SecurityPolicy -------------- .. code-block:: c typedef struct { UA_String uri; /* Verifies the signature of the message using the provided keys in the context. * * @param channelContext the channelContext that contains the key to verify * the supplied message with. * @param message the message to which the signature is supposed to belong. * @param signature the signature of the message, that should be verified. */ UA_StatusCode (*verify)(void *channelContext, const UA_ByteString *message, const UA_ByteString *signature); /* Signs the given message using this policys signing algorithm and the * provided keys in the context. * * @param channelContext the channelContext that contains the key to sign * the supplied message with. * @param message the message to sign. * @param signature an output buffer to which the signature is written. The * buffer needs to be allocated by the caller. The * necessary size can be acquired with the signatureSize * attribute of this module. */ UA_StatusCode (*sign)(void *channelContext, const UA_ByteString *message, UA_ByteString *signature); /* Gets the signature size that depends on the local (private) key. * * @param channelContext the channelContext that contains the * certificate/key. * @return the size of the local signature. Returns 0 if no local * certificate was set. */ size_t (*getLocalSignatureSize)(const void *channelContext); /* Gets the signature size that depends on the remote (public) key. * * @param channelContext the context to retrieve data from. * @return the size of the remote signature. Returns 0 if no * remote certificate was set previousely. */ size_t (*getRemoteSignatureSize)(const void *channelContext); /* Gets the local signing key length. * * @param channelContext the context to retrieve data from. * @return the length of the signing key in bytes. Returns 0 if no length can be found. */ size_t (*getLocalKeyLength)(const void *channelContext); /* Gets the local signing key length. * * @param channelContext the context to retrieve data from. * @return the length of the signing key in bytes. Returns 0 if no length can be found. */ size_t (*getRemoteKeyLength)(const void *channelContext); } UA_SecurityPolicySignatureAlgorithm; typedef struct { UA_String uri; /* Encrypt the given data in place. For asymmetric encryption, the block * size for plaintext and cypher depend on the remote key (certificate). * * @param channelContext the channelContext which contains information about * the keys to encrypt data. * @param data the data that is encrypted. The encrypted data will overwrite * the data that was supplied. */ UA_StatusCode (*encrypt)(void *channelContext, UA_ByteString *data); /* Decrypts the given ciphertext in place. For asymmetric encryption, the * block size for plaintext and cypher depend on the local private key. * * @param channelContext the channelContext which contains information about * the keys needed to decrypt the message. * @param data the data to decrypt. The decryption is done in place. */ UA_StatusCode (*decrypt)(void *channelContext, UA_ByteString *data); /* Returns the length of the key used to encrypt messages in bits. For * asymmetric encryption the key length is for the local private key. * * @param channelContext the context to retrieve data from. * @return the length of the local key. Returns 0 if no * key length is known. */ size_t (*getLocalKeyLength)(const void *channelContext); /* Returns the length of the key to encrypt messages in bits. Depends on the * key (certificate) from the remote side. * * @param channelContext the context to retrieve data from. * @return the length of the remote key. Returns 0 if no * key length is known. */ size_t (*getRemoteKeyLength)(const void *channelContext); /* Returns the size of encrypted blocks for sending. For asymmetric * encryption this depends on the remote key (certificate). For symmetric * encryption the local and remote encrypted block size are identical. * * @param channelContext the context to retrieve data from. * @return the size of encrypted blocks in bytes. Returns 0 if no key length is known. */ size_t (*getRemoteBlockSize)(const void *channelContext); /* Returns the size of plaintext blocks for sending. For asymmetric * encryption this depends on the