RSA Encrypt and Decrypt Strings

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

Download Chilkat RSA Public-Key Encryption ActiveX

LOCAL loRsa
LOCAL lnSuccess
LOCAL lcPublicKey
LOCAL lcPrivateKey
LOCAL lcPlainText
LOCAL loRsaEncryptor
LOCAL lnUsePrivateKey
LOCAL lcEncryptedStr
LOCAL loRsaDecryptor
LOCAL lcDecryptedStr

loRsa = CreateObject('Chilkat.Rsa')

lnSuccess = loRsa.UnlockComponent("Anything for 30-day trial")
IF (lnSuccess <> 1) THEN
    =MESSAGEBOX("RSA component unlock failed")
    QUIT
ENDIF

*  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 16384 bits.
lnSuccess = loRsa.GenerateKey(1024)
IF (lnSuccess <> 1) THEN
    =MESSAGEBOX(loRsa.LastErrorText)
    QUIT
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('Chilkat.Rsa')

*  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.
loRsaEncryptor.ImportPublicKey(lcPublicKey)

lnUsePrivateKey = 0

lcEncryptedStr = loRsaEncryptor.EncryptStringENC(lcPlainText,lnUsePrivateKey)
? lcEncryptedStr

*  Now decrypt:
loRsaDecryptor = CreateObject('Chilkat.Rsa')

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

lnUsePrivateKey = 1

lcDecryptedStr = loRsaDecryptor.DecryptStringENC(lcEncryptedStr,lnUsePrivateKey)

? lcDecryptedStr