Mercurial > vim
view src/sha256.c @ 33664:06b59278bfcf v9.0.2070
patch 9.0.2070: [security] disallow setting env in restricted mode
Commit: https://github.com/vim/vim/commit/6b89dd6a7257a1e2e9c7ea070b407bc4674a5118
Author: Christian Brabandt <cb@256bit.org>
Date: Thu Oct 26 22:14:17 2023 +0200
patch 9.0.2070: [security] disallow setting env in restricted mode
Problem: [security] disallow setting env in restricted mode
Solution: Setting environment variables in restricted mode could
potentially be used to execute shell commands. Disallow this.
restricted mode: disable allow setting of environment variables
Setting environment variables in restricted mode, may have some unwanted
consequences. So, for example by setting $GCONV_PATH in restricted mode
and then calling the iconv() function, one may be able to execute some
unwanted payload, because the `iconv_open()` function internally uses
the `$GCONV_PATH` variable to find its conversion data.
So let's disable setting environment variables, even so this is no
complete protection, since we are not clearing the existing environment.
I tried a few ways but wasn't successful :(
One could also argue to disable the iconv() function completely in
restricted mode, but who knows what other API functions can be
influenced by setting some other unrelated environment variables.
So let's leave it as it is currently.
closes: #13394
See: https://huntr.com/bounties/b0a2eda1-459c-4e36-98e6-0cc7d7faccfe/
Signed-off-by: Christian Brabandt <cb@256bit.org>
author | Christian Brabandt <cb@256bit.org> |
---|---|
date | Thu, 26 Oct 2023 22:30:03 +0200 |
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