Diff: saslclientio.c

Revision:

0:6ae2f7bca550

Child:

1:eab586236bfe

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/saslclientio.c	Fri Apr 08 12:01:10 2016 -0700
@@ -0,0 +1,1101 @@
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+#include <stdlib.h>
+#ifdef _CRTDBG_MAP_ALLOC
+#include <crtdbg.h>
+#endif
+#include <stddef.h>
+#include <stdio.h>
+#include <string.h>
+#include "azure_uamqp_c/saslclientio.h"
+#include "azure_c_shared_utility/xio.h"
+#include "azure_c_shared_utility/xlogging.h"
+#include "azure_uamqp_c/amqpalloc.h"
+#include "azure_uamqp_c/frame_codec.h"
+#include "azure_uamqp_c/sasl_frame_codec.h"
+#include "azure_uamqp_c/amqp_definitions.h"
+#include "azure_uamqp_c/amqpvalue_to_string.h"
+
+typedef enum IO_STATE_TAG
+{
+	IO_STATE_NOT_OPEN,
+	IO_STATE_OPENING_UNDERLYING_IO,
+	IO_STATE_SASL_HANDSHAKE,
+	IO_STATE_OPEN,
+	IO_STATE_CLOSING,
+	IO_STATE_ERROR
+} IO_STATE;
+
+typedef enum SASL_HEADER_EXCHANGE_STATE_TAG
+{
+	SASL_HEADER_EXCHANGE_IDLE,
+	SASL_HEADER_EXCHANGE_HEADER_SENT,
+	SASL_HEADER_EXCHANGE_HEADER_RCVD,
+	SASL_HEADER_EXCHANGE_HEADER_EXCH
+} SASL_HEADER_EXCHANGE_STATE;
+
+typedef enum SASL_CLIENT_NEGOTIATION_STATE_TAG
+{
+	SASL_CLIENT_NEGOTIATION_NOT_STARTED,
+	SASL_CLIENT_NEGOTIATION_MECH_RCVD,
+	SASL_CLIENT_NEGOTIATION_INIT_SENT,
+	SASL_CLIENT_NEGOTIATION_CHALLENGE_RCVD,
+	SASL_CLIENT_NEGOTIATION_RESPONSE_SENT,
+	SASL_CLIENT_NEGOTIATION_OUTCOME_RCVD,
+	SASL_CLIENT_NEGOTIATION_ERROR
+} SASL_CLIENT_NEGOTIATION_STATE;
+
+typedef struct SASL_CLIENT_IO_INSTANCE_TAG
+{
+	XIO_HANDLE underlying_io;
+	ON_BYTES_RECEIVED on_bytes_received;
+	ON_IO_OPEN_COMPLETE on_io_open_complete;
+	ON_IO_CLOSE_COMPLETE on_io_close_complete;
+	ON_IO_ERROR on_io_error;
+    void* on_bytes_received_context;
+	void* on_io_open_complete_context;
+	void* on_io_close_complete_context;
+    void* on_io_error_context;
+	LOGGER_LOG logger_log;
+	SASL_HEADER_EXCHANGE_STATE sasl_header_exchange_state;
+	SASL_CLIENT_NEGOTIATION_STATE sasl_client_negotiation_state;
+	size_t header_bytes_received;
+	SASL_FRAME_CODEC_HANDLE sasl_frame_codec;
+	FRAME_CODEC_HANDLE frame_codec;
+	IO_STATE io_state;
+	SASL_MECHANISM_HANDLE sasl_mechanism;
+} SASL_CLIENT_IO_INSTANCE;
+
+/* Codes_SRS_SASLCLIENTIO_01_002: [The protocol header consists of the upper case ASCII letters “AMQP” followed by a protocol id of three, followed by three unsigned bytes representing the major, minor, and revision of the specification version (currently 1 (SASL-MAJOR), 0 (SASLMINOR), 0 (SASL-REVISION)).] */
+/* Codes_SRS_SASLCLIENTIO_01_124: [SASL-MAJOR 1 major protocol version.] */
+/* Codes_SRS_SASLCLIENTIO_01_125: [SASL-MINOR 0 minor protocol version.] */
+/* Codes_SRS_SASLCLIENTIO_01_126: [SASL-REVISION 0 protocol revision.] */
+const unsigned char sasl_header[] = { 'A', 'M', 'Q', 'P', 3, 1, 0, 0 };
+
+static void indicate_error(SASL_CLIENT_IO_INSTANCE* sasl_client_io_instance)
+{
+	if (sasl_client_io_instance->on_io_error != NULL)
+	{
+		sasl_client_io_instance->on_io_error(sasl_client_io_instance->on_io_error_context);
+	}
+}
+
+static void indicate_open_complete(SASL_CLIENT_IO_INSTANCE* sasl_client_io_instance, IO_OPEN_RESULT open_result)
+{
+	if (sasl_client_io_instance->on_io_open_complete != NULL)
+	{
+		sasl_client_io_instance->on_io_open_complete(sasl_client_io_instance->on_io_open_complete_context, open_result);
+	}
+}
+
+static void indicate_close_complete(SASL_CLIENT_IO_INSTANCE* sasl_client_io_instance)
+{
+	if (sasl_client_io_instance->on_io_close_complete != NULL)
+	{
+		sasl_client_io_instance->on_io_close_complete(sasl_client_io_instance->on_io_close_complete_context);
+	}
+}
+
+static void on_underlying_io_close_complete(void* context)
+{
+	SASL_CLIENT_IO_INSTANCE* sasl_client_io_instance = (SASL_CLIENT_IO_INSTANCE*)context;
+
+	switch (sasl_client_io_instance->io_state)
+	{
+	default:
+		break;
+
+	case IO_STATE_OPENING_UNDERLYING_IO:
+	case IO_STATE_SASL_HANDSHAKE:
+		sasl_client_io_instance->io_state = IO_STATE_NOT_OPEN;
+		indicate_open_complete(sasl_client_io_instance, IO_OPEN_ERROR);
+		break;
+
+	case IO_STATE_CLOSING:
+		sasl_client_io_instance->io_state = IO_STATE_NOT_OPEN;
+		indicate_close_complete(sasl_client_io_instance);
+		break;
+	}
+}
+
+static void handle_error(SASL_CLIENT_IO_INSTANCE* sasl_client_io_instance)
+{
+	switch (sasl_client_io_instance->io_state)
+	{
+	default:
+	case IO_STATE_NOT_OPEN:
+		break;
+
+	case IO_STATE_OPENING_UNDERLYING_IO:
+	case IO_STATE_SASL_HANDSHAKE:
+		if (xio_close(sasl_client_io_instance->underlying_io, on_underlying_io_close_complete, sasl_client_io_instance) != 0)
+		{
+			sasl_client_io_instance->io_state = IO_STATE_NOT_OPEN;
+			indicate_open_complete(sasl_client_io_instance, IO_OPEN_ERROR);
+		}
+		break;
+
+	case IO_STATE_OPEN:
+		sasl_client_io_instance->io_state = IO_STATE_ERROR;
+		indicate_error(sasl_client_io_instance);
+		break;
+	}
+}
+
+static int send_sasl_header(SASL_CLIENT_IO_INSTANCE* sasl_client_io_instance)
+{
+	int result;
+
+	/* Codes_SRS_SASLCLIENTIO_01_078: [SASL client IO shall start the header exchange by sending the SASL header.] */
+	/* Codes_SRS_SASLCLIENTIO_01_095: [Sending the header shall be done by using xio_send.] */
+	if (xio_send(sasl_client_io_instance->underlying_io, sasl_header, sizeof(sasl_header), NULL, NULL) != 0)
+	{
+		result = __LINE__;
+	}
+	else
+	{
+		LOG(sasl_client_io_instance->logger_log, LOG_LINE, "-> Header (AMQP 3.1.0.0)");
+
+		result = 0;
+	}
+
+	return result;
