Security

Cryptography, certificates, security policies, and the certificate store (client and server).

ua::SecPolAes128Sha256RsaOaep

The Aes128_Sha256_RsaOaep RSA security policy.

Concrete SecurityPolicy for the OPC UA Aes128_Sha256_RsaOaep profile: RSA-OAEP (SHA-1) asymmetric encryption, RSA-PKCS#1 v1.5 (SHA-256) asymmetric signatures, AES-128-CBC symmetric encryption, and HMAC-SHA-256 symmetric signatures. Every method reports the fixed cryptographic parameters of this profile; instances are stateless and may be shared across secure channels.

Functions

SecurityPolicyId id() const override

Returns the security-policy identifier for this profile.

Returns: The security-policy identifier for this profile.

String uri() const override

Returns the canonical OPC UA security-policy URI for this profile.

Returns: The canonical OPC UA security-policy URI for this profile.

CertificateType certificate_type() const override

Returns the certificate type accepted by this profile (an RSA certificate type).

Returns: The RSA certificate type accepted by this profile.

bool is_authenticated() const override

Indicates whether this policy authenticates the peer (signs and/or encrypts).

Returns: true if this policy authenticates the peer (signs and/or encrypts).

bool is_rsa() const override

Indicates that this is an RSA-family policy.

Returns: true; this is an RSA-family policy.

bool is_ecc() const override

Indicates that this is an ECC-family policy.

Returns: false; this is not an ECC-family policy.

bool uses_legacy_sequence_no() const override

Indicates whether this policy uses the legacy secure-channel sequence-number scheme.

Returns: true if this policy uses the legacy secure-channel sequence-number scheme.

size_t nonce_length() const override

Returns the required nonce length, in bytes.

Returns: The required nonce length, in bytes.

size_t symmetric_plaintext_block_size() const override

Returns the symmetric cipher plaintext block size, in bytes.

Returns: The symmetric cipher plaintext block size, in bytes.

size_t asymmetric_plaintext_block_size(const X509Certificate *certificate) const override

Returns the asymmetric (RSA-OAEP) plaintext block size for the peer certificate, in bytes.

• certificate (const X509Certificate *) - Peer certificate whose RSA key size sets the block size. Must not be null.

Returns: The largest plaintext block, in bytes, that fits one RSA-OAEP encryption block.

size_t symmetric_ciphertext_block_size() const override

Returns the symmetric cipher ciphertext block size, in bytes.

Returns: The symmetric cipher ciphertext block size, in bytes.

size_t asymmetric_ciphertext_block_size(const X509Certificate *certificate) const override

Returns the asymmetric (RSA) ciphertext block size for the given peer certificate, in bytes.

• certificate (const X509Certificate *) - Peer certificate whose RSA key size sets the block size. Must not be null.

Returns: The RSA encryption block size, in bytes (equal to the modulus length).

size_t symmetric_signature_size() const override

Returns the symmetric signature (HMAC) size, in bytes.

Returns: The symmetric signature (HMAC) size, in bytes.

size_t asymmetric_signature_size(const X509Certificate *certificate) const override

Returns the asymmetric (RSA) signature size for the given peer certificate, in bytes.

• certificate (const X509Certificate *) - Peer certificate whose RSA key size sets the signature size. Not null.

Returns: The RSA signature size, in bytes (equal to the modulus length).

size_t symmetric_signature_key_size() const override

Returns the symmetric signing (HMAC) key size, in bytes.

Returns: The symmetric signing (HMAC) key size, in bytes.

size_t symmetric_encryption_key_size() const override

Returns the symmetric encryption (AES) key size, in bytes.

Returns: The symmetric encryption (AES) key size, in bytes.

size_t symmetric_iv_size() const override

Returns the symmetric encryption initialization-vector size, in bytes.

Returns: The symmetric encryption initialization-vector size, in bytes.

size_t min_asymmetric_key_length() const override

Returns the minimum permitted asymmetric (RSA) key length, in bits.

Returns: The minimum permitted asymmetric (RSA) key length, in bits.

size_t max_asymmetric_key_length() const override

Returns the maximum permitted asymmetric (RSA) key length, in bits.

Returns: The maximum permitted asymmetric (RSA) key length, in bits.

AsymmetricEncryptionAlgorithm asymmetric_encryption_algorithm() const override

Returns the asymmetric encryption algorithm (RSA-OAEP with SHA-1).

Returns: The asymmetric encryption algorithm (RSA-OAEP with SHA-1).

AsymmetricSignatureAlgorithm asymmetric_signature_algorithm() const override

Returns the asymmetric signature algorithm (RSA-PKCS#1 v1.5 with SHA-256).

Returns: The asymmetric signature algorithm (RSA-PKCS#1 v1.5 with SHA-256).

String asymmetric_signature_algorithm_uri() const override

Returns the canonical URI of the asymmetric signature algorithm.

Returns: The canonical URI of the asymmetric signature algorithm.

SymmetricEncryptionAlgorithm symmetric_encryption_algorithm() const override

Returns the symmetric encryption algorithm (AES-128-CBC).

Returns: The symmetric encryption algorithm (AES-128-CBC).

SymmetricSignatureAlgorithm symmetric_signature_algorithm() const override

Returns the symmetric signature algorithm (HMAC-SHA-256).

Returns: The symmetric signature algorithm (HMAC-SHA-256).

void derive_symmetric_keys_async(shared_ptr< SecureChannelContext > context, ByteString localNonce, ByteString remoteNonce, ChannelRole role, std::function< void(DeriveSymmetricKeysResult)> callback) const override

Derives the symmetric signing and encryption keys for a channel from the exchanged nonces.

• context (shared_ptr< SecureChannelContext >) - Secure-channel context the keys are derived for. Must outlive the call.
• localNonce (ByteString) - Nonce generated by this endpoint for the current token.
• remoteNonce (ByteString) - Nonce received from the peer for the current token.
• role (ChannelRole) - Whether this endpoint acts as the server or the client, which fixes nonce ordering during derivation.
• callback (std::function< void(DeriveSymmetricKeysResult)>) - Receives the outcome: on success the Result holds the local and remote SecurityToken::Keys (signing key, encryption key, IV) as a pair; on failure it carries an ErrorDetail. This overload never throws.

ua::SecPolAes256Sha256RsaPss

The Aes256_Sha256_RsaPss RSA-family OPC UA security policy.

Implements the cryptographic parameters and key derivation defined by the http://opcfoundation.org/UA/SecurityPolicy#Aes256_Sha256_RsaPss profile: AES-256-CBC symmetric encryption, HMAC-SHA-256 symmetric signatures, RSA-OAEP (SHA-256) asymmetric encryption, and RSA-PSS (SHA-256) asymmetric signatures.

Instances are immutable and stateless; the same policy object may be shared across secure channels and called concurrently from any thread. SecurityPolicy, SecPolRsa

Functions

SecurityPolicyId id() const override

Returns the policy identifier (SecurityPolicyId::Aes256_Sha256_RsaPss).

Returns: The policy identifier (SecurityPolicyId::Aes256_Sha256_RsaPss).

String uri() const override

Returns the OPC UA security policy URI for this policy.

Returns: The OPC UA security-policy URI for this policy.

CertificateType certificate_type() const override

Returns the certificate type required by this policy (RSA).

Returns: The RSA certificate type required by this policy.

bool is_authenticated() const override

Indicates whether the policy provides message authentication.

Returns: true - this policy signs and (where applicable) encrypts messages.

bool is_rsa() const override

Indicates whether the policy uses RSA asymmetric cryptography.

Returns: true.

bool is_ecc() const override

Indicates whether the policy uses elliptic-curve asymmetric cryptography.

Returns: false.

bool uses_legacy_sequence_no() const override

Indicates whether the policy uses the legacy secure-channel sequence-number scheme.

Returns: true if the policy uses the legacy secure-channel sequence-number scheme.

size_t nonce_length() const override

Returns the required length, in bytes, of the secure-channel nonce.

Returns: The required secure-channel nonce length, in bytes.

size_t symmetric_plaintext_block_size() const override

Returns the symmetric cipher plaintext block size, in bytes.

Returns: The symmetric cipher plaintext block size, in bytes.

size_t asymmetric_plaintext_block_size(const X509Certificate *certificate) const override

Returns the asymmetric cipher plaintext block size, in bytes, for the given certificate.

• certificate (const X509Certificate *) - Certificate whose public-key modulus determines the block size. Borrowed for the call; must remain valid until it returns.

Returns: The asymmetric cipher plaintext block size, in bytes, for certificate.

size_t symmetric_ciphertext_block_size() const override

Returns the symmetric cipher ciphertext block size, in bytes.

