Mercurial > vim
view src/sha256.c @ 34394:a400c8f9506f v9.1.0123
patch 9.1.0123: MS-Windows: system() may deadlock
Commit: https://github.com/vim/vim/commit/52ecc76c7fa1865603f27bc838efaeaa03cad77c
Author: GuyBrush <miguel.barro@live.com>
Date: Wed Feb 21 20:16:38 2024 +0100
patch 9.1.0123: MS-Windows: system() may deadlock
Problem: MS-Windows: system() may deadlock when calling binaries that
expect stdin
Solution: Ignore the SHELL_EXPAND flag
(GuyBrush)
This happens on binaries that expect stdin. For example:
:echo system("xxd")
will cause a deadlock.
SHELL_EXPAND is a flag devoted to support the linux implementation of
the backtick-expansion mechanism.
On linux backtic-expansion relies in the function mch_expand_wildchars()
(os_unix.c) that delegates on each specific shell (bash, sh, csh, zsh)
the expansion. Basically it composes a shell command that does the
expansion and redirects the output to a file and call_shell() it. On
windows backtick-expansion is performed by Vim itself.
On linux SHELL_EXPAND modifies how mch_call_shell_fork() (os_unix.c)
works. This function:
- relies on posix fork() to spawn a child process to execute a
external command.
- Child and parent process communicate using pipes (or pseudoterminal
if available).
User input (type ahead content) is processed in a loop only if
!(SHELL_EXPAND || SHELL_COOKED).
Though signals are used to detect Ctrl-C in all cases (the input
loop is not necessary to interrupt the function).
In the backtick-expansion the external command is the shell command
that provides the expansion. For the child redirection:
- SHELL_EXPAND replaces stdin, stdout & stderr to /dev/null. This is
why the shell command composed includes redirection (otherwise
output would be lost).
- !SHELL_EXPAND replaces stdin, stdout & stderr with the parent
created pipes (or pseudoterminal).
Note that the use of SIGINT signal prevents mch_call_shell_fork()
from hanging vim.
On Windows mch_system_piped() (os_win32.c) (which is only used when the
GUI is running) mimics mch_call_shell_fork() (os_unix.c).
Win32 lacks fork() and relies on CreateProcessW() and only has pipe
support (not pseudoterminal) which makes the implementation much
different.
But, the key idea is that windows lacks signals, the OS provides support
for console apps but gvim is not one. The only way of detecting a Ctrl-C
is actually processing user input (type ahead content). By ignoring the
user input under SHELL_EXPAND the function can hang gvim.
Ignoring SHELL_EXPAND flag has no consequence in Windows because as
mentioned above it is only meaningful in linux.
closes: #13988
Signed-off-by: GuyBrush <miguel.barro@live.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
author | Christian Brabandt <cb@256bit.org> |
---|---|
date | Wed, 21 Feb 2024 20:30:02 +0100 |
parents | c1d1639b52dd |
children |
line wrap: on
line source
