SecKeyCreateSignature(_:_:_:_:)

Declaration

func SecKeyCreateSignature(_ key: SecKey, _ algorithm: SecKeyAlgorithm, _ dataToSign: CFData, _ error: UnsafeMutablePointer<Unmanaged<CFError>?>?) -> CFData?

Parameters

• key:

  The private key to use in creating the signature.

• algorithm:

  The signing algorithm to use. Use one of the signing algorithms listed in Seckeyalgorithm. You can use the Seckeyisalgorithmsupported(_:_:_:) function to test that the key is suitable for the algorithm.

• dataToSign:

  The data whose signature you want.

• error:

  The address of a Cferror object. If an error occurs, this is set to point at an error instance that describes the failure.

Mentioned in

• Signing and Verifying

Return Value

The digital signature or NULL on failure. In Objective-C, call the CFRelease function to free the data’s memory when you are done with it.

Discussion

You later evaluate the combined data and signature with the corresponding public key and a call to the SecKeyVerifySignature(_:_:_:_:_:) function.