From 16d493390f3f645a0570d9b41abd32c87eebba5d Mon Sep 17 00:00:00 2001
From: millert <millert@openbsd.org>
Date: Thu, 2 Mar 2023 16:21:51 +0000
Subject: [PATCH] When parsing %s, the result should be in the local time zone.
 Based on a patch from enh@google.  OK tb@

---
 lib/libc/time/strptime.c | 60 +++++++++++++++++++---------------------
 1 file changed, 29 insertions(+), 31 deletions(-)

diff --git a/lib/libc/time/strptime.c b/lib/libc/time/strptime.c
index 02017880457..2fae1f49220 100644
--- a/lib/libc/time/strptime.c
+++ b/lib/libc/time/strptime.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: strptime.c,v 1.30 2019/05/12 12:49:52 schwarze Exp $ */
+/*	$OpenBSD: strptime.c,v 1.31 2023/03/02 16:21:51 millert Exp $ */
 /*	$NetBSD: strptime.c,v 1.12 1998/01/20 21:39:40 mycroft Exp $	*/
 /*-
  * Copyright (c) 1997, 1998, 2005, 2008 The NetBSD Foundation, Inc.
@@ -29,8 +29,10 @@
  */
 
 #include <ctype.h>
+#include <errno.h>
+#include <limits.h>
 #include <locale.h>
-#include <stdint.h>
+#include <stdlib.h>
 #include <string.h>
 #include <time.h>
 
@@ -72,8 +74,8 @@ static const int mon_lengths[2][MONSPERYEAR] = {
         { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }
 };
 
-static	int _conv_num64(const unsigned char **, int64_t *, int64_t, int64_t);
 static	int _conv_num(const unsigned char **, int *, int, int);
+static	int epoch_to_tm(const unsigned char **, struct tm *);
 static	int leaps_thru_end_of(const int y);
 static	char *_strptime(const char *, const char *, struct tm *, int);
 static	const u_char *_find_string(const u_char *, int *, const char * const *,
@@ -338,15 +340,10 @@ literal:
 			if (!(_conv_num(&bp, &tm->tm_sec, 0, 60)))
 				return (NULL);
 			break;
-		case 's':	/* Seconds since epoch */
-			{
-				int64_t i64;
-				if (!(_conv_num64(&bp, &i64, 0, INT64_MAX)))
-					return (NULL);
-				if (!gmtime_r(&i64, tm))
-					return (NULL);
-				fields = 0xffff;	 /* everything */
-			}
+		case 's':	/* Seconds since epoch. */
+			if (!(epoch_to_tm(&bp, tm)))
+				return (NULL);
+			fields = 0xffff;	 /* everything */
 			break;
 		case 'U':	/* The week of year, beginning on sunday. */
 		case 'W':	/* The week of year, beginning on monday. */
@@ -610,26 +607,27 @@ _conv_num(const unsigned char **buf, int *dest, int llim, int ulim)
 }
 
 static int
-_conv_num64(const unsigned char **buf, int64_t *dest, int64_t llim, int64_t ulim)
+epoch_to_tm(const unsigned char **buf, struct tm *tm)
 {
-	int result = 0;
-	int64_t rulim = ulim;
-
-	if (**buf < '0' || **buf > '9')
-		return (0);
-
-	/* we use rulim to break out of the loop when we run out of digits */
-	do {
-		result *= 10;
-		result += *(*buf)++ - '0';
-		rulim /= 10;
-	} while ((result * 10 <= ulim) && rulim && **buf >= '0' && **buf <= '9');
-
-	if (result < llim || result > ulim)
-		return (0);
-
-	*dest = result;
-	return (1);
+	int saved_errno = errno;
+	int ret = 0;
+	time_t secs;
+	char *ep;
+
+	errno = 0;
+	secs = strtoll(*buf, &ep, 10);
+	if (*buf == (unsigned char *)ep)
+		goto done;
+	if (secs < 0 ||
+	    secs == LLONG_MAX && errno == ERANGE)
+		goto done;
+	if (localtime_r(&secs, tm) == NULL)
+		goto done;
+	ret = 1;
+done:
+	*buf = ep;
+	errno = saved_errno;
+	return (ret);
 }
 
 static const u_char *
-- 
2.20.1