From 4ba74a357376c8f8bf49487f96ae71cf2460c3f3 Mon Sep 17 00:00:00 2001 From: Alexandre Oliva Date: Wed, 10 Oct 2012 07:05:10 -0300 Subject: * crypt/crypt-private.h: Include stdbool.h. (_ufc_setup_salt_r): Return bool. * crypt/crypt-entry.c: Include errno.h. (__crypt_r): Return NULL with EINVAL for bad salt. * crypt/crypt_util.c (bad_for_salt): New. (_ufc_setup_salt_r): Check that salt is long enough and within the specified alphabet. * crypt/badsalttest.c: New file. * crypt/Makefile (tests): Add it. ($(objpfx)badsalttest): New. --- crypt/Makefile | 2 +- crypt/badsalttest.c | 86 +++++++++++++++++++++++++++++++++++++++++++++++++++ crypt/crypt-entry.c | 7 ++++- crypt/crypt-private.h | 3 +- crypt/crypt_util.c | 42 ++++++++++++++++++++++--- 5 files changed, 133 insertions(+), 7 deletions(-) create mode 100644 crypt/badsalttest.c (limited to 'crypt') diff --git a/crypt/Makefile b/crypt/Makefile index 3a61865a1b..3d4f243ed5 100644 --- a/crypt/Makefile +++ b/crypt/Makefile @@ -28,7 +28,7 @@ extra-libs-others := $(extra-libs) libcrypt-routines := crypt-entry md5-crypt sha256-crypt sha512-crypt crypt \ crypt_util -tests := cert md5c-test sha256c-test sha512c-test +tests := cert md5c-test sha256c-test sha512c-test badsalttest include ../Makeconfig diff --git a/crypt/badsalttest.c b/crypt/badsalttest.c new file mode 100644 index 0000000000..e0e207bac3 --- /dev/null +++ b/crypt/badsalttest.c @@ -0,0 +1,86 @@ +/* Test program for bad DES salt detection in crypt. + Copyright (C) 2012 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#include +#include +#include +#include + +static const char *tests[][2] = + { + { "no salt", "" }, + { "single char", "/" }, + { "first char bad", "!x" }, + { "second char bad", "Z%" }, + { "both chars bad", ":@" }, + { "un$upported algorithm", "$2$" }, + { "unsupported_algorithm", "_1" }, + { "end of page", NULL } + }; + +static int +do_test (void) +{ + int result = 0; + struct crypt_data cd; + size_t n = sizeof (tests) / sizeof (*tests); + size_t pagesize = (size_t) sysconf (_SC_PAGESIZE); + char *page; + + /* Check that crypt won't look at the second character if the first + one is invalid. */ + page = mmap (NULL, pagesize * 2, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANON, -1, 0); + if (page == MAP_FAILED) + { + perror ("mmap"); + n--; + } + else + { + if (mmap (page + pagesize, pagesize, 0, + MAP_PRIVATE | MAP_ANON | MAP_FIXED, + -1, 0) != page + pagesize) + perror ("mmap 2"); + page[pagesize - 1] = '*'; + tests[n - 1][1] = &page[pagesize - 1]; + } + + for (size_t i = 0; i < n; i++) + { + if (crypt (tests[i][0], tests[i][1])) + { + result++; + printf ("%s: crypt returned non-NULL with salt \"%s\"\n", + tests[i][0], tests[i][1]); + } + + if (crypt_r (tests[i][0], tests[i][1], &cd)) + { + result++; + printf ("%s: crypt_r returned non-NULL with salt \"%s\"\n", + tests[i][0], tests[i][1]); + } + } + + return result; +} + +#define TIMEOUT 5 +#define TEST_FUNCTION do_test () +#include "../test-skeleton.c" diff --git a/crypt/crypt-entry.c b/crypt/crypt-entry.c index 91e2c4e97b..9fb22bdac4 100644 --- a/crypt/crypt-entry.c +++ b/crypt/crypt-entry.c @@ -27,6 +27,7 @@ #include #endif #include +#include #ifndef STATIC #define STATIC static @@ -108,7 +109,11 @@ __crypt_r (key, salt, data) /* * Hack DES tables according to salt */ - _ufc_setup_salt_r (salt, data); + if (!_ufc_setup_salt_r (salt, data)) + { + __set_errno (EINVAL); + return NULL; + } /* * Setup key schedule diff --git a/crypt/crypt-private.h b/crypt/crypt-private.h index b4bfa8b4ac..54418fcb54 100644 --- a/crypt/crypt-private.h +++ b/crypt/crypt-private.h @@ -26,6 +26,7 @@ #define CRYPT_PRIVATE_H 1 #include +#include /* crypt.c */ extern void _ufc_doit_r (ufc_long itr, struct crypt_data * __restrict __data, @@ -36,7 +37,7 @@ extern void _ufc_doit_r (ufc_long itr, struct crypt_data * __restrict __data, extern void __init_des_r (struct crypt_data * __restrict __data); extern void __init_des (void); -extern void _ufc_setup_salt_r (const char *s, +extern bool _ufc_setup_salt_r (const char *s, struct crypt_data * __restrict __data); extern void _ufc_mk_keytab_r (const char *key, struct crypt_data * __restrict __data); diff --git a/crypt/crypt_util.c b/crypt/crypt_util.c index a1ff88b0da..e08dd8fa99 100644 --- a/crypt/crypt_util.c +++ b/crypt/crypt_util.c @@ -595,24 +595,56 @@ shuffle_sb(k, saltbits) } #endif +/* + * Return false iff C is in the specified alphabet for crypt salt. + */ + +static bool +bad_for_salt (char c) +{ + switch (c) + { + case '0' ... '9': + case 'A' ... 'Z': + case 'a' ... 'z': + case '.': case '/': + return false; + + default: + return true; + } +} + /* * Setup the unit for a new salt * Hopefully we'll not see a new salt in each crypt call. + * Return false if an unexpected character was found in s[0] or s[1]. */ -void +bool _ufc_setup_salt_r(s, __data) const char *s; struct crypt_data * __restrict __data; { ufc_long i, j, saltbits; + char s0, s1; if(__data->initialized == 0) __init_des_r(__data); - if(s[0] == __data->current_salt[0] && s[1] == __data->current_salt[1]) - return; - __data->current_salt[0] = s[0]; __data->current_salt[1] = s[1]; + s0 = s[0]; + if(bad_for_salt (s0)) + return false; + + s1 = s[1]; + if(bad_for_salt (s1)) + return false; + + if(s0 == __data->current_salt[0] && s1 == __data->current_salt[1]) + return true; + + __data->current_salt[0] = s0; + __data->current_salt[1] = s1; /* * This is the only crypt change to DES: @@ -646,6 +678,8 @@ _ufc_setup_salt_r(s, __data) shuffle_sb((LONGG)__data->sb3, __data->current_saltbits ^ saltbits); __data->current_saltbits = saltbits; + + return true; } void -- cgit 1.4.1