+}
+
+static void on_underlying_io_open_complete(void* context, IO_OPEN_RESULT open_result)
+{
+	SASL_CLIENT_IO_INSTANCE* sasl_client_io_instance = (SASL_CLIENT_IO_INSTANCE*)context;
+
+	switch (sasl_client_io_instance->io_state)
+	{
+	default:
+		break;
+
+	case IO_STATE_OPENING_UNDERLYING_IO:
+		if (open_result == IO_OPEN_OK)
+		{
+			sasl_client_io_instance->io_state = IO_STATE_SASL_HANDSHAKE;
+			if (sasl_client_io_instance->sasl_header_exchange_state != SASL_HEADER_EXCHANGE_IDLE)
+			{
+				/* Codes_SRS_SASLCLIENTIO_01_116: [Any underlying IO state changes to state OPEN after the header exchange has been started shall trigger no action.] */
+				handle_error(sasl_client_io_instance);
+			}
+			else
+			{
+				/* Codes_SRS_SASLCLIENTIO_01_105: [start header exchange] */
+				/* Codes_SRS_SASLCLIENTIO_01_001: [To establish a SASL layer, each peer MUST start by sending a protocol header.] */
+				if (send_sasl_header(sasl_client_io_instance) != 0)
+				{
+					/* Codes_SRS_SASLCLIENTIO_01_073: [If the handshake fails (i.e. the outcome is an error) the SASL client IO state shall be switched to IO_STATE_ERROR and the on_state_changed callback shall be triggered.]  */
+					/* Codes_SRS_SASLCLIENTIO_01_077: [If sending the SASL header fails, the SASL client IO state shall be set to IO_STATE_ERROR and the on_state_changed callback shall be triggered.] */
+					handle_error(sasl_client_io_instance);
+				}
+				else
+				{
+					sasl_client_io_instance->sasl_header_exchange_state = SASL_HEADER_EXCHANGE_HEADER_SENT;
+				}
+			}
+		}
+		else
+		{
+			handle_error(sasl_client_io_instance);
+		}
+
+		break;
+	}
+}
+
+static void on_underlying_io_error(void* context)
+{
+	SASL_CLIENT_IO_INSTANCE* sasl_client_io_instance = (SASL_CLIENT_IO_INSTANCE*)context;
+
+	switch (sasl_client_io_instance->io_state)
+	{
+	default:
+		break;
+
+	case IO_STATE_OPENING_UNDERLYING_IO:
+	case IO_STATE_SASL_HANDSHAKE:
+		sasl_client_io_instance->io_state = IO_STATE_NOT_OPEN;
+		indicate_open_complete(sasl_client_io_instance, IO_OPEN_ERROR);
+		break;
+
+	case IO_STATE_OPEN:
+		sasl_client_io_instance->io_state = IO_STATE_ERROR;
+		indicate_error(sasl_client_io_instance);
+		break;
+	}
+}
+
+static const char* get_frame_type_as_string(AMQP_VALUE descriptor)
+{
+	const char* result;
+
+	if (is_sasl_mechanisms_type_by_descriptor(descriptor))
+	{
+		result = "[SASL MECHANISMS]";
+	}
+	else if (is_sasl_init_type_by_descriptor(descriptor))
+	{
+		result = "[SASL INIT]";
+	}
+	else if (is_sasl_challenge_type_by_descriptor(descriptor))
+	{
+		result = "[SASL CHALLENGE]";
+	}
+	else if (is_sasl_response_type_by_descriptor(descriptor))
+	{
+		result = "[SASL RESPONSE]";
+	}
+	else if (is_sasl_outcome_type_by_descriptor(descriptor))
+	{
+		result = "[SASL OUTCOME]";
+	}
+	else
+	{
+		result = "[Unknown]";
+	}
+
+	return result;
+}
+
+static void log_incoming_frame(SASL_CLIENT_IO_INSTANCE* sasl_client_io_instance, AMQP_VALUE performative)
+{
+	if (sasl_client_io_instance->logger_log != NULL)
+	{
+		AMQP_VALUE descriptor = amqpvalue_get_inplace_descriptor(performative);
+		if (descriptor != NULL)
+		{
+			LOG(sasl_client_io_instance->logger_log, 0, "<- ");
+			LOG(sasl_client_io_instance->logger_log, 0, (char*)get_frame_type_as_string(descriptor));
+			char* performative_as_string = NULL;
+			LOG(sasl_client_io_instance->logger_log, LOG_LINE, (performative_as_string = amqpvalue_to_string(performative)));
+			if (performative_as_string != NULL)
+			{
+				amqpalloc_free(performative_as_string);
+			}
+		}
+	}
+}
+
+static void log_outgoing_frame(SASL_CLIENT_IO_INSTANCE* sasl_client_io_instance, AMQP_VALUE performative)
+{
+	if (sasl_client_io_instance->logger_log != NULL)
+	{
+		AMQP_VALUE descriptor = amqpvalue_get_inplace_descriptor(performative);
+		if (descriptor != NULL)
+		{
+			LOG(sasl_client_io_instance->logger_log, 0, "-> ");
+			LOG(sasl_client_io_instance->logger_log, 0, (char*)get_frame_type_as_string(descriptor));
+			char* performative_as_string = NULL;
+			LOG(sasl_client_io_instance->logger_log, LOG_LINE, (performative_as_string = amqpvalue_to_string(performative)));
+			if (performative_as_string != NULL)
+			{
+				amqpalloc_free(performative_as_string);
+			}
+		}
+	}
+}
+
+static int saslclientio_receive_byte(SASL_CLIENT_IO_INSTANCE* sasl_client_io_instance, unsigned char b)
+{
+	int result;
+
+	switch (sasl_client_io_instance->sasl_header_exchange_state)
+	{
+	default:
+		result = __LINE__;
+		break;
+
+	case SASL_HEADER_EXCHANGE_HEADER_EXCH:
+		switch (sasl_client_io_instance->sasl_client_negotiation_state)
+		{
+		case SASL_CLIENT_NEGOTIATION_ERROR:
+			result = __LINE__;
+			break;
+
+		default:
+			/* Codes_SRS_SASLCLIENTIO_01_068: [During the SASL frame exchange that constitutes the handshake the received bytes from the underlying IO shall be fed to the frame_codec instance created in saslclientio_create by calling frame_codec_receive_bytes.] */
+			if (frame_codec_receive_bytes(sasl_client_io_instance->frame_codec, &b, 1) != 0)
+			{
+				/* Codes_SRS_SASLCLIENTIO_01_088: [If frame_codec_receive_bytes fails, the state of SASL client IO shall be switched to IO_STATE_ERROR and the on_state_changed callback shall be triggered.] */
+				result = __LINE__;
+			}
+			else
+			{
+				result = 0;
+			}
+
+			break;
+
+		case SASL_CLIENT_NEGOTIATION_OUTCOME_RCVD:
+			sasl_client_io_instance->on_bytes_received(sasl_client_io_instance->on_bytes_received_context, &b, 1);
