utils.c

/*
 * Copyright IBM Corp. All Rights Reserved.
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include "utils.h"
#include <stdlib.h>
#include <string.h>

int append_string(char* buf, const char* string)
{
    int len = (int)strlen(string);
    if (buf == NULL)
    {
        return len;
    }
    strncpy(buf, string, len + 1);
    return len;
}

void bytes_swap(void* bytes, size_t len)
{
    unsigned char *start, *end;
    for (start = (unsigned char*)bytes, end = start + len - 1; start < end; ++start, --end)
    {
        unsigned char swap = *start;
        *start = *end;
        *end = swap;
    }
}

char* bytes_to_hexstring(uint8_t* bytes, size_t len)
{
    const char* hexdigs = "0123456789abcdef";
    size_t k = len * 2 + 1;
    char* out = malloc(k);
    for (int i = 0; i < len; i++)
    {
        out[i * 2] = hexdigs[bytes[i] >> 4];
        out[i * 2 + 1] = hexdigs[bytes[i] & 0x0f];
    }
    out[k - 1] = '\0';
    return out;
}