(Lianja) Encrypt with Chilkat, Decrypt with OpenSSL

Demonstrates how to RSA encrypt a string using Chilkat, and then shows the corresponding OpenSSL command to RSA decrypt. The OpenSSL command to decrypt is as follows:

openssl rsautl -decrypt -inkey VP_Private.pem -in rsa_encrypted.bin -out original.txt

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

loRsa = createobject("CkRsa")

// Note: RSA encryption uses the public key.  
// RSA decryption uses the private key.
// The reason is that the public key can be freely provided to anybody.  This allows anybody
// to send an encrypted message to the private key owner, and only the private key owner 
// can decrypt.
loKey = createobject("CkPublicKey")

// Load an RSA public key from a PEM file:
llSuccess = loKey.LoadFromFile("qa_data/pem/VP_Public.pem")
if (llSuccess <> .T.) then
    ? loKey.LastErrorText
    release loRsa
    release loKey
    return
endif

// Load the public key into the RSA object.
llSuccess = loRsa.ImportPublicKeyObj(loKey)
if (llSuccess <> .T.) then
    ? loRsa.LastErrorText
    release loRsa
    release loKey
    return
endif

lcStrToEncrypt = "00000000;XYZ2-3BHQ-ABCD-MMVV;6MY1-GHJK-9LRR;0"

// The LittleEndian property is .F. by default, but it is set here
// anyway to show that LittleEndian byte ordering is required for OpenSSL compatibility.
loRsa.LittleEndian = .F.

llUsePrivateKey = .F.

loEncryptedBytes = loRsa.EncryptString(lcStrToEncrypt,llUsePrivateKey)
if (loRsa.LastMethodSuccess <> .T.) then
    ? loRsa.LastErrorText
    release loRsa
    release loKey
    return
endif

// The OpenSSL command to decrypt would be this:
// openssl rsautl -decrypt -inkey VP_Private.pem -in rsa_encrypted.bin -out original.txt

loFac = createobject("CkFileAccess")
llSuccess = loFac.WriteEntireFile("qa_output/rsa_encrypted.bin",loEncryptedBytes)
if (llSuccess <> .T.) then
    ? loFac.LastErrorText
    release loRsa
    release loKey
    release loFac
    return
endif

? "RSA Encryption Succeeded."


release loRsa
release loKey
release loFac