faster.  With the
library there's no need to allocate memory, no need to handle errors,
and the HMAC-SHA256 code is accessed directly without inefficient
indirect calls and other unnecessary API overhead.

Also remove the unnecessary 'hashptr' variable.

For now smb3_crypto_shash_allocate() still allocates a "hmac(sha256)"
crypto_shash.  It will be removed in a later commit.

Reviewed-by: Stefan Metzmacher <metze@samba.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
This commit is contained in:
Eric Biggers 2025-10-11 18:57:32 -07:00 committed by Steve French
parent af5fea5141
commit 4b4c6fdb25
2 changed files with 15 additions and 54 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
fs/smb/client/Kconfig
View File

@ -16,6 +16,7 @@ config CIFS
select CRYPTO_ECB
select CRYPTO_AES
select CRYPTO_LIB_ARC4
select CRYPTO_LIB_SHA256
select CRYPTO_LIB_SHA512
select KEYS
select DNS_RESOLVER

68
fs/smb/client/smb2transport.c
View File

@ -19,6 +19,7 @@
#include <linux/mempool.h>
#include <linux/highmem.h>
#include <crypto/aead.h>
#include <crypto/sha2.h>
#include "cifsglob.h"
#include "cifsproto.h"
#include "smb2proto.h"
@ -336,8 +337,8 @@ static int generate_key(struct cifs_ses *ses, struct kvec label,
__u8 L256[4] = {0, 0, 1, 0};
int rc = 0;
unsigned char prfhash[SMB2_HMACSHA256_SIZE];
unsigned char *hashptr = prfhash;
struct TCP_Server_Info *server = ses->server;
struct hmac_sha256_ctx hmac_ctx;
memset(prfhash, 0x0, SMB2_HMACSHA256_SIZE);
memset(key, 0x0, key_size);
@ -345,67 +346,26 @@ static int generate_key(struct cifs_ses *ses, struct kvec label,
rc = smb3_crypto_shash_allocate(server);
if (rc) {
cifs_server_dbg(VFS, "%s: crypto alloc failed\n", __func__);
goto smb3signkey_ret;
return rc;
}
rc = crypto_shash_setkey(server->secmech.hmacsha256->tfm,
ses->auth_key.response, SMB2_NTLMV2_SESSKEY_SIZE);
if (rc) {
cifs_server_dbg(VFS, "%s: Could not set with session key\n", __func__);
goto smb3signkey_ret;
}
rc = crypto_shash_init(server->secmech.hmacsha256);
if (rc) {
cifs_server_dbg(VFS, "%s: Could not init sign hmac\n", __func__);
goto smb3signkey_ret;
}
rc = crypto_shash_update(server->secmech.hmacsha256, i, 4);
if (rc) {
cifs_server_dbg(VFS, "%s: Could not update with n\n", __func__);
goto smb3signkey_ret;
}
rc = crypto_shash_update(server->secmech.hmacsha256, label.iov_base, label.iov_len);
if (rc) {
cifs_server_dbg(VFS, "%s: Could not update with label\n", __func__);
goto smb3signkey_ret;
}
rc = crypto_shash_update(server->secmech.hmacsha256, &zero, 1);
if (rc) {
cifs_server_dbg(VFS, "%s: Could not update with zero\n", __func__);
goto smb3signkey_ret;
}
rc = crypto_shash_update(server->secmech.hmacsha256, context.iov_base, context.iov_len);
if (rc) {
cifs_server_dbg(VFS, "%s: Could not update with context\n", __func__);
goto smb3signkey_ret;
}
hmac_sha256_init_usingrawkey(&hmac_ctx, ses->auth_key.response,
SMB2_NTLMV2_SESSKEY_SIZE);
hmac_sha256_update(&hmac_ctx, i, 4);
hmac_sha256_update(&hmac_ctx, label.iov_base, label.iov_len);
hmac_sha256_update(&hmac_ctx, &zero, 1);
hmac_sha256_update(&hmac_ctx, context.iov_base, context.iov_len);
if ((server->cipher_type == SMB2_ENCRYPTION_AES256_CCM) ||
(server->cipher_type == SMB2_ENCRYPTION_AES256_GCM)) {
rc = crypto_shash_update(server->secmech.hmacsha256, L256, 4);
hmac_sha256_update(&hmac_ctx, L256, 4);
} else {
rc = crypto_shash_update(server->secmech.hmacsha256, L128, 4);
}
if (rc) {
cifs_server_dbg(VFS, "%s: Could not update with L\n", __func__);
goto smb3signkey_ret;
hmac_sha256_update(&hmac_ctx, L128, 4);
}
hmac_sha256_final(&hmac_ctx, prfhash);
rc = crypto_shash_final(server->secmech.hmacsha256, hashptr);
if (rc) {
cifs_server_dbg(VFS, "%s: Could not generate sha256 hash\n", __func__);
goto smb3signkey_ret;
}
memcpy(key, hashptr, key_size);
smb3signkey_ret:
return rc;
memcpy(key, prfhash, key_size);
return 0;
}
struct derivation {