static bool
_mongoc_server_session_uuid (uint8_t *data /* OUT */, bson_error_t *error)
{
#ifdef MONGOC_ENABLE_CRYPTO
/* https://tools.ietf.org/html/rfc4122#page-14
* o Set the two most significant bits (bits 6 and 7) of the
* clock_seq_hi_and_reserved to zero and one, respectively.
*
* o Set the four most significant bits (bits 12 through 15) of the
* time_hi_and_version field to the 4-bit version number from
* Section 4.1.3.
*
* o Set all the other bits to randomly (or pseudo-randomly) chosen
* values.
*/
if (!_mongoc_rand_bytes (data, 16)) {
bson_set_error (error,
MONGOC_ERROR_CLIENT,
MONGOC_ERROR_CLIENT_SESSION_FAILURE,
"Could not generate UUID for logical session id");
return false;
}
data[6] = (uint8_t) (0x40 | (data[6] & 0xf));
data[8] = (uint8_t) (0x80 | (data[8] & 0x3f));
return true;
#else
/* no _mongoc_rand_bytes without a crypto library */
bson_set_error (error,
MONGOC_ERROR_CLIENT,
MONGOC_ERROR_CLIENT_SESSION_FAILURE,
"Could not generate UUID for logical session id, we need a"
" cryptography library like libcrypto, Common Crypto, or"
" CNG");
return false;
#endif
}
/* generate client-first-message:
* n,a=authzid,n=encoded-username,r=client-nonce
*
* note that a= is optional, so we aren't dealing with that here
*/
static bool
_mongoc_scram_start (mongoc_scram_t *scram,
uint8_t *outbuf,
uint32_t outbufmax,
uint32_t *outbuflen,
bson_error_t *error)
{
uint8_t nonce[24];
const char *ptr;
bool rval = true;
BSON_ASSERT (scram);
BSON_ASSERT (outbuf);
BSON_ASSERT (outbufmax);
BSON_ASSERT (outbuflen);
if (!scram->user) {
bson_set_error (error,
MONGOC_ERROR_SCRAM,
MONGOC_ERROR_SCRAM_PROTOCOL_ERROR,
"SCRAM Failure: username is not set");
goto FAIL;
}
/* auth message is as big as the outbuf just because */
scram->auth_message = (uint8_t *) bson_malloc (outbufmax);
scram->auth_messagemax = outbufmax;
/* the server uses a 24 byte random nonce. so we do as well */
if (1 != _mongoc_rand_bytes (nonce, sizeof (nonce))) {
bson_set_error (error,
MONGOC_ERROR_SCRAM,
MONGOC_ERROR_SCRAM_PROTOCOL_ERROR,
"SCRAM Failure: could not generate a cryptographically "
"secure nonce in sasl step 1");
goto FAIL;
}
scram->encoded_nonce_len = bson_b64_ntop (nonce,
sizeof (nonce),
scram->encoded_nonce,
sizeof (scram->encoded_nonce));
if (-1 == scram->encoded_nonce_len) {
bson_set_error (error,
MONGOC_ERROR_SCRAM,
MONGOC_ERROR_SCRAM_PROTOCOL_ERROR,
"SCRAM Failure: could not encode nonce");
goto FAIL;
}
if (!_mongoc_scram_buf_write ("n,,n=", -1, outbuf, outbufmax, outbuflen)) {
goto BUFFER;
}
for (ptr = scram->user; *ptr; ptr++) {
/* RFC 5802 specifies that ',' and '=' and encoded as '=2C' and '=3D'
* respectively in the user name */
switch (*ptr) {
case ',':
if (!_mongoc_scram_buf_write (
"=2C", -1, outbuf, outbufmax, outbuflen)) {
goto BUFFER;
}
break;
case '=':
if (!_mongoc_scram_buf_write (
"=3D", -1, outbuf, outbufmax, outbuflen)) {
goto BUFFER;
}
break;
default:
if (!_mongoc_scram_buf_write (ptr, 1, outbuf, outbufmax, outbuflen)) {
goto BUFFER;
}
break;
}
}
if (!_mongoc_scram_buf_write (",r=", -1, outbuf, outbufmax, outbuflen)) {
goto BUFFER;
}
if (!_mongoc_scram_buf_write (scram->encoded_nonce,
scram->encoded_nonce_len,
outbuf,
outbufmax,
outbuflen)) {
goto BUFFER;
}
/* we have to keep track of the conversation to create a client proof later
* on. This copies the message we're crafting from the 'n=' portion onwards
* into a buffer we're managing */
if (!_mongoc_scram_buf_write ((char *) outbuf + 3,
*outbuflen - 3,
scram->auth_message,
scram->auth_messagemax,
&scram->auth_messagelen)) {
goto BUFFER_AUTH;
}
if (!_mongoc_scram_buf_write (",",
-1,
scram->auth_message,
scram->auth_messagemax,
&scram->auth_messagelen)) {
goto BUFFER_AUTH;
}
goto CLEANUP;
BUFFER_AUTH:
bson_set_error (
error,
MONGOC_ERROR_SCRAM,
MONGOC_ERROR_SCRAM_PROTOCOL_ERROR,
"SCRAM Failure: could not buffer auth message in sasl step1");
goto FAIL;
BUFFER:
bson_set_error (error,
MONGOC_ERROR_SCRAM,
MONGOC_ERROR_SCRAM_PROTOCOL_ERROR,
"SCRAM Failure: could not buffer sasl step1");
goto FAIL;
FAIL:
rval = false;
CLEANUP:
return rval;
}
