RSA Encryption -- Same Key Different Results

Download 32-bit Chilkat RSA ActiveX (.msi)

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The RSA encryption algorithm produces different results for each call, even when encrypting the same data with the same key. Decryption however, will produce the correct results. This example demonstrates.

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body>
<%
set rsa = Server.CreateObject("Chilkat.Rsa")

success = rsa.UnlockComponent("Anything for 30-day trial")
If (success <> 1) Then
    Response.Write Server.HtmlEncode("RSA component unlock failed") & "<br>"

End If

'  RSA public key in XML format:
publicKey = "<RSAKeyValue><Modulus>xxyv1RDPU0MvfFIIa98HppXdcuI7zSu8uIqyGAy/VoxPvxZFX0acajznvjVRHipHbpcO6ryo2LwXUPf89qOqLb3Qd1lfD2ZnH+TQ6MZXNxfFRxTpTUd+tTR4EBYpd2t6kzq8ZRJYLdlviaMQQqUEwR54k7Op5HJYVKUcHIkP1xE=</Modulus><Exponent>AQAB</Exponent></RSAKeyValue>"

privateKey = "<RSAKeyValue><Modulus>xxyv1RDPU0MvfFIIa98HppXdcuI7zSu8uIqyGAy/VoxPvxZFX0acajznvjVRHipHbpcO6ryo2LwXUPf89qOqLb3Qd1lfD2ZnH+TQ6MZXNxfFRxTpTUd+tTR4EBYpd2t6kzq8ZRJYLdlviaMQQqUEwR54k7Op5HJYVKUcHIkP1xE=</Modulus><Exponent>AQAB</Exponent><P>4cpW9fvG99Jsz8/AO7PDHTl+pPRAglksrR2kClLV2g9DEeFe/bvmCxLUgMCJ+0eGQ1zA6aA7McKr13zTQ7jKpQ==</P><Q>4cCS/kFlq/P1ExF37Fkh4pCodOEGutepLEG7Q/KljT3ZGlAY+2l8fGu4f+hrkUuGoFl7NOMaJflULoPIgQaq/Q==</Q><DP>lkjcSsvzqh3YKRXJiLNkyf3rypV8noYGU4+oEOsDxilkZfFRDafUPUiiQrRk4ui/d/SzvozU+ZDuWfaOk8PatQ==</DP><DQ>SYCD25i7W8Mwdibn3uIecEAdOQDTSh5RjIFSUYs9b8FFYJXXrHPp/jCsf6jS7RmkGa1Iui1/JAIL8KEjtS7QmQ==</DQ><InverseQ>EDAJa3TpNdPQ3GIdBpnTgFTQY5A60DcszsUW/iCYoXQdPVJ9BLBxVTe9jiLzGuNuzLkVBwQlCy0Bf84hACRV9A==</InverseQ><D>cMFdDYKkddlRNczaugOmOH8b1egpx2liSPs6GYZ2gFObAXJiPK8m+r6c2ckls7hrlUP0DZhi4cG6Tn7xANb0Ek17P7QquVhQYOmFy/YHzm+IJbcwwq7pJHhZBhtcjyXqfUZ+BADGE//GQbrSVwVltpOj5KcxG88NAprLn2MMxfE=</D></RSAKeyValue>"

rsa.ImportPublicKey publicKey

'  Encrypt a string and return the encrypted data base64-encoded:
rsa.EncodingMode = "base64"

plainText = "RSA gives different results with each call, weird but OK"

usePrivateKey = 0
encryptedStr1 = rsa.EncryptStringENC(plainText,usePrivateKey)
Response.Write Server.HtmlEncode(encryptedStr1) & "<br>"

'  Do it again. The results are different...
encryptedStr2 = rsa.EncryptStringENC(plainText,usePrivateKey)
Response.Write Server.HtmlEncode(encryptedStr2) & "<br>"

'  Now decrypt both strings, and the results are correct
'  in both cases:
set rsa2 = Server.CreateObject("Chilkat.Rsa")
rsa2.ImportPrivateKey privateKey
rsa2.EncodingMode = "base64"
usePrivateKey = 1

decryptedStr1 = rsa2.DecryptStringENC(encryptedStr1,usePrivateKey)
Response.Write Server.HtmlEncode(decryptedStr1) & "<br>"

decryptedStr2 = rsa2.DecryptStringENC(encryptedStr2,usePrivateKey)
Response.Write Server.HtmlEncode(decryptedStr2) & "<br>"


%>
</body>
</html>