Returns: The symmetric cipher ciphertext block size, in bytes.

size_t asymmetric_ciphertext_block_size(const X509Certificate *certificate) const override

Returns the asymmetric cipher ciphertext block size, in bytes, for the given certificate.

• certificate (const X509Certificate *) - Certificate whose public-key modulus determines the block size. Borrowed for the call; must remain valid until it returns.

Returns: The asymmetric cipher ciphertext block size, in bytes, for certificate.

size_t symmetric_signature_size() const override

Returns the symmetric signature (MAC) size, in bytes.

Returns: The symmetric signature (MAC) size, in bytes.

size_t asymmetric_signature_size(const X509Certificate *certificate) const override

Returns the asymmetric signature size, in bytes, for the given certificate.

• certificate (const X509Certificate *) - Certificate whose private-key length determines the signature size. Borrowed for the call; must remain valid until it returns.

Returns: The asymmetric signature size, in bytes, for certificate.

size_t symmetric_signature_key_size() const override

Returns the symmetric signing (MAC) key size, in bytes.

Returns: The symmetric signing (MAC) key size, in bytes.

size_t symmetric_encryption_key_size() const override

Returns the symmetric encryption key size, in bytes.

Returns: The symmetric encryption key size, in bytes.

size_t symmetric_iv_size() const override

Returns the symmetric initialization-vector size, in bytes.

Returns: The symmetric initialization-vector size, in bytes.

size_t min_asymmetric_key_length() const override

Returns the minimum accepted RSA key length, in bits.

Returns: The minimum accepted RSA key length, in bits.

size_t max_asymmetric_key_length() const override

Returns the maximum accepted RSA key length, in bits.

Returns: The maximum accepted RSA key length, in bits.

AsymmetricEncryptionAlgorithm asymmetric_encryption_algorithm() const override

Returns the asymmetric encryption algorithm used by this policy (RSA-OAEP, SHA-256).

Returns: The asymmetric encryption algorithm (RSA-OAEP, SHA-256).

AsymmetricSignatureAlgorithm asymmetric_signature_algorithm() const override

Returns the asymmetric signature algorithm used by this policy (RSA-PSS, SHA-256).

Returns: The asymmetric signature algorithm (RSA-PSS, SHA-256).

String asymmetric_signature_algorithm_uri() const override

Returns the OPC UA URI of the asymmetric signature algorithm.

Returns: The OPC UA URI of the asymmetric signature algorithm.

SymmetricEncryptionAlgorithm symmetric_encryption_algorithm() const override

Returns the symmetric encryption algorithm used by this policy (AES-256-CBC).

Returns: The symmetric encryption algorithm (AES-256-CBC).

SymmetricSignatureAlgorithm symmetric_signature_algorithm() const override

Returns the symmetric signature algorithm used by this policy (HMAC-SHA-256).

Returns: The symmetric signature algorithm (HMAC-SHA-256).

void derive_symmetric_keys_async(shared_ptr< SecureChannelContext > context, ByteString localNonce, ByteString remoteNonce, ChannelRole role, std::function< void(DeriveSymmetricKeysResult)> callback) const override

Derives the symmetric session keys for a secure channel from the exchanged nonces.

• context (shared_ptr< SecureChannelContext >) - Secure-channel context the derived keys belong to. Held for the duration of the derivation; must outlive the call.
• localNonce (ByteString) - Nonce generated by this endpoint.
• remoteNonce (ByteString) - Nonce received from the peer.
• role (ChannelRole) - Whether this endpoint acts as the channel server or client; selects the per-role nonce ordering.
• callback (std::function< void(DeriveSymmetricKeysResult)>) - Receives the outcome: on success the Result holds the local and remote SecurityToken::Keys; on failure it carries an ErrorDetail. This overload never throws.

ua::SecPolBasic128Rsa15

The deprecated Basic128Rsa15 OPC UA security policy.

Implements the RSA-family SecurityPolicy for the Basic128Rsa15 profile: RSA-PKCS1.5 asymmetric encryption, RSA-SHA1 asymmetric signatures, AES-128-CBC symmetric encryption, and HMAC-SHA1 symmetric signatures. The policy is retained for interoperability only; it is reported as deprecated and should not be selected for new endpoints. Instances are immutable and stateless, so the const accessors are safe to call from any thread.

SecurityPolicy

Functions

SecurityPolicyId id() const override

Returns the policy identifier (Basic128Rsa15).

Returns: The policy identifier (Basic128Rsa15).

String uri() const override

Returns the canonical OPC UA security policy URI for Basic128Rsa15.

Returns: The canonical OPC UA security-policy URI for Basic128Rsa15.

CertificateType certificate_type() const override

Returns the certificate type required by this policy (RSA).

Returns: The RSA certificate type required by this policy.

bool is_authenticated() const override

Returns whether the policy provides message authentication.

Returns: true if the policy provides message authentication.

bool uses_legacy_sequence_no() const override

Returns whether the policy uses the legacy sequence-number handling.

Returns: true if the policy uses the legacy sequence-number handling.

bool is_deprecated() const override

Returns whether the policy is deprecated; always true for Basic128Rsa15.

Returns: true; Basic128Rsa15 is deprecated.

size_t nonce_length() const override

Returns the length in bytes of the nonce exchanged during channel setup.

Returns: The nonce length exchanged during channel setup, in bytes.

size_t symmetric_plaintext_block_size() const override

Returns the symmetric cipher plaintext block size, in bytes.

Returns: The symmetric cipher plaintext block size, in bytes.

size_t asymmetric_plaintext_block_size(const X509Certificate *certificate) const override

Returns the asymmetric plaintext block size for the given certificate, in bytes.

• certificate (const X509Certificate *) - Peer certificate whose key length sizes the block; not retained.

Returns: The plaintext block size in bytes.

size_t symmetric_ciphertext_block_size() const override

Returns the symmetric cipher ciphertext block size, in bytes.

Returns: The symmetric cipher ciphertext block size, in bytes.

size_t asymmetric_ciphertext_block_size(const X509Certificate *certificate) const override

Returns the asymmetric ciphertext block size for the given certificate, in bytes.

• certificate (const X509Certificate *) - Peer certificate whose key length sizes the block; not retained.

Returns: The ciphertext block size in bytes.

size_t symmetric_signature_size() const override

Returns the symmetric signature size, in bytes.

Returns: The symmetric signature size, in bytes.

size_t asymmetric_signature_size(const X509Certificate *certificate) const override

Returns the asymmetric signature size for the given certificate, in bytes.

• certificate (const X509Certificate *) - Peer certificate whose key length sizes the signature; not retained.

Returns: The signature size in bytes.

size_t symmetric_signature_key_size() const override

Returns the symmetric signing key size, in bytes.

Returns: The symmetric signing key size, in bytes.

size_t symmetric_encryption_key_size() const override

Returns the symmetric encryption key size, in bytes.

Returns: The symmetric encryption key size, in bytes.

size_t symmetric_iv_size() const override

Returns the symmetric initialization-vector size, in bytes.

Returns: The symmetric initialization-vector size, in bytes.

size_t min_asymmetric_key_length() const override

Returns the minimum accepted asymmetric (RSA) key length, in bits.

Returns: The minimum accepted asymmetric (RSA) key length, in bits.

size_t max_asymmetric_key_length() const override

Returns the maximum accepted asymmetric (RSA) key length, in bits.

Returns: The maximum accepted asymmetric (RSA) key length, in bits.

AsymmetricEncryptionAlgorithm asymmetric_encryption_algorithm() const override

Returns the asymmetric encryption algorithm (RSA-PKCS1.5).

Returns: The asymmetric encryption algorithm (RSA-PKCS1.5).

AsymmetricSignatureAlgorithm asymmetric_signature_algorithm() const override

Returns the asymmetric signature algorithm (RSA-SHA1).

Returns: The asymmetric signature algorithm (RSA-SHA1).

String asymmetric_signature_algorithm_uri() const override

Returns the URI identifying the asymmetric signature algorithm.

Returns: The URI identifying the asymmetric signature algorithm.

SymmetricEncryptionAlgorithm symmetric_encryption_algorithm() const override

Returns the symmetric encryption algorithm (AES-128-CBC).

Returns: The symmetric encryption algorithm (AES-128-CBC).

SymmetricSignatureAlgorithm symmetric_signature_algorithm() const override

Returns the symmetric signature algorithm (HMAC-SHA1).

Returns: The symmetric signature algorithm (HMAC-SHA1).

void derive_symmetric_keys_async(shared_ptr< SecureChannelContext > context, ByteString localNonce, ByteString remoteNonce, ChannelRole role, std::function< void(DeriveSymmetricKeysResult)> callback) const override

Derives the symmetric key sets for a secure channel from the exchanged nonces.

