open62541/src/ua_securechannel.h

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. 
 *
 *    Copyright 2014-2018 (c) Julius Pfrommer, Fraunhofer IOSB
 *    Copyright 2017 (c) Florian Palm
 *    Copyright 2017 (c) Stefan Profanter, fortiss GmbH
 *    Copyright 2017 (c) Mark Giraud, Fraunhofer IOSB
 */

#ifndef UA_SECURECHANNEL_H_
#define UA_SECURECHANNEL_H_

#ifdef __cplusplus
extern "C" {
#endif

#include "../deps/queue.h"
#include "ua_types.h"
#include "ua_transport_generated.h"
#include "ua_connection_internal.h"
#include "ua_plugin_securitypolicy.h"
#include "ua_plugin_log.h"

#define UA_SECURE_CONVERSATION_MESSAGE_HEADER_LENGTH 12
#define UA_SECURE_MESSAGE_HEADER_LENGTH 24

/* Thread-local variables to force failure modes during testing */
#ifdef UA_ENABLE_UNIT_TEST_FAILURE_HOOKS
extern UA_THREAD_LOCAL UA_StatusCode decrypt_verifySignatureFailure;
extern UA_THREAD_LOCAL UA_StatusCode sendAsym_sendFailure;
extern UA_THREAD_LOCAL UA_StatusCode processSym_seqNumberFailure;
#endif

/* The Session implementation differs between client and server. Still, it is
 * expected that the Session structure begins with the SessionHeader. This is
 * the interface that will be used by the SecureChannel. The lifecycle of
 * Sessions is independent of the underlying SecureChannel. But every Session
 * can be attached to only one SecureChannel. */
struct UA_SessionHeader;
typedef struct UA_SessionHeader UA_SessionHeader;

struct UA_SessionHeader {
    LIST_ENTRY(UA_SessionHeader) pointers;
    UA_NodeId authenticationToken;
    UA_SecureChannel *channel; /* The pointer back to the SecureChannel in the session. */
};

/* For chunked requests */
struct ChunkEntry {
    LIST_ENTRY(ChunkEntry) pointers;
    UA_UInt32 requestId;
    UA_ByteString bytes;
};

typedef enum {
    UA_SECURECHANNELSTATE_FRESH,
    UA_SECURECHANNELSTATE_OPEN,
    UA_SECURECHANNELSTATE_CLOSED
} UA_SecureChannelState;

struct UA_SecureChannel {
    UA_SecureChannelState   state;
    UA_MessageSecurityMode  securityMode;
    UA_ChannelSecurityToken securityToken; /* the channelId is contained in the securityToken */
    UA_ChannelSecurityToken nextSecurityToken;

    /* The endpoint and context of the channel */
    const UA_SecurityPolicy *securityPolicy;
    void *channelContext; /* For interaction with the security policy */
    UA_Connection *connection;

    /* Asymmetric encryption info */
    UA_ByteString remoteCertificate;
    UA_Byte remoteCertificateThumbprint[20]; /* The thumbprint of the remote certificate */

    /* Symmetric encryption info */
    UA_ByteString remoteNonce;
    UA_ByteString localNonce;

    UA_UInt32 receiveSequenceNumber;
    UA_UInt32 sendSequenceNumber;

    LIST_HEAD(session_pointerlist, UA_SessionHeader) sessions;
    LIST_HEAD(chunk_pointerlist, ChunkEntry) chunks;
};

UA_StatusCode
UA_SecureChannel_init(UA_SecureChannel *channel,
                      const UA_SecurityPolicy *securityPolicy,
                      const UA_ByteString *remoteCertificate);
void UA_SecureChannel_deleteMembersCleanup(UA_SecureChannel *channel);

/* Generates new keys and sets them in the channel context */
UA_StatusCode
UA_SecureChannel_generateNewKeys(UA_SecureChannel* channel);

/* Wrapper function for generating nonces for the supplied channel. Uses the
 * random generator of the channels security policy to allocate and generate a
 * nonce with the specified length.
 *
 * @param channel the channel to use.
 * @param nonceLength the length of the nonce to be generated.
 * @param nonce will contain the nonce after being successfully called. */
UA_StatusCode
UA_SecureChannel_generateNonce(const UA_SecureChannel *channel,
                               size_t nonceLength, UA_ByteString *nonce);

