(Visual FoxPro) Verify an RSA Signature Against the Signed Hash

See more Apple Keychain Examples

Demonstrates how to validate an RSA Signature against the hash that was signed.

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

LOCAL loBd
LOCAL i
LOCAL lcSha256_base64
LOCAL lcBase64_rsa_sig
LOCAL loPubKey
LOCAL lnSuccess
LOCAL loRsa

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

FOR i = 0 TO 100
    loBd.AppendEncoded("000102030405060708090A0B0C0D0E0F","hex")
NEXT
lcSha256_base64 = loBd.GetHash("sha256","base64")
? "sha256 hash in base64 format: " + lcSha256_base64

lcBase64_rsa_sig = "AwF2BbOvL6jA5DwmMAc9n6J2Cc8PI6Rj5W079+aKJcIEtPWRzHor0Bvc3aftGM3Jbgj6SXlIC3M3RYS7UZOnfiHKFNZgbxaNT5WwsWooK42ZkC8DBZl0p7OunBUKd5SciUo+TKilioeUkriN3L1Zl9hwi3HVDVqgVo3XXskwIftSqLSFlepTLTmOWj9Y93dp8J4D9RyLtNgFQBc0WB22tyJTsuY56mLcWe1AMF3LizB9OrbwjynF2u16xWlrJdugccz795fJBUV9aQSD+8S3KeqwQhoi8RK1uhD68aGCyaSpBq0NZ8COAkn7MXaF4POxrAAt8udfHM+PRfSOptcH/w=="

* Get the public key to be used for signature verification.
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.PublicKey')
loPubKey = CreateObject('Chilkat.PublicKey')
lnSuccess = loPubKey.LoadFromFile("rsaKeys/chilkat-rsa-2048.pem")
IF (lnSuccess = 0) THEN
    ? loPubKey.LastErrorText
    RELEASE loBd
    RELEASE loPubKey
    CANCEL
ENDIF

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

* Verify the hash against the signature.
loRsa.EncodingMode = "base64"
lnSuccess = loRsa.VerifyHashENC(lcSha256_base64,"sha256",lcBase64_rsa_sig)

IF (lnSuccess = 0) THEN
    ? loRsa.LastErrorText
    ? "Signature invalid."
ELSE
    ? "Signature valid."
ENDIF

RELEASE loBd
RELEASE loPubKey
RELEASE loRsa