(Lianja) Duplicate openssl dgst -sha256 -verify pubKey.pem -signature signature.sig in.dat

Demonstrates how to duplicate this OpenSSL command:

openssl dgst -sha256 -verify pubKey.pem -signature signature.sig in.dat

The in.dat file contains the original data that was signed, and can contain text or binary data of any type. The above OpenSSL command does the following:

Creates a SHA256 digest of the contents of the input file.
Verifies the SHA256 digest using the public key.

Chilkat Lianja Extension Download

Chilkat Lianja Extension

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

loPubKey = createobject("CkPublicKey")

// Load the public key from an PEM file:
llSuccess = loPubKey.LoadFromFile("pubKey.pem")
if (llSuccess <> .T.) then
    ? loPubKey.LastErrorText
    release loPubKey
    return
endif

// Load the data of the original file that was signed.
loBdFileData = createobject("CkBinData")
llSuccess = loBdFileData.LoadFile("in.dat")

// Load the signature.
loBdSig = createobject("CkBinData")
llSuccess = loBdSig.LoadFile("signature.sig")

loRsa = createobject("CkRsa")

// Import the public key into the RSA component:
llSuccess = loRsa.ImportPublicKeyObj(loPubKey)
if (llSuccess <> .T.) then
    ? loRsa.LastErrorText
    release loPubKey
    release loBdFileData
    release loBdSig
    release loRsa
    return
endif

// OpenSSL uses big-endian.
loRsa.LittleEndian = .F.

llSuccess = loRsa.VerifyBd(loBdFileData,"sha256",loBdSig)
if (llSuccess <> .T.) then
    ? loRsa.LastErrorText
    ? "The signature was invalid."
    release loPubKey
    release loBdFileData
    release loBdSig
    release loRsa
    return
endif

? "The signature was verified."


release loPubKey
release loBdFileData
release loBdSig
release loRsa