[thirdparty/openssl.git] / crypto / mem_sec.c

/*
 * Copyright 2004-2014, Akamai Technologies. All Rights Reserved.
 * This file is distributed under the terms of the OpenSSL license.
 */

/*
 * This file is in two halves. The first half implements the public API
 * to be used by external consumers, and to be used by OpenSSL to store
 * data in a "secure arena." The second half implements the secure arena.
 * For details on that implementation, see below (look for uppercase
 * "SECURE HEAP IMPLEMENTATION").
 */
#include <openssl/crypto.h>
#include <e_os.h>

#include <string.h>

#if defined(OPENSSL_SYS_LINUX) || defined(OPENSSL_SYS_UNIX)
# define IMPLEMENTED
# include <stdlib.h>
# include <assert.h>
# include <unistd.h>
# include <sys/types.h>
# include <sys/mman.h>
# include <sys/param.h>
# include <sys/stat.h>
# include <fcntl.h>
# include "internal/threads.h"
#endif

#define CLEAR(p, s) OPENSSL_cleanse(p, s)
#ifndef PAGE_SIZE
# define PAGE_SIZE    4096
#endif

#ifdef IMPLEMENTED
static size_t secure_mem_used;

static int secure_mem_initialized;
static int too_late;

static CRYPTO_RWLOCK *sec_malloc_lock = NULL;

/*
 * These are the functions that must be implemented by a secure heap (sh).
 */
static int sh_init(size_t size, int minsize);
static char *sh_malloc(size_t size);
static void sh_free(char *ptr);
static void sh_done(void);
static int sh_actual_size(char *ptr);
static int sh_allocated(const char *ptr);
#endif

int CRYPTO_secure_malloc_init(size_t size, int minsize)
{
#ifdef IMPLEMENTED
    int ret = 0;

    if (too_late)
        return ret;

    OPENSSL_assert(!secure_mem_initialized);
    if (!secure_mem_initialized) {
        sec_malloc_lock = CRYPTO_THREAD_lock_new();
        if (sec_malloc_lock == NULL)
            return 0;
        ret = sh_init(size, minsize);
        secure_mem_initialized = 1;
    }

    return ret;
#else
    return 0;
#endif /* IMPLEMENTED */
}

void CRYPTO_secure_malloc_done()
{
#ifdef IMPLEMENTED
    sh_done();
    secure_mem_initialized = 0;
    CRYPTO_THREAD_lock_free(sec_malloc_lock);
#endif /* IMPLEMENTED */
}

int CRYPTO_secure_malloc_initialized()
{
#ifdef IMPLEMENTED
    return secure_mem_initialized;
#else
    return 0;
#endif /* IMPLEMENTED */
}

void *CRYPTO_secure_malloc(size_t num, const char *file, int line)
{
#ifdef IMPLEMENTED
    void *ret;
    size_t actual_size;

    if (!secure_mem_initialized) {
        too_late = 1;
        return CRYPTO_malloc(num, file, line);
    }
    CRYPTO_THREAD_write_lock(sec_malloc_lock);
    ret = sh_malloc(num);
    actual_size = ret ? sh_actual_size(ret) : 0;
    secure_mem_used += actual_size;
    CRYPTO_THREAD_unlock(sec_malloc_lock);
    return ret;
#else
    return CRYPTO_malloc(num, file, line);
#endif /* IMPLEMENTED */
}

void *CRYPTO_secure_zalloc(size_t num, const char *file, int line)
{
    void *ret = CRYPTO_secure_malloc(num, file, line);

    if (ret != NULL)
        memset(ret, 0, num);
    return ret;
}

void CRYPTO_secure_free(void *ptr, const char *file, int line)
{
#ifdef IMPLEMENTED
    size_t actual_size;

    if (ptr == NULL)
        return;
    if (!secure_mem_initialized) {
        CRYPTO_free(ptr, file, line);
        return;
    }
    CRYPTO_THREAD_write_lock(sec_malloc_lock);
    actual_size = sh_actual_size(ptr);
    CLEAR(ptr, actual_size);
    secure_mem_used -= actual_size;
    sh_free(ptr);
    CRYPTO_THREAD_unlock(sec_malloc_lock);
#else
    CRYPTO_free(ptr, file, line);
#endif /* IMPLEMENTED */
}

int CRYPTO_secure_allocated(const void *ptr)
{
#ifdef IMPLEMENTED
    int ret;

    if (!secure_mem_initialized)
        return 0;
    CRYPTO_THREAD_write_lock(sec_malloc_lock);
    ret = sh_allocated(ptr);
    CRYPTO_THREAD_unlock(sec_malloc_lock);
    return ret;
#else
    return 0;
#endif /* IMPLEMENTED */
}

size_t CRYPTO_secure_used()
{
#ifdef IMPLEMENTED
    return secure_mem_used;
#else
    return 0;
#endif /* IMPLEMENTED */
}

size_t CRYPTO_secure_actual_size(void *ptr)
{
#ifdef IMPLEMENTED
    size_t actual_size;

    CRYPTO_THREAD_write_lock(sec_malloc_lock);
    actual_size = sh_actual_size(ptr);
    CRYPTO_THREAD_unlock(sec_malloc_lock);
    return actual_size;
#else
    return 0;
#endif
}
/* END OF PAGE ...