+			result = 0;
+			break;
+		}
+
+		break;
+
+	/* Codes_SRS_SASLCLIENTIO_01_003: [Other than using a protocol id of three, the exchange of SASL layer headers follows the same rules specified in the version negotiation section of the transport specification (See Part 2: section 2.2).] */
+	case SASL_HEADER_EXCHANGE_IDLE:
+	case SASL_HEADER_EXCHANGE_HEADER_SENT:
+		if (b != sasl_header[sasl_client_io_instance->header_bytes_received])
+		{
+			result = __LINE__;
+		}
+		else
+		{
+			sasl_client_io_instance->header_bytes_received++;
+			if (sasl_client_io_instance->header_bytes_received == sizeof(sasl_header))
+			{
+				LOG(sasl_client_io_instance->logger_log, LOG_LINE, "<- Header (AMQP 3.1.0.0)");
+
+				switch (sasl_client_io_instance->sasl_header_exchange_state)
+				{
+				default:
+					result = __LINE__;
+					break;
+				
+				case SASL_HEADER_EXCHANGE_HEADER_SENT:
+					/* from this point on we need to decode SASL frames */
+					sasl_client_io_instance->sasl_header_exchange_state = SASL_HEADER_EXCHANGE_HEADER_EXCH;
+					result = 0;
+					break;
+
+				case SASL_HEADER_EXCHANGE_IDLE:
+					sasl_client_io_instance->sasl_header_exchange_state = SASL_HEADER_EXCHANGE_HEADER_RCVD;
+					if (send_sasl_header(sasl_client_io_instance) != 0)
+					{
+						/* Codes_SRS_SASLCLIENTIO_01_077: [If sending the SASL header fails, the SASL client IO state shall be set to IO_STATE_ERROR and the on_state_changed callback shall be triggered.] */
+						result = __LINE__;
+					}
+					else
+					{
+						result = 0;
+					}
+
+					break;
+				}
+			}
+			else
+			{
+				result = 0;
+			}
+		}
+
+		break;
+	}
+
+	return result;
+}
+
+static void on_underlying_io_bytes_received(void* context, const unsigned char* buffer, size_t size)
+{
+	SASL_CLIENT_IO_INSTANCE* sasl_client_io_instance = (SASL_CLIENT_IO_INSTANCE*)context;
+
+	/* Codes_SRS_SASLCLIENTIO_01_028: [If buffer is NULL or size is zero, nothing should be indicated as received and the saslio state shall be switched to ERROR the on_state_changed callback shall be triggered.] */
+	if ((buffer == NULL) ||
+		(size == 0))
+	{
+		handle_error(sasl_client_io_instance);
+	}
+	else
+	{
+		switch (sasl_client_io_instance->io_state)
+		{
+		default:
+			break;
+
+		case IO_STATE_OPEN:
+			/* Codes_SRS_SASLCLIENTIO_01_027: [When the on_bytes_received callback passed to the underlying IO is called and the SASL client IO state is IO_STATE_OPEN, the bytes shall be indicated to the user of SASL client IO by calling the on_bytes_received that was passed in saslclientio_open.] */
+			/* Codes_SRS_SASLCLIENTIO_01_029: [The context argument shall be set to the callback_context passed in saslclientio_open.] */
+			sasl_client_io_instance->on_bytes_received(sasl_client_io_instance->on_bytes_received_context, buffer, size);
+			break;
+
+		case IO_STATE_SASL_HANDSHAKE:
+		{
+			size_t i;
+
+			for (i = 0; i < size; i++)
+			{
+				if (saslclientio_receive_byte(sasl_client_io_instance, buffer[i]) != 0)
+				{
+					break;
+				}
+			}
+
+			if (i < size)
+			{
+				/* Codes_SRS_SASLCLIENTIO_01_073: [If the handshake fails (i.e. the outcome is an error) the SASL client IO state shall be switched to IO_STATE_ERROR and the on_state_changed callback shall be triggered.]  */
+				handle_error(sasl_client_io_instance);
+			}
+
+			break;
+		}
+
+		case IO_STATE_ERROR:
+			/* Codes_SRS_SASLCLIENTIO_01_031: [If bytes are received when the SASL client IO state is IO_STATE_ERROR, SASL client IO shall do nothing.]  */
+			break;
+		}
+	}
+}
+
+static void on_bytes_encoded(void* context, const unsigned char* bytes, size_t length, bool encode_complete)
+{
+	(void)encode_complete;
+
+	SASL_CLIENT_IO_INSTANCE* sasl_client_io_instance = (SASL_CLIENT_IO_INSTANCE*)context;
+
+	/* Codes_SRS_SASLCLIENTIO_01_120: [When SASL client IO is notified by sasl_frame_codec of bytes that have been encoded via the on_bytes_encoded callback and SASL client IO is in the state OPENING, SASL client IO shall send these bytes by using xio_send.] */
+	if (xio_send(sasl_client_io_instance->underlying_io, bytes, length, NULL, NULL) != 0)
+	{
+		/* Codes_SRS_SASLCLIENTIO_01_121: [If xio_send fails, the SASL client IO state shall be switched to IO_STATE_ERROR and the on_state_changed callback shall be triggered.] */
+		handle_error(sasl_client_io_instance);
+	}
+}
+
+static int send_sasl_init(SASL_CLIENT_IO_INSTANCE* sasl_client_io, const char* sasl_mechanism_name)
+{
+	int result;
+
+	SASL_INIT_HANDLE sasl_init;
+	SASL_MECHANISM_BYTES init_bytes;
+
+	/* Codes_SRS_SASLCLIENTIO_01_045: [The name of the SASL mechanism used for the SASL exchange.] */
+	sasl_init = sasl_init_create(sasl_mechanism_name);
+	if (sasl_init == NULL)
+	{
+		/* Codes_SRS_SASLCLIENTIO_01_119: [If any error is encountered when parsing the received frame, the SASL client IO state shall be switched to IO_STATE_ERROR and the on_state_changed callback shall be triggered.] */
+		result = __LINE__;
+	}
+	else
+	{
+		/* Codes_SRS_SASLCLIENTIO_01_048: [The contents of this data are defined by the SASL security mechanism.] */
+		if (saslmechanism_get_init_bytes(sasl_client_io->sasl_mechanism, &init_bytes) != 0)
+		{
+			/* Codes_SRS_SASLCLIENTIO_01_119: [If any error is encountered when parsing the received frame, the SASL client IO state shall be switched to IO_STATE_ERROR and the on_state_changed callback shall be triggered.] */
+			result = __LINE__;
+		}
+		else
+		{
