src/lib/hex-binary.c

/* Copyright (c) 2002-2018 Dovecot authors, see the included COPYING file */

#include "lib.h"
#include "buffer.h"
#include "hex-binary.h"

static void
binary_to_hex_case(unsigned char *dest, const unsigned char *data,
           size_t size, bool ucase)
{
    unsigned char *p;
    char base_char;
    size_t i;
    int value;

    /* @UNSAFE */
    base_char = ucase ? 'A' : 'a';

    p = dest;
    for (i = 0; i < size; i++) {
        value = data[i] >> 4;
        *p++ = value < 10 ? value + '0' : value - 10 + base_char;

        value = data[i] & 0x0f;
        *p++ = value < 10 ? value + '0' : value - 10 + base_char;
    }
}

const char *binary_to_hex(const unsigned char *data, size_t size)
{
    unsigned char *dest = t_malloc_no0(MALLOC_MULTIPLY(size, 2) + 1);

    binary_to_hex_case(dest, data, size, FALSE);
    dest[size*2] = '\0';
    return (char *)dest;
}

const char *binary_to_hex_ucase(const unsigned char *data, size_t size)
{
    unsigned char *dest = t_malloc_no0(MALLOC_MULTIPLY(size, 2) + 1);

    binary_to_hex_case(dest, data, size, TRUE);
    dest[size*2] = '\0';
    return (char *)dest;
}

void binary_to_hex_append(string_t *dest, const unsigned char *data,
              size_t size)
{
    unsigned char *buf;

    buf = buffer_append_space_unsafe(dest, size * 2);
    binary_to_hex_case(buf, data, size, FALSE);
}

int hex_to_binary(const char *data, buffer_t *dest)
{
    int value;

    while (*data != '\0') {
        if (*data >= '0' && *data <= '9')
            value = (*data - '0') << 4;
        else if (*data >= 'a' && *data <= 'f')
            value = (*data - 'a' + 10) << 4;
        else if (*data >= 'A' && *data <= 'F')
            value = (*data - 'A' + 10) << 4;
        else
            return -1;

        data++;
        if (*data >= '0' && *data <= '9')
            value |= *data - '0';
        else if (*data >= 'a' && *data <= 'f')
            value |= *data - 'a' + 10;
        else if (*data >= 'A' && *data <= 'F')
            value |= *data - 'A' + 10;
        else
            return -1;

        buffer_append_c(dest, value);
        data++;
    }

    return 0;
}