(PureBasic) Duplicate PHP RSA Encryption

Demonstrates how to duplicate the following PHP function.

Note: This example requires Chilkat v11.0.0 or greater.

Chilkat PureBasic Module Download Chilkat PureBasic Module

IncludeFile "CkBinData.pb"
IncludeFile "CkXml.pb"
IncludeFile "CkRsa.pb"
IncludeFile "CkPublicKey.pb"

Procedure ChilkatExample()

    success.i = 0

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

    ; Duplicate the following PHP code:
    ; 
    ;    public function encryptRSA($plainText,$rsaMOD,$pubKEY){
    ;         $rsa  = new RSA();
    ;         $rsa->setEncryptionMode(RSA::ENCRYPTION_PKCS1);
    ;         $publicKey = [
    ;             'e' => new BigInteger($pubKEY,16),
    ;             'n' => new BigInteger($rsaMOD,16)
    ;         ];
    ; 		
    ;         $rsa->loadKey($publicKey);
    ;         $ciphertext = $rsa->encrypt($plainText);
    ;         return bin2hex($ciphertext);
    ;     }
    ; 
    ;     $plainText="key=abcdefghijkmnopq&iv=abcdefghijkmnopq&h=12345678&s=12345678"
    ;     $rsaMOD="F0946D8F05604809E24B8CFFD30349CEA9E5F4D320BFD9E9AA1B088863F02C43E7997D37A3E27B4F8F359F1744DB6B20A437067C0D325A80660D12FF56A57673"
    ;     $pubKEY="010001"

    ; We have the RSA modulus in hex
    rsaMOD.s = "F0946D8F05604809E24B8CFFD30349CEA9E5F4D320BFD9E9AA1B088863F02C43E7997D37A3E27B4F8F359F1744DB6B20A437067C0D325A80660D12FF56A57673"

    ; The RSA exponent in hex is "010001", which is 65537 in decimal.  It's typically the exponent that is always used.
    rsaEXP.s = "010001"

    ; Get the RSA modulus and exponent in base64.
    bdMod.i = CkBinData::ckCreate()
    If bdMod.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

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

    success = CkBinData::ckAppendEncoded(bdMod,rsaMOD,"hex")
    success = CkBinData::ckAppendEncoded(bdExp,rsaEXP,"hex")

    ; Build the XML representation of the RSA public key
    xml.i = CkXml::ckCreate()
    If xml.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkXml::setCkTag(xml, "RSAPublicKey")
    CkXml::ckUpdateChildContent(xml,"Modulus",CkBinData::ckGetEncoded(bdMod,"base64"))
    CkXml::ckUpdateChildContent(xml,"Exponent",CkBinData::ckGetEncoded(bdExp,"base64"))

    ; Load the RSA public key into a Chilkat public key object.
    pubkey.i = CkPublicKey::ckCreate()
    If pubkey.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkPublicKey::ckLoadFromString(pubkey,CkXml::ckGetXml(xml))

    ; Setup the RSA object for encryption and do it..
    rsa.i = CkRsa::ckCreate()
    If rsa.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkRsa::setCkVerboseLogging(rsa, 1)
    success = CkRsa::ckUsePublicKey(rsa,pubkey)

    ; Use PKCSv1.5 padding
    CkRsa::setCkPkcsPadding(rsa, 0)

    ; Encrypt and return the string as hex.
    CkRsa::setCkEncodingMode(rsa, "hex")
    plainText.s = "key=abcdefghijkmnopq&iv=abcdefghijkmnopq&h=12345678&s=12345678"
    cipherText.s = CkRsa::ckEncryptStringENC(rsa,plainText,0)
    If CkRsa::ckLastMethodSuccess(rsa) = 0
        Debug CkRsa::ckLastErrorText(rsa)
        CkBinData::ckDispose(bdMod)
        CkBinData::ckDispose(bdExp)
        CkXml::ckDispose(xml)
        CkPublicKey::ckDispose(pubkey)
        CkRsa::ckDispose(rsa)
        ProcedureReturn
    EndIf

    ; Note: The PKCSv1_5 padding incorporates random bytes.  Therefore, the RSA encryption will produce different results each time -- all of which are valid 
    ; and decrypt correctly to the same original text.
    Debug cipherText


    CkBinData::ckDispose(bdMod)
    CkBinData::ckDispose(bdExp)
    CkXml::ckDispose(xml)
    CkPublicKey::ckDispose(pubkey)
    CkRsa::ckDispose(rsa)


    ProcedureReturn
EndProcedure