+			amqp_binary creds = { init_bytes.bytes, init_bytes.length };
+			if ((init_bytes.length > 0) &&
+				/* Codes_SRS_SASLCLIENTIO_01_047: [A block of opaque data passed to the security mechanism.] */
+				(sasl_init_set_initial_response(sasl_init, creds) != 0))
+			{
+				/* Codes_SRS_SASLCLIENTIO_01_119: [If any error is encountered when parsing the received frame, the SASL client IO state shall be switched to IO_STATE_ERROR and the on_state_changed callback shall be triggered.] */
+				result = __LINE__;
+			}
+			else
+			{
+				AMQP_VALUE sasl_init_value = amqpvalue_create_sasl_init(sasl_init);
+				if (sasl_init_value == NULL)
+				{
+					/* Codes_SRS_SASLCLIENTIO_01_119: [If any error is encountered when parsing the received frame, the SASL client IO state shall be switched to IO_STATE_ERROR and the on_state_changed callback shall be triggered.] */
+					result = __LINE__;
+				}
+				else
+				{
+					/* Codes_SRS_SASLCLIENTIO_01_070: [When a frame needs to be sent as part of the SASL handshake frame exchange, the send shall be done by calling sasl_frame_codec_encode_frame.] */
+					if (sasl_frame_codec_encode_frame(sasl_client_io->sasl_frame_codec, sasl_init_value, on_bytes_encoded, sasl_client_io) != 0)
+					{
+						/* Codes_SRS_SASLCLIENTIO_01_071: [If sasl_frame_codec_encode_frame fails, then the state of SASL client IO shall be switched to IO_STATE_ERROR and the on_state_changed callback shall be triggered.] */
+						result = __LINE__;
+					}
+					else
+					{
+						log_outgoing_frame(sasl_client_io, sasl_init_value);
+
+						result = 0;
+					}
+
+					amqpvalue_destroy(sasl_init_value);
+				}
+			}
+		}
+
+		sasl_init_destroy(sasl_init);
+	}
+
+	return result;
+}
+
+static int send_sasl_response(SASL_CLIENT_IO_INSTANCE* sasl_client_io, SASL_MECHANISM_BYTES sasl_response)
+{
+	int result;
+
+	SASL_RESPONSE_HANDLE sasl_response_handle;
+	amqp_binary response_binary_value = { sasl_response.bytes, sasl_response.length };
+
+	/* Codes_SRS_SASLCLIENTIO_01_055: [Send the SASL response data as defined by the SASL specification.] */
+	/* Codes_SRS_SASLCLIENTIO_01_056: [A block of opaque data passed to the security mechanism.] */
+	if ((sasl_response_handle = sasl_response_create(response_binary_value)) == NULL)
+	{
+		result = __LINE__;
+	}
+	else
+	{
+		AMQP_VALUE sasl_response_value = amqpvalue_create_sasl_response(sasl_response_handle);
+		if (sasl_response_value == NULL)
+		{
+			result = __LINE__;
+		}
+		else
+		{
+			/* Codes_SRS_SASLCLIENTIO_01_070: [When a frame needs to be sent as part of the SASL handshake frame exchange, the send shall be done by calling sasl_frame_codec_encode_frame.] */
+			if (sasl_frame_codec_encode_frame(sasl_client_io->sasl_frame_codec, sasl_response_value, on_bytes_encoded, sasl_client_io) != 0)
+			{
+				result = __LINE__;
+			}
+			else
+			{
+				log_outgoing_frame(sasl_client_io, sasl_response_value);
+
+				result = 0;
+			}
+
+			amqpvalue_destroy(sasl_response_value);
+		}
+
+		sasl_response_destroy(sasl_response_handle);
+	}
+
+	return result;
+}
+
+static void sasl_frame_received_callback(void* context, AMQP_VALUE sasl_frame)
+{
+	SASL_CLIENT_IO_INSTANCE* sasl_client_io_instance = (SASL_CLIENT_IO_INSTANCE*)context;
+
+	/* Codes_SRS_SASLCLIENTIO_01_067: [The SASL frame exchange shall be started as soon as the SASL header handshake is done.] */
+	switch (sasl_client_io_instance->io_state)
+	{
+	default:
+		break;
+
+	case IO_STATE_OPEN:
+	case IO_STATE_OPENING_UNDERLYING_IO:
+	case IO_STATE_CLOSING:
+		/* Codes_SRS_SASLCLIENTIO_01_117: [If on_sasl_frame_received_callback is called when the state of the IO is OPEN then the SASL client IO state shall be switched to IO_STATE_ERROR and the on_state_changed callback shall be triggered.] */
+		handle_error(sasl_client_io_instance);
+		break;
+
+	case IO_STATE_SASL_HANDSHAKE:
+		if (sasl_client_io_instance->sasl_header_exchange_state != SASL_HEADER_EXCHANGE_HEADER_EXCH)
+		{
+			/* Codes_SRS_SASLCLIENTIO_01_118: [If on_sasl_frame_received_callback is called in the OPENING state but the header exchange has not yet been completed, then the SASL client IO state shall be switched to IO_STATE_ERROR and the on_state_changed callback shall be triggered.] */
+			handle_error(sasl_client_io_instance);
+		}
+		else
+		{
+			AMQP_VALUE descriptor = amqpvalue_get_inplace_descriptor(sasl_frame);
+			if (descriptor == NULL)
+			{
+				/* Codes_SRS_SASLCLIENTIO_01_119: [If any error is encountered when parsing the received frame, the SASL client IO state shall be switched to IO_STATE_ERROR and the on_state_changed callback shall be triggered.] */
+				handle_error(sasl_client_io_instance);
+			}
+			else
+			{
+				log_incoming_frame(sasl_client_io_instance, sasl_frame);
+
+				/* Codes_SRS_SASLCLIENTIO_01_032: [The peer acting as the SASL server MUST announce supported authentication mechanisms using the sasl-mechanisms frame.] */
+				/* Codes_SRS_SASLCLIENTIO_01_040: [The peer playing the role of the SASL client and the peer playing the role of the SASL server MUST correspond to the TCP client and server respectively.] */
+				/* Codes_SRS_SASLCLIENTIO_01_034: [<-- SASL-MECHANISMS] */
+				if (is_sasl_mechanisms_type_by_descriptor(descriptor))
+				{
+					switch (sasl_client_io_instance->sasl_client_negotiation_state)
+					{
+					case SASL_CLIENT_NEGOTIATION_NOT_STARTED:
+					{
+						SASL_MECHANISMS_HANDLE sasl_mechanisms_handle;
+
