LimeCrypt

LimeCrypt provides an easy C++ interface to some cryptographic functionality without bothering the user with much details while providing secure defaults. LimeCrypt is in essence a wrapper around some of the Crypto++ Libary with an interface that is simple to use and supports C++ standard iostreams.

Table of Contents

• Features
• Building
• Examples
  • RSA
  • AES
• License

Features

Currently the LimeCrypt library provides methods for:

• RSA Public/Private Key cryptography
  • Key pair generation (and store to file, load from file)
  • Signing/Verification (Recovery and Appendix Schemes)
  • Encryption/Decryption
• Symmetric AES encryption/decryption
• Encoding and Decoding Base64 and Hex

Building

LimeCrypt comes with CMake build files and should build almost everywhere and should build everywhere where Crypto++ builds.

Example: Build the library including examples and tests inside the out of source build directory and run the tests.

$ cd lime-crypt
$ mkdir build && cd build
$ cmake .. -DBUILD_EXAMPLES=1 -DBUILD_TESTS=1
$ make
$ make test

Note: You will need to run a

git submodule update

if you have a fresh checkout to build the tests. This will fetch the googletest submodule.

Examples

RSA

For more detailed examples see the examples directory.

Create, Save and Load Keys

#include <lcpubkey.h>
#include <lcencode.h>

// Uninitialized, invalid private key instance.
PrivateKey privKey;
// Create a new random private key with default key size.
if (privKey.create()) std::cout << "Created new private key." << std::endl;
// Create matching public key instance, derived from the private key.
PublicKey pubKey(privKey);

// Save keys to files
privKey.save("privateKey.file");
pubKey.save("publicKey.file");

// Load keys from files
privKey.load("privateKey.file");
pubKey.load("publicKey.file");

// Check if keys are valid
if (!privKey.isValid()) std::cout << "Invalid Private Key..." << std::endl;
if (!pubKey.isValid()) std::cout << "Invalid Public Key..." << std::endl;

Sign and Verify

For more detailed examples see the examples directory.

Sign (Appendix Scheme)

std::stringstream in("This is my message."), signed;
privKey.signWithAppendix(in, signed);

std::cout << "Signed message with recovery - Hex format (")
          << signed.str().size() << " bytes): " << Hex::encode(signed.str());

Simple Verify (Appendix Scheme)

if (pubKey.verifyWithAppendix(signed))
    std::cout << "Signature verified." << std::endl;
else
    std::cout << "Signature verification failed." << std::endl;

AES

For more detailed examples see the examples directory.

Encrypt

#include <lcaes.h>
#include <lcencode.h>

std::stringstream in("Secret Message."), encrypted;
AES::encrypt("MyPassphrase", in, encrypted);
std::cout << "Encrypted Message - Hex format (")
          << encrypted.str().size() << " bytes): "
          << Hex::encode(encrypted.str());

Decrypt

std::stringstream decrypted;
AES::encrypt("MyPassphrase", encrypted, decrypted);
std::cout << "Decrypted Message ("
          << decrypted.str().size() << " bytes): "
          << decrypted.str();

License

See LICENSE.