Function pg_SASL_continue

src/interfaces/libpq/fe-auth.c:631–690

* Exchange a message for SASL communication protocol with the backend. * This should be used after calling pg_SASL_init to set up the status of * the protocol. */

 * the protocol.
 */
static int
pg_SASL_continue(PGconn *conn, int payloadlen, bool final)
{
	char	   *output;
	int			outputlen;
	bool		done;
	bool		success;
	int			res;
	char	   *challenge;

	/* Read the SASL challenge from the AuthenticationSASLContinue message. */
	challenge = malloc(payloadlen + 1);
	if (!challenge)
	{
		appendPQExpBuffer(&conn->errorMessage,
						  libpq_gettext("out of memory allocating SASL buffer (%d)\n"),
						  payloadlen);
		return STATUS_ERROR;
	}

	if (pqGetnchar(challenge, payloadlen, conn))
	{
		free(challenge);
		return STATUS_ERROR;
	}
	/* For safety and convenience, ensure the buffer is NULL-terminated. */
	challenge[payloadlen] = '\0';

	pg_fe_scram_exchange(conn->sasl_state,
						 challenge, payloadlen,
						 &output, &outputlen,
						 &done, &success);
	free(challenge);			/* don't need the input anymore */

	if (final && !done)
	{
		if (outputlen != 0)
			free(output);

		appendPQExpBufferStr(&conn->errorMessage,
							 libpq_gettext("AuthenticationSASLFinal received from server, but SASL authentication was not completed\n"));
		return STATUS_ERROR;
	}
	if (outputlen != 0)
	{
		/*
		 * Send the SASL response to the server.
		 */
		res = pqPacketSend(conn, 'p', output, outputlen);
		free(output);

		if (res != STATUS_OK)
			return STATUS_ERROR;
	}

	if (done && !success)
		return STATUS_ERROR;