auth:ntlmssp: Use GnuTLS RC4 for ntlmssp signing

BUG: https://bugzilla.samba.org/show_bug.cgi?id=14031

Signed-off-by: Andreas Schneider <asn@samba.org>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>

2 files changed, 174 insertions, 43 deletions

diff --git a/auth/ntlmssp/ntlmssp_private.h b/auth/ntlmssp/ntlmssp_private.h
index 95ec6374f51..4d84e3347b6 100644
--- a/auth/ntlmssp/ntlmssp_private.h
+++ b/auth/ntlmssp/ntlmssp_private.h
@@ -20,14 +20,15 @@
 
 /* For structures internal to the NTLMSSP implementation that should not be exposed */
 
-#include "../lib/crypto/arcfour.h"
+#include <gnutls/gnutls.h>
+#include <gnutls/crypto.h>
 
 struct auth_session_info;
 
 struct ntlmssp_crypt_direction {
 	uint32_t seq_num;
 	uint8_t sign_key[16];
-	struct arcfour_state seal_state;
+	gnutls_cipher_hd_t seal_state;
 };
 
 union ntlmssp_crypt_state {
diff --git a/auth/ntlmssp/ntlmssp_sign.c b/auth/ntlmssp/ntlmssp_sign.c
index 8ba2e246b34..89f1aa04f7a 100644
--- a/auth/ntlmssp/ntlmssp_sign.c
+++ b/auth/ntlmssp/ntlmssp_sign.c
@@ -47,9 +47,9 @@
  */
 
 static void dump_arc4_state(const char *description,
-			    struct arcfour_state *state)
+			    gnutls_cipher_hd_t *state)
 {
-	dump_data_pw(description, state->sbox, sizeof(state->sbox));
+	DBG_DEBUG("%s\n", description);
 }
 
 static NTSTATUS calc_ntlmv2_key(uint8_t subkey[16],
@@ -90,13 +90,13 @@ static NTSTATUS ntlmssp_make_packet_signature(struct ntlmssp_state *ntlmssp_stat
 					      enum ntlmssp_direction direction,
 					      DATA_BLOB *sig, bool encrypt_sig)
 {
-	NTSTATUS status;
+	NTSTATUS status = NT_STATUS_UNSUCCESSFUL;
+	int rc;
 
 	if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
 		gnutls_hmac_hd_t hmac_hnd = NULL;
 		uint8_t digest[16];
 		uint8_t seq_num[4];
-		int rc;
 
 		*sig = data_blob_talloc(sig_mem_ctx, NULL, NTLMSSP_SIG_SIZE);
 		if (!sig->data) {
@@ -158,14 +158,24 @@ static NTSTATUS ntlmssp_make_packet_signature(struct ntlmssp_state *ntlmssp_stat
 		if (encrypt_sig && (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_KEY_EXCH)) {
 			switch (direction) {
 			case NTLMSSP_SEND:
-				arcfour_crypt_sbox(&ntlmssp_state->crypt->ntlm2.sending.seal_state,
-						   digest, 8);
+				rc = gnutls_cipher_encrypt(ntlmssp_state->crypt->ntlm2.sending.seal_state,
+							   digest,
+							   8);
 				break;
 			case NTLMSSP_RECEIVE:
-				arcfour_crypt_sbox(&ntlmssp_state->crypt->ntlm2.receiving.seal_state,
-						   digest, 8);
+				rc = gnutls_cipher_encrypt(ntlmssp_state->crypt->ntlm2.receiving.seal_state,
+							   digest,
+							   8);
 				break;
 			}
+			if (rc < 0) {
+				DBG_ERR("gnutls_cipher_encrypt for NTLMv2 EXCH "
+					"%s packet signature failed: %s\n",
+					direction == NTLMSSP_SEND ?
+						"send" : "receive",
+					gnutls_strerror(rc));
+				return gnutls_error_to_ntstatus(rc, NT_STATUS_NTLM_BLOCKED);
+			}
 		}
 