   ... START OF PAGE */

/*
 * SECURE HEAP IMPLEMENTATION
 */
#ifdef IMPLEMENTED


/*
 * The implementation provided here uses a fixed-sized mmap() heap,
 * which is locked into memory, not written to core files, and protected
 * on either side by an unmapped page, which will catch pointer overruns
 * (or underruns) and an attempt to read data out of the secure heap.
 * Free'd memory is zero'd or otherwise cleansed.
 *
 * This is a pretty standard buddy allocator.  We keep areas in a multiple
 * of "sh.minsize" units.  The freelist and bitmaps are kept separately,
 * so all (and only) data is kept in the mmap'd heap.
 *
 * This code assumes eight-bit bytes.  The numbers 3 and 7 are all over the
 * place.
 */

# define TESTBIT(t, b)  (t[(b) >> 3] &  (1 << ((b) & 7)))
# define SETBIT(t, b)   (t[(b) >> 3] |= (1 << ((b) & 7)))
# define CLEARBIT(t, b) (t[(b) >> 3] &= (0xFF & ~(1 << ((b) & 7))))

#define WITHIN_ARENA(p) \
    ((char*)(p) >= sh.arena && (char*)(p) < &sh.arena[sh.arena_size])
#define WITHIN_FREELIST(p) \
    ((char*)(p) >= (char*)sh.freelist && (char*)(p) < (char*)&sh.freelist[sh.freelist_size])


typedef struct sh_list_st
{
    struct sh_list_st *next;
    struct sh_list_st **p_next;
} SH_LIST;

typedef struct sh_st
{
    char* map_result;
    size_t map_size;
    char *arena;
    int arena_size;
    char **freelist;
    int freelist_size;
    int minsize;
    unsigned char *bittable;
    unsigned char *bitmalloc;
    int bittable_size; /* size in bits */
} SH;

static SH sh;

static int sh_getlist(char *ptr)
{
    int list = sh.freelist_size - 1;
    int bit = (sh.arena_size + ptr - sh.arena) / sh.minsize;

    for (; bit; bit >>= 1, list--) {
        if (TESTBIT(sh.bittable, bit))
            break;
        OPENSSL_assert((bit & 1) == 0);
    }

    return list;
}


static int sh_testbit(char *ptr, int list, unsigned char *table)
{
    int bit;

    OPENSSL_assert(list >= 0 && list < sh.freelist_size);
    OPENSSL_assert(((ptr - sh.arena) & ((sh.arena_size >> list) - 1)) == 0);
    bit = (1 << list) + ((ptr - sh.arena) / (sh.arena_size >> list));
    OPENSSL_assert(bit > 0 && bit < sh.bittable_size);
    return TESTBIT(table, bit);
}

static void sh_clearbit(char *ptr, int list, unsigned char *table)
{
    int bit;

    OPENSSL_assert(list >= 0 && list < sh.freelist_size);
    OPENSSL_assert(((ptr - sh.arena) & ((sh.arena_size >> list) - 1)) == 0);
    bit = (1 << list) + ((ptr - sh.arena) / (sh.arena_size >> list));
    OPENSSL_assert(bit > 0 && bit < sh.bittable_size);
    OPENSSL_assert(TESTBIT(table, bit));
    CLEARBIT(table, bit);
}

static void sh_setbit(char *ptr, int list, unsigned char *table)
{
    int bit;

    OPENSSL_assert(list >= 0 && list < sh.freelist_size);
    OPENSSL_assert(((ptr - sh.arena) & ((sh.arena_size >> list) - 1)) == 0);
    bit = (1 << list) + ((ptr - sh.arena) / (sh.arena_size >> list));
    OPENSSL_assert(bit > 0 && bit < sh.bittable_size);
    OPENSSL_assert(!TESTBIT(table, bit));
    SETBIT(table, bit);
}

static void sh_add_to_list(char **list, char *ptr)
{
    SH_LIST *temp;

    OPENSSL_assert(WITHIN_FREELIST(list));
    OPENSSL_assert(WITHIN_ARENA(ptr));

    temp = (SH_LIST *)ptr;
    temp->next = *(SH_LIST **)list;
    OPENSSL_assert(temp->next == NULL || WITHIN_ARENA(temp->next));
    temp->p_next = (SH_LIST **)list;

    if (temp->next != NULL) {
        OPENSSL_assert((char **)temp->next->p_next == list);
        temp->next->p_next = &(temp->next);
    }

    *list = ptr;
}

static void sh_remove_from_list(char *ptr)
{
    SH_LIST *temp, *temp2;

    temp = (SH_LIST *)ptr;
    if (temp->next != NULL)
        temp->next->p_next = temp->p_next;
    *temp->p_next = temp->next;
    if (temp->next == NULL)
        return;

    temp2 = temp->next;
    OPENSSL_assert(WITHIN_FREELIST(temp2->p_next) || WITHIN_ARENA(temp2->p_next));
}


static int sh_init(size_t size, int minsize)
{
    int i, ret;
    size_t pgsize;
    size_t aligned;

    memset(&sh, 0, sizeof sh);

