Crypto.h

#include <openssl/evp.h>
#include <openssl/pem.h>
#include <openssl/aes.h>
#include <openssl/err.h>
#include <openssl/rand.h>


#include <stdio.h>
#include <string.h>

#ifndef CRYPTO_H
#define CRYPTO_H

#define RSA_KEYLEN 2048
#define AES_ROUNDS 6

#define PSEUDO_CLIENT 

//#define USE_PBKDF

#define SUCCESS 0
#define FAILURE -1

#define KEY_SERVER_PRI 0
#define KEY_SERVER_PUB 1
#define KEY_CLIENT_PUB 2
#define KEY_AES        3
#define KEY_AES_IV     4

class Crypto {
  public:
    Crypto();
    Crypto(unsigned char *remotePubKey, size_t remotePubKeyLen);
    ~Crypto();

    int rsaEncrypt(const unsigned char *message, size_t messageLength, unsigned char **encryptedMessage, unsigned char **encryptedKey,
      size_t *encryptedKeyLength, unsigned char **iv, size_t *ivLength);
    int rsaDecrypt(unsigned char *encryptedMessage, size_t encryptedMessageLength, unsigned char *encryptedKey, size_t encryptedKeyLength,
      unsigned char *iv, size_t ivLength, unsigned char **decryptedMessage);

    int aesEncrypt(const unsigned char *message, size_t messageLength, unsigned char **encryptedMessage);
    int aesDecrypt(unsigned char *encryptedMessage, size_t encryptedMessageLength, unsigned char **decryptedMessage);

    int getRemotePublicKey(unsigned char **publicKey);
    int setRemotePublicKey(unsigned char *publicKey, size_t publicKeyLength);

    int getLocalPublicKey(unsigned char **publicKey);
    int getLocalPrivateKey(unsigned char **privateKey);

    int getAesKey(unsigned char **aesKey);
    int setAesKey(unsigned char *aesKey, size_t aesKeyLen);
    unsigned char * getAesKey();

    int getAesIv(unsigned char **aesIv);
    int setAesIv(unsigned char *aesIv, size_t aesIvLen);

    int writeKeyToFile(FILE *file, int key);

  private:
    static EVP_PKEY *localKeypair;
    EVP_PKEY *remotePublicKey;

    EVP_CIPHER_CTX *rsaEncryptContext;
    EVP_CIPHER_CTX *aesEncryptContext;

    EVP_CIPHER_CTX *rsaDecryptContext;
    EVP_CIPHER_CTX *aesDecryptContext;

    unsigned char *aesKey;
    unsigned char *aesIv;

    size_t aesKeyLength;
    size_t aesIvLength;

    int init();
    int generateRsaKeypair(EVP_PKEY **keypair);
    int generateAesKey(unsigned char **aesKey, unsigned char **aesIv);
    int bioToString(BIO *bio, unsigned char **string);
};

#endif