Hex encoding in C

hex_encode

void hex_encode(unsigned char * in, size_t inlen, char * out) {
    size_t i;
    for (i=0;i!=inlen;++i, out+=2) {
        sprintf(out, "%02x", in[i]);
    }
}

char digest[16] = "some_random_data";
char buffer[64];
hex_encode(digest, sizeof(digest), buffer);