(Visual Basic 6.0) RSA Encrypt and OpenSSL Decrypt

Demonstrates how to use Chilkat to RSA encrypt, and then use OpenSSL to decrypt.

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

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

Dim success As Long
success = 0

' This requires the Chilkat API to have been previously unlocked.
' See Global Unlock Sample for sample code.

Dim rsa As New ChilkatRsa

Dim privKey As New PrivateKey
success = rsa.GenKey(2048,privKey)
success = privKey.SavePkcs8PemFile("qa_output/privKey.pem")

Dim pubKey As New PublicKey
success = privKey.ToPublicKey(pubKey)

rsa.EncodingMode = "base64"
Dim plainText As String
plainText = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz01234567890"
Dim bUsePrivateKey As Long
bUsePrivateKey = 0
success = rsa.UsePublicKey(pubKey)
Dim encryptedStr As String
encryptedStr = rsa.EncryptStringENC(plainText,bUsePrivateKey)

Dim bd As New ChilkatBinData
success = bd.AppendEncoded(encryptedStr,"base64")
success = bd.WriteFile("qa_output/enc.dat")

' The OpenSSL command to decrypt is:
' openssl pkeyutl -in enc.dat -inkey privKey.pem -keyform PEM -pkeyopt rsa_padding_mode:pkcs1 -decrypt

Debug.Print "OK"