File openssl-CVE-2015-1789.patch of Package openssl.4105

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File openssl-CVE-2015-1789.patch of Package openssl.4105

commit f48b83b4fb7d6689584cf25f61ca63a4891f5b11
Author: Emilia Kasper <emilia@openssl.org>
Date:   Wed Apr 8 16:56:43 2015 +0200

Fix length checks in X509_cmp_time to avoid out-of-bounds reads.
    
    Also tighten X509_cmp_time to reject more than three fractional
    seconds in the time; and to reject trailing garbage after the offset.
    
    CVE-2015-1789
    
    Reviewed-by: Viktor Dukhovni <viktor@openssl.org>
    Reviewed-by: Richard Levitte <levitte@openssl.org>

Index: openssl-1.0.1i/crypto/x509/x509_vfy.c
===================================================================
--- openssl-1.0.1i.orig/crypto/x509/x509_vfy.c	2015-06-12 09:53:10.174344061 +0200
+++ openssl-1.0.1i/crypto/x509/x509_vfy.c	2015-06-12 10:06:54.613990422 +0200
@@ -1684,49 +1684,87 @@ int X509_cmp_time(const ASN1_TIME *ctm,
 	ASN1_TIME atm;
 	long offset;
 	char buff1[24],buff2[24],*p;
-	int i,j;
+	int i,j,remaining;
 
 	p=buff1;
-	i=ctm->length;
+	remaining=ctm->length;
 	str=(char *)ctm->data;
+    /*
+     * Note that the following (historical) code allows much more slack in the
+     * time format than RFC5280. In RFC5280, the representation is fixed:
+     * UTCTime: YYMMDDHHMMSSZ
+     * GeneralizedTime: YYYYMMDDHHMMSSZ
+     */
 	if (ctm->type == V_ASN1_UTCTIME)
 		{
-		if ((i < 11) || (i > 17)) return 0;
+        	/* YYMMDDHHMM[SS]Z or YYMMDDHHMM[SS](+-)hhmm */
+        	int min_length = sizeof("YYMMDDHHMMZ") - 1;
+        	int max_length = sizeof("YYMMDDHHMMSS+hhmm") - 1;
+        	if (remaining < min_length || remaining > max_length)
+			return 0;
 		memcpy(p,str,10);
 		p+=10;
 		str+=10;
+	        remaining -= 10;
 		}
 	else
 		{
-		if (i < 13) return 0;
+        	/* YYYYMMDDHHMM[SS[.fff]]Z or YYYYMMDDHHMM[SS[.f[f[f]]]](+-)hhmm */
+        	int min_length = sizeof("YYYYMMDDHHMMZ") - 1;
+        	int max_length = sizeof("YYYYMMDDHHMMSS.fff+hhmm") - 1;
+        	if (remaining < min_length || remaining > max_length)
+             		return 0;
 		memcpy(p,str,12);
 		p+=12;
 		str+=12;
+	        remaining -= 12;
 		}
 
 	if ((*str == 'Z') || (*str == '-') || (*str == '+'))
 		{ *(p++)='0'; *(p++)='0'; }
 	else
 		{ 
+        	/* SS (seconds) */
+        	if (remaining < 2)
+            		return 0;
 		*(p++)= *(str++);
 		*(p++)= *(str++);
-		/* Skip any fractional seconds... */
-		if (*str == '.')
-			{
+        remaining -= 2;
+        /*
+         * Skip any (up to three) fractional seconds...
+         * TODO(emilia): in RFC5280, fractional seconds are forbidden.
+         * Can we just kill them altogether?
+         */
+        if (remaining && *str == '.') {
 			str++;
-			while ((*str >= '0') && (*str <= '9')) str++;
+            remaining--;
+            for (i = 0; i < 3 && remaining; i++, str++, remaining--) {
+                if (*str < '0' || *str > '9')
+                    break;
+            }
 			}
 		
 		}
 	*(p++)='Z';
 	*(p++)='\0';
 
-	if (*str == 'Z')
-		offset=0;
-	else
-		{
+    /* We now need either a terminating 'Z' or an offset. */
+    if (!remaining)
+        return 0;
+    if (*str == 'Z') {
+        if (remaining != 1)
+            return 0;
+	offset=0;
+    } else {
+        /* (+-)HHMM */
 		if ((*str != '+') && (*str != '-'))
 			return 0;
+        /* Historical behaviour: the (+-)hhmm offset is forbidden in RFC5280. */
+        if (remaining != 5)
+            return 0;
+        if (str[1] < '0' || str[1] > '9' || str[2] < '0' || str[2] > '9' ||
+            str[3] < '0' || str[3] > '9' || str[4] < '0' || str[4] > '9')
+            return 0;
 		offset=((str[1]-'0')*10+(str[2]-'0'))*60;
 		offset+=(str[3]-'0')*10+(str[4]-'0');
 		if (*str == '-')

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