• context (shared_ptr< SecureChannelContext >) - Secure channel context for which keys are derived; retained for the duration of the asynchronous flow.
• localNonce (ByteString) - Nonce generated by this endpoint.
• remoteNonce (ByteString) - Nonce received from the peer.
• role (ChannelRole) - Whether this endpoint is the server or the client, fixing nonce ordering.
• callback (std::function< void(DeriveSymmetricKeysResult)>) - Receives the outcome: on success the Result holds the derived { local, remote } key pair; on failure it carries an ErrorDetail. This overload never throws.

ua::SecPolBasic256

The OPC UA Basic256 security policy (RSA family).

Implements SecurityPolicy for the Basic256 suite: RSA-OAEP (SHA-1) asymmetric encryption, RSA-PKCS#1 v1.5 SHA-1 asymmetric signatures, AES-256-CBC symmetric encryption, and HMAC-SHA-1 symmetric signatures. The accessors below report the fixed cryptographic parameters of this suite and key derivation uses the P-SHA1 scheme.

This policy is deprecated by the OPC UA specification (SHA-1 is no longer considered secure); prefer SecPolBasic256Sha256 or an AES-GCM policy for new deployments. It remains for interoperability with legacy peers.

Instances are stateless and created via SecurityPolicy::create.

SecurityPolicy, SecPolBasic256Sha256

Functions

SecurityPolicyId id() const override

Returns the policy identifier, SecurityPolicyId::Basic256.

Returns: SecurityPolicyId::Basic256.

String uri() const override

Returns the policy URI string that identifies Basic256 on the wire.

Returns: The Basic256 security policy URI.

CertificateType certificate_type() const override

Returns the certificate type this policy requires (RSA).

Returns: The required certificate type (RSA).

bool is_authenticated() const override

Reports whether the policy provides authentication (signing).

Returns: true; Basic256 signs message chunks.

bool uses_legacy_sequence_no() const override

Reports whether the policy uses the legacy sequence-number scheme.

Returns: true; Basic256 predates the modern sequence-number rules.

bool is_deprecated() const override

Reports whether the policy is deprecated by the OPC UA specification.

Returns: true; Basic256 relies on SHA-1 and should be avoided for new use.

size_t nonce_length() const override

Returns the required nonce length in bytes for key derivation.

Returns: The nonce length in bytes.

size_t symmetric_plaintext_block_size() const override

Returns the symmetric cipher plaintext block size in bytes (AES-256-CBC).

Returns: The symmetric plaintext block size in bytes.

size_t asymmetric_plaintext_block_size(const X509Certificate *certificate) const override

Returns the asymmetric plaintext block size in bytes for the given certificate.

• certificate (const X509Certificate *) - Peer certificate whose RSA key size determines the block size; must not be null.

Returns: Maximum plaintext bytes that fit in one RSA-OAEP encryption block.

size_t symmetric_ciphertext_block_size() const override

Returns the symmetric cipher ciphertext block size in bytes (AES-256-CBC).

Returns: The symmetric ciphertext block size in bytes.

size_t asymmetric_ciphertext_block_size(const X509Certificate *certificate) const override

Returns the asymmetric ciphertext block size in bytes for the given certificate.

• certificate (const X509Certificate *) - Peer certificate whose RSA key size determines the block size; must not be null.

Returns: Size in bytes of one RSA ciphertext block (the RSA modulus size).

size_t symmetric_signature_size() const override

Returns the symmetric signature size in bytes (HMAC-SHA-1).

Returns: The symmetric signature size in bytes.

size_t asymmetric_signature_size(const X509Certificate *certificate) const override

Returns the asymmetric signature size in bytes for the given certificate.

• certificate (const X509Certificate *) - Signing certificate whose RSA key size determines the signature size; must not be null.

Returns: Size in bytes of one RSA signature (the RSA modulus size).

size_t symmetric_signature_key_size() const override

Returns the symmetric signing key length in bytes (HMAC-SHA-1).

Returns: The symmetric signing key length in bytes.

size_t symmetric_encryption_key_size() const override

Returns the symmetric encryption key length in bytes (AES-256).

Returns: The symmetric encryption key length in bytes.

size_t symmetric_iv_size() const override

Returns the symmetric initialization vector size in bytes (AES block size).

Returns: The symmetric initialization vector size in bytes.

size_t min_asymmetric_key_length() const override

Returns the minimum permitted RSA key length in bits for this policy.

Returns: The minimum permitted RSA key length in bits.

size_t max_asymmetric_key_length() const override

Returns the maximum permitted RSA key length in bits for this policy.

Returns: The maximum permitted RSA key length in bits.

AsymmetricEncryptionAlgorithm asymmetric_encryption_algorithm() const override

Returns the asymmetric encryption algorithm (RSA-OAEP with SHA-1).

Returns: The asymmetric encryption algorithm (RSA-OAEP with SHA-1).

AsymmetricSignatureAlgorithm asymmetric_signature_algorithm() const override

Returns the asymmetric signature algorithm (RSA-PKCS#1 v1.5 with SHA-1).

Returns: The asymmetric signature algorithm (RSA-PKCS#1 v1.5 with SHA-1).

String asymmetric_signature_algorithm_uri() const override

Returns the URI identifying the asymmetric signature algorithm on the wire.

Returns: The URI identifying the asymmetric signature algorithm.

SymmetricEncryptionAlgorithm symmetric_encryption_algorithm() const override

Returns the symmetric encryption algorithm (AES-256-CBC).

Returns: The symmetric encryption algorithm (AES-256-CBC).

SymmetricSignatureAlgorithm symmetric_signature_algorithm() const override

Returns the symmetric signature algorithm (HMAC-SHA-1).

Returns: The symmetric signature algorithm (HMAC-SHA-1).

void derive_symmetric_keys_async(shared_ptr< SecureChannelContext > context, ByteString localNonce, ByteString remoteNonce, ChannelRole role, std::function< void(DeriveSymmetricKeysResult)> callback) const override

Derives the symmetric session keys for a secure channel from the exchanged nonces.

• context (shared_ptr< SecureChannelContext >) - Secure channel context the derived keys belong to; must outlive the operation.
• localNonce (ByteString) - Nonce generated by this endpoint.
• remoteNonce (ByteString) - Nonce received from the peer.
• role (ChannelRole) - Whether this endpoint is the server or the client, which fixes the nonce ordering per the spec.
• callback (std::function< void(DeriveSymmetricKeysResult)>) - Receives the outcome: on success the Result holds the {local, remote} key pair; on failure it carries an ErrorDetail. This overload never throws.

ua::SecPolBasic256Sha256

The Basic256Sha256 OPC UA security policy.

Implements the RSA-family security policy http://opcfoundation.org/UA/SecurityPolicy#Basic256Sha256: RSA-OAEP (SHA-1) asymmetric encryption, RSA-PKCS#1.5 (SHA-256) asymmetric signatures, AES-256-CBC symmetric encryption, and HMAC-SHA-256 symmetric signatures, with P-SHA-256 key derivation. Instances are immutable and stateless; the cryptographic parameters reported by the accessors are fixed by the policy and do not depend on instance state. Obtain one via SecurityPolicy::create rather than constructing it directly.

SecPolRsa, SecurityPolicy

Functions

SecurityPolicyId id() const override

Returns the policy identifier, SecurityPolicyId::Basic256Sha256.

Returns: SecurityPolicyId::Basic256Sha256.

String uri() const override

Returns the policy URI, http://opcfoundation.org/UA/SecurityPolicy#Basic256Sha256.

Returns: The Basic256Sha256 security policy URI.

CertificateType certificate_type() const override

Returns the certificate type required by this policy (RSA-SHA-256).

Returns: The required certificate type (RSA-SHA-256).

bool is_authenticated() const override

Returns whether the policy authenticates message exchanges; always true for Basic256Sha256.

Returns: true; Basic256Sha256 signs message chunks.

bool uses_legacy_sequence_no() const override

Returns whether the policy uses the legacy (pre-1.04) sequence-number handling.

Returns: true; Basic256Sha256 uses the legacy sequence-number scheme.

size_t nonce_length() const override

Returns the length in bytes of the nonces exchanged during secure-channel setup.

Returns: The nonce length in bytes.

size_t symmetric_plaintext_block_size() const override

Returns the symmetric plaintext block size in bytes (AES block size).

Returns: The symmetric plaintext block size in bytes.

size_t asymmetric_plaintext_block_size(const X509Certificate *certificate) const override

Returns the asymmetric plaintext block size in bytes for the given certificate's key.

• certificate (const X509Certificate *) - Certificate whose public key determines the modulus length. Must be non-null; not retained beyond the call.

Returns: The usable plaintext block size in bytes.

size_t symmetric_ciphertext_block_size() const override

Returns the symmetric ciphertext block size in bytes (AES block size).

