(Xojo Plugin) RSA Encrypt Bytes to Base64 and Reverse

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Demonstrates how to RSA encrypt bytes to base64 and the reverse.

Chilkat Xojo Plugin Download Xojo Plugin for Windows, Linux, Mac OS X, and ARM, ARM64

// 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.
Dim pubKey As New Chilkat.PublicKey
// In all Chilkat methods expecting a path, you pass either absolute or relative paths.
Dim success As Boolean
success = pubKey.LoadFromFile("qa_data/rsaKeys/myTestRsaPublic.pem")
If (success = False) Then
    System.DebugLog(pubKey.LastErrorText)
    Return
End If

Dim rsa As New Chilkat.Rsa

// Tell RSA to use the public key.
success = rsa.ImportPublicKeyObj(pubKey)

// 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.
Dim prng As New Chilkat.Prng
Dim keyBytes As MemoryBlock
keyBytes = prng.GenRandomBytes(32)

rsa.EncodingMode = "base64"
Dim encryptedB64 As String
encryptedB64 = rsa.EncryptBytesENC(keyBytes,False)

System.DebugLog("Result:")
System.DebugLog(encryptedB64)

// Sample output:
// hTTV4Lbmm2V7NCw/HaoJL8Aq/MM/HXblQnjitrF9HY1zBlISwui2jGVVZDtZcZ/rICOpPw44w8Qb8AswFVE1sryydmNEvcIfYAp/xgdBPXBERAS0y4AoEzUfuC5TJmJFvnFkl2lX8GAclANfcTik38V+k3EXu5wPzHKNFb07c6jnwh3Jm4f3PRUhmmB2NO5kSWqHsx0dNglOTq5BUZx34nxlXL5G8d7mXqITsUtrOHXAO/Gb7IrvB81Xk2vc5p4yHhiY/rFTHTTmZyzte2qHGm7V6xPRNURjiivnMY2jQU0Um1JKQcAiSe8Suwvd2LXP5PIhl71VLgO+fokjnynfRg==

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

// Load the matching 2048-bit RSA private key.
Dim privKey As New Chilkat.PrivateKey
Dim password As String
password = "secret"
success = privKey.LoadAnyFormatFile("qa_data/rsaKeys/myTestRsaPrivate.pem",password)
If (success = False) Then
    System.DebugLog(privKey.LastErrorText)
    Return
End If

// Tell the RSA object to use the private key.
success = rsa.ImportPrivateKeyObj(privKey)

Dim decBytes As MemoryBlock
decBytes = rsa.DecryptBytesENC(encryptedB64,True)
If (success = False) Then
    System.DebugLog(rsa.LastErrorText)
    Return
End If

System.DebugLog("Success.")