libcli/smb/smb2_signing: implement aes_cmac_128 based signing for SMB 2.24

metze

diff --git a/libcli/smb/smb2_signing.c b/libcli/smb/smb2_signing.c
index 62a5ade0439255aede3ace06a96a9fe26338068b..4204ed1f85a13a5e9c2628d0f6488951861f74ec 100644 (file)
--- a/libcli/smb/smb2_signing.c
+++ b/libcli/smb/smb2_signing.c
@@ -30,8 +30,7 @@ NTSTATUS smb2_signing_sign_pdu(DATA_BLOB signing_key,
 {
        uint8_t *hdr;
        uint64_t session_id;
-       struct HMACSHA256Context m;
-       uint8_t res[SHA256_DIGEST_LENGTH];
+       uint8_t res[16];
        int i;
 
        if (count < 2) {
@@ -63,13 +62,33 @@ NTSTATUS smb2_signing_sign_pdu(DATA_BLOB signing_key,
 
        SIVAL(hdr, SMB2_HDR_FLAGS, IVAL(hdr, SMB2_HDR_FLAGS) | SMB2_HDR_FLAG_SIGNED);
 
-       ZERO_STRUCT(m);
-       hmac_sha256_init(signing_key.data, MIN(signing_key.length, 16), &m);
-       for (i=0; i < count; i++) {
-               hmac_sha256_update((const uint8_t *)vector[i].iov_base,
-                                  vector[i].iov_len, &m);
+       if (protocol >= PROTOCOL_SMB2_24) {
+               struct aes_cmac_128_context ctx;
+               uint8_t key[AES_BLOCK_SIZE];
+
+               ZERO_STRUCT(key);
+               memcpy(key, signing_key.data, MIN(signing_key.length, 16));
+
+               aes_cmac_128_init(&ctx, key);
+               for (i=0; i < count; i++) {
+                       aes_cmac_128_update(&ctx,
+                                       (const uint8_t *)vector[i].iov_base,
+                                       vector[i].iov_len);
+               }
+               aes_cmac_128_final(&ctx, res);
+       } else {
+               struct HMACSHA256Context m;
+               uint8_t digest[SHA256_DIGEST_LENGTH];
+
+               ZERO_STRUCT(m);
+               hmac_sha256_init(signing_key.data, MIN(signing_key.length, 16), &m);
+               for (i=0; i < count; i++) {
+                       hmac_sha256_update((const uint8_t *)vector[i].iov_base,
+                                          vector[i].iov_len, &m);
+               }
+               hmac_sha256_final(digest, &m);
+               memcpy(res, digest, 16);
        }
-       hmac_sha256_final(res, &m);
        DEBUG(5,("signed SMB2 message\n"));
 
        memcpy(hdr + SMB2_HDR_SIGNATURE, res, 16);
@@ -85,8 +104,7 @@ NTSTATUS smb2_signing_check_pdu(DATA_BLOB signing_key,
        const uint8_t *hdr;
        const uint8_t *sig;
        uint64_t session_id;
-       struct HMACSHA256Context m;
-       uint8_t res[SHA256_DIGEST_LENGTH];
+       uint8_t res[16];
        static const uint8_t zero_sig[16] = { 0, };
        int i;
 
@@ -116,15 +134,37 @@ NTSTATUS smb2_signing_check_pdu(DATA_BLOB signing_key,
 
        sig = hdr+SMB2_HDR_SIGNATURE;
 
-       ZERO_STRUCT(m);
-       hmac_sha256_init(signing_key.data, MIN(signing_key.length, 16), &m);
-       hmac_sha256_update(hdr, SMB2_HDR_SIGNATURE, &m);
-       hmac_sha256_update(zero_sig, 16, &m);
-       for (i=1; i < count; i++) {
-               hmac_sha256_update((const uint8_t *)vector[i].iov_base,
-                                  vector[i].iov_len, &m);
+       if (protocol >= PROTOCOL_SMB2_24) {
+               struct aes_cmac_128_context ctx;
+               uint8_t key[AES_BLOCK_SIZE];
+
+               ZERO_STRUCT(key);
+               memcpy(key, signing_key.data, MIN(signing_key.length, 16));
+
+               aes_cmac_128_init(&ctx, key);
+               aes_cmac_128_update(&ctx, hdr, SMB2_HDR_SIGNATURE);
+               aes_cmac_128_update(&ctx, zero_sig, 16);
+               for (i=1; i < count; i++) {
+                       aes_cmac_128_update(&ctx,
+                                       (const uint8_t *)vector[i].iov_base,
+                                       vector[i].iov_len);
+               }
+               aes_cmac_128_final(&ctx, res);
+       } else {
+               struct HMACSHA256Context m;
+               uint8_t digest[SHA256_DIGEST_LENGTH];
+
+               ZERO_STRUCT(m);
+               hmac_sha256_init(signing_key.data, MIN(signing_key.length, 16), &m);
+               hmac_sha256_update(hdr, SMB2_HDR_SIGNATURE, &m);
+               hmac_sha256_update(zero_sig, 16, &m);
+               for (i=1; i < count; i++) {
+                       hmac_sha256_update((const uint8_t *)vector[i].iov_base,
+                                          vector[i].iov_len, &m);
+               }
+               hmac_sha256_final(digest, &m);
+               memcpy(res, digest, 16);
        }
-       hmac_sha256_final(res, &m);
 
        if (memcmp(res, sig, 16) != 0) {
                DEBUG(0,("Bad SMB2 signature for message\n"));