 		SIVAL(sig->data, 0, NTLMSSP_SIGN_VERSION);
@@ -194,8 +204,15 @@ static NTSTATUS ntlmssp_make_packet_signature(struct ntlmssp_state *ntlmssp_stat
 
 		dump_arc4_state("ntlmssp hash: \n",
 				&ntlmssp_state->crypt->ntlm.seal_state);
-		arcfour_crypt_sbox(&ntlmssp_state->crypt->ntlm.seal_state,
-				   sig->data+4, sig->length-4);
+		rc = gnutls_cipher_encrypt(ntlmssp_state->crypt->ntlm.seal_state,
+					   sig->data + 4,
+					   sig->length - 4);
+		if (rc < 0) {
+			DBG_ERR("gnutls_cipher_encrypt for NTLM packet "
+				"signature failed: %s\n",
+				gnutls_strerror(rc));
+			return gnutls_error_to_ntstatus(rc, NT_STATUS_NTLM_BLOCKED);
+		}
 	}
 
 	return NT_STATUS_OK;
@@ -317,6 +334,8 @@ NTSTATUS ntlmssp_seal_packet(struct ntlmssp_state *ntlmssp_state,
 			     const uint8_t *whole_pdu, size_t pdu_length,
 			     DATA_BLOB *sig)
 {
+	int rc;
+
 	if (!(ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_SEAL)) {
 		DEBUG(3, ("NTLMSSP Sealing not negotiated - cannot seal packet!\n"));
 		return NT_STATUS_INVALID_PARAMETER;
@@ -353,11 +372,25 @@ NTSTATUS ntlmssp_seal_packet(struct ntlmssp_state *ntlmssp_state,
 			return nt_status;
 		}
 
-		arcfour_crypt_sbox(&ntlmssp_state->crypt->ntlm2.sending.seal_state,
-				   data, length);
+		rc = gnutls_cipher_encrypt(ntlmssp_state->crypt->ntlm2.sending.seal_state,
+					   data,
+					   length);
+		if (rc < 0) {
+			DBG_ERR("gnutls_cipher_encrypt ntlmv2 sealing the data "
+				"failed: %s\n",
+				gnutls_strerror(rc));
+			return gnutls_error_to_ntstatus(rc, NT_STATUS_NTLM_BLOCKED);
+		}
 		if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_KEY_EXCH) {
-			arcfour_crypt_sbox(&ntlmssp_state->crypt->ntlm2.sending.seal_state,
-					   sig->data+4, 8);
+			rc = gnutls_cipher_encrypt(ntlmssp_state->crypt->ntlm2.sending.seal_state,
+						    sig->data + 4,
+						    8);
+			if (rc < 0) {
+				DBG_ERR("gnutls_cipher_encrypt ntlmv2 sealing "
+					"the EXCH signature data failed: %s\n",
+					gnutls_strerror(rc));
+				return gnutls_error_to_ntstatus(rc, NT_STATUS_NTLM_BLOCKED);
+			}
 		}
 	} else {
 		NTSTATUS status;
@@ -381,17 +414,30 @@ NTSTATUS ntlmssp_seal_packet(struct ntlmssp_state *ntlmssp_state,
 		 * is not constant, but is is rather updated with
 		 * each iteration
 		 */
-
 		dump_arc4_state("ntlmv1 arc4 state:\n",
 				&ntlmssp_state->crypt->ntlm.seal_state);
-		arcfour_crypt_sbox(&ntlmssp_state->crypt->ntlm.seal_state,
-				   data, length);
+		rc = gnutls_cipher_encrypt(ntlmssp_state->crypt->ntlm.seal_state,
+					   data,
+					   length);
+		if (rc < 0) {
+			DBG_ERR("gnutls_cipher_encrypt ntlmv1 sealing data"
+				"failed: %s\n",
+				gnutls_strerror(rc));
+			return gnutls_error_to_ntstatus(rc, NT_STATUS_NTLM_BLOCKED);
+		}
 
 		dump_arc4_state("ntlmv1 arc4 state:\n",
 				&ntlmssp_state->crypt->ntlm.seal_state);
 
