smbencrypt.c

samba-3.0.22.tar.gz 编译smb服务器的源码

{
	uchar p24[24];
	uchar partial_lm_hash[16];
	
	memcpy(partial_lm_hash, lm_hash, 8);
	memset(partial_lm_hash + 8, 0xbd, 8);    

	SMBOWFencrypt(partial_lm_hash, lm_resp, p24);
	
	memcpy(sess_key, p24, 16);

#ifdef DEBUG_PASSWORD
	DEBUG(100, ("SMBsesskeygen_lmv1_jerry:\n"));
	dump_data(100, (const char *)sess_key, 16);
#endif
}

DATA_BLOB NTLMv2_generate_names_blob(const char *hostname, 
				     const char *domain)
{
	DATA_BLOB names_blob = data_blob(NULL, 0);
	
	msrpc_gen(&names_blob, "aaa", 
		  NTLMSSP_NAME_TYPE_DOMAIN, domain,
		  NTLMSSP_NAME_TYPE_SERVER, hostname,
		  0, "");
	return names_blob;
}

static DATA_BLOB NTLMv2_generate_client_data(const DATA_BLOB *names_blob) 
{
	uchar client_chal[8];
	DATA_BLOB response = data_blob(NULL, 0);
	char long_date[8];

	generate_random_buffer(client_chal, sizeof(client_chal));

	put_long_date(long_date, time(NULL));

	/* See http://www.ubiqx.org/cifs/SMB.html#SMB.8.5 */

	msrpc_gen(&response, "ddbbdb", 
		  0x00000101,     /* Header  */
		  0,              /* 'Reserved'  */
		  long_date, 8,	  /* Timestamp */
		  client_chal, 8, /* client challenge */
		  0,		  /* Unknown */
		  names_blob->data, names_blob->length);	/* End of name list */

	return response;
}

static DATA_BLOB NTLMv2_generate_response(const uchar ntlm_v2_hash[16],
					  const DATA_BLOB *server_chal,
					  const DATA_BLOB *names_blob)
{
	uchar ntlmv2_response[16];
	DATA_BLOB ntlmv2_client_data;
	DATA_BLOB final_response;
	
	/* NTLMv2 */
	/* generate some data to pass into the response function - including
	   the hostname and domain name of the server */
	ntlmv2_client_data = NTLMv2_generate_client_data(names_blob);

	/* Given that data, and the challenge from the server, generate a response */
	SMBOWFencrypt_ntv2(ntlm_v2_hash, server_chal, &ntlmv2_client_data, ntlmv2_response);
	
	final_response = data_blob(NULL, sizeof(ntlmv2_response) + ntlmv2_client_data.length);

	memcpy(final_response.data, ntlmv2_response, sizeof(ntlmv2_response));

	memcpy(final_response.data+sizeof(ntlmv2_response), 
	       ntlmv2_client_data.data, ntlmv2_client_data.length);

	data_blob_free(&ntlmv2_client_data);

	return final_response;
}

static DATA_BLOB LMv2_generate_response(const uchar ntlm_v2_hash[16],
					const DATA_BLOB *server_chal)
{
	uchar lmv2_response[16];
	DATA_BLOB lmv2_client_data = data_blob(NULL, 8);
	DATA_BLOB final_response = data_blob(NULL, 24);
	
	/* LMv2 */
	/* client-supplied random data */
	generate_random_buffer(lmv2_client_data.data, lmv2_client_data.length);	

	/* Given that data, and the challenge from the server, generate a response */
	SMBOWFencrypt_ntv2(ntlm_v2_hash, server_chal, &lmv2_client_data, lmv2_response);
	memcpy(final_response.data, lmv2_response, sizeof(lmv2_response));

	/* after the first 16 bytes is the random data we generated above, 
	   so the server can verify us with it */
	memcpy(final_response.data+sizeof(lmv2_response), 
	       lmv2_client_data.data, lmv2_client_data.length);

	data_blob_free(&lmv2_client_data);

	return final_response;
}

BOOL SMBNTLMv2encrypt(const char *user, const char *domain, const char *password, 
		      const DATA_BLOB *server_chal, 
		      const DATA_BLOB *names_blob,
		      DATA_BLOB *lm_response, DATA_BLOB *nt_response, 
		      DATA_BLOB *user_session_key) 
{
	uchar nt_hash[16];
	uchar ntlm_v2_hash[16];
	E_md4hash(password, nt_hash);

	/* We don't use the NT# directly.  Instead we use it mashed up with
	   the username and domain.
	   This prevents username swapping during the auth exchange
	*/
	if (!ntv2_owf_gen(nt_hash, user, domain, True, ntlm_v2_hash)) {
		return False;
	}
	
	if (nt_response) {
		*nt_response = NTLMv2_generate_response(ntlm_v2_hash, server_chal,
							names_blob); 
		if (user_session_key) {
			*user_session_key = data_blob(NULL, 16);
			
			/* The NTLMv2 calculations also provide a session key, for signing etc later */
			/* use only the first 16 bytes of nt_response for session key */
			SMBsesskeygen_ntv2(ntlm_v2_hash, nt_response->data, user_session_key->data);
		}
	}
	
