Signature

Question

Create a signature with ECDsaP256

Solution

// Signature.cpp : main project file.

#include "stdafx.h"

#using <System.Core.dll>

#using <mscorlib.dll>

using namespace System;

using namespace System::Security::Cryptography;

using namespace System::Text;

int main(array<System::String ^> ^args)

{

//Creates a CngKey object that represents a new key

CngKey^ aliceKeySignature = CngKey::Create(CngAlgorithm::ECDsaP256);

// Get Alice public key

array<unsigned char, 1>^ alicePubKeyBlob = aliceKeySignature->Export(CngKeyBlobFormat::GenericPublicBlob);

array<unsigned char>^ aliceData = Encoding::UTF8->GetBytes("Alice");

// Encoding signiture with public key

ECDsaCng^ signingAlg = gcnew ECDsaCng(aliceKeySignature);

array<unsigned char>^ aliceSignature;

try{

aliceSignature = signingAlg->SignData(aliceData);

signingAlg->Clear();

}

finally{

delete signingAlg;

}

Console::WriteLine("Alice created signature: {0}",Convert::ToBase64String(aliceSignature));

// Verify signature

bool matched = false;

CngKey^ key = CngKey::Import(alicePubKeyBlob, CngKeyBlobFormat::GenericPublicBlob);

signingAlg = gcnew ECDsaCng(key);

try{

matched = signingAlg->VerifyData(aliceData, aliceSignature);

signingAlg->Clear();

Console::WriteLine(matched);

}

finally{

delete signingAlg;

}

return 0;

}

Output

Alice created signature: dywy5jpWv3D4IlMuum6bIDj+L60j/xsZvPA6fGFkPtMkITik8ZnWwU9GnNuI6MYUbvxjOsue2jlUB1j+Y7rhJg==

True

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