UA_SessionHeader *
UA_SecureChannel_getSession(UA_SecureChannel *channel,
                            const UA_NodeId *authenticationToken);

UA_StatusCode
UA_SecureChannel_revolveTokens(UA_SecureChannel *channel);

/**
 * Sending Messages
 * ---------------- */

UA_StatusCode
UA_SecureChannel_sendAsymmetricOPNMessage(UA_SecureChannel *channel, UA_UInt32 requestId,
                                          const void *content, const UA_DataType *contentType);

UA_StatusCode
UA_SecureChannel_sendSymmetricMessage(UA_SecureChannel *channel, UA_UInt32 requestId,
                                      UA_MessageType messageType, void *payload,
                                      const UA_DataType *payloadType);

/* The MessageContext is forwarded into the encoding layer so that we can send
 * chunks before continuing to encode. This lets us reuse a fixed chunk-sized
 * messages buffer. */
typedef struct {
    UA_SecureChannel *channel;
    UA_UInt32 requestId;
    UA_UInt32 messageType;

    UA_UInt16 chunksSoFar;
    size_t messageSizeSoFar;

    UA_ByteString messageBuffer;
    UA_Byte *buf_pos;
    const UA_Byte *buf_end;

    UA_Boolean final;
} UA_MessageContext;

/* Start the context of a new symmetric message. */
UA_StatusCode
UA_MessageContext_begin(UA_MessageContext *mc, UA_SecureChannel *channel,
                        UA_UInt32 requestId, UA_MessageType messageType);

/* Encode the content and send out full chunks. If the return code is good, then
 * the ChunkInfo contains encoded content that has not been sent. If the return
 * code is bad, then the ChunkInfo has been cleaned up internally. */
UA_StatusCode
UA_MessageContext_encode(UA_MessageContext *mc, const void *content,
                         const UA_DataType *contentType);

/* Sends a symmetric message already encoded in the context. The context is
 * cleaned up, also in case of errors. */
UA_StatusCode
UA_MessageContext_finish(UA_MessageContext *mc);

/* To be used when a failure occures when a MessageContext is open. Note that
 * the _encode and _finish methods will clean up internally. _abort can be run
 * on a MessageContext that has already been cleaned up before. */
void
UA_MessageContext_abort(UA_MessageContext *mc);

/**
 * Process Received Chunks
 * ----------------------- */

typedef UA_StatusCode
(UA_ProcessMessageCallback)(void *application, UA_SecureChannel *channel,
                            UA_MessageType messageType, UA_UInt32 requestId,
                            const UA_ByteString *message);

/* Process a single chunk. This also decrypts the chunk if required. The
 * callback function is called with the complete message body if the message is
 * complete.
 *
 * Symmetric callback is ERR, MSG, CLO only
 * Asymmetric callback is OPN only
 *
 * @param channel the channel the chunks were received on.
 * @param chunks the memory region where the chunks are stored.
 * @param callback the callback function that gets called with the complete
 *                 message body, once a final chunk is processed.
 * @param application data pointer to application specific data that gets passed
 *                    on to the callback function. */
UA_StatusCode
UA_SecureChannel_processChunk(UA_SecureChannel *channel, UA_ByteString *chunk,
                              UA_ProcessMessageCallback callback,
                              void *application);

/**
 * Log Helper
 * ----------
 * C99 requires at least one element for the variadic argument. If the log
 * statement has no variable arguments, supply an additional NULL. It will be
 * ignored by printf.
 *
 * We have to jump through some hoops to enable the use of format strings
 * without arguments since (pedantic) C99 does not allow variadic macros with
 * zero arguments. So we add a dummy argument that is not printed (%.0s is
 * string of length zero). */

#define UA_LOG_TRACE_CHANNEL_INTERNAL(LOGGER, CHANNEL, MSG, ...)              \
    UA_LOG_TRACE(LOGGER, UA_LOGCATEGORY_SECURECHANNEL,                        \
                 "Connection %i | SecureChannel %i | " MSG "%.0s",            \
                 ((CHANNEL)->connection ? (CHANNEL)->connection->sockfd : 0), \
                 (CHANNEL)->securityToken.channelId, __VA_ARGS__)

