diff options
| -rw-r--r-- | TODO | 1 | ||||
| -rw-r--r-- | include/string.h | 14 | ||||
| -rw-r--r-- | src/string/memfrob.c | 39 |
3 files changed, 52 insertions, 2 deletions
@@ -1,7 +1,6 @@ functions to lock and unlock pages (3.4.3 p76) character class determination for wide characters (4.3 p82) collation functions (5.6 p109) -trivial encryption (5.10 p124) encode binary data (5.11 p125) argz and envz vectors (5.12 p127) characer-set handling (6 p133) diff --git a/include/string.h b/include/string.h index 68a0134..c43b41d 100644 --- a/include/string.h +++ b/include/string.h @@ -1100,7 +1100,19 @@ char* __gnu_basename(const char*) * @param anagram An anagram of the output, will be modified. * @retrun The string, which will `== anagram`. */ -char* strfry(char* anagram); +char* strfry(char*); + +/** + * Performs an inplace bitwise XOR:ing of + * a memory segment. The pattern is 00101010. + * + * This is a GNU extension. + * + * @param segment The memory segment. + * @param size The size of the memory segment. + * @return `segment` is returned + */ +char* memfrob(char*, size_t); #endif diff --git a/src/string/memfrob.c b/src/string/memfrob.c new file mode 100644 index 0000000..e43496a --- /dev/null +++ b/src/string/memfrob.c @@ -0,0 +1,39 @@ +/** + * slibc — Yet another C library + * Copyright © 2015 Mattias Andrée (maandree@member.fsf.org) + * + * 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 <string.h> +#include <stddef.h> + + + +/** + * Performs an inplace bitwise XOR:ing of + * a memory segment. The pattern is 00101010. + * + * This is a GNU extension. + * + * @param segment The memory segment. + * @param size The size of the memory segment. + * @return `segment` is returned + */ +char* memfrob(char* segment, size_t size) +{ + while (--size) + segment[size] ^= 0x2A; + return segment; +} + |