/* 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. * * FIPS-180-2 compliant SHA-256 implementation * GPL by Christophe Devine, applies to older version. * Modified for md5deep, in public domain. * Modified For Vim, Mohsin Ahmed, http://www.cs.albany.edu/~mosh * Mohsin Ahmed states this work is distributed under the VIM License or GPL, * at your choice. * * Vim specific notes: * Functions exported by this file: * 1. sha256_key() hashes the password to 64 bytes char string. * 2. sha2_seed() generates a random header. * sha256_self_test() is implicitly called once. */ #include "vim.h" #if defined(FEAT_CRYPT) || defined(FEAT_PERSISTENT_UNDO) #define GET_UINT32(n, b, i) \ { \ (n) = ( (UINT32_T)(b)[(i) ] << 24) \ | ( (UINT32_T)(b)[(i) + 1] << 16) \ | ( (UINT32_T)(b)[(i) + 2] << 8) \ | ( (UINT32_T)(b)[(i) + 3] ); \ } #define PUT_UINT32(n,b,i) \ { \ (b)[(i) ] = (char_u)((n) >> 24); \ (b)[(i) + 1] = (char_u)((n) >> 16); \ (b)[(i) + 2] = (char_u)((n) >> 8); \ (b)[(i) + 3] = (char_u)((n) ); \ } void sha256_start(context_sha256_T *ctx) { ctx->total[0] = 0; ctx->total[1] = 0; ctx->state[0] = 0x6A09E667; ctx->state[1] = 0xBB67AE85; ctx->state[2] = 0x3C6EF372; ctx->state[3] = 0xA54FF53A; ctx->state[4] = 0x510E527F; ctx->state[5] = 0x9B05688C; ctx->state[6] = 0x1F83D9AB; ctx->state[7] = 0x5BE0CD19; } static void sha256_process(context_sha256_T *ctx, char_u data[64]) { UINT32_T temp1, temp2, W[64]; UINT32_T A, B, C, D, E, F, G, H; GET_UINT32(W[0], data, 0); GET_UINT32(W[1], data, 4); GET_UINT32(W[2], data, 8); GET_UINT32(W[3], data, 12); GET_UINT32(W[4], data, 16); GET_UINT32(W[5], data, 20); GET_UINT32(W[6], data, 24); GET_UINT32(W[7], data, 28); GET_UINT32(W[8], data, 32); GET_UINT32(W[9], data, 36); GET_UINT32(W[10], data, 40); GET_UINT32(W[11], data, 44); GET_UINT32(W[12], data, 48); GET_UINT32(W[13], data, 52); GET_UINT32(W[14], data, 56); GET_UINT32(W[15], data, 60); #define SHR(x, n) (((x) & 0xFFFFFFFF) >> (n)) #define ROTR(x, n) (SHR(x, n) | ((x) << (32 - (n)))) #define S0(x) (ROTR(x, 7) ^ ROTR(x, 18) ^ SHR(x, 3)) #define S1(x) (ROTR(x, 17) ^ ROTR(x, 19) ^ SHR(x, 10)) #define S2(x) (ROTR(x, 2) ^ ROTR(x, 13) ^ ROTR(x, 22)) #define S3(x) (ROTR(x, 6) ^ ROTR(x, 11) ^ ROTR(x, 25)) #define F0(x, y, z) (((x) & (y)) | ((z) & ((x) | (y)))) #define F1(x, y, z) ((z) ^ ((x) & ((y) ^ (z)))) #define R(t) \ ( \ W[t] = S1(W[(t) - 2]) + W[(t) - 7] + \ S0(W[(t) - 15]) + W[(t) - 16] \ ) #define P(a,b,c,d,e,f,g,h,x,K) \ { \ temp1 = (h) + S3(e) + F1(e, f, g) + (K) + (x); \ temp2 = S2(a) + F0(a, b, c); \ (d) += temp1; (h) = temp1 + temp2; \ } A = ctx->state[0]; B = ctx->state[1]; C = ctx->state[2]; D = ctx->state[3]; E = ctx->state[4]; F = ctx->state[5]; G = ctx->state[6]; H = ctx->state[7]; P( A, B, C, D, E, F, G, H, W[ 0], 0x428A2F98); P( H, A, B, C, D, E, F, G, W[ 1], 0x71374491); P( G, H, A, B, C, D, E, F, W[ 2], 0xB5C0FBCF); P( F, G, H, A, B, C, D, E, W[ 3], 0xE9B5DBA5); P( E, F, G, H, A, B, C, D, W[ 4], 0x3956C25B); P( D, E, F, G, H, A, B, C, W[ 5], 0x59F111F1); P( C, D, E, F, G, H, A, B, W[ 6], 0x923F82A4); P( B, C, D, E, F, G, H, A, W[ 7], 0xAB1C5ED5); P( A, B, C, D, E, F, G, H, W[ 8], 0xD807AA98); P( H, A, B, C, D, E, F, G, W[ 9], 0x12835B01); P( G, H, A, B, C, D, E, F, W[10], 0x243185BE); P( F, G, H, A, B, C, D, E, W[11], 0x550C7DC3); P( E, F, G, H, A, B, C, D, W[12], 0x72BE5D74); P( D, E, F, G, H, A, B, C, W[13], 0x80DEB1FE); P( C, D, E, F, G, H, A, B, W[14], 0x9BDC06A7); P( B, C, D, E, F, G, H, A, W[15], 0xC19BF174); P( A, B, C, D, E, F, G, H, R(16), 0xE49B69C1); P( H, A, B, C, D, E, F, G, R(17), 0xEFBE4786); P( G, H, A, B, C, D, E, F, R(18), 0x0FC19DC6); P( F, G, H, A, B, C, D, E, R(19), 0x240CA1CC); P( E, F, G, H, A, B, C, D, R(20), 0x2DE92C6F); P( D, E, F, G, H, A, B, C, R(21), 0x4A7484AA); P( C, D, E, F, G, H, A, B, R(22), 0x5CB0A9DC); P( B, C, D, E, F, G, H, A, R(23), 0x76F988DA); P( A, B, C, D, E, F, G, H, R(24), 