KeyAgreementAlgorithm

internal enum KeyAgreementAlgorithm

The Key Agreement is a cryptographic method that allows users to compute shared secret key, after their public keys have been exchanged, allowing the use of a cryptographic algorithm.

Key Pair Generation


                    
                    
                    generateKeyPair(for:using:)

Generate a new key pair for the specified KeyAgreementAlgorithm and StandardizedDomainParameters.

Important

The returned reference to the key pair has to be freed by the caller. The pointer will reference a EVP_PKEY structure (so use EVP_PKEY_free then).

Declaration

Swift

internal static func generateKeyPair(for algorithm: KeyAgreementAlgorithm, using params: StandardizedDomainParameters) throws -> OpaquePointer

Parameters

`algorithm`	The used `KeyAgreementAlgorithm` (DH or ECDH).
`params`	The used `StandardizedDomainParameters`. It may be a standardized elliptic curve for ECDH or an algebric set for DH. Parameters includes the prime p, the generator g and the size of the prime-order subgroup generated by g.

Return Value

A reference to the generated key pair.


                    
                    
                    generateKeyPair(params:)

Generate a new key pair using the specified StandardizedDomainParameters.

Important

The returned reference to the key pair has to be freed by the caller. The pointer will reference a EVP_PKEY structure (so use EVP_PKEY_free then).

Declaration

Swift

internal func generateKeyPair(params: StandardizedDomainParameters) throws -> OpaquePointer

Parameters


                                params

The used StandardizedDomainParameters. It may be a standardized elliptic curve for ECDH or an algebric set for DH. Parameters includes the prime p, the generator g and the size of the prime-order subgroup generated by g.

Return Value

A reference to the generated key pair.


                    
                    
                    generateKeyPair(withParamsFrom:)

Generate a key pair based on the parameters of an existing public key.

Throws

An error if key pair generation fails.

Important

The returned reference to the key pair has to be freed by the caller. The pointer will reference a EVP_PKEY structure (so use EVP_PKEY_free then).

Declaration

Swift

internal static func generateKeyPair(withParamsFrom publicKey: OpaquePointer) throws -> OpaquePointer

Parameters


                                publicKey

A reference to an existing public key.

Return Value

A reference to the generated key pair.

Shared Secret Computation


                    
                    
                    computeSharedSecret(personalKeyPair:externalPublicKey:using:)

Compute the shared secret from the personal private key and the external public key using the specified KeyAgreementAlgorithm.

Tip: If you want to convert the returned reference to the shared secret into a byte representation as [UInt8], you can use convertToBytes(key:keyPair:for:) or convertToBytes(key:keyPair:) functions.

Important

The returned reference to the shared secret has to be freed by the caller. If the used algorithm is DH, the pointer will reference a BN structure (so use BN_free then), otherwise the pointer will reference a EC_POINT stucture (so use EC_POINT_free then). If you don’t know the used KeyAgreementAlgorithm or it is dynamic, you can also call free(sharedSecret:) or free(sharedSecret:for:) functions.

Declaration

Swift

internal static func computeSharedSecret(personalKeyPair: OpaquePointer, externalPublicKey: [UInt8], using algorithm: KeyAgreementAlgorithm) throws -> OpaquePointer

Parameters

`personalKeyPair`	The personal key pair object containg personal public/private keys and used params.
`externalPublicKey`	The bytes representing the external public key.
`algorithm`	The used `KeyAgreementAlgorithm` (DH or ECDH)

Return Value

A reference to the computed shared secret.


                    
                    
                    computeSharedSecret(personalKeyPair:externalPublicKey:)

Compute the shared secret from the personal private key and the external public key.

Tip: If you want to convert the returned reference to the shared secret into a byte representation as [UInt8], you can use convertToBytes(key:keyPair:for:) or convertToBytes(key:keyPair:) functions.

Important

Declaration

Swift

internal func computeSharedSecret(personalKeyPair: OpaquePointer, externalPublicKey: [UInt8]) throws -> OpaquePointer

Parameters

`personalKeyPair`	The personal key pair object containg personal public/private keys and used params.
`externalPublicKey`	The bytes representing the external public key.

