(PureBasic) RSA Encrypt and OpenSSL Decrypt

Demonstrates how to use Chilkat to RSA encrypt, and then use OpenSSL to decrypt.

Chilkat PureBasic Module Download Chilkat PureBasic Module

IncludeFile "CkBinData.pb"
IncludeFile "CkPrivateKey.pb"
IncludeFile "CkRsa.pb"

Procedure ChilkatExample()

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

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

    success.i = CkRsa::ckGenerateKey(rsa,2048)

    privKey.i = CkRsa::ckExportPrivateKeyObj(rsa)
    success = CkPrivateKey::ckSavePkcs8PemFile(privKey,"qa_output/privKey.pem")
    CkPrivateKey::ckDispose(privKey)

    CkRsa::setCkEncodingMode(rsa, "base64")
    plainText.s = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz01234567890"
    bUsePrivateKey.i = 0
    encryptedStr.s = CkRsa::ckEncryptStringENC(rsa,plainText,bUsePrivateKey)

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

    CkBinData::ckAppendEncoded(bd,encryptedStr,"base64")
    success = CkBinData::ckWriteFile(bd,"qa_output/enc.dat")

    ;  The OpenSSL command to decrypt is:
    ;  openssl pkeyutl -in enc.dat -inkey privKey.pem -keyform PEM -pkeyopt rsa_padding_mode:pkcs1 -decrypt

    Debug "OK"


    CkRsa::ckDispose(rsa)
    CkBinData::ckDispose(bd)


    ProcedureReturn
EndProcedure