(PureBasic) Apple Keychain - Create RSA Signature

See more Apple Keychain Examples

Using an RSA private key stored in the Apple Keychain, create a signature by signing the SHA-256 hash of the provided string, then return the signature encoded in Base64 format.

Note: This example requires Chilkat v10.0.0 or greater.

Chilkat PureBasic Module Download

Chilkat PureBasic Module

IncludeFile "CkRsa.pb"
IncludeFile "CkCert.pb"

Procedure ChilkatExample()

    ; This example requires the Chilkat API to have been previously unlocked.
    ; See Global Unlock Sample for sample code.

    cert.i = CkCert::ckCreate()
    If cert.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; On MacOS and iOS, the LoadByCommonName function will search the Apple Keychain for the matching certificate.

    ; A digital certificate's Common Name (CN) is a field in the certificate that specifies the name of the entity the 
    ; certificate is issued to. It is often used to identify the domain name, hostname, or organization the certificate represents. 

    ; For example:
    ; - In an SSL/TLS certificate for a website, the CN typically contains the domain name (e.g., "www.example.com").
    ; - For certificates representing individuals or organizations, the CN might include the person's name or the organization's name.

    ; The CN is part of the certificate's Subject field and is crucial for verifying that the certificate corresponds 
    ; to the intended entity, especially in SSL/TLS communications.

    success.i = CkCert::ckLoadByCommonName(cert,"Example, Inc.")
    If success = 0
        Debug CkCert::ckLastErrorText(cert)
        CkCert::ckDispose(cert)
        ProcedureReturn
    EndIf

    rsa.i = CkRsa::ckCreate()
    If rsa.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkRsa::ckSetX509Cert(rsa,cert,1)
    If success = 0
        Debug CkRsa::ckLastErrorText(rsa)
        CkCert::ckDispose(cert)
        CkRsa::ckDispose(rsa)
        ProcedureReturn
    EndIf

    ; Generate an RSA signature by signing the SHA-256 hash of the provided string, 
    ; then return the signature encoded in Base64 format.
    CkRsa::setCkEncodingMode(rsa, "base64")
    sigBase64.s = CkRsa::ckSignStringENC(rsa,"to be signed","sha256")
    If CkRsa::ckLastMethodSuccess(rsa) = 0
        Debug CkRsa::ckLastErrorText(rsa)
        CkCert::ckDispose(cert)
        CkRsa::ckDispose(rsa)
        ProcedureReturn
    EndIf

    Debug "RSA Signature:"
    Debug sigBase64


    CkCert::ckDispose(cert)
    CkRsa::ckDispose(rsa)


    ProcedureReturn
EndProcedure