On Fri, Oct 27, 2017 at 01:50:26AM +0200, Jan Engelhardt wrote:
> #include <openssl/des.h>
> int main(void) {
> char salt[3] = {0xf8, 0xd0, 0x00};
> char out[32];
> DES_fcrypt("foo", salt, out);
> }
This program produces a Segmentation fault in OpenBSD current.
> openssl 1.1.x has it fixed (but 1.0.2l does not!) - their commit
> seems to be 6493e4801e9edbe1ad1e256d4ce9cd55c8aa2242 in
> https://github.com/openssl/openssl .
Their fix changes the semantics of DES_crypt() and DES_fcrypt().
They may fail and return NULL now. This was never the case before
so we may expect that programs do not check it. With DES_fcrypt()
it is very likely that some uninitilaized content of the return
string is used.
So I have extended the workaround that was there already. Read the
comment above the fix. If the salt does not consist of two ascii
characters, replace it with "AA". This gives a safe result in all
cases.
ok?
bluhm
Index: lib/libcrypto/des/fcrypt.c
===================================================================
RCS file: /data/mirror/openbsd/cvs/src/lib/libcrypto/des/fcrypt.c,v
retrieving revision 1.12
diff -u -p -r1.12 fcrypt.c
--- lib/libcrypto/des/fcrypt.c 26 Dec 2016 21:30:10 -0000 1.12
+++ lib/libcrypto/des/fcrypt.c 5 Dec 2017 16:03:57 -0000
@@ -78,9 +78,15 @@ char *DES_fcrypt(const char *buf, const
* crypt to "*". This was found when replacing the crypt in
* our shared libraries. People found that the disabled
* accounts effectively had no passwd :-(. */
- x=ret[0]=((salt[0] == '\0')?'A':salt[0]);
+ x = salt[0];
+ if (x == 0 || x >= sizeof(con_salt))
+ x = 'A';
+ ret[0] = x;
Eswap0=con_salt[x]<<2;
- x=ret[1]=((salt[1] == '\0')?'A':salt[1]);
+ x = (salt[0] == '\0') ? 'A' : salt[1];
+ if (x == 0 || x >= sizeof(con_salt))
+ x = 'A';
+ ret[1] = x;
Eswap1=con_salt[x]<<6;
/* EAY
r=strlen(buf);
Index: regress/lib/libcrypto/des/destest.c
===================================================================
RCS file: /data/mirror/openbsd/cvs/src/regress/lib/libcrypto/des/destest.c,v
retrieving revision 1.3
diff -u -p -r1.3 destest.c
--- regress/lib/libcrypto/des/destest.c 30 Oct 2015 15:58:40 -0000 1.3
+++ regress/lib/libcrypto/des/destest.c 5 Dec 2017 16:02:18 -0000
@@ -749,18 +749,38 @@ plain[8+4], plain[8+5], plain[8+6], plai
}
printf("\n");
printf("fast crypt test ");
- str=crypt("testing","ef");
+ str=DES_crypt("testing","ef");
if (strcmp("efGnQx2725bI2",str) != 0)
{
printf("fast crypt error, %s should be efGnQx2725bI2\n",str);
err=1;
}
- str=crypt("bca76;23","yA");
+ str=DES_crypt("bca76;23","yA");
if (strcmp("yA1Rp/1hZXIJk",str) != 0)
{
printf("fast crypt error, %s should be yA1Rp/1hZXIJk\n",str);
err=1;
}
+ str = DES_crypt("testing", "\202B");
+ if (strncmp("AB",str,2) != 0) {
+ printf("salt %s first non ascii not replaced with A\n", str);
+ err = 1;
+ }
+ str = DES_crypt("testing", "B\202");
+ if (strncmp("BA",str,2) != 0) {
+ printf("salt %s second non ascii not replaced with A\n", str);
+ err = 1;
+ }
+ str = DES_crypt("testing", "\0B");
+ if (strncmp("AA",str,2) != 0) {
+ printf("salt %s first NUL not replaced with AA\n", str);
+ err = 1;
+ }
+ str = DES_crypt("testing", "B");
+ if (strncmp("BA",str,2) != 0) {
+ printf("salt %s second NUL not replaced with A\n", str);
+ err = 1;
+ }
printf("\n");
return(err);
}