Returns: The symmetric ciphertext block size in bytes.

size_t asymmetric_ciphertext_block_size(const X509Certificate *certificate) const override

Returns the asymmetric ciphertext block size in bytes for the given certificate's key.

• certificate (const X509Certificate *) - Certificate whose public key determines the modulus length. Must be non-null; not retained beyond the call.

Returns: The ciphertext block size in bytes.

size_t symmetric_signature_size() const override

Returns the symmetric signature (HMAC-SHA-256) size in bytes.

Returns: The symmetric signature (HMAC-SHA-256) size in bytes.

size_t asymmetric_signature_size(const X509Certificate *certificate) const override

Returns the asymmetric signature size in bytes for the given certificate's key.

• certificate (const X509Certificate *) - Certificate whose public key determines the signature length. Must be non-null; not retained beyond the call.

Returns: The asymmetric signature size in bytes.

size_t symmetric_signature_key_size() const override

Returns the size in bytes of the derived symmetric signing key.

Returns: The symmetric signing key size in bytes.

size_t symmetric_encryption_key_size() const override

Returns the size in bytes of the derived symmetric encryption key (32 bytes for AES-256).

Returns: The symmetric encryption key size in bytes (32 for AES-256).

size_t symmetric_iv_size() const override

Returns the size in bytes of the symmetric initialisation vector (AES block size).

Returns: The symmetric initialisation vector size in bytes.

size_t min_asymmetric_key_length() const override

Returns the minimum permitted asymmetric (RSA) key length in bits.

Returns: The minimum permitted RSA key length in bits.

size_t max_asymmetric_key_length() const override

Returns the maximum permitted asymmetric (RSA) key length in bits.

Returns: The maximum permitted RSA key length in bits.

AsymmetricEncryptionAlgorithm asymmetric_encryption_algorithm() const override

Returns the asymmetric encryption algorithm used by this policy (RSA-OAEP with SHA-1).

Returns: The asymmetric encryption algorithm (RSA-OAEP with SHA-1).

AsymmetricSignatureAlgorithm asymmetric_signature_algorithm() const override

Returns the asymmetric signature algorithm used by this policy (RSA-PKCS#1.5 with SHA-256).

Returns: The asymmetric signature algorithm (RSA-PKCS#1.5 with SHA-256).

String asymmetric_signature_algorithm_uri() const override

Returns the URI identifying the asymmetric signature algorithm.

Returns: The URI identifying the asymmetric signature algorithm.

SymmetricEncryptionAlgorithm symmetric_encryption_algorithm() const override

Returns the symmetric encryption algorithm used by this policy (AES-256-CBC).

Returns: The symmetric encryption algorithm (AES-256-CBC).

SymmetricSignatureAlgorithm symmetric_signature_algorithm() const override

Returns the symmetric signature algorithm used by this policy (HMAC-SHA-256).

Returns: The symmetric signature algorithm (HMAC-SHA-256).

void derive_symmetric_keys_async(shared_ptr< SecureChannelContext > context, ByteString localNonce, ByteString remoteNonce, ChannelRole role, std::function< void(DeriveSymmetricKeysResult)> callback) const override

Derives the symmetric signing, encryption, and IV keys for both directions of the channel.

• context (shared_ptr< SecureChannelContext >) - Secure-channel context the derivation runs against; shared ownership is held for the duration of the operation.
• localNonce (ByteString) - Nonce generated by this endpoint.
• remoteNonce (ByteString) - Nonce received from the peer.
• role (ChannelRole) - Whether this endpoint acts as ChannelRole::Server or ChannelRole::Client, which fixes the nonce ordering.
• callback (std::function< void(DeriveSymmetricKeysResult)>) - Receives the outcome: on success the Result holds the derived local and remote key sets; on failure it carries an ErrorDetail. This overload never throws.

ua::SecPolEcc

Shared base for the elliptic-curve (ECC) OPC UA security policies.

Implements the parts of SecurityPolicy common to every ECC curve and cipher suite (NIST P-256/P-384, Brainpool, Curve25519/448), and leaves the per-suite choices - ephemeral-key algorithm, certificate-key algorithm, key derivation hash and AEAD vs. CBC framing - as pure-virtual hooks for the concrete curve subclasses to supply.

Instances are immutable after construction and shared via shared_ptr<SecurityPolicy>; all members are safe to call concurrently from any thread.

SecurityPolicy, SecPolRsa

Static functions

ByteString construct_per_message_iv(span< const byte > baseIv, uint32_t tokenId, uint32_t sequenceNumber)

Builds the per-message initialization vector from the channel base IV and counters.

• baseIv (span< const byte >) - The security token's base initialization vector.
• tokenId (uint32_t) - Identifier of the active security token.
• sequenceNumber (uint32_t) - Per-message sequence number.

Returns: The constructed per-message IV.

Functions

bool is_rsa() const override

Returns false: ECC policies are never RSA-based.

Returns: false; ECC policies are never RSA-based.

bool is_ecc() const override

Returns true: every policy in this family is elliptic-curve based.

Returns: true; every policy in this family is elliptic-curve based.

bool is_authenticated() const override

Reports whether the policy authenticates the peer at the channel layer.

Returns: true if the policy authenticates the peer at the channel layer.

bool is_deprecated() const override

Reports whether the policy is deprecated by the OPC UA specification.

Returns: true if the policy is deprecated by the OPC UA specification.

bool uses_legacy_sequence_no() const override

Reports whether the policy uses the legacy (pre-1.04) sequence-number scheme.

Returns: true if the policy uses the legacy (pre-1.04) sequence-number scheme.

AsymmetricEncryptionAlgorithm asymmetric_encryption_algorithm() const override

Returns the asymmetric encryption algorithm used for the handshake.

Returns: The asymmetric encryption algorithm; a no-encryption variant, as ECC policies perform no asymmetric message encryption.

size_t min_asymmetric_key_length() const override

Returns the minimum permitted asymmetric (certificate) key length, in bits.

Returns: The minimum permitted asymmetric (certificate) key length, in bits.

size_t max_asymmetric_key_length() const override

Returns the maximum permitted asymmetric (certificate) key length, in bits.

Returns: The maximum permitted asymmetric (certificate) key length, in bits.

size_t asymmetric_plaintext_block_size(const X509Certificate *certificate) const override

Returns the asymmetric plaintext block size, in bytes, for certificate.

• certificate (const X509Certificate *) - Peer certificate whose key sizes the block size, or nullptr to size against the policy's own key parameters.

Returns: The asymmetric plaintext block size, in bytes.

size_t asymmetric_ciphertext_block_size(const X509Certificate *certificate) const override

Returns the asymmetric ciphertext block size, in bytes, for certificate.

• certificate (const X509Certificate *) - Peer certificate whose key sizes the block size, or nullptr to size against the policy's own key parameters.

Returns: The asymmetric ciphertext block size, in bytes.

size_t asymmetric_signature_size(const X509Certificate *certificate) const override

Returns the asymmetric signature size, in bytes, for certificate.

• certificate (const X509Certificate *) - Peer certificate whose key sizes the signature, or nullptr to size against the policy's own key parameters.

Returns: The asymmetric signature size, in bytes.

void derive_symmetric_keys_async(shared_ptr< SecureChannelContext > context, ByteString localNonce, ByteString remoteNonce, ChannelRole role, std::function< void(DeriveSymmetricKeysResult)> callback) const override

Derives the symmetric channel keys from the agreed ECDH nonces.

• context (shared_ptr< SecureChannelContext >) - Secure-channel context the derived keys belong to; kept alive for the duration of the call.
• localNonce (ByteString) - This endpoint's ephemeral nonce.
• remoteNonce (ByteString) - The peer's ephemeral nonce.
• role (ChannelRole) - Whether this endpoint is the server or the client; selects the nonce ordering required by the spec.
• callback (std::function< void(DeriveSymmetricKeysResult)>) - Receives the outcome: on success the DeriveSymmetricKeysResult holds the (local, remote) key pair; on failure it carries an ErrorDetail. This overload never throws.

EphemeralKeyAlgorithm ephemeral_key_algorithm() const =0

Returns the ephemeral-key (ECDH) algorithm used for key agreement.

Returns: The ephemeral-key (ECDH) key-agreement algorithm.

CertificateKeyAlgorithm certificate_key_algorithm() const =0

Returns the algorithm of the long-term certificate key required by this policy.

Returns: The required certificate key algorithm.

std::span< const CertificateKeyAlgorithm > permitted_certificate_key_algorithms() const =0

Returns the certificate key algorithms permitted for remote certificates under this policy.

Returns: The permitted certificate key algorithms, in preference order.

HashAlgorithm key_derivation_hash() const =0

Returns the hash algorithm used by the key-derivation function.

Returns: The hash algorithm used by the key-derivation function.

