LXR qemu/util/base64.c

   1/*
   2 * QEMU base64 helpers
   3 *
   4 * Copyright (c) 2015 Red Hat, Inc.
   5 *
   6 * This library is free software; you can redistribute it and/or
   7 * modify it under the terms of the GNU Lesser General Public
   8 * License as published by the Free Software Foundation; either
   9 * version 2 of the License, or (at your option) any later version.
  10 *
  11 * This library is distributed in the hope that it will be useful,
  12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 * Lesser General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU Lesser General Public
  17 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  18 *
  19 */
  20
  21#include "qemu/osdep.h"
  22#include "qapi/error.h"
  23#include "qemu/base64.h"
  24
  25static const char *base64_valid_chars =
  26    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=\n";
  27
  28uint8_t *qbase64_decode(const char *input,
  29                        size_t in_len,
  30                        size_t *out_len,
  31                        Error **errp)
  32{
  33    *out_len = 0;
  34
  35    if (in_len != -1) {
  36        /* Lack of NUL terminator is an error */
  37        if (input[in_len] != '\0') {
  38            error_setg(errp, "Base64 data is not NUL terminated");
  39            return NULL;
  40        }
  41        /* Check there's no NULs embedded since we expect
  42         * this to be valid base64 data */
  43        if (memchr(input, '\0', in_len) != NULL) {
  44            error_setg(errp, "Base64 data contains embedded NUL characters");
  45            return NULL;
  46        }
  47
  48        /* Now we know its a valid nul terminated string
  49         * strspn is safe to use... */
  50    } else {
  51        in_len = strlen(input);
  52    }
  53
  54    if (strspn(input, base64_valid_chars) != in_len) {
  55        error_setg(errp, "Base64 data contains invalid characters");
  56        return NULL;
  57    }
  58
  59    return g_base64_decode(input, out_len);
  60}
  61