    /* make sure size and minsize are powers of 2 */
    OPENSSL_assert(size > 0);
    OPENSSL_assert((size & (size - 1)) == 0);
    OPENSSL_assert(minsize > 0);
    OPENSSL_assert((minsize & (minsize - 1)) == 0);
    if (size <= 0 || (size & (size - 1)) != 0)
        goto err;
    if (minsize <= 0 || (minsize & (minsize - 1)) != 0)
        goto err;

    sh.arena_size = size;
    sh.minsize = minsize;
    sh.bittable_size = (sh.arena_size / sh.minsize) * 2;

    sh.freelist_size = -1;
    for (i = sh.bittable_size; i; i >>= 1)
        sh.freelist_size++;

    sh.freelist = OPENSSL_zalloc(sh.freelist_size * sizeof (char *));
    OPENSSL_assert(sh.freelist != NULL);
    if (sh.freelist == NULL)
        goto err;

    sh.bittable = OPENSSL_zalloc(sh.bittable_size >> 3);
    OPENSSL_assert(sh.bittable != NULL);
    if (sh.bittable == NULL)
        goto err;

    sh.bitmalloc = OPENSSL_zalloc(sh.bittable_size >> 3);
    OPENSSL_assert(sh.bitmalloc != NULL);
    if (sh.bitmalloc == NULL)
        goto err;

    /* Allocate space for heap, and two extra pages as guards */
#if defined(_SC_PAGE_SIZE) || defined (_SC_PAGESIZE)
    {
# if defined(_SC_PAGE_SIZE)
        long tmppgsize = sysconf(_SC_PAGE_SIZE);
# else
        long tmppgsize = sysconf(_SC_PAGESIZE);
# endif
        if (tmppgsize < 1)
            pgsize = PAGE_SIZE;
        else
            pgsize = (size_t)tmppgsize;
    }
#else
    pgsize = PAGE_SIZE;
#endif
    sh.map_size = pgsize + sh.arena_size + pgsize;
    if (1) {
#ifdef MAP_ANON
        sh.map_result = mmap(NULL, sh.map_size,
                             PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE, -1, 0);
    } else {
#endif
        int fd;

        sh.map_result = MAP_FAILED;
        if ((fd = open("/dev/zero", O_RDWR)) >= 0) {
            sh.map_result = mmap(NULL, sh.map_size,
                                 PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
            close(fd);
        }
    }
    OPENSSL_assert(sh.map_result != MAP_FAILED);
    if (sh.map_result == MAP_FAILED)
        goto err;
    sh.arena = (char *)(sh.map_result + pgsize);
    sh_setbit(sh.arena, 0, sh.bittable);
    sh_add_to_list(&sh.freelist[0], sh.arena);

    /* Now try to add guard pages and lock into memory. */
    ret = 1;

    /* Starting guard is already aligned from mmap. */
    if (mprotect(sh.map_result, pgsize, PROT_NONE) < 0)
        ret = 2;

    /* Ending guard page - need to round up to page boundary */
    aligned = (pgsize + sh.arena_size + (pgsize - 1)) & ~(pgsize - 1);
    if (mprotect(sh.map_result + aligned, pgsize, PROT_NONE) < 0)
        ret = 2;

    if (mlock(sh.arena, sh.arena_size) < 0)
        ret = 2;
#ifdef MADV_DONTDUMP
    if (madvise(sh.arena, sh.arena_size, MADV_DONTDUMP) < 0)
        ret = 2;
#endif

    return ret;

 err:
    sh_done();
    return 0;
}

static void sh_done()
{
    OPENSSL_free(sh.freelist);
    OPENSSL_free(sh.bittable);
    OPENSSL_free(sh.bitmalloc);
    if (sh.map_result != NULL && sh.map_size)
        munmap(sh.map_result, sh.map_size);
    memset(&sh, 0, sizeof sh);
}

static int sh_allocated(const char *ptr)
{
    return WITHIN_ARENA(ptr) ? 1 : 0;
}

static char *sh_find_my_buddy(char *ptr, int list)
{
    int bit;
    char *chunk = NULL;

    bit = (1 << list) + (ptr - sh.arena) / (sh.arena_size >> list);
    bit ^= 1;

    if (TESTBIT(sh.bittable, bit) && !TESTBIT(sh.bitmalloc, bit))
        chunk = sh.arena + ((bit & ((1 << list) - 1)) * (sh.arena_size >> list));

    return chunk;
}

static char *sh_malloc(size_t size)
{
    int list, slist;
    size_t i;
    char *chunk;

    list = sh.freelist_size - 1;
    for (i = sh.minsize; i < size; i <<= 1)
        list--;
    if (list < 0)
        return NULL;

    /* try to find a larger entry to split */
    for (slist = list; slist >= 0; slist--)
        if (sh.freelist[slist] != NULL)
            break;
    if (slist < 0)
        return NULL;

    /* split larger entry */
    while (slist != list) {
        char *temp = sh.freelist[slist];

        /* remove from bigger list */
        OPENSSL_assert(!sh_testbit(temp, slist, sh.bitmalloc));
        sh_clearbit(temp, slist, sh.bittable);
        sh_remove_from_list(temp);
        OPENSSL_assert(temp != sh.freelist[slist]);

        /* done with bigger list */
        slist++;