-		arcfour_crypt_sbox(&ntlmssp_state->crypt->ntlm.seal_state,
-				   sig->data+4, sig->length-4);
+		rc = gnutls_cipher_encrypt(ntlmssp_state->crypt->ntlm.seal_state,
+					    sig->data + 4,
+					    sig->length - 4);
+		if (rc < 0) {
+			DBG_ERR("gnutls_cipher_encrypt ntlmv1 sealing signing "
+				"data failed: %s\n",
+				gnutls_strerror(rc));
+			return gnutls_error_to_ntstatus(rc, NT_STATUS_NTLM_BLOCKED);
+		}
 
 		ntlmssp_state->crypt->ntlm.seq_num++;
 	}
@@ -412,6 +458,8 @@ NTSTATUS ntlmssp_unseal_packet(struct ntlmssp_state *ntlmssp_state,
 			       const DATA_BLOB *sig)
 {
 	NTSTATUS status;
+	int rc;
+
 	if (!ntlmssp_state->session_key.length) {
 		DEBUG(3, ("NO session key, cannot unseal packet\n"));
 		return NT_STATUS_NO_USER_SESSION_KEY;
@@ -422,14 +470,29 @@ NTSTATUS ntlmssp_unseal_packet(struct ntlmssp_state *ntlmssp_state,
 
 	if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
 		/* First unseal the data. */
-		arcfour_crypt_sbox(&ntlmssp_state->crypt->ntlm2.receiving.seal_state,
-				   data, length);
+		rc = gnutls_cipher_decrypt(ntlmssp_state->crypt->ntlm2.receiving.seal_state,
+					   data,
+					   length);
+		if (rc < 0) {
+			DBG_ERR("gnutls_cipher_decrypt ntlmv2 unsealing the "
+				"data failed: %s\n",
+				gnutls_strerror(rc));
+			return gnutls_error_to_ntstatus(rc, NT_STATUS_NTLM_BLOCKED);
+		}
 		dump_data_pw("ntlmv2 clear data\n", data, length);
 	} else {
-		arcfour_crypt_sbox(&ntlmssp_state->crypt->ntlm.seal_state,
-				   data, length);
+		rc = gnutls_cipher_decrypt(ntlmssp_state->crypt->ntlm.seal_state,
+					   data,
+					   length);
+		if (rc < 0) {
+			DBG_ERR("gnutls_cipher_decrypt ntlmv1 unsealing the "
+				"data failed: %s\n",
+				gnutls_strerror(rc));
+			return gnutls_error_to_ntstatus(rc, NT_STATUS_NTLM_BLOCKED);
+		}
 		dump_data_pw("ntlmv1 clear data\n", data, length);
 	}
+
 	status = ntlmssp_check_packet(ntlmssp_state,
 				      data, length,
 				      whole_pdu, pdu_length,
@@ -555,6 +618,8 @@ NTSTATUS ntlmssp_unwrap(struct ntlmssp_state *ntlmssp_state,
 NTSTATUS ntlmssp_sign_reset(struct ntlmssp_state *ntlmssp_state,
 			    bool reset_seqnums)
 {
+	int rc;
+
 	DEBUG(3, ("NTLMSSP Sign/Seal - Initialising with flags:\n"));
 	debug_ntlmssp_flags(ntlmssp_state->neg_flags);
 
