s4:ntlmssp Use common code for ntlmssp_sign.c

The common code does not have a mem_ctx on ntlmssp_check_packet() and
ntlmssp_unseal_packet().

We do however need some internal working of the code exposed, so some
structures are moved to ntlmssp_sign.h

Andrew Bartlett

2 files changed, 2 insertions, 508 deletions

diff --git a/source4/auth/ntlmssp/ntlmssp_sign.c b/source4/auth/ntlmssp/ntlmssp_sign.c
index 0a86235a10..8cde44150a 100644
--- a/source4/auth/ntlmssp/ntlmssp_sign.c
+++ b/source4/auth/ntlmssp/ntlmssp_sign.c
@@ -21,512 +21,8 @@
 
 #include "includes.h"
 #include "auth/ntlmssp/ntlmssp.h"
-#include "../libcli/auth/libcli_auth.h"
-#include "../lib/crypto/crypto.h"
 #include "auth/gensec/gensec.h"
-
-#define CLI_SIGN "session key to client-to-server signing key magic constant"
-#define CLI_SEAL "session key to client-to-server sealing key magic constant"
-#define SRV_SIGN "session key to server-to-client signing key magic constant"
-#define SRV_SEAL "session key to server-to-client sealing key magic constant"
-
-/**
- * Some notes on the NTLM2 code:
- *
- * NTLM2 is a AEAD system.  This means that the data encrypted is not
- * all the data that is signed.  In DCE-RPC case, the headers of the
- * DCE-RPC packets are also signed.  This prevents some of the
- * fun-and-games one might have by changing them.
- *
- */
-
-static void dump_arc4_state(const char *description,
-			    struct arcfour_state *state)
-{
-	dump_data_pw(description, state->sbox, sizeof(state->sbox));
-}
-
-static void calc_ntlmv2_key(uint8_t subkey[16],
-			    DATA_BLOB session_key,
-			    const char *constant)
-{
-	struct MD5Context ctx3;
-	MD5Init(&ctx3);
-	MD5Update(&ctx3, session_key.data, session_key.length);
-	MD5Update(&ctx3, (const uint8_t *)constant, strlen(constant)+1);
-	MD5Final(subkey, &ctx3);
-}
-
-enum ntlmssp_direction {
-	NTLMSSP_SEND,
-	NTLMSSP_RECEIVE
-};
-
-struct ntlmssp_crypt_direction {
-	uint32_t seq_num;
-	uint8_t sign_key[16];
-	struct arcfour_state seal_state;
-};
-
-union ntlmssp_crypt_state {
-	/* NTLM */
-	struct ntlmssp_crypt_direction ntlm;
-
-	/* NTLM2 */
-	struct {
-		struct ntlmssp_crypt_direction sending;
-		struct ntlmssp_crypt_direction receiving;
-	} ntlm2;
-};
-
-static NTSTATUS ntlmssp_make_packet_signature(struct ntlmssp_state *ntlmssp_state,
-					      TALLOC_CTX *sig_mem_ctx,
-					      const uint8_t *data, size_t length,
-					      const uint8_t *whole_pdu, size_t pdu_length,
-					      enum ntlmssp_direction direction,
-					      DATA_BLOB *sig, bool encrypt_sig)
-{
-	if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
-		HMACMD5Context ctx;
-		uint8_t digest[16];
-		uint8_t seq_num[4];
-
-		*sig = data_blob_talloc(sig_mem_ctx, NULL, NTLMSSP_SIG_SIZE);
-		if (!sig->data) {
-			return NT_STATUS_NO_MEMORY;
-		}
-
-		switch (direction) {
-		case NTLMSSP_SEND:
-			SIVAL(seq_num, 0, ntlmssp_state->crypt->ntlm2.sending.seq_num);
-			ntlmssp_state->crypt->ntlm2.sending.seq_num++;
-			hmac_md5_init_limK_to_64(ntlmssp_state->crypt->ntlm2.sending.sign_key, 16, &ctx);
-			break;
-		case NTLMSSP_RECEIVE:
-			SIVAL(seq_num, 0, ntlmssp_state->crypt->ntlm2.receiving.seq_num);
-			ntlmssp_state->crypt->ntlm2.receiving.seq_num++;
-			hmac_md5_init_limK_to_64(ntlmssp_state->crypt->ntlm2.receiving.sign_key, 16, &ctx);
-			break;
-		}
-		hmac_md5_update(seq_num, sizeof(seq_num), &ctx);
-		hmac_md5_update(whole_pdu, pdu_length, &ctx);
-		hmac_md5_final(digest, &ctx);
-
-		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);
-				break;
-			case NTLMSSP_RECEIVE:
-				arcfour_crypt_sbox(&ntlmssp_state->crypt->ntlm2.receiving.seal_state,
-						   digest, 8);
-				break;
-			}
-		}
-
-		SIVAL(sig->data, 0, NTLMSSP_SIGN_VERSION);
-		memcpy(sig->data + 4, digest, 8);
-		memcpy(sig->data + 12, seq_num, 4);
-
-		DEBUG(10,("NTLM2: created signature over %llu bytes of input:\n",