        /* add to smaller list */
        OPENSSL_assert(!sh_testbit(temp, slist, sh.bitmalloc));
        sh_setbit(temp, slist, sh.bittable);
        sh_add_to_list(&sh.freelist[slist], temp);
        OPENSSL_assert(sh.freelist[slist] == temp);

        /* split in 2 */
        temp += sh.arena_size >> slist;
        OPENSSL_assert(!sh_testbit(temp, slist, sh.bitmalloc));
        sh_setbit(temp, slist, sh.bittable);
        sh_add_to_list(&sh.freelist[slist], temp);
        OPENSSL_assert(sh.freelist[slist] == temp);

        OPENSSL_assert(temp-(sh.arena_size >> slist) == sh_find_my_buddy(temp, slist));
    }

    /* peel off memory to hand back */
    chunk = sh.freelist[list];
    OPENSSL_assert(sh_testbit(chunk, list, sh.bittable));
    sh_setbit(chunk, list, sh.bitmalloc);
    sh_remove_from_list(chunk);

    OPENSSL_assert(WITHIN_ARENA(chunk));

    return chunk;
}

static void sh_free(char *ptr)
{
    int list;
    char *buddy;

    if (ptr == NULL)
        return;
    OPENSSL_assert(WITHIN_ARENA(ptr));
    if (!WITHIN_ARENA(ptr))
        return;

    list = sh_getlist(ptr);
    OPENSSL_assert(sh_testbit(ptr, list, sh.bittable));
    sh_clearbit(ptr, list, sh.bitmalloc);
    sh_add_to_list(&sh.freelist[list], ptr);

    /* Try to coalesce two adjacent free areas. */
    while ((buddy = sh_find_my_buddy(ptr, list)) != NULL) {
        OPENSSL_assert(ptr == sh_find_my_buddy(buddy, list));
        OPENSSL_assert(ptr != NULL);
        OPENSSL_assert(!sh_testbit(ptr, list, sh.bitmalloc));
        sh_clearbit(ptr, list, sh.bittable);
        sh_remove_from_list(ptr);
        OPENSSL_assert(!sh_testbit(ptr, list, sh.bitmalloc));
        sh_clearbit(buddy, list, sh.bittable);
        sh_remove_from_list(buddy);

        list--;

        if (ptr > buddy)
            ptr = buddy;

        OPENSSL_assert(!sh_testbit(ptr, list, sh.bitmalloc));
        sh_setbit(ptr, list, sh.bittable);
        sh_add_to_list(&sh.freelist[list], ptr);
        OPENSSL_assert(sh.freelist[list] == ptr);
    }
}

static int sh_actual_size(char *ptr)
{
    int list;

