ibrcommon/ibrcommon/ssl/RSASHA256Stream.cpp

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#include "ibrcommon/ssl/RSASHA256Stream.h"
#include "ibrcommon/Logger.h"
#include <openssl/err.h>

namespace ibrcommon
{
        RSASHA256Stream::RSASHA256Stream(EVP_PKEY * const pkey, bool verify)
         : ostream(this), out_buf_(new char[BUFF_SIZE]), _pkey(pkey), _verify(verify), _sign_valid(false)
        {
                // Initialize get pointer.  This should be zero so that underflow is called upon first read.
                setp(out_buf_, out_buf_ + BUFF_SIZE - 1);
                EVP_MD_CTX_init(&_ctx);

                if (!_verify)
                {
                        if (!EVP_SignInit_ex(&_ctx, EVP_sha256(), NULL))
                        {
                                IBRCOMMON_LOGGER(critical) << "failed to initialize the signature function" << IBRCOMMON_LOGGER_ENDL;
                                ERR_print_errors_fp(stderr);
                        }
                }
                else
                {
                        if (!EVP_VerifyInit_ex(&_ctx, EVP_sha256(), NULL))
                        {
                                IBRCOMMON_LOGGER(critical) << "failed to initialize the verfication function" << IBRCOMMON_LOGGER_ENDL;
                                ERR_print_errors_fp(stderr);
                        }
                }
        }

        RSASHA256Stream::~RSASHA256Stream()
        {
                EVP_MD_CTX_cleanup(&_ctx);
                delete[] out_buf_;
        }

        void RSASHA256Stream::reset()
        {
                EVP_MD_CTX_cleanup(&_ctx);

                EVP_MD_CTX_init(&_ctx);

                if (!_verify)
                {
                        if (!EVP_SignInit_ex(&_ctx, EVP_sha256(), NULL))
                        {
                                IBRCOMMON_LOGGER(critical) << "failed to initialize the signature function" << IBRCOMMON_LOGGER_ENDL;
                                ERR_print_errors_fp(stderr);
                        }
                }
                else
                {
                        if (!EVP_VerifyInit_ex(&_ctx, EVP_sha256(), NULL))
                        {
                                IBRCOMMON_LOGGER(critical) << "failed to initialize the verfication function" << IBRCOMMON_LOGGER_ENDL;
                                ERR_print_errors_fp(stderr);
                        }
                }

                _sign_valid = false;
        }

        const std::pair< const int, const std::string > RSASHA256Stream::getSign()
        {
                // check if data was feed into the stream and the sign needs to be
                // recalculated
                if (!_sign_valid)
                {
                        sync();
                        unsigned char * sign = new unsigned char[EVP_PKEY_size(_pkey)];
                        unsigned int size;

                        _return_code = EVP_SignFinal(&_ctx, sign, &size, _pkey);

                        _sign = std::string(reinterpret_cast<const char * const>(sign), size);
                        delete [] sign;
                        _sign_valid = true;
                }
                return std::pair<const int, const std::string>(_return_code, _sign);
        }

        int RSASHA256Stream::getVerification(const std::string& their_sign)
        {
                // check if data was feed into the stream and the sign needs to be
                // recalculated
                if (!_sign_valid)
                {
                        sync();
                        _return_code = EVP_VerifyFinal(&_ctx, reinterpret_cast<const unsigned char *>(their_sign.c_str()), their_sign.size(), _pkey);
                        _sign_valid = true;
                }
                return _return_code;
        }

        int RSASHA256Stream::sync()
        {
                int ret = std::char_traits<char>::eq_int_type(this->overflow(
                                std::char_traits<char>::eof()), std::char_traits<char>::eof()) ? -1
                                : 0;

                return ret;
        }

        RSASHA256Stream::traits::int_type RSASHA256Stream::overflow(RSASHA256Stream::traits::int_type c)
        {
                char *ibegin = out_buf_;
                char *iend = pptr();

                // mark the buffer as free
                setp(out_buf_, out_buf_ + BUFF_SIZE - 1);

                if (!std::char_traits<char>::eq_int_type(c, std::char_traits<char>::eof()))
                {
                        //TODO writing one byte after the buffer?
                        *iend++ = std::char_traits<char>::to_char_type(c);
                }

                // if there is nothing to send, just return
                if ((iend - ibegin) == 0)
                {
                        return std::char_traits<char>::not_eof(c);
                }

                if (!_verify)
                        // hashing
                {
                        if (!EVP_SignUpdate(&_ctx, reinterpret_cast<unsigned char*>(out_buf_), iend - ibegin))
                        {
                                IBRCOMMON_LOGGER(critical) << "failed to feed data into the signature function" << IBRCOMMON_LOGGER_ENDL;
                                ERR_print_errors_fp(stderr);
                        }
                }
                else
                {
                        if (!EVP_VerifyUpdate(&_ctx, reinterpret_cast<unsigned char*>(out_buf_), iend - ibegin))
                        {
                                IBRCOMMON_LOGGER(critical) << "failed to feed data into the verfication function" << IBRCOMMON_LOGGER_ENDL;
                                ERR_print_errors_fp(stderr);
                        }
                }

                return std::char_traits<char>::not_eof(c);
        }
}