	/* LMv2 */
	
	if (lm_response) {
		*lm_response = LMv2_generate_response(ntlm_v2_hash, server_chal);
	}
	
	return True;
}

/***********************************************************
 encode a password buffer with a unicode password.  The buffer
 is filled with random data to make it harder to attack.
************************************************************/
BOOL encode_pw_buffer(uint8 buffer[516], const char *password, int string_flags)
{
	uchar new_pw[512];
	size_t new_pw_len;

	new_pw_len = push_string(NULL, new_pw,
				 password, 
				 sizeof(new_pw), string_flags);
	
	memcpy(&buffer[512 - new_pw_len], new_pw, new_pw_len);

	generate_random_buffer(buffer, 512 - new_pw_len);

	/* 
	 * The length of the new password is in the last 4 bytes of
	 * the data buffer.
	 */
	SIVAL(buffer, 512, new_pw_len);
	ZERO_STRUCT(new_pw);
	return True;
}


/***********************************************************
 decode a password buffer
 *new_pw_len is the length in bytes of the possibly mulitbyte
 returned password including termination.
************************************************************/

BOOL decode_pw_buffer(uint8 in_buffer[516], char *new_pwrd,
		      int new_pwrd_size, uint32 *new_pw_len,
		      int string_flags)
{
	int byte_len=0;

	/*
	  Warning !!! : This function is called from some rpc call.
	  The password IN the buffer may be a UNICODE string.
	  The password IN new_pwrd is an ASCII string
	  If you reuse that code somewhere else check first.
	*/

	/* The length of the new password is in the last 4 bytes of the data buffer. */

	byte_len = IVAL(in_buffer, 512);

#ifdef DEBUG_PASSWORD
	dump_data(100, (const char *)in_buffer, 516);
#endif

	/* Password cannot be longer than the size of the password buffer */
	if ( (byte_len < 0) || (byte_len > 512)) {
		DEBUG(0, ("decode_pw_buffer: incorrect password length (%d).\n", byte_len));
		DEBUG(0, ("decode_pw_buffer: check that 'encrypt passwords = yes'\n"));
		return False;
	}

	/* decode into the return buffer.  Buffer length supplied */
 	*new_pw_len = pull_string(NULL, new_pwrd, &in_buffer[512 - byte_len], new_pwrd_size, 
				  byte_len, string_flags);

#ifdef DEBUG_PASSWORD
	DEBUG(100,("decode_pw_buffer: new_pwrd: "));
	dump_data(100, (const char *)new_pwrd, *new_pw_len);
	DEBUG(100,("multibyte len:%d\n", *new_pw_len));
	DEBUG(100,("original char len:%d\n", byte_len/2));
#endif
	
	return True;
}

/***********************************************************
 Encrypt/Decrypt used for LSA secrets and trusted domain
 passwords.
************************************************************/

void sess_crypt_blob(DATA_BLOB *out, const DATA_BLOB *in, const DATA_BLOB *session_key, int forward)
{
	int i, k;

	for (i=0,k=0;
	     i<in->length;
	     i += 8, k += 7) {
		uint8 bin[8], bout[8], key[7];

		memset(bin, 0, 8);
		memcpy(bin,  &in->data[i], MIN(8, in->length-i));

		if (k + 7 > session_key->length) {
			k = (session_key->length - k);
		}
		memcpy(key, &session_key->data[k], 7);

		des_crypt56(bout, bin, key, forward?1:0);

		memcpy(&out->data[i], bout, MIN(8, in->length-i));
        }
}

/* Decrypts password-blob with session-key
 * @param pass		password for session-key
 * @param data_in 	DATA_BLOB encrypted password
 *
 * Returns cleartext password in CH_UNIX 
 * Caller must free the returned string
 */

char *decrypt_trustdom_secret(const char *pass, DATA_BLOB *data_in)
{
	DATA_BLOB data_out, sess_key;
	uchar nt_hash[16];
	uint32_t length;
	uint32_t version;
	fstring cleartextpwd;

	if (!data_in || !pass)
		return NULL;

	/* generate md4 password-hash derived from the NT UNICODE password */
	E_md4hash(pass, nt_hash);

	/* hashed twice with md4 */
	mdfour(nt_hash, nt_hash, 16);

	/* 16-Byte session-key */
	sess_key = data_blob(nt_hash, 16);
	if (sess_key.data == NULL)
		return NULL;
	
	data_out = data_blob(NULL, data_in->length);
	if (data_out.data == NULL)
		return NULL;
	
	/* decrypt with des3 */
	sess_crypt_blob(&data_out, data_in, &sess_key, 0);

	/* 4 Byte length, 4 Byte version */
	length  = IVAL(data_out.data, 0);
	version = IVAL(data_out.data, 4);

	if (length > data_in->length - 8) {
		DEBUG(0,("decrypt_trustdom_secret: invalid length (%d)\n", length));
		return NULL;
	}
	
	if (version != 1) {
		DEBUG(0,("decrypt_trustdom_secret: unknown version number (%d)\n", version));
		return NULL;
	}
	
	rpcstr_pull(cleartextpwd, data_out.data + 8, sizeof(fstring), length, 0 );

#ifdef DEBUG_PASSWORD
	DEBUG(100,("decrypt_trustdom_secret: length is: %d, version is: %d, password is: %s\n", 
				length, version, cleartextpwd));
#endif

	data_blob_free(&data_out);
	data_blob_free(&sess_key);
	
	return SMB_STRDUP(cleartextpwd);

}