generate secondary session key and ciphertext and send it if signing enabled

Commit Message

Shirish Pargaonkar Sept. 7, 2010, 3:35 a.m. UTC

None

Patch

diff --git a/fs/cifs/cifsencrypt.c b/fs/cifs/cifsencrypt.c
index 5fbd19b..0c1e9f2 100644
--- a/fs/cifs/cifsencrypt.c
+++ b/fs/cifs/cifsencrypt.c
@@ -435,6 +435,47 @@  void CalcNTLMv2_response(const struct cifsSesInfo *ses,
 /*	cifs_dump_mem("v2_sess_rsp: ", v2_session_response, 32); */
 }
 
+int
+calc_seckey(struct TCP_Server_Info *server)
+{
+	int rc;
+	struct crypto_blkcipher *tfm_arc4;
+	struct scatterlist sgin, sgout;
+	struct blkcipher_desc desc;
+
+	if (!server) {
+		cERROR(1, "%s: Can't determine ciphertext key\n", __func__);
+		return 1;
+	}
+
+	if (server->cphready)
+		return 0;
+
+	get_random_bytes(server->ntlmssp.sec_key, CIFS_NTLMV2_SESSKEY_SIZE);
+
+	tfm_arc4 = crypto_alloc_blkcipher("ecb(arc4)",
+						0, CRYPTO_ALG_ASYNC);
+	if (!tfm_arc4 || IS_ERR(tfm_arc4)) {
+		cERROR(1, "could not allocate " "master crypto API arc4\n");
+		return 1;
+	}
+
+	desc.tfm = tfm_arc4;
+
+	crypto_blkcipher_setkey(tfm_arc4,
+		server->session_key.data.ntlmv2.key, CIFS_CPHTXT_SIZE);
+	sg_init_one(&sgin, server->ntlmssp.sec_key, CIFS_CPHTXT_SIZE);
+	sg_init_one(&sgout, server->ntlmssp.ciphertext, CIFS_CPHTXT_SIZE);
+	rc = crypto_blkcipher_encrypt(&desc, &sgout, &sgin, CIFS_CPHTXT_SIZE);
+
+	crypto_free_blkcipher(tfm_arc4);
+
+	server->sequence_number = 0;
+	server->cphready = true;
+
+	return 0;
+}
+
 void
 cifs_crypto_shash_release(struct TCP_Server_Info *server)
 {
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index d1b9bc4..7c115a8 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -372,6 +372,7 @@  extern int setup_ntlmv2_rsp(struct cifsSesInfo *, char *,
 			     const struct nls_table *);
 extern int cifs_crypto_shash_allocate(struct TCP_Server_Info *);
 extern void cifs_crypto_shash_release(struct TCP_Server_Info *);
+extern int calc_seckey(struct TCP_Server_Info *);
 #ifdef CONFIG_CIFS_WEAK_PW_HASH
 extern void calc_lanman_hash(const char *password, const char *cryptkey,
 				bool encrypt, char *lnm_session_key);
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 47b51eb..3da32aa 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -1589,6 +1589,7 @@  cifs_get_tcp_session(struct smb_vol *volume_info)
 		goto out_err2;
 	}
 
+	tcp_ses->cphready = false;
 	tcp_ses->noblocksnd = volume_info->noblocksnd;
 	tcp_ses->noautotune = volume_info->noautotune;
 	tcp_ses->tcp_nodelay = volume_info->sockopt_tcp_nodelay;
diff --git a/fs/cifs/sess.c b/fs/cifs/sess.c
index f7fc3dc..238d5cb 100644
--- a/fs/cifs/sess.c
+++ b/fs/cifs/sess.c
@@ -444,10 +444,12 @@  static void build_ntlmssp_negotiate_blob(unsigned char *pbuffer,
 		NTLMSSP_NEGOTIATE_128 | NTLMSSP_NEGOTIATE_UNICODE |
 		NTLMSSP_NEGOTIATE_NTLM;
 	if (ses->server->secMode &
-	   (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
+			(SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED)) {
 		flags |= NTLMSSP_NEGOTIATE_SIGN;
-	if (ses->server->secMode & SECMODE_SIGN_REQUIRED)
-		flags |= NTLMSSP_NEGOTIATE_ALWAYS_SIGN;
+		if (!ses->server->cphready)
+			flags |= NTLMSSP_NEGOTIATE_KEY_XCH |
+				NTLMSSP_NEGOTIATE_EXTENDED_SEC;
+	}
 
 	sec_blob->NegotiateFlags |= cpu_to_le32(flags);
 
@@ -553,9 +555,19 @@  static int build_ntlmssp_auth_blob(unsigned char *pbuffer,
 	sec_blob->WorkstationName.MaximumLength = 0;
 	tmp += 2;
 
-	sec_blob->SessionKey.BufferOffset = cpu_to_le32(tmp - pbuffer);
-	sec_blob->SessionKey.Length = 0;
-	sec_blob->SessionKey.MaximumLength = 0;
+	if ((ses->server->ntlmssp.server_flags & NTLMSSP_NEGOTIATE_KEY_XCH) &&
+			!calc_seckey(ses->server)) {
+		memcpy(tmp, ses->server->ntlmssp.ciphertext, CIFS_CPHTXT_SIZE);
+		sec_blob->SessionKey.BufferOffset = cpu_to_le32(tmp - pbuffer);
+		sec_blob->SessionKey.Length = cpu_to_le16(CIFS_CPHTXT_SIZE);
+		sec_blob->SessionKey.MaximumLength =
+			cpu_to_le16(CIFS_CPHTXT_SIZE);
+		tmp += CIFS_CPHTXT_SIZE;
+	} else {
+		sec_blob->SessionKey.BufferOffset = cpu_to_le32(tmp - pbuffer);
+		sec_blob->SessionKey.Length = 0;
+		sec_blob->SessionKey.MaximumLength = 0;
+	}
 
 setup_ntlmv2_ret:
 	if (ses->server->tilen > 0)