remote key (certificate). For symmetric * encryption the local and remote plaintext block size are identical. * * @param channelContext the context to retrieve data from. * @return the size of plaintext blocks in bytes. Returns 0 if no key length is known. */ size_t (*getRemotePlainTextBlockSize)(const void *channelContext); } UA_SecurityPolicyEncryptionAlgorithm; typedef struct { /* The algorithm used to sign and verify certificates. */ UA_SecurityPolicySignatureAlgorithm signatureAlgorithm; /* The algorithm used to encrypt and decrypt messages. */ UA_SecurityPolicyEncryptionAlgorithm encryptionAlgorithm; } UA_SecurityPolicyCryptoModule; typedef struct { /* Generates a thumbprint for the specified certificate. * * @param certificate the certificate to make a thumbprint of. * @param thumbprint an output buffer for the resulting thumbprint. Always * has the length specified in the thumbprintLength in the * asymmetricModule. */ UA_StatusCode (*makeCertificateThumbprint)(const UA_SecurityPolicy *securityPolicy, const UA_ByteString *certificate, UA_ByteString *thumbprint) ; /* Compares the supplied certificate with the certificate in the endpoint context. * * @param securityPolicy the policy data that contains the certificate * to compare to. * @param certificateThumbprint the certificate thumbprint to compare to the * one stored in the context. * @return if the thumbprints match UA_STATUSCODE_GOOD is returned. If they * don't match or an error occurred an error code is returned. */ UA_StatusCode (*compareCertificateThumbprint)(const UA_SecurityPolicy *securityPolicy, const UA_ByteString *certificateThumbprint) ; UA_SecurityPolicyCryptoModule cryptoModule; } UA_SecurityPolicyAsymmetricModule; typedef struct { /* Pseudo random function that is used to generate the symmetric keys. * * For information on what parameters this function receives in what situation, * refer to the OPC UA specification 1.03 Part6 Table 33 * * @param policyContext The context of the policy instance * @param secret * @param seed * @param out an output to write the data to. The length defines the maximum * number of output bytes that are produced. */ UA_StatusCode (*generateKey)(void *policyContext, const UA_ByteString *secret, const UA_ByteString *seed, UA_ByteString *out) ; /* Random generator for generating nonces. * * @param policyContext The context of the policy instance * @param out pointer to a buffer to store the nonce in. Needs to be * allocated by the caller. The buffer is filled with random * data. */ UA_StatusCode (*generateNonce)(void *policyContext, UA_ByteString *out) ; /* * The length of the nonce used in the SecureChannel as specified in the standard. */ size_t secureChannelNonceLength; UA_SecurityPolicyCryptoModule cryptoModule; } UA_SecurityPolicySymmetricModule; typedef struct { /* This method creates a new context data object. * * The caller needs to call delete on the received object to free allocated * memory. Memory is only allocated if the function succeeds so there is no * need to manually free the memory pointed to by *channelContext or to * call delete in case of failure. * * @param securityPolicy the policy context of the endpoint that is connected * to. It will be stored in the channelContext for * further access by the policy. * @param remoteCertificate the remote certificate contains the remote * asymmetric key. The certificate will be verified * and then stored in the context so that its * details may be accessed. * @param channelContext the initialized channelContext that is passed to * functions that work on a context. */ UA_StatusCode (*newContext)(const UA_SecurityPolicy *securityPolicy, const UA_ByteString *remoteCertificate, void **channelContext) ; /* Deletes the the security context. */ void (*deleteContext)(void *channelContext); /* Sets the local encrypting key in the supplied context. * * @param channelContext the context to work on. * @param key the local encrypting key to store in the context. */ UA_StatusCode (*setLocalSymEncryptingKey)(void *channelContext, const UA_ByteString *key) ; /* Sets the local signing key in the supplied context. * * @param channelContext the context to work on. * @param key the local signing key to store in the context. */ UA_StatusCode (*setLocalSymSigningKey)(void *channelContext, const UA_ByteString *key) ; /* Sets the local initialization vector in the supplied context. * * @param channelContext the context to work on. * @param iv the local initialization vector to store in the context. */ UA_StatusCode (*setLocalSymIv)(void *channelContext, const UA_ByteString *iv) ; /* Sets the remote encrypting key in the supplied context. * * @param channelContext the context to work on. * @param key the remote encrypting key to store in the context. */ UA_StatusCode (*setRemoteSymEncryptingKey)(void *channelContext, const UA_ByteString *key) ; /* Sets the remote signing key in the supplied context. * * @param channelContext the context to work on. * @param key the remote signing key to store in the context. */ UA_StatusCode (*setRemoteSymSigningKey)(void *channelContext, const UA_ByteString *key) ; /* Sets the remote initialization vector in the supplied context. * * @param channelContext the context to work on. * @param iv the remote initialization vector to store in the context. */ UA_StatusCode (*setRemoteSymIv)(void *channelContext, const UA_ByteString *iv) ; /* Compares the supplied certificate with the certificate in the channel * context. * * @param channelContext the channel context data that contains the * certificate to compare to. * @param certificate the certificate to compare to the one stored in the context. * @return if the certificates match UA_STATUSCODE_GOOD is returned. If they * don't match or an errror occurred an error code is returned. */ UA_StatusCode (*compareCertificate)(const void *channelContext, const UA_ByteString *certificate) ; } UA_SecurityPolicyChannelModule; struct UA_SecurityPolicy { /* Additional data */ void *policyContext; /* The policy uri that identifies the implemented algorithms */ UA_String policyUri; /* The local certificate is specific for each SecurityPolicy since it * depends on the used key length. */ UA_ByteString localCertificate; /* Function pointers grouped into modules */ UA_SecurityPolicyAsymmetricModule asymmetricModule; UA_SecurityPolicySymmetricModule symmetricModule; UA_SecurityPolicySignatureAlgorithm certificateSigningAlgorithm; UA_SecurityPolicyChannelModule channelModule; const UA_Logger *logger; /* Updates the ApplicationInstanceCertificate and the corresponding private * key at runtime. */ UA_StatusCode (*updateCertificateAndPrivateKey)(UA_SecurityPolicy *policy, const UA_ByteString newCertificate, const UA_ByteString newPrivateKey); /* Deletes the dynamic content of the policy */ void (*clear)(UA_SecurityPolicy *policy); }; PubSub SecurityPolicy --------------------- For PubSub encryption, the message nonce is part of the (unencrypted) SecurityHeader. The nonce is required for the de- and encryption and has to be set in the channel context before de/encrypting. .. code-block:: c #ifdef UA_ENABLE_PUBSUB_ENCRYPTION struct UA_PubSubSecurityPolicy; typedef struct UA_PubSubSecurityPolicy UA_PubSubSecurityPolicy; struct UA_PubSubSecurityPolicy { UA_String policyUri; /* The policy uri that identifies the implemented * algorithms */ UA_SecurityPolicySymmetricModule symmetricModule; /* Create the context for the WriterGroup. The keys and nonce can be NULL * here. Then they have to be set before the first encryption or signing * operation. */ UA_StatusCode (*newContext)(void *policyContext, const UA_ByteString *signingKey, const UA_ByteString *encryptingKey, const UA_ByteString *keyNonce, void **wgContext); /* Delete the WriterGroup SecurityPolicy context */ void (*deleteContext)(void *wgContext); /* Set the keys and nonce for the WriterGroup. This is returned from the * GetSecurityKeys method of a Security Key Service (SKS). Otherwise, set * manually via out-of-band transmission of the keys. */ UA_StatusCode (*setSecurityKeys)(void *wgContext, const UA_ByteString *signingKey, const UA_ByteString *encryptingKey, const UA_ByteString *keyNonce) ; /* The nonce is contained in the NetworkMessage SecurityHeader. Set before * each en-/decryption step. */ UA_StatusCode (*setMessageNonce)(void *wgContext, const UA_ByteString *nonce) ; const UA_Logger *logger; /* Deletes the dynamic content of the policy */ void (*clear)(UA_PubSubSecurityPolicy *policy); void *policyContext; }; #endif