Commit 9a7a36db authored by Richard Levitte's avatar Richard Levitte
Browse files

Add OPENSSL_cleanse() to help cleanse memory and avoid certain compiler 

and linker optimizations.
PR: 343
parent 60b5a288

CHANGES

+8 −0
Original line number Diff line number Diff line
@@ -4,6 +4,14 @@ 


 Changes between 0.9.6g and 0.9.6h  [xx XXX xxxx]



  *) New function OPENSSL_cleanse(), which is used to cleanse a section of

     memory from it's contents.  This is done with a counter that will

     place alternating values in each byte.  This can be used to solve

     two issues: 1) the removal of calls to memset() by highly optimizing

     compilers, and 2) cleansing with other values than 0, since those can

     be read through on certain media, for example a swap space on disk.

     [Geoff Thorpe]



  *) Bugfix: client side session caching did not work with external caching,

     because the session->cipher setting was not restored when reloading

     from the external cache. This problem was masked, when

crypto/Makefile.ssl

+5 −2
Original line number Diff line number Diff line
@@ -34,8 +34,8 @@ SDIRS= md2 md5 sha mdc2 hmac ripemd \ 
GENERAL=Makefile README crypto-lib.com install.com



LIB= $(TOP)/libcrypto.a

LIBSRC=	cryptlib.c mem.c mem_dbg.c cversion.c ex_data.c tmdiff.c cpt_err.c ebcdic.c uid.c

LIBOBJ= cryptlib.o mem.o mem_dbg.o cversion.o ex_data.o tmdiff.o cpt_err.o ebcdic.o uid.o

LIBSRC=	cryptlib.c mem.c mem_clr.c mem_dbg.c cversion.c ex_data.c tmdiff.c cpt_err.c ebcdic.c uid.c

LIBOBJ= cryptlib.o mem.o mem_clr.o mem_dbg.o cversion.o ex_data.o tmdiff.o cpt_err.o ebcdic.o uid.o



SRC= $(LIBSRC)
@@ -185,6 +185,9 @@ mem.o: ../include/openssl/e_os2.h ../include/openssl/err.h 
mem.o: ../include/openssl/lhash.h ../include/openssl/opensslconf.h

mem.o: ../include/openssl/opensslv.h ../include/openssl/safestack.h

mem.o: ../include/openssl/stack.h ../include/openssl/symhacks.h cryptlib.h

mem_clr.o: ../include/openssl/crypto.h ../include/openssl/opensslv.h

mem_clr.o: ../include/openssl/safestack.h ../include/openssl/stack.h

mem_clr.o: ../include/openssl/symhacks.h

mem_dbg.o: ../include/openssl/bio.h ../include/openssl/buffer.h

mem_dbg.o: ../include/openssl/crypto.h ../include/openssl/e_os.h

mem_dbg.o: ../include/openssl/e_os2.h ../include/openssl/err.h

crypto/crypto-lib.com

+1 −1
Original line number Diff line number Diff line
@@ -174,7 +174,7 @@ $! 
$ APPS_DES = "DES/DES,CBC3_ENC"

$ APPS_PKCS7 = "ENC/ENC;DEC/DEC;SIGN/SIGN;VERIFY/VERIFY,EXAMPLE"

$

$ LIB_ = "cryptlib,mem,mem_dbg,cversion,ex_data,tmdiff,cpt_err,ebcdic,uid"

$ LIB_ = "cryptlib,mem,mem_clr,mem_dbg,cversion,ex_data,tmdiff,cpt_err,ebcdic,uid"

$ LIB_MD2 = "md2_dgst,md2_one"

$ LIB_MD4 = "md4_dgst,md4_one"

$ LIB_MD5 = "md5_dgst,md5_one"

crypto/crypto.h

+2 −0
Original line number Diff line number Diff line
@@ -345,6 +345,8 @@ void CRYPTO_free(void *); 
void *CRYPTO_realloc(void *addr,int num, const char *file, int line);

void *CRYPTO_remalloc(void *addr,int num, const char *file, int line);



void OPENSSL_cleanse(void *ptr, size_t len);



void CRYPTO_set_mem_debug_options(long bits);

long CRYPTO_get_mem_debug_options(void);

crypto/mem.c

+14 −0
Original line number Diff line number Diff line
@@ -173,6 +173,7 @@ void CRYPTO_get_mem_debug_functions(void (**m)(void *,int,const char *,int,int), 
void *CRYPTO_malloc_locked(int num, const char *file, int line)

	{

	void *ret = NULL;

	extern unsigned char cleanse_ctr;



	allow_customize = 0;

	if (malloc_debug_func != NULL)
@@ -187,6 +188,12 @@ void *CRYPTO_malloc_locked(int num, const char *file, int line) 
	if (malloc_debug_func != NULL)

		malloc_debug_func(ret, num, file, line, 1);



        /* Create a dependency on the value of 'cleanse_ctr' so our memory

         * sanitisation function can't be optimised out. NB: We only do

         * this for >2Kb so the overhead doesn't bother us. */

        if(ret && (num > 2048))

		((unsigned char *)ret)[0] = cleanse_ctr;



	return ret;

	}
@@ -205,6 +212,7 @@ void CRYPTO_free_locked(void *str) 
void *CRYPTO_malloc(int num, const char *file, int line)

	{

	void *ret = NULL;

	extern unsigned char cleanse_ctr;



	allow_customize = 0;

	if (malloc_debug_func != NULL)
@@ -219,6 +227,12 @@ void *CRYPTO_malloc(int num, const char *file, int line) 
	if (malloc_debug_func != NULL)

		malloc_debug_func(ret, num, file, line, 1);



        /* Create a dependency on the value of 'cleanse_ctr' so our memory

         * sanitisation function can't be optimised out. NB: We only do

         * this for >2Kb so the overhead doesn't bother us. */

        if(ret && (num > 2048))

                ((unsigned char *)ret)[0] = cleanse_ctr;



	return ret;

	}