@@ -584,12 +649,16 @@ NTSTATUS ntlmssp_sign_reset(struct ntlmssp_state *ntlmssp_state,
 		const char *send_seal_const;
 		const char *recv_sign_const;
 		const char *recv_seal_const;
-		uint8_t send_seal_key[16];
-		DATA_BLOB send_seal_blob = data_blob_const(send_seal_key,
-					   sizeof(send_seal_key));
-		uint8_t recv_seal_key[16];
-		DATA_BLOB recv_seal_blob = data_blob_const(recv_seal_key,
-					   sizeof(recv_seal_key));
+		uint8_t send_seal_key[16] = {0};
+		gnutls_datum_t send_seal_blob = {
+			.data = send_seal_key,
+			.size = sizeof(send_seal_key),
+		};
+		uint8_t recv_seal_key[16] = {0};
+		gnutls_datum_t recv_seal_blob = {
+			.data = recv_seal_key,
+			.size = sizeof(recv_seal_key),
+		};
 		NTSTATUS status;
 
 		switch (ntlmssp_state->role) {
@@ -648,10 +717,22 @@ NTSTATUS ntlmssp_sign_reset(struct ntlmssp_state *ntlmssp_state,
 		if (!NT_STATUS_IS_OK(status)) {
 			return status;
 		}
-		dump_data_pw("NTLMSSP send seal key:\n", send_seal_key, 16);
+		dump_data_pw("NTLMSSP send seal key:\n",
+			     send_seal_key,
+			     sizeof(send_seal_key));
 
-		arcfour_init(&ntlmssp_state->crypt->ntlm2.sending.seal_state,
-			     &send_seal_blob);
+		if (ntlmssp_state->crypt->ntlm2.sending.seal_state != NULL) {
+			gnutls_cipher_deinit(ntlmssp_state->crypt->ntlm2.sending.seal_state);
+		}
+		rc = gnutls_cipher_init(&ntlmssp_state->crypt->ntlm2.sending.seal_state,
+					GNUTLS_CIPHER_ARCFOUR_128,
+					&send_seal_blob,
+					NULL);
+		if (rc < 0) {
+			DBG_ERR("gnutls_cipher_init failed: %s\n",
+				gnutls_strerror(rc));
+			return gnutls_error_to_ntstatus(rc, NT_STATUS_NTLM_BLOCKED);
+		}
 
 		dump_arc4_state("NTLMSSP send seal arc4 state:\n",
 				&ntlmssp_state->crypt->ntlm2.sending.seal_state);
@@ -677,10 +758,22 @@ NTSTATUS ntlmssp_sign_reset(struct ntlmssp_state *ntlmssp_state,
 		if (!NT_STATUS_IS_OK(status)) {
 			return status;
 		}
-		dump_data_pw("NTLMSSP recv seal key:\n", recv_seal_key, 16);
+		dump_data_pw("NTLMSSP recv seal key:\n",
+			     recv_seal_key,
+			     sizeof(recv_seal_key));
 
-		arcfour_init(&ntlmssp_state->crypt->ntlm2.receiving.seal_state,
-			     &recv_seal_blob);
+		if (ntlmssp_state->crypt->ntlm2.receiving.seal_state != NULL) {
+			gnutls_cipher_deinit(ntlmssp_state->crypt->ntlm2.receiving.seal_state);
+		}
+		rc = gnutls_cipher_init(&ntlmssp_state->crypt->ntlm2.receiving.seal_state,
+					GNUTLS_CIPHER_ARCFOUR_128,
+					&recv_seal_blob,
+					NULL);
+		if (rc < 0) {
+			DBG_ERR("gnutls_cipher_init failed: %s\n",
+				gnutls_strerror(rc));
+			return gnutls_error_to_ntstatus(rc, NT_STATUS_NTLM_BLOCKED);
+		}
 
 		dump_arc4_state("NTLMSSP recv seal arc4 state:\n",
 				&ntlmssp_state->crypt->ntlm2.receiving.seal_state);
@@ -690,8 +783,10 @@ NTSTATUS ntlmssp_sign_reset(struct ntlmssp_state *ntlmssp_state,
 			ntlmssp_state->crypt->ntlm2.receiving.seq_num = 0;
 		}
 	} else {
-		uint8_t weak_session_key[8];
-		DATA_BLOB seal_session_key = ntlmssp_state->session_key;
+		gnutls_datum_t seal_session_key = {
+			.data = ntlmssp_state->session_key.data,
+			.size = ntlmssp_state->session_key.length,
+		};
 		bool do_weak = false;
 