0x983E5152); P( H, A, B, C, D, E, F, G, R(25), 0xA831C66D); P( G, H, A, B, C, D, E, F, R(26), 0xB00327C8); P( F, G, H, A, B, C, D, E, R(27), 0xBF597FC7); P( E, F, G, H, A, B, C, D, R(28), 0xC6E00BF3); P( D, E, F, G, H, A, B, C, R(29), 0xD5A79147); P( C, D, E, F, G, H, A, B, R(30), 0x06CA6351); P( B, C, D, E, F, G, H, A, R(31), 0x14292967); P( A, B, C, D, E, F, G, H, R(32), 0x27B70A85); P( H, A, B, C, D, E, F, G, R(33), 0x2E1B2138); P( G, H, A, B, C, D, E, F, R(34), 0x4D2C6DFC); P( F, G, H, A, B, C, D, E, R(35), 0x53380D13); P( E, F, G, H, A, B, C, D, R(36), 0x650A7354); P( D, E, F, G, H, A, B, C, R(37), 0x766A0ABB); P( C, D, E, F, G, H, A, B, R(38), 0x81C2C92E); P( B, C, D, E, F, G, H, A, R(39), 0x92722C85); P( A, B, C, D, E, F, G, H, R(40), 0xA2BFE8A1); P( H, A, B, C, D, E, F, G, R(41), 0xA81A664B); P( G, H, A, B, C, D, E, F, R(42), 0xC24B8B70); P( F, G, H, A, B, C, D, E, R(43), 0xC76C51A3); P( E, F, G, H, A, B, C, D, R(44), 0xD192E819); P( D, E, F, G, H, A, B, C, R(45), 0xD6990624); P( C, D, E, F, G, H, A, B, R(46), 0xF40E3585); P( B, C, D, E, F, G, H, A, R(47), 0x106AA070); P( A, B, C, D, E, F, G, H, R(48), 0x19A4C116); P( H, A, B, C, D, E, F, G, R(49), 0x1E376C08); P( G, H, A, B, C, D, E, F, R(50), 0x2748774C); P( F, G, H, A, B, C, D, E, R(51), 0x34B0BCB5); P( E, F, G, H, A, B, C, D, R(52), 0x391C0CB3); P( D, E, F, G, H, A, B, C, R(53), 0x4ED8AA4A); P( C, D, E, F, G, H, A, B, R(54), 0x5B9CCA4F); P( B, C, D, E, F, G, H, A, R(55), 0x682E6FF3); P( A, B, C, D, E, F, G, H, R(56), 0x748F82EE); P( H, A, B, C, D, E, F, G, R(57), 0x78A5636F); P( G, H, A, B, C, D, E, F, R(58), 0x84C87814); P( F, G, H, A, B, C, D, E, R(59), 0x8CC70208); P( E, F, G, H, A, B, C, D, R(60), 0x90BEFFFA); P( D, E, F, G, H, A, B, C, R(61), 0xA4506CEB); P( C, D, E, F, G, H, A, B, R(62), 0xBEF9A3F7); P( B, C, D, E, F, G, H, A, R(63), 0xC67178F2); ctx->state[0] += A; ctx->state[1] += B; ctx->state[2] += C; ctx->state[3] += D; ctx->state[4] += E; ctx->state[5] += F; ctx->state[6] += G; ctx->state[7] += H; } void sha256_update(context_sha256_T *ctx, char_u *input, UINT32_T length) { UINT32_T left, fill; if (length == 0) return; left = ctx->total[0] & 0x3F; fill = 64 - left; ctx->total[0] += length; ctx->total[0] &= 0xFFFFFFFF; if (ctx->total[0] < length) ctx->total[1]++; if (left && length >= fill) { memcpy((void *)(ctx->buffer + left), (void *)input, fill); sha256_process(ctx, ctx->buffer); length -= fill; input += fill; left = 0; } while (length >= 64) { sha256_process(ctx, input); length -= 64; input += 64; } if (length) memcpy((void *)(ctx->buffer + left), (void *)input, length); } static char_u sha256_padding[64] = { 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; void sha256_finish(context_sha256_T *ctx, char_u digest[32]) { UINT32_T last, padn; UINT32_T high, low; char_u msglen[8]; high = (ctx->total[0] >> 29) | (ctx->total[1] << 3); low = (ctx->total[0] << 3); PUT_UINT32(high, msglen, 0); PUT_UINT32(low, msglen, 4); last = ctx->total[0] & 0x3F; padn = (last < 56) ? (56 - last) : (120 - last); sha256_update(ctx, sha256_padding, padn); sha256_update(ctx, msglen, 8); PUT_UINT32(ctx->state[0], digest, 0); PUT_UINT32(ctx->state[1], digest, 4); PUT_UINT32(ctx->state[2], digest, 8); PUT_UINT32(ctx->state[3], digest, 12); PUT_UINT32(ctx->state[4], digest, 16); PUT_UINT32(ctx->state[5], digest, 20); PUT_UINT32(ctx->state[6], digest, 