Return Value

A reference to the computed shared secret.

Utils methods


                    
                    
                    extractPublicKey(from:)

Extract and return the public key from an OpaquePointer key pair.

Throws

An error if the extraction process fails or if the key type is not supported.

Declaration

Swift

internal static func extractPublicKey(from keyPair: OpaquePointer) throws -> [UInt8]

Parameters


                                keyPair

An OpaquePointer representing a key pair.

Return Value

An array of bytes representing the extracted public key.


                    
                    
                    extractPublicKey(from:)

Extract and return the public key from an OpaquePointer key pair.

Throws

An error if the extraction process fails.

Declaration

Swift

internal func extractPublicKey(from keyPair: OpaquePointer) throws -> [UInt8]

Parameters


                                keyPair

An OpaquePointer representing a key pair.

Return Value

An array of bytes representing the extracted public key.


                    
                    
                    decodePublicKey(from:withParams:)

Decode a public key from a byte array using the specified OpaquePointer parameters.

Throws

An error if the decoding process fails or if the key type is not supported.

Important

The returned reference to the public key has to be freed by the caller. The pointer will reference a EVP_PKEY structure (so use EVP_PKEY_free then).

Declaration

Swift

internal static func decodePublicKey(from bytes: [UInt8], withParams params: OpaquePointer) throws -> OpaquePointer

Parameters

`bytes`	The byte array representing the public key.
`params`	`OpaquePointer` parameters for the decoding operation.

Return Value

An OpaquePointer representing the decoded public key.


                    
                    
                    decodePublicKey(from:withParams:)

Decode a public key from a byte array using the specified OpaquePointer parameters.

Throws

An error if the decoding process fails.

Important

The returned reference to the public key has to be freed by the caller. The pointer will reference a EVP_PKEY structure (so use EVP_PKEY_free then).

Declaration

Swift

internal func decodePublicKey(from bytes: [UInt8], withParams params: OpaquePointer) throws -> OpaquePointer

Parameters

`bytes`	The byte array representing the public key.
`params`	`OpaquePointer` parameters for the decoding operation.

Return Value

An OpaquePointer representing the decoded public key.


                    
                    
                    convertToBytes(key:keyPair:for:)

Convert a key into an array of bytes using the specified KeyAgreementAlgorithm.

Throws

An error if the conversion fails.

Tip: keyPair is required just using ECDH.

Declaration

Swift

internal static func convertToBytes(key: OpaquePointer, keyPair: OpaquePointer? = nil, for algorithm: KeyAgreementAlgorithm) throws -> [UInt8]

Parameters

`key`	A key as an `OpaquePointer`.
`keyPair`	A key pair as an `OpaquePointer?` (default `nil`).
`algorithm`	The `KeyAgreementAlgorithm` used to perform the conversion.

Return Value

An array of bytes representing the shared secret.


                    
                    
                    convertToBytes(key:keyPair:)

Convert a key into an array of bytes.

Throws

An error if the conversion fails.

Tip: keyPair is required just using ECDH.

Declaration

Swift

internal func convertToBytes(key: OpaquePointer, keyPair: OpaquePointer? = nil) throws -> [UInt8]

Parameters

`sharedSecret`	A key as an `OpaquePointer`.
`keyPair`	A key pair as an `OpaquePointer?` (default `nil`).

Return Value

An array of bytes representing the shared secret.


                    
                    
                    free(sharedSecret:for:)

Free the shared secret reference computed with the given KeyAgreementAlgorithm.

Declaration

Swift

internal static func free(sharedSecret: OpaquePointer, for algorithm: KeyAgreementAlgorithm)

Parameters

`sharedSecret`	The shared secret reference.
`algorithm`	The `KeyAgreementAlgorithm` used to compute the secret.


                    
                    
                    free(sharedSecret:)

Free the shared secret reference.

Declaration

Swift

internal func free(sharedSecret: OpaquePointer)

Parameters


                                sharedSecret

The shared secret reference.