-			  (unsigned long long)pdu_length));
-		dump_data(11, sig->data, sig->length);
-	} else {
-		bool ok;
-		uint32_t crc;
-
-		crc = crc32_calc_buffer(data, length);
-
-		ok = msrpc_gen(sig_mem_ctx,
-			       sig, "dddd",
-			       NTLMSSP_SIGN_VERSION, 0, crc,
-			       ntlmssp_state->crypt->ntlm.seq_num);
-		if (!ok) {
-			return NT_STATUS_NO_MEMORY;
-		}
-		ntlmssp_state->crypt->ntlm.seq_num++;
-
-		arcfour_crypt_sbox(&ntlmssp_state->crypt->ntlm.seal_state,
-				   sig->data+4, sig->length-4);
-
-		DEBUG(10,("NTLM1: created signature over %llu bytes of input:\n",
-			  (unsigned long long)length));
-		dump_data(11, sig->data, sig->length);
-	}
-	return NT_STATUS_OK;
-}
-
-NTSTATUS ntlmssp_sign_packet(struct ntlmssp_state *ntlmssp_state,
-			     TALLOC_CTX *sig_mem_ctx,
-			     const uint8_t *data, size_t length,
-			     const uint8_t *whole_pdu, size_t pdu_length,
-			     DATA_BLOB *sig)
-{
-	NTSTATUS nt_status;
-
-	nt_status = ntlmssp_make_packet_signature(ntlmssp_state,
-						  sig_mem_ctx,
-						  data, length,
-						  whole_pdu, pdu_length,
-						  NTLMSSP_SEND, sig, true);
-
-	return nt_status;
-}
-
-/**
- * Check the signature of an incoming packet 
- *
- */
-
-NTSTATUS ntlmssp_check_packet(struct ntlmssp_state *ntlmssp_state,
-			      TALLOC_CTX *sig_mem_ctx,
-			      const uint8_t *data, size_t length,
-			      const uint8_t *whole_pdu, size_t pdu_length,
-			      const DATA_BLOB *sig)
-{
-	DATA_BLOB local_sig;
-	NTSTATUS nt_status;
-
-	if (!ntlmssp_state->session_key.length) {
-		DEBUG(3, ("NO session key, cannot check packet signature\n"));
-		return NT_STATUS_NO_USER_SESSION_KEY;
-	}
-
-	nt_status = ntlmssp_make_packet_signature(ntlmssp_state,
-						  sig_mem_ctx,
-						  data, length,
-						  whole_pdu, pdu_length,
-						  NTLMSSP_RECEIVE,
-						  &local_sig, true);
-	
-	if (!NT_STATUS_IS_OK(nt_status)) {
-		DEBUG(0,("NTLMSSP packet sig creation failed with %s\n",
-			 nt_errstr(nt_status)));
-		return nt_status;
-	}
-
-	if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
-		if (local_sig.length != sig->length ||
-		    memcmp(local_sig.data, sig->data, sig->length) != 0) {
-
-			DEBUG(10,("BAD SIG NTLM2: wanted signature over %llu bytes of input:\n",
-				  (unsigned long long)pdu_length));
-			dump_data(10, local_sig.data, local_sig.length);
-
-			DEBUG(10,("BAD SIG: got signature over %llu bytes of input:\n",
-				  (unsigned long long)pdu_length));
-			dump_data(10, sig->data, sig->length);
-
-			data_blob_free(&local_sig);
-			return NT_STATUS_ACCESS_DENIED;
-		}
-	} else {
-		if (local_sig.length != sig->length ||
-		    memcmp(local_sig.data + 8, sig->data + 8, sig->length - 8) != 0) {
-			DEBUG(10,("BAD SIG NTLM1: wanted signature of %llu bytes of input:\n",
-				  (unsigned long long)length));
-			dump_data(5, local_sig.data, local_sig.length);
-
-			DEBUG(10,("BAD SIG: got signature of %llu bytes of input:\n",
-				  (unsigned long long)length));
-			dump_data(10, sig->data, sig->length);
-
-			data_blob_free(&local_sig);
-			return NT_STATUS_ACCESS_DENIED;
-		}
-	}
-	dump_data_pw("checked ntlmssp signature\n", sig->data, sig->length);
-
-	data_blob_free(&local_sig);
-	return NT_STATUS_OK;
-}
-
-
-/**
- * Seal data with the NTLMSSP algorithm
- *
- */
-
-NTSTATUS ntlmssp_seal_packet(struct ntlmssp_state *ntlmssp_state,
-			     TALLOC_CTX *sig_mem_ctx,
-			     uint8_t *data, size_t length,
-			     const uint8_t *whole_pdu, size_t pdu_length,
-			     DATA_BLOB *sig)
-{
-	if (!ntlmssp_state->session_key.length) {
-		DEBUG(3, ("NO session key, cannot seal packet\n"));
-		return NT_STATUS_NO_USER_SESSION_KEY;
-	}
-
-	DEBUG(10,("ntlmssp_seal_data: seal\n"));
-	dump_data_pw("ntlmssp clear data\n", data, length);
-	if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
-		NTSTATUS nt_status;
-		/*
