xref: /openbmc/qemu/util/base64.c (revision 623d7e3551a6fc5693c06ea938c60fe281b52e27)
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 2.1 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  
25  static const char *base64_valid_chars =
26      "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=\n";
27  
28  uint8_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