    OPENSSL_assert(WITHIN_ARENA(ptr));
    if (!WITHIN_ARENA(ptr))
        return 0;
    list = sh_getlist(ptr);
    OPENSSL_assert(sh_testbit(ptr, list, sh.bittable));
    return sh.arena_size / (1 << list);
}
#endif /* IMPLEMENTED */
Commit	Line	Data
74924dcb RS	1	/*
	2	* Copyright 2004-2014, Akamai Technologies. All Rights Reserved.
	3	* This file is distributed under the terms of the OpenSSL license.
	4	*/
	5
	6	/*
	7	* This file is in two halves. The first half implements the public API
	8	* to be used by external consumers, and to be used by OpenSSL to store
	9	* data in a "secure arena." The second half implements the secure arena.
	10	* For details on that implementation, see below (look for uppercase
	11	* "SECURE HEAP IMPLEMENTATION").
	12	*/
	13	#include <openssl/crypto.h>
	14	#include <e_os.h>
74924dcb	15
183733f8 RL	16	#include <string.h>
183733f8 RL	17
74924dcb RS	18	#if defined(OPENSSL_SYS_LINUX) \|\| defined(OPENSSL_SYS_UNIX)
74924dcb RS	19	# define IMPLEMENTED
d4dfb0ba	20	# include <stdlib.h>
d4dfb0ba RS	21	# include <assert.h>
d4dfb0ba RS	22	# include <unistd.h>
27186da7	23	# include <sys/types.h>
74924dcb RS	24	# include <sys/mman.h>
74924dcb RS	25	# include <sys/param.h>
27186da7 AP	26	# include <sys/stat.h>
27186da7 AP	27	# include <fcntl.h>
9471f776	28	# include "internal/threads.h"
74924dcb RS	29	#endif
74924dcb RS	30
74924dcb	31	#define CLEAR(p, s) OPENSSL_cleanse(p, s)
34750dc2 BL	32	#ifndef PAGE_SIZE
	33	# define PAGE_SIZE 4096
	34	#endif
74924dcb RS	35
74924dcb RS	36	#ifdef IMPLEMENTED
df2ee0e2	37	static size_t secure_mem_used;
74924dcb RS	38
	39	static int secure_mem_initialized;
	40	static int too_late;
	41
9471f776 MC	42	static CRYPTO_RWLOCK *sec_malloc_lock = NULL;
9471f776 MC	43
74924dcb RS	44	/*
	45	* These are the functions that must be implemented by a secure heap (sh).
	46	*/
	47	static int sh_init(size_t size, int minsize);
	48	static char *sh_malloc(size_t size);
	49	static void sh_free(char *ptr);
	50	static void sh_done(void);
	51	static int sh_actual_size(char *ptr);
	52	static int sh_allocated(const char *ptr);
	53	#endif
	54
	55	int CRYPTO_secure_malloc_init(size_t size, int minsize)
	56	{
	57	#ifdef IMPLEMENTED
	58	int ret = 0;
	59
	60	if (too_late)
	61	return ret;
9471f776	62
74924dcb RS	63	OPENSSL_assert(!secure_mem_initialized);
74924dcb RS	64	if (!secure_mem_initialized) {
9471f776 MC	65	sec_malloc_lock = CRYPTO_THREAD_lock_new();
	66	if (sec_malloc_lock == NULL)
	67	return 0;
74924dcb RS	68	ret = sh_init(size, minsize);
	69	secure_mem_initialized = 1;
	70	}
9471f776	71
74924dcb RS	72	return ret;
	73	#else
	74	return 0;
	75	#endif /* IMPLEMENTED */
	76	}
	77
	78	void CRYPTO_secure_malloc_done()
	79	{
	80	#ifdef IMPLEMENTED
74924dcb RS	81	sh_done();
74924dcb RS	82	secure_mem_initialized = 0;
9471f776	83	CRYPTO_THREAD_lock_free(sec_malloc_lock);
74924dcb RS	84	#endif /* IMPLEMENTED */
	85	}
	86
	87	int CRYPTO_secure_malloc_initialized()
	88	{
	89	#ifdef IMPLEMENTED
	90	return secure_mem_initialized;
	91	#else
	92	return 0;
	93	#endif /* IMPLEMENTED */
	94	}
	95
ff842856	96	void CRYPTO_secure_malloc(size_t num, const char file, int line)
74924dcb RS	97	{
	98	#ifdef IMPLEMENTED
	99	void *ret;
	100	size_t actual_size;
	101
	102	if (!secure_mem_initialized) {
	103	too_late = 1;
	104	return CRYPTO_malloc(num, file, line);
	105	}
9471f776	106	CRYPTO_THREAD_write_lock(sec_malloc_lock);
74924dcb RS	107	ret = sh_malloc(num);
	108	actual_size = ret ? sh_actual_size(ret) : 0;
	109	secure_mem_used += actual_size;
9471f776	110	CRYPTO_THREAD_unlock(sec_malloc_lock);
74924dcb RS	111	return ret;
	112	#else
	113	return CRYPTO_malloc(num, file, line);
	114	#endif /* IMPLEMENTED */
	115	}
	116
3538c7da RS	117	void CRYPTO_secure_zalloc(size_t num, const char file, int line)
	118	{
	119	void *ret = CRYPTO_secure_malloc(num, file, line);
	120
	121	if (ret != NULL)
	122	memset(ret, 0, num);
	123	return ret;
	124	}
	125
05c7b163	126	void CRYPTO_secure_free(void ptr, const char file, int line)
74924dcb RS	127	{
	128	#ifdef IMPLEMENTED
	129	size_t actual_size;
	130
	131	if (ptr == NULL)
	132	return;
	133	if (!secure_mem_initialized) {
05c7b163	134	CRYPTO_free(ptr, file, line);
74924dcb RS	135	return;