-		 * The order of these two operations matters - we
-		 * must first seal the packet, then seal the
-		 * sequence number - this is because the
-		 * send_seal_hash is not constant, but is is rather
-		 * updated with each iteration
-		 */
-		nt_status = ntlmssp_make_packet_signature(ntlmssp_state,
-							  sig_mem_ctx,
-							  data, length,
-							  whole_pdu, pdu_length,
-							  NTLMSSP_SEND,
-							  sig, false);
-		if (!NT_STATUS_IS_OK(nt_status)) {
-			return nt_status;
-		}
-
-		arcfour_crypt_sbox(&ntlmssp_state->crypt->ntlm2.sending.seal_state,
-				   data, length);
-		if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_KEY_EXCH) {
-			arcfour_crypt_sbox(&ntlmssp_state->crypt->ntlm2.sending.seal_state,
-					   sig->data+4, 8);
-		}
-	} else {
-		bool ok;
-		uint32_t crc;
-
-		crc = crc32_calc_buffer(data, length);
-
-		ok = msrpc_gen(sig_mem_ctx,
-			       sig, "dddd",
-			       NTLMSSP_SIGN_VERSION, 0, crc,
-			       ntlmssp_state->crypt->ntlm.seq_num);
-		if (!ok) {
-			return NT_STATUS_NO_MEMORY;
-		}
-
-		/*
-		 * The order of these two operations matters - we
-		 * must first seal the packet, then seal the
-		 * sequence number - this is because the ntlmv1_arc4_state
-		 * is not constant, but is is rather updated with
-		 * each iteration
-		 */
-
-		arcfour_crypt_sbox(&ntlmssp_state->crypt->ntlm.seal_state,
-				   data, length);
-
-		arcfour_crypt_sbox(&ntlmssp_state->crypt->ntlm.seal_state,
-				   sig->data+4, sig->length-4);
-
-		ntlmssp_state->crypt->ntlm.seq_num++;
-	}
-	dump_data_pw("ntlmssp signature\n", sig->data, sig->length);
-	dump_data_pw("ntlmssp sealed data\n", data, length);
-
-	return NT_STATUS_OK;
-}
-
-/**
- * Unseal data with the NTLMSSP algorithm
- *
- */
-
-NTSTATUS ntlmssp_unseal_packet(struct ntlmssp_state *ntlmssp_state,
-			       TALLOC_CTX *sig_mem_ctx,
-			       uint8_t *data, size_t length,
-			       const uint8_t *whole_pdu, size_t pdu_length,
-			       const DATA_BLOB *sig)
-{
-	NTSTATUS status;
-
-	if (!ntlmssp_state->session_key.length) {
-		DEBUG(3, ("NO session key, cannot unseal packet\n"));
-		return NT_STATUS_NO_USER_SESSION_KEY;
-	}
-
-	dump_data_pw("ntlmssp sealed data\n", data, length);
-	if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
-		arcfour_crypt_sbox(&ntlmssp_state->crypt->ntlm2.receiving.seal_state,
-				   data, length);
-	} else {
-		arcfour_crypt_sbox(&ntlmssp_state->crypt->ntlm.seal_state,
-				   data, length);
-	}
-	dump_data_pw("ntlmssp clear data\n", data, length);
-	status = ntlmssp_check_packet(ntlmssp_state,
-				      sig_mem_ctx,
-				      data, length,
-				      whole_pdu, pdu_length,
-				      sig);
-
-	if (!NT_STATUS_IS_OK(status)) {
-		DEBUG(1,("NTLMSSP packet check for unseal failed due to invalid signature on %llu bytes of input:\n",
-			 (unsigned long long)length));
-	}
-	return status;
-}
-
-/**
-   Initialise the state for NTLMSSP signing.
-*/
-NTSTATUS ntlmssp_sign_init(struct ntlmssp_state *ntlmssp_state)
-{
-	DEBUG(3, ("NTLMSSP Sign/Seal - Initialising with flags:\n"));
-	debug_ntlmssp_flags(ntlmssp_state->neg_flags);
-
-	if (ntlmssp_state->session_key.length < 8) {
-		DEBUG(3, ("NO session key, cannot intialise signing\n"));
-		return NT_STATUS_NO_USER_SESSION_KEY;
-	}
-
-	ntlmssp_state->crypt = talloc_zero(ntlmssp_state,
-					   union ntlmssp_crypt_state);
-	if (ntlmssp_state->crypt == NULL) {
-		return NT_STATUS_NO_MEMORY;
-	}
-
-	if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
-		DATA_BLOB weak_session_key = ntlmssp_state->session_key;
-		const char *send_sign_const;
-		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));
-
-		switch (ntlmssp_state->role) {
-		case NTLMSSP_CLIENT:
-			send_sign_const = CLI_SIGN;
-			send_seal_const = CLI_SEAL;
-			recv_sign_const = SRV_SIGN;
-			recv_seal_const = SRV_SEAL;
-			break;
-		case NTLMSSP_SERVER:
