(Visual FoxPro) RSA Encrypt and Decrypt Strings

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

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

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

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

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Rsa')
loRsa = CreateObject('Chilkat.Rsa')

* 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.
lnSuccess = loRsa.GenerateKey(1024)
IF (lnSuccess <> 1) THEN
    ? loRsa.LastErrorText
    RELEASE loRsa
    CANCEL
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:
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Rsa')
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.
lnSuccess = loRsaEncryptor.ImportPublicKey(lcPublicKey)

lnUsePrivateKey = 0
lcEncryptedStr = loRsaEncryptor.EncryptStringENC(lcPlainText,lnUsePrivateKey)
? lcEncryptedStr

* Now decrypt:
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Rsa')
loRsaDecryptor = CreateObject('Chilkat.Rsa')

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

lnUsePrivateKey = 1
lcDecryptedStr = loRsaDecryptor.DecryptStringENC(lcEncryptedStr,lnUsePrivateKey)

? lcDecryptedStr

RELEASE loRsa
RELEASE loRsaEncryptor
RELEASE loRsaDecryptor