SymmetricKeyDerivationAlgorithm key_derivation_algorithm() const =0

Returns the symmetric key-derivation algorithm (the KDF) this policy applies.

Returns: The symmetric key-derivation algorithm (the KDF) this policy applies.

bool uses_aead() const =0

Reports whether the policy uses authenticated encryption with associated data (AEAD).

Returns: true for AEAD suites (e.g. ChaCha20-Poly1305), false for encrypt-then-MAC (CBC) suites.

void construct_per_message_signing_key_async(const Crypto &crypto, std::optional< boost::asio::strand< boost::asio::any_io_executor > > strand, span< const byte > baseKey, uint32_t tokenId, uint32_t sequenceNumber, std::function< void(ByteStringResult)> callback) const

Derives the per-message signing key from the token's base signing key.

• crypto (const Crypto &) - Crypto provider used to run the derivation.
• strand (std::optional< boost::asio::strand< boost::asio::any_io_executor > >) - Optional strand on which to post the callback; pass std::nullopt to run inline on the completing thread.
• baseKey (span< const byte >) - The token's base signing key; viewed, not copied - must stay valid until the callback runs.
• tokenId (uint32_t) - Identifier of the active security token.
• sequenceNumber (uint32_t) - Per-message sequence number.
• callback (std::function< void(ByteStringResult)>) - Receives the outcome: on success the ByteStringResult holds the derived signing key; on failure it carries an ErrorDetail. Never throws.

ua::SecPolEccAead

An ECC security policy whose symmetric layer uses AEAD encryption.

Specialises SecPolEcc for the ECC policies that combine encryption and authentication in a single AEAD pass (AES-GCM) rather than the encrypt-then-MAC scheme used by the legacy policies. Concrete curve-specific policies derive from this class; it overrides only the symmetric message hooks, inheriting all asymmetric handshake behaviour from SecPolEcc.

Functions

bool uses_aead() const override

Reports that this policy authenticates symmetric messages with AEAD.

Returns: Always true; an AEAD tag replaces the separate symmetric signature.

ua::SecPolEccBrainpoolP256r1

The OPC UA ECC_brainpoolP256r1 security policy.

A concrete CBC-mode elliptic-curve policy bound to the Brainpool P-256r1 (256-bit) curve, SHA-256 hashing, and AES-128-CBC symmetric encryption. Each method returns a fixed policy parameter prescribed by OPC UA Part 7 for this policy; instances are stateless and the accessors are safe to call from any thread.

Functions

SecurityPolicyId id() const override

Returns the security policy identifier for this policy (ECC_brainpoolP256r1).

Returns: The ECC_brainpoolP256r1 security policy identifier.

String uri() const override

Returns the canonical security policy URI for this policy.

Returns: The canonical ECC_brainpoolP256r1 security policy URI.

CertificateType certificate_type() const override

Returns the certificate type required by this policy (a Brainpool P-256 ECC certificate).

Returns: The required certificate type (a Brainpool P-256 ECC certificate).

EphemeralKeyAlgorithm ephemeral_key_algorithm() const override

Returns the ephemeral key agreement algorithm used to establish symmetric keys.

Returns: The ephemeral key agreement algorithm used to establish symmetric keys.

CertificateKeyAlgorithm certificate_key_algorithm() const override

Returns the key algorithm a certificate must use to be valid under this policy.

Returns: The certificate key algorithm required by this policy.

std::span< const CertificateKeyAlgorithm > permitted_certificate_key_algorithms() const override

Returns the certificate key algorithms accepted for a remote peer's certificate.

Returns: A view over the accepted peer certificate key algorithms (P-256 and P-384); valid for the lifetime of the policy instance.

HashAlgorithm key_derivation_hash() const override

Returns the hash algorithm used in symmetric key derivation (SHA-256).

Returns: The key-derivation hash algorithm (SHA-256).

SymmetricKeyDerivationAlgorithm key_derivation_algorithm() const override

Returns the symmetric key derivation algorithm used to expand the shared secret.

Returns: The symmetric key-derivation algorithm.

AsymmetricSignatureAlgorithm asymmetric_signature_algorithm() const override

Returns the algorithm used to sign and verify asymmetric (handshake) messages.

Returns: The asymmetric (handshake) signature algorithm.

String asymmetric_signature_algorithm_uri() const override

Returns the URI identifying this policy's asymmetric signature algorithm.

Returns: The URI identifying this policy's asymmetric signature algorithm.

SymmetricEncryptionAlgorithm symmetric_encryption_algorithm() const override

Returns the symmetric encryption algorithm used for message bodies (AES-128-CBC).

Returns: The symmetric encryption algorithm (AES-128-CBC).

SymmetricSignatureAlgorithm symmetric_signature_algorithm() const override

Returns the symmetric signature (MAC) algorithm used for message bodies.

Returns: The symmetric signature (MAC) algorithm.

size_t nonce_length() const override

Returns the length, in bytes, of the nonces exchanged during key derivation.

Returns: The nonce length in bytes.

size_t symmetric_plaintext_block_size() const override

Returns the symmetric cipher's plaintext block size, in bytes.

Returns: The symmetric plaintext block size in bytes.

size_t symmetric_ciphertext_block_size() const override

Returns the symmetric cipher's ciphertext block size, in bytes.

Returns: The symmetric ciphertext block size in bytes.

size_t symmetric_signature_size() const override

Returns the size, in bytes, of a symmetric message signature (MAC).

Returns: The symmetric signature (MAC) size in bytes.

size_t symmetric_signature_key_size() const override

Returns the size, in bytes, of the symmetric signing (MAC) key.

Returns: The symmetric signing (MAC) key size in bytes.

size_t symmetric_encryption_key_size() const override

Returns the size, in bytes, of the symmetric encryption key.

Returns: The symmetric encryption key size in bytes.

size_t symmetric_iv_size() const override

Returns the size, in bytes, of the symmetric encryption initialization vector.

Returns: The symmetric encryption initialization vector size in bytes.

ua::SecPolEccBrainpoolP384r1

The ECC_brainpoolP384r1 elliptic-curve OPC UA security policy.

Implements the cryptographic parameters and key derivation defined by the http://opcfoundation.org/UA/SecurityPolicy#ECC_brainpoolP384r1 profile: ephemeral ECDH and ECDSA (SHA-384) over the Brainpool P-384r1 curve, HKDF-SHA-384 key derivation, AES-256-CBC symmetric encryption, and HMAC-SHA-384 symmetric signatures.

Instances are immutable and stateless; the same policy object may be shared across secure channels and called concurrently from any thread. SecurityPolicy, SecPolEcc, SecPolEccCbc

Functions

SecurityPolicyId id() const override

Returns the policy identifier (SecurityPolicyId::EccBrainpoolP384r1).

Returns: The policy identifier, SecurityPolicyId::EccBrainpoolP384r1.

String uri() const override

Returns the OPC UA security policy URI for this policy.

Returns: The ECC_brainpoolP384r1 security policy URI.

CertificateType certificate_type() const override

Returns the certificate type required by this policy (Brainpool P-384r1 application certificate).

Returns: The required certificate type (Brainpool P-384r1 application certificate).

EphemeralKeyAlgorithm ephemeral_key_algorithm() const override

Returns the ephemeral key-agreement algorithm used by this policy (ECDH over Brainpool P-384r1).

Returns: The ephemeral key-agreement algorithm (ECDH over Brainpool P-384r1).

CertificateKeyAlgorithm certificate_key_algorithm() const override

Returns the certificate key algorithm required by this policy (Brainpool P-384r1).

Returns: The required certificate key algorithm (Brainpool P-384r1).

std::span< const CertificateKeyAlgorithm > permitted_certificate_key_algorithms() const override

Returns the certificate key algorithms permitted for remote certificates under this policy.

Returns: A view over a static, single-element list containing only Brainpool P-384r1; the referenced storage outlives the policy and is never reallocated.

HashAlgorithm key_derivation_hash() const override

Returns the hash algorithm used by the key-derivation function (SHA-384).

Returns: The key-derivation hash algorithm (SHA-384).

SymmetricKeyDerivationAlgorithm key_derivation_algorithm() const override

Returns the symmetric key-derivation algorithm used by this policy (HKDF-SHA-384).

Returns: The symmetric key-derivation algorithm (HKDF-SHA-384).

AsymmetricSignatureAlgorithm asymmetric_signature_algorithm() const override

Returns the asymmetric signature algorithm used by this policy (ECDSA, SHA-384).

Returns: The asymmetric signature algorithm (ECDSA, SHA-384).

String asymmetric_signature_algorithm_uri() const override

Returns the OPC UA URI of the asymmetric signature algorithm.

Returns: The URI of the asymmetric signature algorithm.

SymmetricEncryptionAlgorithm symmetric_encryption_algorithm() const override

Returns the symmetric encryption algorithm used by this policy (AES-256-CBC).