-			send_sign_const = SRV_SIGN;
-			send_seal_const = SRV_SEAL;
-			recv_sign_const = CLI_SIGN;
-			recv_seal_const = CLI_SEAL;
-			break;
-		default:
-			return NT_STATUS_INTERNAL_ERROR;
-		}
-
-		/*
-		 * Weaken NTLMSSP keys to cope with down-level
-		 * clients, servers and export restrictions.
-		 *
-		 * We probably should have some parameters to
-		 * control this, once we get NTLM2 working.
-		 *
-		 * Key weakening was not performed on the master key
-		 * for NTLM2, but must be done on the encryption subkeys only.
-		 */
-
-		if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_128) {
-			/* nothing to do */
-		} else if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_56) {
-			weak_session_key.length = 7;
-		} else { /* forty bits */
-			weak_session_key.length = 5;
-		}
-
-		dump_data_pw("NTLMSSP weakend master key:\n",
-			     weak_session_key.data,
-			     weak_session_key.length);
-
-		/* SEND: sign key */
-		calc_ntlmv2_key(ntlmssp_state->crypt->ntlm2.sending.sign_key,
-				ntlmssp_state->session_key, send_sign_const);
-		dump_data_pw("NTLMSSP send sign key:\n",
-			     ntlmssp_state->crypt->ntlm2.sending.sign_key, 16);
-
-		/* SEND: seal ARCFOUR pad */
-		calc_ntlmv2_key(send_seal_key,
-				weak_session_key, send_seal_const);
-		dump_data_pw("NTLMSSP send seal key:\n", send_seal_key, 16);
-
-		arcfour_init(&ntlmssp_state->crypt->ntlm2.sending.seal_state,
-			     &send_seal_blob);
-
-		dump_arc4_state("NTLMSSP send seal arc4 state:\n",
-				&ntlmssp_state->crypt->ntlm2.sending.seal_state);
-
-		/* SEND: seq num */
-		ntlmssp_state->crypt->ntlm2.sending.seq_num = 0;
-
-		/* RECV: sign key */
-		calc_ntlmv2_key(ntlmssp_state->crypt->ntlm2.receiving.sign_key,
-				ntlmssp_state->session_key, recv_sign_const);
-		dump_data_pw("NTLMSSP recv sign key:\n",
-			     ntlmssp_state->crypt->ntlm2.receiving.sign_key, 16);
-
-		/* RECV: seal ARCFOUR pad */
-		calc_ntlmv2_key(recv_seal_key,
-				weak_session_key, recv_seal_const);
-		dump_data_pw("NTLMSSP recv seal key:\n", recv_seal_key, 16);
-
-		arcfour_init(&ntlmssp_state->crypt->ntlm2.receiving.seal_state,
-			     &recv_seal_blob);
-
-		dump_arc4_state("NTLMSSP recv seal arc4 state:\n",
-				&ntlmssp_state->crypt->ntlm2.receiving.seal_state);
-
-		/* RECV: seq num */
-		ntlmssp_state->crypt->ntlm2.receiving.seq_num = 0;
-	} else {
-		uint8_t weak_session_key[8];
-		DATA_BLOB seal_session_key = ntlmssp_state->session_key;
-		bool do_weak = false;
-
-		DEBUG(5, ("NTLMSSP Sign/Seal - using NTLM1\n"));
-
-		/*
-		 * Key weakening not performed on the master key for NTLM2
-		 * and does not occour for NTLM1. Therefore we only need
-		 * to do this for the LM_KEY.
-		 */
-		if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_LM_KEY) {
-			do_weak = true;
-		}
-
-		/*
-		 * Nothing to weaken.
-		 * We certainly don't want to 'extend' the length...
-		 */
-		if (seal_session_key.length < 16) {
-			/* TODO: is this really correct? */
-			do_weak = false;
-		}
-
-		if (do_weak) {
-			memcpy(weak_session_key, seal_session_key.data, 8);
-			seal_session_key = data_blob_const(weak_session_key, 8);
-
-			/*
-			 * LM key doesn't support 128 bit crypto, so this is
-			 * the best we can do. If you negotiate 128 bit, but
-			 * not 56, you end up with 40 bit...
-			 */
-			if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_56) {
-				weak_session_key[7] = 0xa0;
-			} else { /* forty bits */
-				weak_session_key[5] = 0xe5;
-				weak_session_key[6] = 0x38;
-				weak_session_key[7] = 0xb0;
-			}
-		}
-
-		arcfour_init(&ntlmssp_state->crypt->ntlm.seal_state,
-			     &seal_session_key);
-
-		dump_arc4_state("NTLMv1 arc4 state:\n",
-				&ntlmssp_state->crypt->ntlm.seal_state);
-
-		ntlmssp_state->crypt->ntlm.seq_num = 0;
-	}
-
-	return NT_STATUS_OK;
-}
+#include "../libcli/auth/ntlmssp_private.h"
 
