sslCheckSum.cpp

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#include "sslCheckSum.h"
#include "block.h"
#include <iomanip>
#include <iostream>
#include <sstream>
#include <vector>
#include <openssl/objects.h>
#include <list>
namespace checksum {
    void sslSum::createFactoryCallback(const OBJ_NAME *obj, void */*arg*/) {
        std::string name(obj->name);
        for (const auto& unwanted : {
                    "With", "with", "Encryption", "ssl2-", "ssl3-", "160"
                }) {
            if (name.find(unwanted) != decltype(name)::npos) {
                return;
            }
        }
        if (name.front() >= 'A' && name.front() <= 'Z') {
            return;
        }
        new base::factoryTemplate<sslSum>(name);
    }
    bool sslSum::createFactories() {
        OpenSSL_add_all_digests();
        OBJ_NAME_do_all(OBJ_NAME_TYPE_MD_METH, createFactoryCallback, nullptr);
        return true;
    }
    decltype(sslSum::factoryInitStateDummy) sslSum::factoryInitStateDummy(createFactories());
 
    sslSum::sslSum(const std::string& aName ): base(aName) {
        ctx = EVP_MD_CTX_create();
 
        mdType = EVP_get_digestbyname(name.c_str());
        if (mdType == nullptr) {
            throw std::runtime_error("got no ssl digest named " + name);
        }
        EVP_MD_CTX_init(ctx);
        EVP_DigestInit_ex(ctx, mdType, nullptr);
    }
    sslSum::~sslSum() {
        EVP_MD_CTX_destroy(ctx);
    }
 
    void  sslSum::update(void *data, size_t size) {
        EVP_DigestUpdate(ctx, data, size);
    }
    void  sslSum::update(size_t size) { // case for block of zeroes
        for (size_t bytes_done = 0; bytes_done < size;) {
            auto missing = size - bytes_done;
            auto bytes = std::min(missing, block::nullBufferSize());
            EVP_DigestUpdate(ctx, block::nullBuffer(), bytes);
            bytes_done += bytes;
        }
    }
 
    void sslSum::finish() {
        std::vector<unsigned char> md(EVP_MD_size(mdType));
        EVP_DigestFinal_ex(ctx, md.data(), nullptr);
        std::ostringstream hashBuffer;
 
        for (auto c : md) {
            hashBuffer << std::hex << std::setw(2) << std::setfill('0') << static_cast<unsigned int>(c);
        }
 
        result = hashBuffer.str();
    }
}; // end namespace checksum