使用Poco库进行加解密和签名验签

最近一个朋友让我帮忙找一下使用Poco库进行非对称加密的例子，通过百度，Google找到两个不错的在此总结一下：

Poco开源代码库地址：https://github.com/pocoproject/poco

在Crypto/testsuit/src/RSATest.h和RSATest..cpp有示例代码可以参考。

下面是摘自另一个网站上的部分代码，图文并茂，感觉讲得很好，拿来分享给大家。

非对称加解密过程如图：

代码如下：

#include "Poco/Crypto/RSAKey.h"
#include "Poco/Crypto/RSADigestEngine.h“

auto& factory = CipherFactory::defaultFactory();
string transmission;

{
  Cipher* alice = factory.createCipher(RSAKey( "public_bob.pem"));
  transmission = alice->encryptString(
    "Tall tree, Spy-glass shoulder, ... Skeleton Island ESE and by E");
}

{
  Cipher* bob = factory.createCipher(RSAKey( "", "private_bob.pem", "bobbob"));
  string decrypted = bob->decryptString(transmission);
  assert(decrypted == "Tall tree, Spy-glass shoulder, ... Skeleton Island ESE and by E");
}

签名&验签过程如图：

代码如下：

// Poco::DigestEngine::Digest is std::vector 
tuple transmission;

{
  string contract = 
    "Alice will give Bob $100 and Bob will give Alice two magic mushrooms";
  RSADigestEngine bob(RSAKey("", "private_bob.pem", "bobbob"));
  bob.update(contract);
  transmission = make_tuple(contract, bob.signature());
}

{
  RSADigestEngine alice(RSAKey("public_bob.pem"));
  alice.update(get<0>(transmission));
  bool isValid = alice.verify(get<1>(transmission));
  assert(isValid == true);
}