Returns: The symmetric encryption algorithm (AES-256-CBC).

SymmetricSignatureAlgorithm symmetric_signature_algorithm() const override

Returns the symmetric signature algorithm used by this policy (HMAC-SHA-384).

Returns: The symmetric signature algorithm (HMAC-SHA-384).

size_t nonce_length() const override

Returns the required length, in bytes, of the secure-channel nonce.

Returns: The nonce length in bytes.

size_t symmetric_plaintext_block_size() const override

Returns the symmetric cipher plaintext block size, in bytes.

Returns: The symmetric plaintext block size in bytes.

size_t symmetric_ciphertext_block_size() const override

Returns the symmetric cipher ciphertext block size, in bytes.

Returns: The symmetric ciphertext block size in bytes.

size_t symmetric_signature_size() const override

Returns the symmetric signature (MAC) size, in bytes.

Returns: The symmetric signature (MAC) size in bytes.

size_t symmetric_signature_key_size() const override

Returns the symmetric signing (MAC) key size, in bytes.

Returns: The symmetric signing (MAC) key size in bytes.

size_t symmetric_encryption_key_size() const override

Returns the symmetric encryption key size, in bytes.

Returns: The symmetric encryption key size in bytes.

size_t symmetric_iv_size() const override

Returns the symmetric initialization-vector size, in bytes.

Returns: The symmetric initialization-vector size in bytes.

ua::SecPolEccCbc

Base for ECC security policies that protect symmetric messages with a CBC block cipher.

Specialises SecPolEcc for the non-AEAD branch: symmetric chunks are encrypted with a CBC-mode block cipher and authenticated by a separate HMAC, rather than by an authenticated cipher. The AEAD counterpart is SecPolEccAead. Concrete curve policies (NIST P-256/P-384, Brainpool) derive from this class; it is an intermediate base and is not instantiated directly. Instances are immutable and stateless, so a single instance is safe to share across secure channels and threads.

SecPolEcc, SecPolEccAead

Functions

bool uses_aead() const override

Reports whether this policy uses an authenticated cipher (AEAD); always false for CBC.

Returns: Always false; a separate HMAC authenticates each CBC-encrypted chunk.

ua::SecPolEccCurve25519ChaCha20Poly1305

The ECC_curve25519_ChaCha20Poly1305 OPC UA security policy.

Implements the ECC AEAD security policy http://opcfoundation.org/UA/SecurityPolicy#ECC_curve25519_ChaCha20Poly1305: X25519 ephemeral key agreement, Ed25519 (PureEdDSA) asymmetric signatures, and ChaCha20-Poly1305 authenticated symmetric encryption, with HKDF-SHA-256 key derivation. As an AEAD policy, confidentiality and integrity are provided together by the single ChaCha20-Poly1305 transform rather than by separate encryption and signing passes. Instances are immutable and stateless; the cryptographic parameters reported by the accessors are fixed by the policy and do not depend on instance state. Obtain one via SecurityPolicy::create rather than constructing it directly.

SecPolEccAead, SecPolEccCurve448ChaCha20Poly1305, SecurityPolicy

Functions

SecurityPolicyId id() const override

Returns the policy identifier, SecurityPolicyId::EccCurve25519ChaCha20Poly1305.

Returns: The identifier SecurityPolicyId::EccCurve25519ChaCha20Poly1305.

String uri() const override

Returns the policy URI, http://opcfoundation.org/UA/SecurityPolicy#ECC_curve25519_ChaCha20Poly1305.

Returns: The URI http://opcfoundation.org/UA/SecurityPolicy#ECC_curve25519_ChaCha20Poly1305.

CertificateType certificate_type() const override

Returns the certificate type required by this policy (Curve25519 application certificate).

Returns: The required certificate type (Curve25519 application certificate).

EphemeralKeyAlgorithm ephemeral_key_algorithm() const override

Returns the ephemeral key-agreement algorithm used by this policy (X25519).

Returns: The ephemeral key-agreement algorithm (X25519).

CertificateKeyAlgorithm certificate_key_algorithm() const override

Returns the certificate key algorithm required by this policy (Curve25519).

Returns: The required certificate key algorithm (Curve25519).

std::span< const CertificateKeyAlgorithm > permitted_certificate_key_algorithms() const override

Returns the certificate key algorithms permitted for remote certificates under this policy.

Returns: A span over a static, immutable list; valid for the program lifetime.

HashAlgorithm key_derivation_hash() const override

Returns the hash algorithm used by the key-derivation function (SHA-256).

Returns: The key-derivation hash algorithm (SHA-256).

SymmetricKeyDerivationAlgorithm key_derivation_algorithm() const override

Returns the symmetric key-derivation algorithm used by this policy (HKDF-SHA-256).

Returns: The symmetric key-derivation algorithm (HKDF-SHA-256).

AsymmetricSignatureAlgorithm asymmetric_signature_algorithm() const override

Returns the asymmetric signature algorithm used by this policy (Ed25519, PureEdDSA).

Returns: The asymmetric signature algorithm (Ed25519, PureEdDSA).

String asymmetric_signature_algorithm_uri() const override

Returns the URI identifying the asymmetric signature algorithm, http://opcfoundation.org/UA/security/PureEdDsa25519.

Returns: The URI http://opcfoundation.org/UA/security/PureEdDsa25519.

SymmetricEncryptionAlgorithm symmetric_encryption_algorithm() const override

Returns the symmetric encryption algorithm used by this policy (ChaCha20-Poly1305 AEAD).

Returns: The symmetric encryption algorithm (ChaCha20-Poly1305 AEAD).

SymmetricSignatureAlgorithm symmetric_signature_algorithm() const override

Returns the symmetric signature algorithm used by this policy (Poly1305 authentication tag).

Returns: The symmetric signature algorithm (Poly1305 authentication tag).

size_t nonce_length() const override

Returns the length in bytes of the nonces exchanged during secure-channel setup.

Returns: The nonce length in bytes (32).

size_t symmetric_plaintext_block_size() const override

Returns the symmetric plaintext block size in bytes.

Returns: The symmetric plaintext block size in bytes (1).

size_t symmetric_ciphertext_block_size() const override

Returns the symmetric ciphertext block size in bytes.

Returns: The symmetric ciphertext block size in bytes (1).

size_t symmetric_signature_size() const override

Returns the symmetric signature size in bytes (the 16-byte Poly1305 authentication tag).

Returns: The symmetric signature size in bytes (16).

size_t symmetric_signature_key_size() const override

Returns the size in bytes of the derived symmetric signing key.

Returns: The symmetric signing-key size in bytes (32).

size_t symmetric_encryption_key_size() const override

Returns the size in bytes of the derived symmetric encryption key (32 bytes for ChaCha20).

Returns: The symmetric encryption-key size in bytes (32).

size_t symmetric_iv_size() const override

Returns the size in bytes of the symmetric initialisation vector (12-byte ChaCha20 nonce).

Returns: The symmetric IV size in bytes (12).

ua::SecPolEccCurve448ChaCha20Poly1305

The ECC_curve448_ChaCha20Poly1305 OPC UA security policy.

Implements the ECC AEAD policy http://opcfoundation.org/UA/SecurityPolicy#ECC_curve448_ChaCha20Poly1305: Curve448 (X448) ephemeral key agreement, Ed448 (PureEdDSA) asymmetric signatures, and ChaCha20-Poly1305 authenticated symmetric encryption, with HKDF-SHA-256 key derivation. As an AEAD policy, confidentiality and integrity are provided together by the single ChaCha20-Poly1305 transform rather than by separate encryption and signing passes; the AEAD message hooks are inherited from SecPolEccAead. Instances are immutable and stateless, so the same policy object may be shared across secure channels and called concurrently from any thread. Obtain one via SecurityPolicy::create rather than constructing it directly.

SecPolEccAead, SecPolEccCurve25519ChaCha20Poly1305, SecurityPolicy

Functions

SecurityPolicyId id() const override

Returns the policy identifier, SecurityPolicyId::EccCurve448ChaCha20Poly1305.

Returns: The identifier SecurityPolicyId::EccCurve448ChaCha20Poly1305.

String uri() const override

Returns the policy URI, http://opcfoundation.org/UA/SecurityPolicy#ECC_curve448_ChaCha20Poly1305.

Returns: The URI http://opcfoundation.org/UA/SecurityPolicy#ECC_curve448_ChaCha20Poly1305.

CertificateType certificate_type() const override

Returns the certificate type required by this policy (Curve448 application certificate).

Returns: The required certificate type (Curve448 application certificate).

EphemeralKeyAlgorithm ephemeral_key_algorithm() const override

Returns the ephemeral key-agreement algorithm used by this policy (X448).

Returns: The ephemeral key-agreement algorithm (X448).