+						if (amqpvalue_get_sasl_mechanisms(sasl_frame, &sasl_mechanisms_handle) != 0)
+						{
+							/* Codes_SRS_SASLCLIENTIO_01_119: [If any error is encountered when parsing the received frame, the SASL client IO state shall be switched to IO_STATE_ERROR and the on_state_changed callback shall be triggered.] */
+							handle_error(sasl_client_io_instance);
+						}
+						else
+						{
+							AMQP_VALUE sasl_server_mechanisms;
+							uint32_t mechanisms_count;
+
+							if ((sasl_mechanisms_get_sasl_server_mechanisms(sasl_mechanisms_handle, &sasl_server_mechanisms) != 0) ||
+								(amqpvalue_get_array_item_count(sasl_server_mechanisms, &mechanisms_count) != 0) ||
+								(mechanisms_count == 0))
+							{
+								/* Codes_SRS_SASLCLIENTIO_01_042: [It is invalid for this list to be null or empty.] */
+								handle_error(sasl_client_io_instance);
+							}
+							else
+							{
+								const char* sasl_mechanism_name = saslmechanism_get_mechanism_name(sasl_client_io_instance->sasl_mechanism);
+								if (sasl_mechanism_name == NULL)
+								{
+									/* Codes_SRS_SASLCLIENTIO_01_119: [If any error is encountered when parsing the received frame, the SASL client IO state shall be switched to IO_STATE_ERROR and the on_state_changed callback shall be triggered.] */
+									handle_error(sasl_client_io_instance);
+								}
+								else
+								{
+									uint32_t i;
+
+									for (i = 0; i < mechanisms_count; i++)
+									{
+										AMQP_VALUE sasl_server_mechanism;
+										sasl_server_mechanism = amqpvalue_get_array_item(sasl_server_mechanisms, i);
+										if (sasl_server_mechanism == NULL)
+										{
+											i = mechanisms_count;
+										}
+										else
+										{
+											const char* sasl_server_mechanism_name;
+											if (amqpvalue_get_symbol(sasl_server_mechanism, &sasl_server_mechanism_name) != 0)
+											{
+												i = mechanisms_count;
+											}
+											else
+											{
+												if (strcmp(sasl_mechanism_name, sasl_server_mechanism_name) == 0)
+												{
+                                                    amqpvalue_destroy(sasl_server_mechanism);
+                                                    break;
+												}
+											}
+
+                                            amqpvalue_destroy(sasl_server_mechanism);
+                                        }
+									}
+
+									if (i == mechanisms_count)
+									{
+										/* Codes_SRS_SASLCLIENTIO_01_119: [If any error is encountered when parsing the received frame, the SASL client IO state shall be switched to IO_STATE_ERROR and the on_state_changed callback shall be triggered.] */
+										handle_error(sasl_client_io_instance);
+									}
+									else
+									{
+										sasl_client_io_instance->sasl_client_negotiation_state = SASL_CLIENT_NEGOTIATION_MECH_RCVD;
+
+										/* Codes_SRS_SASLCLIENTIO_01_035: [SASL-INIT -->] */
+										/* Codes_SRS_SASLCLIENTIO_01_033: [The partner MUST then choose one of the supported mechanisms and initiate a sasl exchange.] */
+										/* Codes_SRS_SASLCLIENTIO_01_054: [Selects the sasl mechanism and provides the initial response if needed.] */
+										if (send_sasl_init(sasl_client_io_instance, sasl_mechanism_name) != 0)
+										{
+											/* Codes_SRS_SASLCLIENTIO_01_119: [If any error is encountered when parsing the received frame, the SASL client IO state shall be switched to IO_STATE_ERROR and the on_state_changed callback shall be triggered.] */
+											handle_error(sasl_client_io_instance);
+										}
+										else
+										{
+											sasl_client_io_instance->sasl_client_negotiation_state = SASL_CLIENT_NEGOTIATION_INIT_SENT;
+										}
+									}
+								}
+							}
+
+							sasl_mechanisms_destroy(sasl_mechanisms_handle);
+						}
+
+						break;
+					}
+					}
+				}
+				/* Codes_SRS_SASLCLIENTIO_01_052: [Send the SASL challenge data as defined by the SASL specification.] */
+				/* Codes_SRS_SASLCLIENTIO_01_036: [<-- SASL-CHALLENGE *] */
+				/* Codes_SRS_SASLCLIENTIO_01_039: [the SASL challenge/response step can occur zero or more times depending on the details of the SASL mechanism chosen.] */
+				else if (is_sasl_challenge_type_by_descriptor(descriptor))
+				{
+					/* Codes_SRS_SASLCLIENTIO_01_032: [The peer acting as the SASL server MUST announce supported authentication mechanisms using the sasl-mechanisms frame.] */
+					if ((sasl_client_io_instance->sasl_client_negotiation_state != SASL_CLIENT_NEGOTIATION_INIT_SENT) &&
+						(sasl_client_io_instance->sasl_client_negotiation_state != SASL_CLIENT_NEGOTIATION_RESPONSE_SENT))
+					{
+						handle_error(sasl_client_io_instance);
+					}
+					else
+					{
+						SASL_CHALLENGE_HANDLE sasl_challenge_handle;
+
+						if (amqpvalue_get_sasl_challenge(sasl_frame, &sasl_challenge_handle) != 0)
+						{
+							/* Codes_SRS_SASLCLIENTIO_01_119: [If any error is encountered when parsing the received frame, the SASL client IO state shall be switched to IO_STATE_ERROR and the on_state_changed callback shall be triggered.] */
+							handle_error(sasl_client_io_instance);
+						}
+						else
+						{
+							amqp_binary challenge_binary_value;
+							SASL_MECHANISM_BYTES response_bytes;
+
+							/* Codes_SRS_SASLCLIENTIO_01_053: [Challenge information, a block of opaque binary data passed to the security mechanism.] */
+							if (sasl_challenge_get_challenge(sasl_challenge_handle, &challenge_binary_value) != 0)