#define UA_LOG_TRACE_CHANNEL(LOGGER, CHANNEL, ...)        \
    UA_MACRO_EXPAND(UA_LOG_TRACE_CHANNEL_INTERNAL(LOGGER, CHANNEL, __VA_ARGS__, ""))

#define UA_LOG_DEBUG_CHANNEL_INTERNAL(LOGGER, CHANNEL, MSG, ...)              \
    UA_LOG_DEBUG(LOGGER, UA_LOGCATEGORY_SECURECHANNEL,                        \
                 "Connection %i | SecureChannel %i | " MSG "%.0s",            \
                 ((CHANNEL)->connection ? (CHANNEL)->connection->sockfd : 0), \
                 (CHANNEL)->securityToken.channelId, __VA_ARGS__)

#define UA_LOG_DEBUG_CHANNEL(LOGGER, CHANNEL, ...)        \
    UA_MACRO_EXPAND(UA_LOG_DEBUG_CHANNEL_INTERNAL(LOGGER, CHANNEL, __VA_ARGS__, ""))

#define UA_LOG_INFO_CHANNEL_INTERNAL(LOGGER, CHANNEL, MSG, ...)               \
    UA_LOG_INFO(LOGGER, UA_LOGCATEGORY_SECURECHANNEL,                         \
                 "Connection %i | SecureChannel %i | " MSG "%.0s",            \
                 ((CHANNEL)->connection ? (CHANNEL)->connection->sockfd : 0), \
                 (CHANNEL)->securityToken.channelId, __VA_ARGS__)

#define UA_LOG_INFO_CHANNEL(LOGGER, CHANNEL, ...)        \
    UA_MACRO_EXPAND(UA_LOG_INFO_CHANNEL_INTERNAL(LOGGER, CHANNEL, __VA_ARGS__, ""))

#define UA_LOG_WARNING_CHANNEL_INTERNAL(LOGGER, CHANNEL, MSG, ...)            \
    UA_LOG_WARNING(LOGGER, UA_LOGCATEGORY_SECURECHANNEL,                      \
                 "Connection %i | SecureChannel %i | " MSG "%.0s",            \
                 ((CHANNEL)->connection ? (CHANNEL)->connection->sockfd : 0), \
                 (CHANNEL)->securityToken.channelId, __VA_ARGS__)

#define UA_LOG_WARNING_CHANNEL(LOGGER, CHANNEL, ...)        \
    UA_MACRO_EXPAND(UA_LOG_WARNING_CHANNEL_INTERNAL(LOGGER, CHANNEL, __VA_ARGS__, ""))

#define UA_LOG_ERROR_CHANNEL_INTERNAL(LOGGER, CHANNEL, MSG, ...)              \
    UA_LOG_ERROR(LOGGER, UA_LOGCATEGORY_SECURECHANNEL,                        \
                 "Connection %i | SecureChannel %i | " MSG "%.0s",            \
                 ((CHANNEL)->connection ? (CHANNEL)->connection->sockfd : 0), \
                 (CHANNEL)->securityToken.channelId, __VA_ARGS__)

#define UA_LOG_ERROR_CHANNEL(LOGGER, CHANNEL, ...)        \
    UA_MACRO_EXPAND(UA_LOG_ERROR_CHANNEL_INTERNAL(LOGGER, CHANNEL, __VA_ARGS__, ""))

#define UA_LOG_FATAL_CHANNEL_INTERNAL(LOGGER, CHANNEL, MSG, ...)              \
    UA_LOG_FATAL(LOGGER, UA_LOGCATEGORY_SECURECHANNEL,                        \
                 "Connection %i | SecureChannel %i | " MSG "%.0s",            \
                 ((CHANNEL)->connection ? (CHANNEL)->connection->sockfd : 0), \
                 (CHANNEL)->securityToken.channelId, __VA_ARGS__)

#define UA_LOG_FATAL_CHANNEL(LOGGER, CHANNEL, ...)        \
    UA_MACRO_EXPAND(UA_LOG_FATAL_CHANNEL_INTERNAL(LOGGER, CHANNEL, __VA_ARGS__, ""))

#ifdef __cplusplus
} // extern "C"
#endif

#endif /* UA_SECURECHANNEL_H_ */