CertificateKeyAlgorithm certificate_key_algorithm() const override

Returns the certificate key algorithm required by this policy (Curve448).

Returns: The required certificate key algorithm (Curve448).

std::span< const CertificateKeyAlgorithm > permitted_certificate_key_algorithms() const override

Returns the certificate key algorithms permitted for remote certificates under this policy.

Returns: A span over a static, immutable list; valid for the program lifetime.

HashAlgorithm key_derivation_hash() const override

Returns the hash algorithm used by the key-derivation function (SHA-256).

Returns: The key-derivation hash algorithm (SHA-256).

SymmetricKeyDerivationAlgorithm key_derivation_algorithm() const override

Returns the symmetric key-derivation algorithm used by this policy (HKDF-SHA-256).

Returns: The symmetric key-derivation algorithm (HKDF-SHA-256).

AsymmetricSignatureAlgorithm asymmetric_signature_algorithm() const override

Returns the asymmetric signature algorithm used by this policy (Ed448, PureEdDSA).

Returns: The asymmetric signature algorithm (Ed448, PureEdDSA).

String asymmetric_signature_algorithm_uri() const override

Returns the URI identifying the asymmetric signature algorithm, http://opcfoundation.org/UA/security/PureEdDsa448.

Returns: The URI http://opcfoundation.org/UA/security/PureEdDsa448.

SymmetricEncryptionAlgorithm symmetric_encryption_algorithm() const override

Returns the symmetric encryption algorithm used by this policy (ChaCha20-Poly1305 AEAD).

Returns: The symmetric encryption algorithm (ChaCha20-Poly1305 AEAD).

SymmetricSignatureAlgorithm symmetric_signature_algorithm() const override

Returns the symmetric signature algorithm used by this policy (Poly1305 authentication tag).

Returns: The symmetric signature algorithm (Poly1305 authentication tag).

size_t nonce_length() const override

Returns the length in bytes of the nonces exchanged during secure-channel setup.

Returns: The nonce length in bytes (56).

size_t symmetric_plaintext_block_size() const override

Returns the symmetric plaintext block size in bytes.

Returns: The symmetric plaintext block size in bytes (1).

size_t symmetric_ciphertext_block_size() const override

Returns the symmetric ciphertext block size in bytes.

Returns: The symmetric ciphertext block size in bytes (1).

size_t symmetric_signature_size() const override

Returns the symmetric signature size in bytes (the 16-byte Poly1305 authentication tag).

Returns: The symmetric signature size in bytes (16).

size_t symmetric_signature_key_size() const override

Returns the size in bytes of the derived symmetric signing key.

Returns: The symmetric signing-key size in bytes (32).

size_t symmetric_encryption_key_size() const override

Returns the size in bytes of the derived symmetric encryption key (32 bytes for ChaCha20).

Returns: The symmetric encryption-key size in bytes (32).

size_t symmetric_iv_size() const override

Returns the size in bytes of the symmetric initialisation vector (12-byte ChaCha20 nonce).

Returns: The symmetric IV size in bytes (12).

ua::SecPolEccNistP256

The OPC UA ECC_nistP256 security policy.

A concrete CBC-mode elliptic-curve policy bound to the NIST P-256 (secp256r1, 256-bit) curve, SHA-256 hashing, and AES-128-CBC symmetric encryption. Each method returns a fixed policy parameter prescribed by OPC UA Part 7 for this policy; instances are stateless and the accessors are safe to call from any thread.

Functions

SecurityPolicyId id() const override

Returns the security policy identifier for this policy (ECC_nistP256).

Returns: The identifier SecurityPolicyId::EccNistP256.

String uri() const override

Returns the canonical security policy URI for this policy.

Returns: The URI http://opcfoundation.org/UA/SecurityPolicy#ECC_nistP256.

CertificateType certificate_type() const override

Returns the certificate type required by this policy (a NIST P-256 ECC certificate).

Returns: The required certificate type (NIST P-256 application certificate).

EphemeralKeyAlgorithm ephemeral_key_algorithm() const override

Returns the ephemeral key agreement algorithm used to establish symmetric keys.

Returns: The ephemeral ECDH key-agreement algorithm over NIST P-256.

CertificateKeyAlgorithm certificate_key_algorithm() const override

Returns the key algorithm a certificate must use to be valid under this policy.

Returns: The required certificate key algorithm (NIST P-256).

std::span< const CertificateKeyAlgorithm > permitted_certificate_key_algorithms() const override

Returns the certificate key algorithms accepted for a remote peer's certificate.

Returns: The accepted certificate key algorithms (NIST P-256 and P-384), in preference order.

HashAlgorithm key_derivation_hash() const override

Returns the hash algorithm used in symmetric key derivation (SHA-256).

Returns: The key-derivation hash algorithm (SHA-256).

SymmetricKeyDerivationAlgorithm key_derivation_algorithm() const override

Returns the symmetric key derivation algorithm used to expand the shared secret.

Returns: The symmetric key-derivation algorithm (HKDF-SHA-256).

AsymmetricSignatureAlgorithm asymmetric_signature_algorithm() const override

Returns the algorithm used to sign and verify asymmetric (handshake) messages.

Returns: The asymmetric handshake signature algorithm (ECDSA, SHA-256).

String asymmetric_signature_algorithm_uri() const override

Returns the URI identifying this policy's asymmetric signature algorithm.

Returns: The URI of this policy's asymmetric signature algorithm.

SymmetricEncryptionAlgorithm symmetric_encryption_algorithm() const override

Returns the symmetric encryption algorithm used for message bodies (AES-128-CBC).

Returns: The symmetric encryption algorithm (AES-128-CBC).

SymmetricSignatureAlgorithm symmetric_signature_algorithm() const override

Returns the symmetric signature (MAC) algorithm used for message bodies.

Returns: The symmetric signature (MAC) algorithm (HMAC-SHA-256).

size_t nonce_length() const override

Returns the nonce length in bytes (65 - an uncompressed P-256 public key: 1 + 32 + 32).

Returns: The nonce length in bytes (65).

size_t symmetric_plaintext_block_size() const override

Returns the symmetric cipher's plaintext block size in bytes (16, the AES block size).

Returns: The symmetric plaintext block size in bytes (16).

size_t symmetric_ciphertext_block_size() const override

Returns the symmetric cipher's ciphertext block size in bytes (16, the AES block size).

Returns: The symmetric ciphertext block size in bytes (16).

size_t symmetric_signature_size() const override

Returns the symmetric message signature (MAC) size in bytes (32, the SHA-256 output).

Returns: The symmetric signature size in bytes (32).

size_t symmetric_signature_key_size() const override

Returns the symmetric signing (MAC) key size in bytes (32).

Returns: The symmetric signing-key size in bytes (32).

size_t symmetric_encryption_key_size() const override

Returns the symmetric encryption key size in bytes (16, for AES-128).

Returns: The symmetric encryption-key size in bytes (16).

size_t symmetric_iv_size() const override

Returns the symmetric encryption IV size in bytes (16, the AES block size).

Returns: The symmetric IV size in bytes (16).

ua::SecPolEccNistP384

The ECC_nistP384 elliptic-curve OPC UA security policy.

Implements the cryptographic parameters and key derivation defined by the http://opcfoundation.org/UA/SecurityPolicy#ECC_nistP384 profile: ephemeral ECDH and ECDSA (SHA-384) over the NIST P-384 (secp384r1) curve, HKDF-SHA-384 key derivation, AES-256-CBC symmetric encryption, and HMAC-SHA-384 symmetric signatures.

Instances are immutable and stateless; the same policy object may be shared across secure channels and called concurrently from any thread. SecurityPolicy, SecPolEcc, SecPolEccCbc

Functions

SecurityPolicyId id() const override

Returns the policy identifier (SecurityPolicyId::EccNistP384).

Returns: The identifier SecurityPolicyId::EccNistP384.

String uri() const override

Returns the OPC UA security policy URI for this policy.

Returns: The URI http://opcfoundation.org/UA/SecurityPolicy#ECC_nistP384.

CertificateType certificate_type() const override

Returns the certificate type required by this policy (NIST P-384 application certificate).

Returns: The required certificate type (NIST P-384 application certificate).

EphemeralKeyAlgorithm ephemeral_key_algorithm() const override

Returns the ephemeral key-agreement algorithm used by this policy (ECDH over NIST P-384).

Returns: The ephemeral ECDH key-agreement algorithm over NIST P-384.

CertificateKeyAlgorithm certificate_key_algorithm() const override

Returns the certificate key algorithm required by this policy (NIST P-384).

Returns: The required certificate key algorithm (NIST P-384).

std::span< const CertificateKeyAlgorithm > permitted_certificate_key_algorithms() const override

Returns the certificate key algorithms permitted for remote certificates under this policy.