+							{
+								/* Codes_SRS_SASLCLIENTIO_01_119: [If any error is encountered when parsing the received frame, the SASL client IO state shall be switched to IO_STATE_ERROR and the on_state_changed callback shall be triggered.] */
+								handle_error(sasl_client_io_instance);
+							}
+							else
+							{
+								SASL_MECHANISM_BYTES challenge = { challenge_binary_value.bytes, challenge_binary_value.length };
+
+								/* Codes_SRS_SASLCLIENTIO_01_057: [The contents of this data are defined by the SASL security mechanism.] */
+								/* Codes_SRS_SASLCLIENTIO_01_037: [SASL-RESPONSE -->] */
+								if ((saslmechanism_challenge(sasl_client_io_instance->sasl_mechanism, &challenge, &response_bytes) != 0) ||
+									(send_sasl_response(sasl_client_io_instance, response_bytes) != 0))
+								{
+									/* Codes_SRS_SASLCLIENTIO_01_119: [If any error is encountered when parsing the received frame, the SASL client IO state shall be switched to IO_STATE_ERROR and the on_state_changed callback shall be triggered.] */
+									handle_error(sasl_client_io_instance);
+								}
+							}
+
+							sasl_challenge_destroy(sasl_challenge_handle);
+						}
+					}
+				}
+				/* Codes_SRS_SASLCLIENTIO_01_058: [This frame indicates the outcome of the SASL dialog.] */
+				/* Codes_SRS_SASLCLIENTIO_01_038: [<-- SASL-OUTCOME] */
+				else if (is_sasl_outcome_type_by_descriptor(descriptor))
+				{
+					/* Codes_SRS_SASLCLIENTIO_01_032: [The peer acting as the SASL server MUST announce supported authentication mechanisms using the sasl-mechanisms frame.] */
+					if ((sasl_client_io_instance->sasl_client_negotiation_state != SASL_CLIENT_NEGOTIATION_INIT_SENT) &&
+						(sasl_client_io_instance->sasl_client_negotiation_state != SASL_CLIENT_NEGOTIATION_RESPONSE_SENT))
+					{
+						handle_error(sasl_client_io_instance);
+					}
+					else
+					{
+						SASL_OUTCOME_HANDLE sasl_outcome;
+
+						sasl_client_io_instance->sasl_client_negotiation_state = SASL_CLIENT_NEGOTIATION_OUTCOME_RCVD;
+
+						if (amqpvalue_get_sasl_outcome(sasl_frame, &sasl_outcome) != 0)
+						{
+							handle_error(sasl_client_io_instance);
+						}
+						else
+						{
+							sasl_code sasl_code;
+
+							/* Codes_SRS_SASLCLIENTIO_01_060: [A reply-code indicating the outcome of the SASL dialog.] */
+							if (sasl_outcome_get_code(sasl_outcome, &sasl_code) != 0)
+							{
+								handle_error(sasl_client_io_instance);
+							}
+							else
+							{
+								switch (sasl_code)
+								{
+								default:
+								case sasl_code_auth:
+									/* Codes_SRS_SASLCLIENTIO_01_063: [1 Connection authentication failed due to an unspecified problem with the supplied credentials.] */
+								case sasl_code_sys:
+									/* Codes_SRS_SASLCLIENTIO_01_064: [2 Connection authentication failed due to a system error.] */
+								case sasl_code_sys_perm:
+									/* Codes_SRS_SASLCLIENTIO_01_065: [3 Connection authentication failed due to a system error that is unlikely to be corrected without intervention.] */
+								case sasl_code_sys_temp:
+									/* Codes_SRS_SASLCLIENTIO_01_066: [4 Connection authentication failed due to a transient system error.] */
+									handle_error(sasl_client_io_instance);
+									break;
+
+								case sasl_code_ok:
+									/* Codes_SRS_SASLCLIENTIO_01_059: [Upon successful completion of the SASL dialog the security layer has been established] */
+									/* Codes_SRS_SASLCLIENTIO_01_062: [0 Connection authentication succeeded.]  */
+									sasl_client_io_instance->io_state = IO_STATE_OPEN;
+									indicate_open_complete(sasl_client_io_instance, IO_OPEN_OK);
+									break;
+								}
+							}
+
+							sasl_outcome_destroy(sasl_outcome);
+						}
+					}
+				}
+				else
+				{
+					LOG(sasl_client_io_instance->logger_log, LOG_LINE, "Bad SASL frame");
+				}
+			}
+		}
+		break;
+	}
+}
+
+static void on_frame_codec_error(void* context)
+{
+	SASL_CLIENT_IO_INSTANCE* sasl_client_io_instance = (SASL_CLIENT_IO_INSTANCE*)context;
+
+	/* Codes_SRS_SASLCLIENTIO_01_122: [When on_frame_codec_error is called while in the OPENING or OPEN state the SASL client IO state shall be switched to IO_STATE_ERROR and the on_state_changed callback shall be triggered.] */
+	/* Codes_SRS_SASLCLIENTIO_01_123: [When on_frame_codec_error is called in the ERROR state nothing shall be done.] */
+	handle_error(sasl_client_io_instance);
+}
+
+static void on_sasl_frame_codec_error(void* context)
+{
+	SASL_CLIENT_IO_INSTANCE* sasl_client_io_instance = (SASL_CLIENT_IO_INSTANCE*)context;
+
+	/* Codes_SRS_SASLCLIENTIO_01_124: [**When on_sasl_frame_codec_error is called while in the OPENING or OPEN state the SASL client IO state shall be switched to IO_STATE_ERROR and the on_state_changed callback shall be triggered.] */
+	/* Codes_SRS_SASLCLIENTIO_01_125: [When on_sasl_frame_codec_error is called in the ERROR state nothing shall be done.] */
+	handle_error(sasl_client_io_instance);
+}
+
+CONCRETE_IO_HANDLE saslclientio_create(void* io_create_parameters, LOGGER_LOG logger_log)
+{
+	SASLCLIENTIO_CONFIG* sasl_client_io_config = io_create_parameters;
+	SASL_CLIENT_IO_INSTANCE* result;
+
+	/* Codes_SRS_SASLCLIENTIO_01_005: [If xio_create_parameters is NULL, saslclientio_create shall fail and return NULL.] */
+	if ((sasl_client_io_config == NULL) ||
+		/* Codes_SRS_SASLCLIENTIO_01_092: [If any of the sasl_mechanism or underlying_io members of the configuration structure are NULL, saslclientio_create shall fail and return NULL.] */