74924dcb RS	136	}
9471f776	137	CRYPTO_THREAD_write_lock(sec_malloc_lock);
74924dcb RS	138	actual_size = sh_actual_size(ptr);
	139	CLEAR(ptr, actual_size);
	140	secure_mem_used -= actual_size;
	141	sh_free(ptr);
9471f776	142	CRYPTO_THREAD_unlock(sec_malloc_lock);
74924dcb	143	#else
6a78ae28	144	CRYPTO_free(ptr, file, line);
74924dcb RS	145	#endif /* IMPLEMENTED */
	146	}
	147
	148	int CRYPTO_secure_allocated(const void *ptr)
	149	{
	150	#ifdef IMPLEMENTED
	151	int ret;
	152
	153	if (!secure_mem_initialized)
	154	return 0;
9471f776	155	CRYPTO_THREAD_write_lock(sec_malloc_lock);
74924dcb	156	ret = sh_allocated(ptr);
9471f776	157	CRYPTO_THREAD_unlock(sec_malloc_lock);
74924dcb RS	158	return ret;
	159	#else
	160	return 0;
	161	#endif /* IMPLEMENTED */
	162	}
	163
bbd86bf5 RS	164	size_t CRYPTO_secure_used()
	165	{
	166	#ifdef IMPLEMENTED
	167	return secure_mem_used;
	168	#else
	169	return 0;
	170	#endif /* IMPLEMENTED */
	171	}
	172
d594199b RS	173	size_t CRYPTO_secure_actual_size(void *ptr)
	174	{
	175	#ifdef IMPLEMENTED
	176	size_t actual_size;
	177
9471f776	178	CRYPTO_THREAD_write_lock(sec_malloc_lock);
d594199b	179	actual_size = sh_actual_size(ptr);
9471f776	180	CRYPTO_THREAD_unlock(sec_malloc_lock);
d594199b RS	181	return actual_size;
	182	#else
	183	return 0;
	184	#endif
	185	}
74924dcb RS	186	/* END OF PAGE ...
	187
	188	... START OF PAGE */
	189
	190	/*
	191	* SECURE HEAP IMPLEMENTATION
	192	*/
	193	#ifdef IMPLEMENTED
	194
	195
	196	/*
	197	* The implementation provided here uses a fixed-sized mmap() heap,
	198	* which is locked into memory, not written to core files, and protected
	199	* on either side by an unmapped page, which will catch pointer overruns
	200	* (or underruns) and an attempt to read data out of the secure heap.
	201	* Free'd memory is zero'd or otherwise cleansed.
	202	*
	203	* This is a pretty standard buddy allocator. We keep areas in a multiple
	204	* of "sh.minsize" units. The freelist and bitmaps are kept separately,
	205	* so all (and only) data is kept in the mmap'd heap.
	206	*
	207	* This code assumes eight-bit bytes. The numbers 3 and 7 are all over the
	208	* place.
	209	*/
	210
	211	# define TESTBIT(t, b) (t[(b) >> 3] & (1 << ((b) & 7)))
	212	# define SETBIT(t, b) (t[(b) >> 3] \|= (1 << ((b) & 7)))
	213	# define CLEARBIT(t, b) (t[(b) >> 3] &= (0xFF & ~(1 << ((b) & 7))))
	214
	215	#define WITHIN_ARENA(p) \
	216	((char)(p) >= sh.arena && (char)(p) < &sh.arena[sh.arena_size])
	217	#define WITHIN_FREELIST(p) \
	218	((char)(p) >= (char)sh.freelist && (char)(p) < (char)&sh.freelist[sh.freelist_size])
	219
	220
	221	typedef struct sh_list_st
	222	{
	223	struct sh_list_st *next;
	224	struct sh_list_st **p_next;
	225	} SH_LIST;
	226
	227	typedef struct sh_st
	228	{
	229	char* map_result;
	230	size_t map_size;
	231	char *arena;
	232	int arena_size;
	233	char **freelist;
	234	int freelist_size;
	235	int minsize;
	236	unsigned char *bittable;
	237	unsigned char *bitmalloc;
	238	int bittable_size; /* size in bits */
	239	} SH;
	240
	241	static SH sh;
	242
	243	static int sh_getlist(char *ptr)
	244	{
	245	int list = sh.freelist_size - 1;
	246	int bit = (sh.arena_size + ptr - sh.arena) / sh.minsize;
	247
	248	for (; bit; bit >>= 1, list--) {
	249	if (TESTBIT(sh.bittable, bit))
250	break;
251	OPENSSL_assert((bit & 1) == 0);
252	}
253
254	return list;
255	}
256
257
258	static int sh_testbit(char ptr, int list, unsigned char table)
259	{
260	int bit;
261
262	OPENSSL_assert(list >= 0 && list < sh.freelist_size);
263	OPENSSL_assert(((ptr - sh.arena) & ((sh.arena_size >> list) - 1)) == 0);
264	bit = (1 << list) + ((ptr - sh.arena) / (sh.arena_size >> list));
265	OPENSSL_assert(bit > 0 && bit < sh.bittable_size);
266	return TESTBIT(table, bit);
267	}
268
269	static void sh_clearbit(char ptr, int list, unsigned char table)
270	{
271	int bit;
272
273	OPENSSL_assert(list >= 0 && list < sh.freelist_size);
274	OPENSSL_assert(((ptr - sh.arena) & ((sh.arena_size >> list) - 1)) == 0);
275	bit = (1 << list) + ((ptr - sh.arena) / (sh.arena_size >> list));
276	OPENSSL_assert(bit > 0 && bit < sh.bittable_size);
277	OPENSSL_assert(TESTBIT(table, bit));
278	CLEARBIT(table, bit);
279	}
280
281	static void sh_setbit(char ptr, int list, unsigned char table)
