(Lianja) RSA Encrypt and Decrypt Strings

Lianja sample code to RSA public-key encrypt and decrypt strings using public and private keys.

Chilkat Lianja Extension Download Chilkat Lianja Extension

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

loRsa = createobject("CkRsa")

// This example also generates the public and private
// keys to be used in the RSA encryption.
// Normally, you would generate a key pair once,
// and distribute the public key to your partner.
// Anything encrypted with the public key can be
// decrypted with the private key.  The reverse is 
// also true: anything encrypted using the private
// key can be decrypted using the public key.

// Generate a 1024-bit key.  Chilkat RSA supports
// key sizes ranging from 512 bits to 4096 bits.
llSuccess = loRsa.GenerateKey(1024)
if (llSuccess <> .T.) then
    ? loRsa.LastErrorText
    release loRsa
    return
endif

// Keys are exported in XML format:
lcPublicKey = loRsa.ExportPublicKey()
lcPrivateKey = loRsa.ExportPrivateKey()

lcPlainText = "Encrypting and decrypting should be easy!"

// Start with a new RSA object to demonstrate that all we
// need are the keys previously exported:
loRsaEncryptor = createobject("CkRsa")

// Encrypted output is always binary.  In this case, we want
// to encode the encrypted bytes in a printable string.
// Our choices are "hex", "base64", "url", "quoted-printable".
loRsaEncryptor.EncodingMode = "hex"

// We'll encrypt with the public key and decrypt with the private
// key.  It's also possible to do the reverse.
llSuccess = loRsaEncryptor.ImportPublicKey(lcPublicKey)

llUsePrivateKey = .F.
lcEncryptedStr = loRsaEncryptor.EncryptStringENC(lcPlainText,llUsePrivateKey)
? lcEncryptedStr

// Now decrypt:
loRsaDecryptor = createobject("CkRsa")

loRsaDecryptor.EncodingMode = "hex"
llSuccess = loRsaDecryptor.ImportPrivateKey(lcPrivateKey)

llUsePrivateKey = .T.
lcDecryptedStr = loRsaDecryptor.DecryptStringENC(lcEncryptedStr,llUsePrivateKey)

? lcDecryptedStr


release loRsa
release loRsaEncryptor
release loRsaDecryptor