Diffstat (limited to 'pwmanager/libcrypt/crypt/stdmem.c') (more/less context) (ignore whitespace changes)
| -rw-r--r-- | pwmanager/libcrypt/crypt/stdmem.c | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/pwmanager/libcrypt/crypt/stdmem.c b/pwmanager/libcrypt/crypt/stdmem.c new file mode 100644 index 0000000..659bc4e --- a/dev/null +++ b/pwmanager/libcrypt/crypt/stdmem.c @@ -0,0 +1,195 @@ +/* stdmem.c - private memory allocator + * Copyright (C) 1998, 2000, 2002 Free Software Foundation, Inc. + * + * This file is part of Libgcrypt. + * + * Libgcrypt 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. + * + * Libgcrypt 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 this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA + */ + +#include <config.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <stdarg.h> + +#include "g10lib.h" +#include "stdmem.h" +#include "secmem.h" + + +#define MAGIC_NOR_BYTE 0x55 +#define MAGIC_SEC_BYTE 0xcc +#define MAGIC_END_BYTE 0xaa + +#if SIZEOF_UNSIGNED_LONG == 8 +#define EXTRA_ALIGN 4 +#else +#define EXTRA_ALIGN 0 +#endif + + +static int use_m_guard = 0; + +/**************** + * Warning: Never use this function after any of the functions + * here have been used. + */ +void +_gcry_private_enable_m_guard(void) +{ + use_m_guard = 1; +} + +/**************** + * Allocate memory of size n. + * Return NULL if we are out of memory. + */ +void * +_gcry_private_malloc( size_t n) +{ + if(!n) + return NULL; /* allocating 0 bytes is undefined - better return + an error */ + if( use_m_guard ) { + char *p; + + if( !(p = malloc( n + EXTRA_ALIGN+5 )) ) + return NULL; + ((byte*)p)[EXTRA_ALIGN+0] = n; + ((byte*)p)[EXTRA_ALIGN+1] = n >> 8 ; + ((byte*)p)[EXTRA_ALIGN+2] = n >> 16 ; + ((byte*)p)[EXTRA_ALIGN+3] = MAGIC_NOR_BYTE; + p[4+EXTRA_ALIGN+n] = MAGIC_END_BYTE; + return p+EXTRA_ALIGN+4; + } + else { + return malloc( n ); + } +} + +/**************** + * Allocate memory of size n from the secure memory pool. + * Return NULL if we are out of memory. + */ +void * +_gcry_private_malloc_secure( size_t n) +{ + if(!n) + return NULL; /* allocating 0 bytes is undefined - better return + an error */ + if( use_m_guard ) { + char *p; + + if( !(p = _gcry_secmem_malloc( n +EXTRA_ALIGN+ 5 )) ) + return NULL; + ((byte*)p)[EXTRA_ALIGN+0] = n; + ((byte*)p)[EXTRA_ALIGN+1] = n >> 8 ; + ((byte*)p)[EXTRA_ALIGN+2] = n >> 16 ; + ((byte*)p)[EXTRA_ALIGN+3] = MAGIC_SEC_BYTE; + p[4+EXTRA_ALIGN+n] = MAGIC_END_BYTE; + return p+EXTRA_ALIGN+4; + } + else { + return _gcry_secmem_malloc( n ); + } +} + + +/**************** + * realloc and clear the old space + * Return NULL if there is not enoug memory. + */ +void * +_gcry_private_realloc( void *a, size_t n ) +{ + if( use_m_guard ) { + unsigned char *p = a; + char *b; + size_t len; + + if (!a) + return _gcry_private_malloc(n); + + _gcry_private_check_heap(p); + len = p[-4]; + len |= p[-3] << 8; + len |= p[-2] << 16; + if( len >= n ) /* we don't shrink for now */ + return a; + if( p[-1] == MAGIC_SEC_BYTE ) + b = _gcry_private_malloc_secure(n); + else + b = _gcry_private_malloc(n); + if( !b ) + return NULL; + memcpy(b, a, len ); + memset(b+len, 0, n-len ); + _gcry_private_free( p ); + return b; + } + else if( _gcry_private_is_secure(a) ) { + return _gcry_secmem_realloc( a, n ); + } + else { + return realloc( a, n ); + } +} + + +void +_gcry_private_check_heap( const void *a ) +{ + if( use_m_guard ) { + const byte *p = a; + size_t len; + + if( !p ) + return; + + if( !(p[-1] == MAGIC_NOR_BYTE || p[-1] == MAGIC_SEC_BYTE) ) + _gcry_log_fatal("memory at %p corrupted (underflow=%02x)\n", p, p[-1] ); + len = p[-4]; + len |= p[-3] << 8; + len |= p[-2] << 16; + if( p[len] != MAGIC_END_BYTE ) + _gcry_log_fatal("memory at %p corrupted (overflow=%02x)\n", p, p[-1] ); + } +} + +/**************** + * Free a memory block allocated by this opr the secmem module + */ +void +_gcry_private_free( void *a ) +{ + byte *p = a; + + if( !p ) + return; + if( use_m_guard ) { + _gcry_private_check_heap(p); + if( _gcry_private_is_secure(a) ) + _gcry_secmem_free(p-EXTRA_ALIGN-4); + else { + free(p-EXTRA_ALIGN-4); + } + } + else if( _gcry_private_is_secure(a) ) + _gcry_secmem_free(p); + else + free(p); +} + + |