 NTSTATUS gensec_ntlmssp_sign_packet(struct gensec_security *gensec_security,
 				    TALLOC_CTX *sig_mem_ctx,
@@ -560,7 +56,6 @@ NTSTATUS gensec_ntlmssp_check_packet(struct gensec_security *gensec_security,
 	NTSTATUS nt_status;
 
 	nt_status = ntlmssp_check_packet(gensec_ntlmssp->ntlmssp_state,
-					 sig_mem_ctx,
 					 data, length,
 					 whole_pdu, pdu_length,
 					 sig);
@@ -603,7 +98,6 @@ NTSTATUS gensec_ntlmssp_unseal_packet(struct gensec_security *gensec_security,
 	NTSTATUS nt_status;
 
 	nt_status = ntlmssp_unseal_packet(gensec_ntlmssp->ntlmssp_state,
-					  sig_mem_ctx,
 					  data, length,
 					  whole_pdu, pdu_length,
 					  sig);
diff --git a/source4/auth/ntlmssp/wscript_build b/source4/auth/ntlmssp/wscript_build
index a47bb6cd73..05d206936a 100644
--- a/source4/auth/ntlmssp/wscript_build
+++ b/source4/auth/ntlmssp/wscript_build
@@ -1,7 +1,7 @@
 #!/usr/bin/env python
 
 bld.SAMBA_MODULE('gensec_ntlmssp',
-	source='ntlmssp.c ntlmssp_sign.c ntlmssp_client.c ntlmssp_server.c',
+	source='ntlmssp.c ntlmssp_sign.c ../../../libcli/auth/ntlmssp_sign.c ntlmssp_client.c ntlmssp_server.c',
 	autoproto='proto.h',
 	subsystem='gensec',
 	init_function='gensec_ntlmssp_init',