282	{
283	int bit;
284
285	OPENSSL_assert(list >= 0 && list < sh.freelist_size);
286	OPENSSL_assert(((ptr - sh.arena) & ((sh.arena_size >> list) - 1)) == 0);
287	bit = (1 << list) + ((ptr - sh.arena) / (sh.arena_size >> list));
288	OPENSSL_assert(bit > 0 && bit < sh.bittable_size);
289	OPENSSL_assert(!TESTBIT(table, bit));
290	SETBIT(table, bit);
291	}
292
293	static void sh_add_to_list(char *list, char ptr)
294	{
295	SH_LIST *temp;
296
297	OPENSSL_assert(WITHIN_FREELIST(list));
298	OPENSSL_assert(WITHIN_ARENA(ptr));
299
300	temp = (SH_LIST *)ptr;
301	temp->next = (SH_LIST *)list;
302	OPENSSL_assert(temp->next == NULL \|\| WITHIN_ARENA(temp->next));
303	temp->p_next = (SH_LIST **)list;
304
305	if (temp->next != NULL) {
306	OPENSSL_assert((char **)temp->next->p_next == list);
307	temp->next->p_next = &(temp->next);
308	}
309
310	*list = ptr;
311	}
312
a773b52a	313	static void sh_remove_from_list(char *ptr)
74924dcb RS	314	{
	315	SH_LIST temp, temp2;
	316
	317	temp = (SH_LIST *)ptr;
	318	if (temp->next != NULL)
	319	temp->next->p_next = temp->p_next;
	320	*temp->p_next = temp->next;
	321	if (temp->next == NULL)
	322	return;
	323
	324	temp2 = temp->next;
	325	OPENSSL_assert(WITHIN_FREELIST(temp2->p_next) \|\| WITHIN_ARENA(temp2->p_next));
	326	}
	327
	328
	329	static int sh_init(size_t size, int minsize)
	330	{
	331	int i, ret;
	332	size_t pgsize;
	333	size_t aligned;
	334
	335	memset(&sh, 0, sizeof sh);
	336
	337	/* make sure size and minsize are powers of 2 */
	338	OPENSSL_assert(size > 0);
	339	OPENSSL_assert((size & (size - 1)) == 0);
	340	OPENSSL_assert(minsize > 0);
	341	OPENSSL_assert((minsize & (minsize - 1)) == 0);
	342	if (size <= 0 \|\| (size & (size - 1)) != 0)
	343	goto err;
	344	if (minsize <= 0 \|\| (minsize & (minsize - 1)) != 0)
	345	goto err;
	346
	347	sh.arena_size = size;
	348	sh.minsize = minsize;
	349	sh.bittable_size = (sh.arena_size / sh.minsize) * 2;
	350
	351	sh.freelist_size = -1;
	352	for (i = sh.bittable_size; i; i >>= 1)
	353	sh.freelist_size++;
	354
b51bce94	355	sh.freelist = OPENSSL_zalloc(sh.freelist_size * sizeof (char *));
74924dcb RS	356	OPENSSL_assert(sh.freelist != NULL);
	357	if (sh.freelist == NULL)
	358	goto err;
74924dcb	359
b51bce94	360	sh.bittable = OPENSSL_zalloc(sh.bittable_size >> 3);
74924dcb RS	361	OPENSSL_assert(sh.bittable != NULL);
	362	if (sh.bittable == NULL)
	363	goto err;
74924dcb	364
b51bce94	365	sh.bitmalloc = OPENSSL_zalloc(sh.bittable_size >> 3);
74924dcb RS	366	OPENSSL_assert(sh.bitmalloc != NULL);
	367	if (sh.bitmalloc == NULL)
	368	goto err;
74924dcb RS	369
74924dcb RS	370	/* Allocate space for heap, and two extra pages as guards */
9ae720b4 MC	371	#if defined(_SC_PAGE_SIZE) \|\| defined (_SC_PAGESIZE)
	372	{
	373	# if defined(_SC_PAGE_SIZE)
	374	long tmppgsize = sysconf(_SC_PAGE_SIZE);
	375	# else
	376	long tmppgsize = sysconf(_SC_PAGESIZE);
	377	# endif
	378	if (tmppgsize < 1)
	379	pgsize = PAGE_SIZE;
	380	else
	381	pgsize = (size_t)tmppgsize;
	382	}
74924dcb RS	383	#else
	384	pgsize = PAGE_SIZE;
	385	#endif
	386	sh.map_size = pgsize + sh.arena_size + pgsize;
27186da7 AP	387	if (1) {
	388	#ifdef MAP_ANON
	389	sh.map_result = mmap(NULL, sh.map_size,
	390	PROT_READ\|PROT_WRITE, MAP_ANON\|MAP_PRIVATE, -1, 0);
	391	} else {
	392	#endif
	393	int fd;
	394
	395	sh.map_result = MAP_FAILED;
	396	if ((fd = open("/dev/zero", O_RDWR)) >= 0) {
	397	sh.map_result = mmap(NULL, sh.map_size,
	398	PROT_READ\|PROT_WRITE, MAP_PRIVATE, fd, 0);
	399	close(fd);
	400	}
	401	}
74924dcb RS	402	OPENSSL_assert(sh.map_result != MAP_FAILED);
	403	if (sh.map_result == MAP_FAILED)
	404	goto err;
	405	sh.arena = (char *)(sh.map_result + pgsize);
	406	sh_setbit(sh.arena, 0, sh.bittable);
	407	sh_add_to_list(&sh.freelist[0], sh.arena);
	408
	409	/* Now try to add guard pages and lock into memory. */
	410	ret = 1;
	411
	412	/* Starting guard is already aligned from mmap. */
	413	if (mprotect(sh.map_result, pgsize, PROT_NONE) < 0)
	414	ret = 2;
	415
	416	/* Ending guard page - need to round up to page boundary */
	417	aligned = (pgsize + sh.arena_size + (pgsize - 1)) & ~(pgsize - 1);
	418	if (mprotect(sh.map_result + aligned, pgsize, PROT_NONE) < 0)
	419	ret = 2;
	420
