Annotation of embedaddon/sudo/plugins/sudoers/base64.c, revision 1.1
1.1 ! misho 1: /*
! 2: * Copyright (c) 2013 Todd C. Miller <Todd.Miller@courtesan.com>
! 3: *
! 4: * Permission to use, copy, modify, and distribute this software for any
! 5: * purpose with or without fee is hereby granted, provided that the above
! 6: * copyright notice and this permission notice appear in all copies.
! 7: *
! 8: * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
! 9: * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
! 10: * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
! 11: * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
! 12: * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
! 13: * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
! 14: * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
! 15: * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
! 16: * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
! 17: */
! 18:
! 19: #include <config.h>
! 20:
! 21: #include <sys/types.h>
! 22: #include <stdio.h>
! 23: #ifdef STDC_HEADERS
! 24: # include <stdlib.h>
! 25: # include <stddef.h>
! 26: #else
! 27: # ifdef HAVE_STDLIB_H
! 28: # include <stdlib.h>
! 29: # endif
! 30: #endif /* STDC_HEADERS */
! 31: #ifdef HAVE_STRING_H
! 32: # include <string.h>
! 33: #endif /* HAVE_STRING_H */
! 34: #ifdef HAVE_STRINGS_H
! 35: # include <strings.h>
! 36: #endif /* HAVE_STRINGS_H */
! 37:
! 38: #include "missing.h"
! 39: #include "sudo_debug.h"
! 40:
! 41: /*
! 42: * Decode a NUL-terminated string in base64 format and store the
! 43: * result in dst.
! 44: */
! 45: size_t
! 46: base64_decode(const char *str, unsigned char *dst, size_t dsize)
! 47: {
! 48: static const char b64[] =
! 49: "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
! 50: const unsigned char *dst0 = dst;
! 51: const unsigned char *dend = dst + dsize;
! 52: unsigned char ch[4];
! 53: char *pos;
! 54: int i;
! 55: debug_decl(base64_decode, SUDO_DEBUG_MATCH)
! 56:
! 57: /*
! 58: * Convert from base64 to binary. Each base64 char holds 6 bits of data
! 59: * so 4 base64 chars equals 3 chars of data.
! 60: * Padding (with the '=' char) may or may not be present.
! 61: */
! 62: while (*str != '\0') {
! 63: for (i = 0; i < 4; i++) {
! 64: switch (*str) {
! 65: case '=':
! 66: str++;
! 67: /* FALLTHROUGH */
! 68: case '\0':
! 69: ch[i] = '=';
! 70: break;
! 71: default:
! 72: if ((pos = strchr(b64, *str++)) == NULL)
! 73: debug_return_size_t((size_t)-1);
! 74: ch[i] = (unsigned char)(pos - b64);
! 75: break;
! 76: }
! 77: }
! 78: if (ch[0] == '=' || ch[1] == '=' || dst == dend)
! 79: break;
! 80: *dst++ = (ch[0] << 2) | ((ch[1] & 0x30) >> 4);
! 81: if (ch[2] == '=' || dst == dend)
! 82: break;
! 83: *dst++ = ((ch[1] & 0x0f) << 4) | ((ch[2] & 0x3c) >> 2);
! 84: if (ch[3] == '=' || dst == dend)
! 85: break;
! 86: *dst++ = ((ch[2] & 0x03) << 6) | ch[3];
! 87: }
! 88: debug_return_size_t((size_t)(dst - dst0));
! 89: }
FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>