+		(sasl_client_io_config->underlying_io == NULL) ||
+		(sasl_client_io_config->sasl_mechanism == NULL))
+	{
+		result = NULL;
+	}
+	else
+	{
+		result = amqpalloc_malloc(sizeof(SASL_CLIENT_IO_INSTANCE));
+		/* Codes_SRS_SASLCLIENTIO_01_006: [If memory cannot be allocated for the new instance, saslclientio_create shall fail and return NULL.] */
+		if (result != NULL)
+		{
+			result->underlying_io = sasl_client_io_config->underlying_io;
+			if (result->underlying_io == NULL)
+			{
+				amqpalloc_free(result);
+				result = NULL;
+			}
+			else
+			{
+				/* Codes_SRS_SASLCLIENTIO_01_089: [saslclientio_create shall create a frame_codec to be used for encoding/decoding frames bycalling frame_codec_create and passing the underlying_io as argument.] */
+				result->frame_codec = frame_codec_create(on_frame_codec_error, result, logger_log);
+				if (result->frame_codec == NULL)
+				{
+					/* Codes_SRS_SASLCLIENTIO_01_090: [If frame_codec_create fails, then saslclientio_create shall fail and return NULL.] */
+					amqpalloc_free(result);
+					result = NULL;
+				}
+				else
+				{
+					/* Codes_SRS_SASLCLIENTIO_01_084: [saslclientio_create shall create a sasl_frame_codec to be used for SASL frame encoding/decoding by calling sasl_frame_codec_create and passing the just created frame_codec as argument.] */
+					result->sasl_frame_codec = sasl_frame_codec_create(result->frame_codec, sasl_frame_received_callback, on_sasl_frame_codec_error, result);
+					if (result->sasl_frame_codec == NULL)
+					{
+						frame_codec_destroy(result->frame_codec);
+						amqpalloc_free(result);
+						result = NULL;
+					}
+					else
+					{
+						/* Codes_SRS_SASLCLIENTIO_01_004: [saslclientio_create shall return on success a non-NULL handle to a new SASL client IO instance.] */
+						result->on_bytes_received = NULL;
+						result->on_io_open_complete = NULL;
+						result->on_io_error = NULL;
+						result->on_io_close_complete = NULL;
+						result->logger_log = logger_log;
+                        result->on_bytes_received_context = NULL;
+						result->on_io_open_complete_context = NULL;
+						result->on_io_close_complete_context = NULL;
+                        result->on_io_error_context = NULL;
+						result->sasl_mechanism = sasl_client_io_config->sasl_mechanism;
+
+						result->io_state = IO_STATE_NOT_OPEN;
+					}
+				}
+			}
+		}
+	}
+
+	return result;
+}
+
+void saslclientio_destroy(CONCRETE_IO_HANDLE sasl_client_io)
+{
+	if (sasl_client_io != NULL)
+	{
+		SASL_CLIENT_IO_INSTANCE* sasl_client_io_instance = (SASL_CLIENT_IO_INSTANCE*)sasl_client_io;
+
+		/* Codes_SRS_SASLCLIENTIO_01_007: [saslclientio_destroy shall free all resources associated with the SASL client IO handle.] */
+		/* Codes_SRS_SASLCLIENTIO_01_086: [saslclientio_destroy shall destroy the sasl_frame_codec created in saslclientio_create by calling sasl_frame_codec_destroy.] */
+		sasl_frame_codec_destroy(sasl_client_io_instance->sasl_frame_codec);
+
+		/* Codes_SRS_SASLCLIENTIO_01_091: [saslclientio_destroy shall destroy the frame_codec created in saslclientio_create by calling frame_codec_destroy.] */
+		frame_codec_destroy(sasl_client_io_instance->frame_codec);
+		amqpalloc_free(sasl_client_io);
+	}
+}
+
+int saslclientio_open(CONCRETE_IO_HANDLE sasl_client_io, ON_IO_OPEN_COMPLETE on_io_open_complete, void* on_io_open_complete_context, ON_BYTES_RECEIVED on_bytes_received, void* on_bytes_received_context, ON_IO_ERROR on_io_error, void* on_io_error_context)
+{
+	int result = 0;
+
+	/* Codes_SRS_SASLCLIENTIO_01_011: [If any of the sasl_client_io or on_bytes_received arguments is NULL, saslclientio_open shall fail and return a non-zero value.] */
+	if ((sasl_client_io == NULL) ||
+		(on_bytes_received == NULL))
+	{
+		result = __LINE__;
+	}
+	else
+	{
+		SASL_CLIENT_IO_INSTANCE* sasl_client_io_instance = (SASL_CLIENT_IO_INSTANCE*)sasl_client_io;
+
+		if (sasl_client_io_instance->io_state != IO_STATE_NOT_OPEN)
+		{
+			result = __LINE__;
+		}
+		else
+		{
+			sasl_client_io_instance->on_bytes_received = on_bytes_received;
+			sasl_client_io_instance->on_io_open_complete = on_io_open_complete;
+			sasl_client_io_instance->on_io_error = on_io_error;
+			sasl_client_io_instance->on_bytes_received_context = on_bytes_received_context;
+            sasl_client_io_instance->on_io_open_complete_context = on_io_open_complete_context;
+            sasl_client_io_instance->on_io_error_context = on_io_error_context;
+			sasl_client_io_instance->sasl_header_exchange_state = SASL_HEADER_EXCHANGE_IDLE;
+			sasl_client_io_instance->sasl_client_negotiation_state = SASL_CLIENT_NEGOTIATION_NOT_STARTED;
+			sasl_client_io_instance->header_bytes_received = 0;
+			sasl_client_io_instance->io_state = IO_STATE_OPENING_UNDERLYING_IO;
+
+			/* Codes_SRS_SASLCLIENTIO_01_009: [saslclientio_open shall call xio_open on the underlying_io passed to saslclientio_create.] */
+			/* Codes_SRS_SASLCLIENTIO_01_013: [saslclientio_open shall pass to xio_open a callback for receiving bytes and a state changed callback for the underlying_io state changes.] */
+			if (xio_open(sasl_client_io_instance->underlying_io, on_underlying_io_open_complete, sasl_client_io_instance, on_underlying_io_bytes_received, sasl_client_io_instance, on_underlying_io_error, sasl_client_io_instance) != 0)
+			{
