void sha1_hash(char* hash, const char* data, size_t data_nbytes) {
    boost::uuids::detail::sha1 sha1;

    unsigned int digest[5];

    sha1.process_bytes(data, data_nbytes);
    sha1.get_digest(digest);

    for(int i = 0; i < 5; ++i) {
        const char* tmp = reinterpret_cast<char*>(digest);
        hash[i*4] = tmp[i*4+3];
        hash[i*4+1] = tmp[i*4+2];
        hash[i*4+2] = tmp[i*4+1];
        hash[i*4+3] = tmp[i*4];
    }
}

unsigned int base64_encode(char* dest, const char* src, unsigned int len) {
    char tail[3] = {0,0,0};

    unsigned int one_third_len = len/3;
    unsigned int len_rounded_down = one_third_len*3;
    unsigned int j = len_rounded_down + one_third_len;

    std::copy(base64_enc(src), base64_enc(src + len_rounded_down), dest);

    if (len_rounded_down != len) {
        unsigned int i=0;
        for(; i < len - len_rounded_down; ++i) {
            tail[i] = src[len_rounded_down+i];
        }

        std::copy(base64_enc(tail), base64_enc(tail + 3), dest + j);

        for(i=len + one_third_len + 1; i < j+4; ++i) {
            dest[i] = '=';
        }

        return i;
    }

    return j;
}