(Visual FoxPro) RSA Encrypt/Decrypt Bytes

See more RSA Examples

Demonstrates how to RSA encrypt and decrypt byte data.

Note: This example requires Chilkat v11.0.0 or greater.

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ActiveX for 32-bit and 64-bit Windows

LOCAL lnSuccess
LOCAL loPubKey
LOCAL loRsa
LOCAL loPrng
LOCAL loKeyBytes
LOCAL loEncBytes
LOCAL loPrivKey
LOCAL lcPassword
LOCAL loDecBytes

lnSuccess = 0

* The RSA public key is used for encryption, and the private key for decryption.

* The public key's role is to make encryption accessible to anyone while ensuring that
* only the private key holder can decrypt the messages.
* The public key is designed to be widely distributed so anyone can use it to encrypt messages
* intended for the owner of the private key.

* Load our 2048-bit RSA public key.
loPubKey = CreateObject('Chilkat.PublicKey')
* In all Chilkat methods expecting a path, you pass either absolute or relative paths.
lnSuccess = loPubKey.LoadFromFile("qa_data/rsaKeys/myTestRsaPublic.pem")
IF (lnSuccess = 0) THEN
    ? loPubKey.LastErrorText
    RELEASE loPubKey
    CANCEL
ENDIF

loRsa = CreateObject('Chilkat.Rsa')

* Tell RSA to use the public key.
loRsa.UsePublicKey(loPubKey)

* RSA encryption is for small amounts of data, on the order of 200 bytes or less.
* The maximum number of bytes that can be RSA encrypted depends
* on the RSA key size and padding scheme (OAEP padding vs PKCS#1 v1.5 padding).
* For specific limits, see: RSA Encryption Maximum Number of Bytes

* A typical use for RSA is to encrypt symmetric encryption keys, such as an AES key.
loPrng = CreateObject('Chilkat.Prng')

loKeyBytes = loPrng.GenRandomBytes(32)

loEncBytes = loRsa.EncryptBytes(loKeyBytes,0)

* ------------------------------------------------------------------------------------------------------------------------
* Let's decrypt, which requires the matching private key...

* Load the matching 2048-bit RSA private key.
loPrivKey = CreateObject('Chilkat.PrivateKey')
lcPassword = "secret"
lnSuccess = loPrivKey.LoadAnyFormatFile("qa_data/rsaKeys/myTestRsaPrivate.pem",lcPassword)
IF (lnSuccess = 0) THEN
    ? loPrivKey.LastErrorText
    RELEASE loPubKey
    RELEASE loRsa
    RELEASE loPrng
    RELEASE loPrivKey
    CANCEL
ENDIF

* Tell the RSA object to use the private key.
loRsa.UsePrivateKey(loPrivKey)

loDecBytes = loRsa.DecryptBytes(loEncBytes,1)
IF (lnSuccess = 0) THEN
    ? loRsa.LastErrorText
    RELEASE loPubKey
    RELEASE loRsa
    RELEASE loPrng
    RELEASE loPrivKey
    CANCEL
ENDIF

? "Success."

RELEASE loPubKey
RELEASE loRsa
RELEASE loPrng
RELEASE loPrivKey