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author | Rich Salz <rsalz@akamai.com> | 2015-12-16 23:05:20 +0100 |
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committer | Rich Salz <rsalz@openssl.org> | 2015-12-17 04:09:39 +0100 |
commit | 3b089ca21b782f66083a11dbb51ba7279a4c2187 (patch) | |
tree | 7152c8e513198c9575887903d372c652bcefe9e5 /crypto/mem_sec.c | |
parent | Fix typo. (diff) | |
download | openssl-3b089ca21b782f66083a11dbb51ba7279a4c2187.tar.xz openssl-3b089ca21b782f66083a11dbb51ba7279a4c2187.zip |
Rename sec_mem to mem_sec, like other files.
Reviewed-by: Tim Hudson <tjh@openssl.org>
Diffstat (limited to 'crypto/mem_sec.c')
-rw-r--r-- | crypto/mem_sec.c | 538 |
1 files changed, 538 insertions, 0 deletions
diff --git a/crypto/mem_sec.c b/crypto/mem_sec.c new file mode 100644 index 0000000000..0b2f1fda77 --- /dev/null +++ b/crypto/mem_sec.c @@ -0,0 +1,538 @@ +/* + * 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> + +#if defined(OPENSSL_SYS_LINUX) || defined(OPENSSL_SYS_UNIX) +# define IMPLEMENTED +# include <stdlib.h> +# include <string.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> +#endif + +#define LOCK() CRYPTO_w_lock(CRYPTO_LOCK_MALLOC) +#define UNLOCK() CRYPTO_w_unlock(CRYPTO_LOCK_MALLOC) +#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; + +/* + * 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; + LOCK(); + OPENSSL_assert(!secure_mem_initialized); + if (!secure_mem_initialized) { + ret = sh_init(size, minsize); + secure_mem_initialized = 1; + } + UNLOCK(); + return ret; +#else + return 0; +#endif /* IMPLEMENTED */ +} + +void CRYPTO_secure_malloc_done() +{ +#ifdef IMPLEMENTED + LOCK(); + sh_done(); + secure_mem_initialized = 0; + UNLOCK(); +#endif /* IMPLEMENTED */ +} + +int CRYPTO_secure_malloc_initialized() +{ +#ifdef IMPLEMENTED + return secure_mem_initialized; +#else + return 0; +#endif /* IMPLEMENTED */ +} + +void *CRYPTO_secure_malloc(int 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); + } + LOCK(); + ret = sh_malloc(num); + actual_size = ret ? sh_actual_size(ret) : 0; + secure_mem_used += actual_size; + UNLOCK(); + return ret; +#else + return CRYPTO_malloc(num, file, line); +#endif /* IMPLEMENTED */ +} + +void CRYPTO_secure_free(void *ptr) +{ +#ifdef IMPLEMENTED + size_t actual_size; + + if (ptr == NULL) + return; + if (!secure_mem_initialized) { + CRYPTO_free(ptr); + return; + } + LOCK(); + actual_size = sh_actual_size(ptr); + CLEAR(ptr, actual_size); + secure_mem_used -= actual_size; + sh_free(ptr); + UNLOCK(); +#else + CRYPTO_free(ptr); +#endif /* IMPLEMENTED */ +} + +int CRYPTO_secure_allocated(const void *ptr) +{ +#ifdef IMPLEMENTED + int ret; + + if (!secure_mem_initialized) + return 0; + LOCK(); + ret = sh_allocated(ptr); + UNLOCK(); + return ret; +#else + return 0; +#endif /* IMPLEMENTED */ +} + +/* 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, char *list) +{ + 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, sh.freelist[slist]); + 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, sh.freelist[list]); + + 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, sh.freelist[list]); + OPENSSL_assert(!sh_testbit(ptr, list, sh.bitmalloc)); + sh_clearbit(buddy, list, sh.bittable); + sh_remove_from_list(buddy, sh.freelist[list]); + + 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 */ |