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Diffstat (limited to 'lib/util/base64.c')
| -rw-r--r-- | lib/util/base64.c | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/lib/util/base64.c b/lib/util/base64.c new file mode 100644 index 0000000..7acc83d --- /dev/null +++ b/lib/util/base64.c @@ -0,0 +1,169 @@ +/* + Unix SMB/CIFS implementation. + Samba utility functions + + Copyright (C) Andrew Tridgell 1992-2001 + Copyright (C) Simo Sorce 2001-2002 + Copyright (C) Martin Pool 2003 + Copyright (C) James Peach 2006 + Copyright (C) Jeremy Allison 1992-2007 + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 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 General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. +*/ + +#include "replace.h" +#include "lib/util/base64.h" + +static const char b64[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; + +/** + * Decode a base64 string into a DATA_BLOB - simple and slow algorithm. + * + * A DATA_BLOB like {.data = NULL, length = 0} indicates memory error. + * + * Decoding stops at the first invalid character. + **/ +_PUBLIC_ DATA_BLOB base64_decode_data_blob_talloc(TALLOC_CTX *mem_ctx, const char *s) +{ + int bit_offset, byte_offset, idx, i, n; + DATA_BLOB decoded = data_blob_talloc(mem_ctx, s, strlen(s)+1); + unsigned char *d = decoded.data; + char *p; + + if (decoded.data == NULL) { + decoded.length = 0; + return decoded; + } + + 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] = (idx << (8-(bit_offset-2))) & 0xFF; + n = byte_offset+2; + } + s++; i++; + } + + if ((n > 0) && (*s == '=')) { + n -= 1; + } + + /* fix up length */ + decoded.length = n; + decoded.data = talloc_realloc(mem_ctx, decoded.data, uint8_t, n); + return decoded; +} + +/** + * Decode a base64 string into a DATA_BLOB - simple and slow algorithm + **/ +_PUBLIC_ DATA_BLOB base64_decode_data_blob(const char *s) +{ + return base64_decode_data_blob_talloc(NULL, s); +} + +/** + * Decode a base64 string in-place - wrapper for the above + **/ +_PUBLIC_ void base64_decode_inplace(char *s) +{ + DATA_BLOB decoded = base64_decode_data_blob(s); + + if ( decoded.length != 0 ) { + memcpy(s, decoded.data, decoded.length); + + /* null terminate */ + s[decoded.length] = '\0'; + } else { + *s = '\0'; + } + + data_blob_free(&decoded); +} + +/** + * Encode a base64 string into a talloc()ed string caller to free. + * + * From SQUID: adopted from http://ftp.sunet.se/pub2/gnu/vm/base64-encode.c + * with adjustments + **/ + +_PUBLIC_ char *base64_encode_data_blob(TALLOC_CTX *mem_ctx, DATA_BLOB data) +{ + int bits = 0; + int char_count = 0; + size_t out_cnt, len, output_len; + char *result; + + /* + * Note: we return NULL for a zero-length blob, even though it can be + * encoded as a zero length string in base64. + * + * FIXME, perhaps, but we need to check carefully before changing + * this. + */ + if (data.length == 0 || data.data == NULL) { + return NULL; + } + + out_cnt = 0; + len = data.length; + output_len = data.length * 2 + 4; /* Account for closing bytes. 4 is + * random but should be enough for + * the = and \0 */ + result = talloc_array(mem_ctx, char, output_len); /* get us plenty of space */ + if (result == NULL) { + return NULL; + } + + while (len--) { + int c = (unsigned char) *(data.data++); + bits += c; + char_count++; + if (char_count == 3) { + result[out_cnt++] = b64[bits >> 18]; + result[out_cnt++] = b64[(bits >> 12) & 0x3f]; + result[out_cnt++] = b64[(bits >> 6) & 0x3f]; + result[out_cnt++] = b64[bits & 0x3f]; + bits = 0; + char_count = 0; + } else { + bits <<= 8; + } + } + if (char_count != 0) { + bits <<= 16 - (8 * char_count); + result[out_cnt++] = b64[bits >> 18]; + result[out_cnt++] = b64[(bits >> 12) & 0x3f]; + if (char_count == 1) { + result[out_cnt++] = '='; + result[out_cnt++] = '='; + } else { + result[out_cnt++] = b64[(bits >> 6) & 0x3f]; + result[out_cnt++] = '='; + } + } + result[out_cnt] = '\0'; /* terminate */ + return result; +} + |