24); PUT_UINT32(ctx->state[7], digest, 28); } #endif // FEAT_CRYPT || FEAT_PERSISTENT_UNDO #if defined(FEAT_CRYPT) || defined(PROTO) /* * Returns hex digest of "buf[buf_len]" in a static array. * if "salt" is not NULL also do "salt[salt_len]". */ char_u * sha256_bytes( char_u *buf, int buf_len, char_u *salt, int salt_len) { char_u sha256sum[32]; static char_u hexit[65]; int j; context_sha256_T ctx; sha256_self_test(); sha256_start(&ctx); sha256_update(&ctx, buf, buf_len); if (salt != NULL) sha256_update(&ctx, salt, salt_len); sha256_finish(&ctx, sha256sum); for (j = 0; j < 32; j++) sprintf((char *)hexit + j * 2, "%02x", sha256sum[j]); hexit[sizeof(hexit) - 1] = '\0'; return hexit; } /* * Returns sha256(buf) as 64 hex chars in static array. */ char_u * sha256_key( char_u *buf, char_u *salt, int salt_len) { // No passwd means don't encrypt if (buf == NULL || *buf == NUL) return (char_u *)""; return sha256_bytes(buf, (int)STRLEN(buf), salt, salt_len); } /* * These are the standard FIPS-180-2 test vectors */ static char *sha_self_test_msg[] = { "abc", "abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq", NULL }; static char *sha_self_test_vector[] = { "ba7816bf8f01cfea414140de5dae2223" \ "b00361a396177a9cb410ff61f20015ad", "248d6a61d20638b8e5c026930c3e6039" \ "a33ce45964ff2167f6ecedd419db06c1", "cdc76e5c9914fb9281a1c7e284d73e67" \ "f1809a48a497200e046d39ccc7112cd0" }; /* * Perform a test on the SHA256 algorithm. * Return FAIL or OK. */ int sha256_self_test(void) { int i, j; char output[65]; context_sha256_T ctx; char_u buf[1000]; char_u sha256sum[32]; static int failures = 0; char_u *hexit; static int sha256_self_tested = 0; if (sha256_self_tested > 0) return failures > 0 ? FAIL : OK; sha256_self_tested = 1; for (i = 0; i < 3; i++) { if (i < 2) { hexit = sha256_bytes((char_u *)sha_self_test_msg[i], (int)STRLEN(sha_self_test_msg[i]), NULL, 0); STRCPY(output, hexit); } else { sha256_start(&ctx); vim_memset(buf, 'a', 1000); for (j = 0; j < 1000; j++) sha256_update(&ctx, (char_u *)buf, 1000); sha256_finish(&ctx, sha256sum); for (j = 0; j < 32; j++) sprintf(output + j * 2, "%02x", sha256sum[j]); } if (memcmp(output, sha_self_test_vector[i], 64)) { failures++; output[sizeof(output) - 1] = '\0'; // printf("sha256_self_test %d failed %s\n", i, output); } } return failures > 0 ? FAIL : OK; } static unsigned int get_some_time(void) { # ifdef HAVE_GETTIMEOFDAY struct timeval tv; // Using usec makes it less predictable. gettimeofday(&tv, NULL); return (unsigned int)(tv.tv_sec + tv.tv_usec); # else return (unsigned int)time(NULL); # endif } /* * Fill "header[header_len]" with random_data. * Also "salt[salt_len]" when "salt" is not NULL. */ void sha2_seed( char_u *header, int header_len, char_u *salt, int salt_len) { int i; static char_u random_data[1000]; char_u sha256sum[32]; context_sha256_T ctx; srand(get_some_time()); for (i = 0; i < (int)sizeof(random_data) - 1; i++) random_data[i] = (char_u)((get_some_time() ^ rand()) & 0xff); sha256_start(&ctx); sha256_update(&ctx, (char_u *)random_data, sizeof(random_data)); sha256_finish(&ctx, sha256sum); // put first block into header. for (i = 0; i < header_len; i++) header[i] = sha256sum[i % sizeof(sha256sum)]; // put remaining block into salt. if (salt != NULL) for (i = 0; i < salt_len; i++) salt[i] = sha256sum[(i + header_len) % sizeof(sha256sum)]; } #endif // FEAT_CRYPT