1 #ident "$Id: unbase64.c,v 1.1 2005/01/21 00:49:46 hpa Exp $"
2 /* ----------------------------------------------------------------------- *
4 * Copyright 2005 H. Peter Anvin - All Rights Reserved
6 * Permission is hereby granted, free of charge, to any person
7 * obtaining a copy of this software and associated documentation
8 * files (the "Software"), to deal in the Software without
9 * restriction, including without limitation the rights to use,
10 * copy, modify, merge, publish, distribute, sublicense, and/or
11 * sell copies of the Software, and to permit persons to whom
12 * the Software is furnished to do so, subject to the following
15 * The above copyright notice and this permission notice shall
16 * be included in all copies or substantial portions of the Software.
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
19 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
20 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
21 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
22 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
23 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
24 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
25 * OTHER DEALINGS IN THE SOFTWARE.
27 * ----------------------------------------------------------------------- */
32 * Convert a string in base64 format to a byte array.
38 static const unsigned char _base64chars[] =
39 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789./";
41 size_t unbase64(unsigned char *buffer, size_t bufsiz, const char *txt)
43 unsigned int bits = 0;
51 memset(base64tbl, -1, sizeof base64tbl);
53 for ( i = 0 ; _base64chars[i] ; i++ ) {
54 base64tbl[_base64chars[i]] = i;
57 /* Also support filesystem safe alternate base64 encoding */
62 if ( (v = base64tbl[(unsigned char) *txt]) >= 0 ) {
67 if ( nbytes < bufsiz )
68 *buffer++ = (bits >> (nbits-8));