Mercurial > vim
view src/crypt_zip.c @ 33096:828bcb1a37e7 v9.0.1833
patch 9.0.1833: [security] runtime file fixes
Commit: https://github.com/vim/vim/commit/816fbcc262687b81fc46f82f7bbeb1453addfe0c
Author: Christian Brabandt <cb@256bit.org>
Date: Thu Aug 31 23:52:30 2023 +0200
patch 9.0.1833: [security] runtime file fixes
Problem: runtime files may execute code in current dir
Solution: only execute, if not run from current directory
The perl, zig and ruby filetype plugins and the zip and gzip autoload
plugins may try to load malicious executable files from the current
working directory. This is especially a problem on windows, where the
current directory is implicitly in your $PATH and windows may even run a
file with the extension `.bat` because of $PATHEXT.
So make sure that we are not trying to execute a file from the current
directory. If this would be the case, error out (for the zip and gzip)
plugins or silently do not run those commands (for the ftplugins).
This assumes, that only the current working directory is bad. For all
other directories, it is assumed that those directories were
intentionally set to the $PATH by the user.
Signed-off-by: Christian Brabandt <cb@256bit.org>
author | Christian Brabandt <cb@256bit.org> |
---|---|
date | Fri, 01 Sep 2023 00:00:02 +0200 |
parents | 3d4e28569a6d |
children |
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/* vi:set ts=8 sts=4 sw=4 noet: * * VIM - Vi IMproved by Bram Moolenaar * * Do ":help uganda" in Vim to read copying and usage conditions. * Do ":help credits" in Vim to see a list of people who contributed. * See README.txt for an overview of the Vim source code. */ /* * crypt_zip.c: Zip encryption support. */ #include "vim.h" #if defined(FEAT_CRYPT) || defined(PROTO) /* * Optional encryption support. * Mohsin Ahmed, mosh@sasi.com, 98-09-24 * Based on zip/crypt sources. * * NOTE FOR USA: Since 2000 exporting this code from the USA is allowed to * most countries. There are a few exceptions, but that still should not be a * problem since this code was originally created in Europe and India. */ // Need a type that should be 32 bits. 64 also works but wastes space. typedef unsigned int u32_T; // int is at least 32 bits // The state of encryption, referenced by cryptstate_T. typedef struct { u32_T keys[3]; } zip_state_T; static u32_T crc_32_table[256]; /* * Fill the CRC table, if not done already. */ static void make_crc_tab(void) { u32_T s, t, v; static int done = FALSE; if (done) return; for (t = 0; t < 256; t++) { v = t; for (s = 0; s < 8; s++) v = (v >> 1) ^ ((v & 1) * (u32_T)0xedb88320L); crc_32_table[t] = v; } done = TRUE; } #define CRC32(c, b) (crc_32_table[((int)(c) ^ (b)) & 0xff] ^ ((c) >> 8)) /* * Return the next byte in the pseudo-random sequence. */ #define DECRYPT_BYTE_ZIP(keys, t) \ { \ short_u temp = (short_u)keys[2] | 2; \ t = (int)(((unsigned)(temp * (temp ^ 1U)) >> 8) & 0xff); \ } /* * Update the encryption keys with the next byte of plain text. */ #define UPDATE_KEYS_ZIP(keys, c) do { \ keys[0] = CRC32(keys[0], (c)); \ keys[1] += keys[0] & 0xff; \ keys[1] = keys[1] * 134775813L + 1; \ keys[2] = CRC32(keys[2], (int)(keys[1] >> 24)); \ } while (0) /* * Initialize for encryption/decryption. */ int crypt_zip_init( cryptstate_T *state, char_u *key, crypt_arg_T *arg UNUSED) { char_u *p; zip_state_T *zs; zs = ALLOC_ONE(zip_state_T); if (zs == NULL) return FAIL; state->method_state = zs; make_crc_tab(); zs->keys[0] = 305419896L; zs->keys[1] = 591751049L; zs->keys[2] = 878082192L; for (p = key; *p != NUL; ++p) UPDATE_KEYS_ZIP(zs->keys, (int)*p); return OK; } /* * Encrypt "from[len]" into "to[len]". * "from" and "to" can be equal to encrypt in place. */ void crypt_zip_encode( cryptstate_T *state, char_u *from, size_t len, char_u *to, int last UNUSED) { zip_state_T *zs = state->method_state; size_t i; int ztemp, t; for (i = 0; i < len; ++i) { ztemp = from[i]; DECRYPT_BYTE_ZIP(zs->keys, t); UPDATE_KEYS_ZIP(zs->keys, ztemp); to[i] = t ^ ztemp; } } /* * Decrypt "from[len]" into "to[len]". */ void crypt_zip_decode( cryptstate_T *state, char_u *from, size_t len, char_u *to, int last UNUSED) { zip_state_T *zs = state->method_state; size_t i; short_u temp; for (i = 0; i < len; ++i) { temp = (short_u)zs->keys[2] | 2; temp = (int)(((unsigned)(temp * (temp ^ 1U)) >> 8) & 0xff); UPDATE_KEYS_ZIP(zs->keys, to[i] = from[i] ^ temp); } } #endif // FEAT_CRYPT