cipher.h

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/*
BSD 3-Clause License
 
Copyright (c) 2022, Stable Cloud Computing, Inc.
 
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
 
1. Redistributions of source code must retain the above copyright notice, this
   list of conditions and the following disclaimer.
 
2. Redistributions in binary form must reproduce the above copyright notice,
   this list of conditions and the following disclaimer in the documentation
   and/or other materials provided with the distribution.
 
3. Neither the name of the copyright holder nor the names of its
   contributors may be used to endorse or promote products derived from
   this software without specific prior written permission.
 
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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*/
#ifndef _SCC_CRYPTO_CIPHER_H
#define _SCC_CRYPTO_CIPHER_H
 
#include <stdint.h>
#include <string>
#include <vector>
//#include <util/iobase.h>
 
namespace scc::crypto {
 
class CipherBase
{
public:
    virtual void reset(const void*, int, const void*, int/*, uint64_t*/) = 0;
    virtual void aad(const void*, int) = 0;
    virtual void encrypt(const void*, int, void*, int) = 0;
    virtual void decrypt(const void*, int, void*, int) = 0;
    virtual void auth_tag(void*, int) = 0;
};
 
class Cipher
{
    CipherBase* m_ctx;
    int m_type;
public:
 
    enum Type
    {
        aes_gcm_type            =1000,
        aes_ccm_type            =2000,
    };
 
    Cipher(Type type, const void* key_loc, int key_len, int = 16);
    Cipher(Type type, const std::vector<char>& key, int tag_len = 16) : Cipher(type, key.data(), key.size(), tag_len) {}
    Cipher(Type type, const std::string& key, int tag_len = 16) : Cipher(type, key.data(), key.size(), tag_len) {}
    virtual ~Cipher();
    Cipher(const Cipher&) = delete;         // no copy
    Cipher& operator=(const Cipher&) = delete;
    Cipher(Cipher&& other)
    {
        m_ctx = other.m_ctx;
        m_type = other.m_type;
        other.m_ctx = nullptr;
        other.m_type = 0;
    }
    Cipher& operator=(Cipher&& other)
    {
        m_ctx = other.m_ctx;
        m_type = other.m_type;
        other.m_ctx = nullptr;
        other.m_type = 0;
        return *this;
    }
 
    size_t nonce_min() const
    {
        switch (m_type)
        {
            case aes_gcm_type: return 1;
            case aes_ccm_type: return 8;
        }
    }
    size_t nonce_max() const
    {
        switch (m_type)
        {
            case aes_gcm_type: return 128;      // not specified
            case aes_ccm_type: return 12;
        }
    }
 
    void reset(const void* nonce_loc, int nonce_len, const void* aad_loc = nullptr, int aad_len = 0/*, size_t msg_len*/)
    {
        m_ctx->reset(nonce_loc, nonce_len, aad_loc, aad_len);
    }
 
    void aad(const void* aad_loc, int aad_len)
    {
        m_ctx->aad(aad_loc, aad_len);
    }
 
    void encrypt(const void* msg_loc, int msg_len, void* cipher_loc, int cipher_len)
    {
        m_ctx->encrypt(msg_loc, msg_len, cipher_loc, cipher_len);
    }
 
    void decrypt(const void* cipher_loc, int cipher_len, void* msg_loc, int msg_len)
    {
        m_ctx->decrypt(cipher_loc, cipher_len, msg_loc, msg_len);
    }
 
    void auth_tag(char* tag_loc, int tag_len)
    {
        m_ctx->auth_tag(tag_loc, tag_len);
    }
};
}   // namespace
 
#endif