| -rw-r--r-- | rsync/base64.c | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/rsync/base64.c b/rsync/base64.c new file mode 100644 index 0000000..cbe7a8c --- a/dev/null +++ b/rsync/base64.c @@ -0,0 +1,101 @@ +/*= -*- c-basic-offset: 4; indent-tabs-mode: nil; -*- + * + * librsync -- the library for network deltas + * $Id$ + * + * Copyright (C) 2000 by Martin Pool <mbp@samba.org> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public License + * as published by the Free Software Foundation; either version 2.1 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + + +#include <config_rsync.h> + +#include <string.h> +#include <stdlib.h> +#include <stdio.h> + +#include "rsync.h" + +/* + * Decode a base64 string in-place - simple and slow algorithm + * + * See RFC1521 for the specification of base64. + */ +size_t rs_unbase64(char *s) +{ + char const *b64 = + "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; + int bit_offset, byte_offset, idx, i, n; + unsigned char *d = (unsigned char *) s; + char *p; + + n = i = 0; + + while (*s && (p = strchr(b64, *s))) { + idx = (int) (p - b64); + byte_offset = (i * 6) / 8; + bit_offset = (i * 6) % 8; + d[byte_offset] &= ~((1 << (8 - bit_offset)) - 1); + if (bit_offset < 3) { + d[byte_offset] |= (idx << (2 - bit_offset)); + n = byte_offset + 1; + } else { + d[byte_offset] |= (idx >> (bit_offset - 2)); + d[byte_offset + 1] = 0; + d[byte_offset + 1] |= (idx << (8 - (bit_offset - 2))) & 0xFF; + n = byte_offset + 2; + } + s++; + i++; + } + + return n; +} + +/* + * Encode a buffer as base64 - simple and slow algorithm. + */ +void +rs_base64(unsigned char const *buf, int n, char *out) +{ + char const *b64 = + "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; + int bytes, i; + + /* work out how many bytes of output there are */ + bytes = ((n * 8) + 5) / 6; + + for (i = 0; i < bytes; i++) { + int byte = (i * 6) / 8; + int bit = (i * 6) % 8; + + if (bit < 3) { + if (byte >= n) + abort(); + *out = b64[(buf[byte] >> (2 - bit)) & 0x3F]; + } else { + if (byte + 1 == n) { + *out = b64[(buf[byte] << (bit - 2)) & 0x3F]; + } else { + *out = b64[(buf[byte] << (bit - 2) | + buf[byte + 1] >> (10 - bit)) & 0x3F]; + } + } + out++; + } + *out = 0; +} + |