+				/* Codes_SRS_SASLCLIENTIO_01_012: [If the open of the underlying_io fails, saslclientio_open shall fail and return non-zero value.] */
+				result = __LINE__;
+			}
+			else
+			{
+				/* Codes_SRS_SASLCLIENTIO_01_010: [On success, saslclientio_open shall return 0.] */
+				result = 0;
+			}
+		}
+	}
+	
+	return result;
+}
+
+int saslclientio_close(CONCRETE_IO_HANDLE sasl_client_io, ON_IO_CLOSE_COMPLETE on_io_close_complete, void* on_io_close_complete_context)
+{
+	int result = 0;
+
+	/* Codes_SRS_SASLCLIENTIO_01_017: [If sasl_client_io is NULL, saslclientio_close shall fail and return a non-zero value.] */
+	if (sasl_client_io == NULL)
+	{
+		result = __LINE__;
+	}
+	else
+	{
+		SASL_CLIENT_IO_INSTANCE* sasl_client_io_instance = (SASL_CLIENT_IO_INSTANCE*)sasl_client_io;
+
+		/* Codes_SRS_SASLCLIENTIO_01_098: [saslclientio_close shall only perform the close if the state is OPEN, OPENING or ERROR.] */
+		if ((sasl_client_io_instance->io_state == IO_STATE_NOT_OPEN) ||
+			(sasl_client_io_instance->io_state == IO_STATE_CLOSING))
+		{
+			result = __LINE__;
+		}
+		else
+		{
+			sasl_client_io_instance->io_state = IO_STATE_CLOSING;
+
+            sasl_client_io_instance->on_io_close_complete = on_io_close_complete;
+            sasl_client_io_instance->on_io_close_complete_context = on_io_close_complete_context;
+
+			/* Codes_SRS_SASLCLIENTIO_01_015: [saslclientio_close shall close the underlying io handle passed in saslclientio_create by calling xio_close.] */
+			if (xio_close(sasl_client_io_instance->underlying_io, on_underlying_io_close_complete, sasl_client_io_instance) != 0)
+			{
+				/* Codes_SRS_SASLCLIENTIO_01_018: [If xio_close fails, then saslclientio_close shall return a non-zero value.] */
+				result = __LINE__;
+			}
+			else
+			{
+				/* Codes_SRS_SASLCLIENTIO_01_016: [On success, saslclientio_close shall return 0.] */
+				result = 0;
+			}
+		}
+	}
+
+	return result;
+}
+
+int saslclientio_send(CONCRETE_IO_HANDLE sasl_client_io, const void* buffer, size_t size, ON_SEND_COMPLETE on_send_complete, void* callback_context)
+{
+	int result;
+
+	/* Codes_SRS_SASLCLIENTIO_01_022: [If the saslio or buffer argument is NULL, saslclientio_send shall fail and return a non-zero value.] */
+	if ((sasl_client_io == NULL) ||
+		(buffer == NULL) ||
+		/* Codes_SRS_SASLCLIENTIO_01_023: [If size is 0, saslclientio_send shall fail and return a non-zero value.] */
+		(size == 0))
+	{
+		/* Invalid arguments */
+		result = __LINE__;
+	}
+	else
+	{
+		SASL_CLIENT_IO_INSTANCE* sasl_client_io_instance = (SASL_CLIENT_IO_INSTANCE*)sasl_client_io;
+
+		if (sasl_client_io_instance->logger_log != NULL)
+		{
+			size_t i;
+			for (i = 0; i < size; i++)
+			{
+				LOG(sasl_client_io_instance->logger_log, 0, " %02x", ((const unsigned char*)buffer)[i]);
+			}
+		}
+
+		/* Codes_SRS_SASLCLIENTIO_01_019: [If saslclientio_send is called while the SASL client IO state is not IO_STATE_OPEN, saslclientio_send shall fail and return a non-zero value.] */
+		if (sasl_client_io_instance->io_state != IO_STATE_OPEN)
+		{
+			result = __LINE__;
+		}
+		else
+		{
+			/* Codes_SRS_SASLCLIENTIO_01_020: [If the SASL client IO state is IO_STATE_OPEN, saslclientio_send shall call xio_send on the underlying_io passed to saslclientio_create, while passing as arguments the buffer, size, on_send_complete and callback_context.] */
+			if (xio_send(sasl_client_io_instance->underlying_io, buffer, size, on_send_complete, callback_context) != 0)
+			{
+				/* Codes_SRS_SASLCLIENTIO_01_024: [If the call to xio_send fails, then saslclientio_send shall fail and return a non-zero value.] */
+				result = __LINE__;
+			}
+			else
+			{
+				/* Codes_SRS_SASLCLIENTIO_01_021: [On success, saslclientio_send shall return 0.] */
+				result = 0;
+			}
+		}
+	}
+
+	return result;
+}
+
+void saslclientio_dowork(CONCRETE_IO_HANDLE sasl_client_io)
+{
+	/* Codes_SRS_SASLCLIENTIO_01_026: [If the sasl_client_io argument is NULL, saslclientio_dowork shall do nothing.] */
+	if (sasl_client_io != NULL)
+	{
+		SASL_CLIENT_IO_INSTANCE* sasl_client_io_instance = (SASL_CLIENT_IO_INSTANCE*)sasl_client_io;
+
+		/* Codes_SRS_SASLCLIENTIO_01_025: [saslclientio_dowork shall call the xio_dowork on the underlying_io passed in saslclientio_create.] */
+		if (sasl_client_io_instance->io_state != IO_STATE_NOT_OPEN)
+		{
+			/* Codes_SRS_SASLCLIENTIO_01_025: [saslclientio_dowork shall call the xio_dowork on the underlying_io passed in saslclientio_create.] */
+			xio_dowork(sasl_client_io_instance->underlying_io);
+		}
+	}
+}
+
+/* Codes_SRS_SASLCLIENTIO_03_001: [saslclientio_setoption does not support any options and shall always return non-zero value.]*/
+int saslclientio_setoption(CONCRETE_IO_HANDLE socket_io, const char* optionName, const void* value)
+{
+    return __LINE__;
+}
+
+static const IO_INTERFACE_DESCRIPTION sasl_client_io_interface_description =
+{
+	saslclientio_create,
+	saslclientio_destroy,
+	saslclientio_open,
+	saslclientio_close,
+	saslclientio_send,
+	saslclientio_dowork,
+    saslclientio_setoption
+};
+
+/* Codes_SRS_SASLCLIENTIO_01_087: [saslclientio_get_interface_description shall return a pointer to an IO_INTERFACE_DESCRIPTION structure that contains pointers to the functions: saslclientio_create, saslclientio_destroy, saslclientio_open, saslclientio_close, saslclientio_send and saslclientio_dowork.] */
+const IO_INTERFACE_DESCRIPTION* saslclientio_get_interface_description(void)
+{
+	return &sasl_client_io_interface_description;
+}