	421	if (mlock(sh.arena, sh.arena_size) < 0)
	422	ret = 2;
	423	#ifdef MADV_DONTDUMP
	424	if (madvise(sh.arena, sh.arena_size, MADV_DONTDUMP) < 0)
	425	ret = 2;
	426	#endif
	427
	428	return ret;
	429
	430	err:
	431	sh_done();
	432	return 0;
	433	}
	434
	435	static void sh_done()
	436	{
	437	OPENSSL_free(sh.freelist);
	438	OPENSSL_free(sh.bittable);
	439	OPENSSL_free(sh.bitmalloc);
	440	if (sh.map_result != NULL && sh.map_size)
	441	munmap(sh.map_result, sh.map_size);
	442	memset(&sh, 0, sizeof sh);
	443	}
	444
	445	static int sh_allocated(const char *ptr)
	446	{
	447	return WITHIN_ARENA(ptr) ? 1 : 0;
	448	}
	449
	450	static char sh_find_my_buddy(char ptr, int list)
	451	{
	452	int bit;
	453	char *chunk = NULL;
	454
	455	bit = (1 << list) + (ptr - sh.arena) / (sh.arena_size >> list);
	456	bit ^= 1;
	457
	458	if (TESTBIT(sh.bittable, bit) && !TESTBIT(sh.bitmalloc, bit))
	459	chunk = sh.arena + ((bit & ((1 << list) - 1)) * (sh.arena_size >> list));
	460
	461	return chunk;
	462	}
	463
	464	static char *sh_malloc(size_t size)
	465	{
466	int list, slist;
467	size_t i;
468	char *chunk;
469
470	list = sh.freelist_size - 1;
471	for (i = sh.minsize; i < size; i <<= 1)
472	list--;
473	if (list < 0)
474	return NULL;
475
476	/* try to find a larger entry to split */
477	for (slist = list; slist >= 0; slist--)
478	if (sh.freelist[slist] != NULL)
479	break;
480	if (slist < 0)
481	return NULL;
482
483	/* split larger entry */
484	while (slist != list) {
485	char *temp = sh.freelist[slist];
486
487	/* remove from bigger list */
488	OPENSSL_assert(!sh_testbit(temp, slist, sh.bitmalloc));
489	sh_clearbit(temp, slist, sh.bittable);
a773b52a	490	sh_remove_from_list(temp);
74924dcb RS	491	OPENSSL_assert(temp != sh.freelist[slist]);
	492
	493	/* done with bigger list */
	494	slist++;
	495
	496	/* add to smaller list */
	497	OPENSSL_assert(!sh_testbit(temp, slist, sh.bitmalloc));
	498	sh_setbit(temp, slist, sh.bittable);
	499	sh_add_to_list(&sh.freelist[slist], temp);
	500	OPENSSL_assert(sh.freelist[slist] == temp);
	501
	502	/* split in 2 */
	503	temp += sh.arena_size >> slist;
	504	OPENSSL_assert(!sh_testbit(temp, slist, sh.bitmalloc));
	505	sh_setbit(temp, slist, sh.bittable);
	506	sh_add_to_list(&sh.freelist[slist], temp);
	507	OPENSSL_assert(sh.freelist[slist] == temp);
	508
	509	OPENSSL_assert(temp-(sh.arena_size >> slist) == sh_find_my_buddy(temp, slist));
	510	}
	511
	512	/* peel off memory to hand back */
	513	chunk = sh.freelist[list];
	514	OPENSSL_assert(sh_testbit(chunk, list, sh.bittable));
	515	sh_setbit(chunk, list, sh.bitmalloc);
a773b52a	516	sh_remove_from_list(chunk);
74924dcb RS	517
	518	OPENSSL_assert(WITHIN_ARENA(chunk));
	519
	520	return chunk;
	521	}
	522
	523	static void sh_free(char *ptr)
	524	{
	525	int list;
	526	char *buddy;
	527
	528	if (ptr == NULL)
	529	return;
	530	OPENSSL_assert(WITHIN_ARENA(ptr));
	531	if (!WITHIN_ARENA(ptr))
	532	return;
	533
	534	list = sh_getlist(ptr);
	535	OPENSSL_assert(sh_testbit(ptr, list, sh.bittable));
	536	sh_clearbit(ptr, list, sh.bitmalloc);
	537	sh_add_to_list(&sh.freelist[list], ptr);
	538
	539	/* Try to coalesce two adjacent free areas. */
	540	while ((buddy = sh_find_my_buddy(ptr, list)) != NULL) {
	541	OPENSSL_assert(ptr == sh_find_my_buddy(buddy, list));
	542	OPENSSL_assert(ptr != NULL);
	543	OPENSSL_assert(!sh_testbit(ptr, list, sh.bitmalloc));
	544	sh_clearbit(ptr, list, sh.bittable);
a773b52a	545	sh_remove_from_list(ptr);
74924dcb RS	546	OPENSSL_assert(!sh_testbit(ptr, list, sh.bitmalloc));
74924dcb RS	547	sh_clearbit(buddy, list, sh.bittable);
a773b52a	548	sh_remove_from_list(buddy);
74924dcb RS	549
	550	list--;
	551
	552	if (ptr > buddy)
	553	ptr = buddy;
	554
	555	OPENSSL_assert(!sh_testbit(ptr, list, sh.bitmalloc));
	556	sh_setbit(ptr, list, sh.bittable);
	557	sh_add_to_list(&sh.freelist[list], ptr);
	558	OPENSSL_assert(sh.freelist[list] == ptr);
	559	}
	560	}
	561
	562	static int sh_actual_size(char *ptr)
	563	{
	564	int list;
	565
	566	OPENSSL_assert(WITHIN_ARENA(ptr));
	567	if (!WITHIN_ARENA(ptr))
	568	return 0;
	569	list = sh_getlist(ptr);
	570	OPENSSL_assert(sh_testbit(ptr, list, sh.bittable));
	571	return sh.arena_size / (1 << list);
	572	}
	573	#endif /* IMPLEMENTED */