 		DEBUG(5, ("NTLMSSP Sign/Seal - using NTLM1\n"));
@@ -709,14 +804,19 @@ NTSTATUS ntlmssp_sign_reset(struct ntlmssp_state *ntlmssp_state,
 		 * Nothing to weaken.
 		 * We certainly don't want to 'extend' the length...
 		 */
-		if (seal_session_key.length < 16) {
+		if (ntlmssp_state->session_key.length < 16) {
 			/* TODO: is this really correct? */
 			do_weak = false;
 		}
 
 		if (do_weak) {
+			uint8_t weak_session_key[8];
+
 			memcpy(weak_session_key, seal_session_key.data, 8);
-			seal_session_key = data_blob_const(weak_session_key, 8);
+			seal_session_key = (gnutls_datum_t) {
+				.data = weak_session_key,
+				.size = sizeof(weak_session_key),
+			};
 
 			/*
 			 * LM key doesn't support 128 bit crypto, so this is
@@ -732,8 +832,18 @@ NTSTATUS ntlmssp_sign_reset(struct ntlmssp_state *ntlmssp_state,
 			}
 		}
 
-		arcfour_init(&ntlmssp_state->crypt->ntlm.seal_state,
-			     &seal_session_key);
+		if (ntlmssp_state->crypt->ntlm.seal_state != NULL) {
+			gnutls_cipher_deinit(ntlmssp_state->crypt->ntlm.seal_state);
+		}
+		rc = gnutls_cipher_init(&ntlmssp_state->crypt->ntlm.seal_state,
+					GNUTLS_CIPHER_ARCFOUR_128,
+					&seal_session_key,
+					NULL);
+		if (rc < 0) {
+			DBG_ERR("gnutls_cipher_init failed: %s\n",
+				gnutls_strerror(rc));
+			return gnutls_error_to_ntstatus(rc, NT_STATUS_NTLM_BLOCKED);
+		}
 
 		dump_arc4_state("NTLMv1 arc4 state:\n",
 				&ntlmssp_state->crypt->ntlm.seal_state);
@@ -746,6 +856,24 @@ NTSTATUS ntlmssp_sign_reset(struct ntlmssp_state *ntlmssp_state,
 	return NT_STATUS_OK;
 }
 
+static int ntlmssp_crypt_free_gnutls_cipher_state(union ntlmssp_crypt_state *c)
+{
+	if (c->ntlm2.sending.seal_state != NULL) {
+		gnutls_cipher_deinit(c->ntlm2.sending.seal_state);
+		c->ntlm2.sending.seal_state = NULL;
+	}
+	if (c->ntlm2.receiving.seal_state != NULL) {
+		gnutls_cipher_deinit(c->ntlm2.receiving.seal_state);
+		c->ntlm2.receiving.seal_state = NULL;
+	}
+	if (c->ntlm.seal_state != NULL) {
+		gnutls_cipher_deinit(c->ntlm.seal_state);
+		c->ntlm.seal_state = NULL;
+	}
+
+	return 0;
+}
+
 NTSTATUS ntlmssp_sign_init(struct ntlmssp_state *ntlmssp_state)
 {
 	if (ntlmssp_state->session_key.length < 8) {
@@ -758,6 +886,8 @@ NTSTATUS ntlmssp_sign_init(struct ntlmssp_state *ntlmssp_state)
 	if (ntlmssp_state->crypt == NULL) {
 		return NT_STATUS_NO_MEMORY;
 	}
+	talloc_set_destructor(ntlmssp_state->crypt,
+			      ntlmssp_crypt_free_gnutls_cipher_state);
 
 	return ntlmssp_sign_reset(ntlmssp_state, true);
 }