Returns: A view over a static, single-element list containing only NIST P-384; the referenced storage outlives the policy and is never reallocated.

HashAlgorithm key_derivation_hash() const override

Returns the hash algorithm used by the key-derivation function (SHA-384).

Returns: The key-derivation hash algorithm (SHA-384).

SymmetricKeyDerivationAlgorithm key_derivation_algorithm() const override

Returns the symmetric key-derivation algorithm used by this policy (HKDF-SHA-384).

Returns: The symmetric key-derivation algorithm (HKDF-SHA-384).

AsymmetricSignatureAlgorithm asymmetric_signature_algorithm() const override

Returns the asymmetric signature algorithm used by this policy (ECDSA, SHA-384).

Returns: The asymmetric signature algorithm (ECDSA, SHA-384).

String asymmetric_signature_algorithm_uri() const override

Returns the OPC UA URI of the asymmetric signature algorithm.

Returns: The URI of this policy's asymmetric signature algorithm.

SymmetricEncryptionAlgorithm symmetric_encryption_algorithm() const override

Returns the symmetric encryption algorithm used by this policy (AES-256-CBC).

Returns: The symmetric encryption algorithm (AES-256-CBC).

SymmetricSignatureAlgorithm symmetric_signature_algorithm() const override

Returns the symmetric signature algorithm used by this policy (HMAC-SHA-384).

Returns: The symmetric signature (MAC) algorithm (HMAC-SHA-384).

size_t nonce_length() const override

Returns the required nonce length in bytes (97 - an uncompressed NIST P-384 ephemeral public key: 1 + 48 + 48).

Returns: The nonce length in bytes (97).

size_t symmetric_plaintext_block_size() const override

Returns the symmetric cipher plaintext block size in bytes (16, the AES block size).

Returns: The symmetric plaintext block size in bytes (16).

size_t symmetric_ciphertext_block_size() const override

Returns the symmetric cipher ciphertext block size in bytes (16, the AES block size).

Returns: The symmetric ciphertext block size in bytes (16).

size_t symmetric_signature_size() const override

Returns the symmetric signature (MAC) size in bytes (48, the SHA-384 output).

Returns: The symmetric signature size in bytes (48).

size_t symmetric_signature_key_size() const override

Returns the symmetric signing (MAC) key size in bytes (48).

Returns: The symmetric signing-key size in bytes (48).

size_t symmetric_encryption_key_size() const override

Returns the symmetric encryption key size in bytes (32, for AES-256).

Returns: The symmetric encryption-key size in bytes (32).

size_t symmetric_iv_size() const override

Returns the symmetric initialization-vector size in bytes (16, the AES block size).

Returns: The symmetric IV size in bytes (16).

ua::SecPolNone

The OPC UA SecurityPolicy#None policy: messages are neither signed nor encrypted.

This policy applies no cryptography. Secure channels using it transmit plaintext, perform no certificate-based authentication, and derive no symmetric keys. The signature, key, and nonce accessors report zero and the algorithm accessors report the "no algorithm" variants; the block-size accessors report 1 (a unit block keeps the chunk-size arithmetic well-defined with no cipher). Use it only where confidentiality and integrity are provided by another layer (or are not required).

Instances are obtained through SecurityPolicy::create rather than constructed directly, and are shared via shared_ptr. Like every SecurityPolicy the object is immutable and stateless, so its methods are safe to call concurrently from any thread.

SecurityPolicy

Functions

SecurityPolicyId id() const override

Returns SecurityPolicyId::None.

Returns: The identifier SecurityPolicyId::None.

String uri() const override

Returns the policy URI http://opcfoundation.org/UA/SecurityPolicy#None.

Returns: The URI http://opcfoundation.org/UA/SecurityPolicy#None.

CertificateType certificate_type() const override

Returns the certificate type required by this policy.

Returns: The certificate type, reflecting that no specific certificate type is required.

bool is_authenticated() const override

Returns false: the None policy performs no certificate-based authentication.

Returns: false; the None policy performs no certificate-based authentication.

bool is_rsa() const override

Returns false: the None policy is not an RSA-family policy.

Returns: false; the None policy is not an RSA-family policy.

bool is_ecc() const override

Returns false: the None policy is not an ECC-family policy.

Returns: false; the None policy is not an ECC-family policy.

bool uses_legacy_sequence_no() const override

Returns false: the None policy uses the modern sequence-number scheme.

Returns: false; the None policy uses the modern sequence-number scheme.

size_t nonce_length() const override

Returns the length, in bytes, of the nonce exchanged during channel setup.

Returns: The nonce length in bytes (0).

size_t symmetric_plaintext_block_size() const override

Returns the symmetric plaintext block size in bytes.

Returns: The symmetric plaintext block size in bytes (1).

size_t asymmetric_plaintext_block_size(const X509Certificate *certificate) const override

Returns the asymmetric plaintext block size in bytes.

• certificate (const X509Certificate *) - Certificate whose key size would normally determine the block size; ignored by this policy and may be null.

Returns: The asymmetric plaintext block size in bytes (1).

size_t symmetric_ciphertext_block_size() const override

Returns the symmetric ciphertext block size in bytes (1; no cipher, a unit block keeps chunk arithmetic well-defined).

Returns: The symmetric ciphertext block size in bytes (1).

size_t asymmetric_ciphertext_block_size(const X509Certificate *certificate) const override

Returns the asymmetric ciphertext block size in bytes (1; no cipher, a unit block keeps chunk arithmetic well-defined).

• certificate (const X509Certificate *) - Certificate whose key size would normally determine the block size; ignored by this policy and may be null.

Returns: The asymmetric ciphertext block size in bytes (1).

size_t symmetric_signature_size() const override

Returns the symmetric signature size in bytes (zero; messages are not signed).

Returns: The symmetric signature size in bytes (0).

size_t asymmetric_signature_size(const X509Certificate *certificate) const override

Returns the asymmetric signature size in bytes (zero; messages are not signed).

• certificate (const X509Certificate *) - Signing certificate; ignored by this policy and may be null.

Returns: The asymmetric signature size in bytes (0).

size_t symmetric_signature_key_size() const override

Returns the symmetric signature key size in bytes (zero; no key material is derived).

Returns: The symmetric signature-key size in bytes (0).

size_t symmetric_encryption_key_size() const override

Returns the symmetric encryption key size in bytes (zero; no key material is derived).

Returns: The symmetric encryption-key size in bytes (0).

size_t symmetric_iv_size() const override

Returns the symmetric initialization-vector size in bytes (zero; no symmetric encryption).

Returns: The symmetric IV size in bytes (0).

size_t min_asymmetric_key_length() const override

Returns the minimum accepted asymmetric key length in bits (zero; no asymmetric keys are used).

Returns: The minimum accepted asymmetric key length in bits (0).

size_t max_asymmetric_key_length() const override

Returns the maximum accepted asymmetric key length in bits (zero; no asymmetric keys are used).

Returns: The maximum accepted asymmetric key length in bits (0).

AsymmetricEncryptionAlgorithm asymmetric_encryption_algorithm() const override

Returns the none/no-encryption asymmetric algorithm.

Returns: The none/no-encryption AsymmetricEncryptionAlgorithm variant.

AsymmetricSignatureAlgorithm asymmetric_signature_algorithm() const override

Returns the none/no-signature asymmetric algorithm.

Returns: The none/no-signature AsymmetricSignatureAlgorithm variant.

String asymmetric_signature_algorithm_uri() const override

Returns the asymmetric signature algorithm URI, which is empty for the None policy.

Returns: The asymmetric signature algorithm URI, empty for the None policy.

SymmetricEncryptionAlgorithm symmetric_encryption_algorithm() const override

Returns the none/no-encryption symmetric algorithm.

Returns: The none/no-encryption SymmetricEncryptionAlgorithm variant.

SymmetricSignatureAlgorithm symmetric_signature_algorithm() const override

Returns the none/no-signature symmetric algorithm.

Returns: The none/no-signature SymmetricSignatureAlgorithm variant.

void derive_symmetric_keys_async(shared_ptr< SecureChannelContext > context, ByteString localNonce, ByteString remoteNonce, ChannelRole role, std::function< void(DeriveSymmetricKeysResult)> callback) const override

Derives the symmetric key set for a secure channel.

• context (shared_ptr< SecureChannelContext >) - Secure channel context the keys belong to; must outlive the call.
• localNonce (ByteString) - This endpoint's nonce; ignored by the None policy and may be empty.
• remoteNonce (ByteString) - The peer's nonce; ignored by the None policy and may be empty.
• role (ChannelRole) - Whether this endpoint is the channel's server or client.
• callback (std::function< void(DeriveSymmetricKeysResult)>) - Receives the derived key pair, or an ErrorDetail on failure.

ua::SecPolRsa