Import strlcpy/strlcat from OpenBSD, start using them.

strcpy()/strcat() are inherently dangerous, even when
used with great care.  strlcpy() and strlcat() are
much safer replacements, and are available from OpenBSD
under a very liberal license.  Import them and start
using them.

Between pointer vectors, malloz, stralloc and now
strlcpy/strlcat, Magicka has much safer, simpler and
more performant infrastructure for dealing with
strings and dynamic collections of various kinds.

Signed-off-by: Dan Cross <patchdev@fat-dragon.org>

src/GNUmakefile.common

@@ -50,7 +50,8 @@ HDRS:=		bbs.h
 OBJS:=		inih/ini.o bbs.o main.o users.o main_menu.o mail_menu.o \
 		doors.o bbs_list.o chat_system.o email.o files.o settings.o \
 		lua_glue.o strings.o bluewave.o hashmap/hashmap.o menus.o \
-		nodelist.o blog.o util.o stralloc/stralloc.o
+		nodelist.o blog.o util.o stralloc/stralloc.o strlcpy/strlcpy.o \
+		strlcpy/strlcat.o
 
 WWWOBJS:=	../deps/aha/aha.o ../deps/hashids/hashids.o www.o www_email.o \
 		www_msgs.o www_last10.o www_blog.o www_files.o ${OBJS}

src/bbs.c

@@ -536,7 +536,7 @@ void s_readstring_inject(char *buffer, int max, char *inject) {
 		return;
 	}
 
-	strcpy(buffer, inject);
+	strlcpy(buffer, inject, max);
 
 	s_printf("%s", inject);
 
@@ -686,8 +686,8 @@ void record_last10_callers(struct user_record *user) {
 
 	if (strcasecmp(conf.sysop_name, user->loginname) != 0) {
 		memset(&new_entry, 0, sizeof(struct last10_callers));
-		strcpy(new_entry.name, user->loginname);
+		strlcpy(new_entry.name, user->loginname, sizeof(new_entry.name));
-		strcpy(new_entry.location, user->location);
+		strlcpy(new_entry.location, user->location, sizeof(new_entry.location));
 		new_entry.time = time(NULL);
 		new_entry.calls = user->timeson;
 		if (i == 10) {
@@ -777,7 +777,7 @@ void automessage_write() {
 		timen = time(NULL);
 		localtime_r(&timen, &timenow);
 
-		sprintf(automsg, get_string(15), gUser->loginname, asctime(&timenow));
+		snprintf(automsg, sizeof automsg, get_string(15), gUser->loginname, asctime(&timenow));
 
 		automsg[strlen(automsg) - 1] = '\r';
 		automsg[strlen(automsg)] = '\n';
@@ -785,8 +785,8 @@ void automessage_write() {
 		for (i = 0; i < 4; i++) {
 			s_printf("\r\n%d: ", i);
 			s_readstring(buffer, 75);
-			strcat(automsg, buffer);
+			strlcat(automsg, buffer, sizeof automsg);
-			strcat(automsg, "\r\n");
+			strlcat(automsg, "\r\n", sizeof automsg);
 		}
 
 		fptr = fopen("automessage.txt", "w");
@@ -1346,7 +1346,7 @@ char *str_replace(const char *str, const char *from, const char *to) {
 
 	if (count == 0) {
 		/* If no matches, then just duplicate the string. */
-		strcpy(ret, str);
+		strlcpy(ret, str, retlen + 1);
 	} else {
 		/* Otherwise, duplicate the string whilst performing
 		 * the replacements using the position cache. */

src/bbs.h

@@ -3,6 +3,7 @@
 
 #include <sys/types.h>
 
+#include <stddef.h>
 #include <time.h>
 #include <termios.h>
 #ifdef __APPLE__
@@ -11,12 +12,17 @@
 #if defined(ENABLE_WWW)
 #include <microhttpd.h>
 #endif
+#include <string.h>
 #include "lua/lua.h"
 #include "lua/lauxlib.h"
 #include "jamlib/jam.h"
 
 #include "stralloc/stralloc.h"
 
+#ifndef __linux__
+#define HAVE_STRLCPY
+#endif
+
 #define VERSION_MAJOR 0
 #define VERSION_MINOR 12
 #define VERSION_STR "alpha"
@@ -405,6 +411,11 @@ extern char *str4dup(const char *a, const char *b, const char *c, const char *d)
 extern char *str3dup(const char *a, const char *b, const char *c);
 extern char *str2dup(const char *a, const char *b);
 
+#if !defined(HAVE_STRLCPY)
+extern size_t strlcat(char *dst, const char *src, size_t dsize);
+extern size_t strlcpy(char *dst, const char *src, size_t dsize);
+#endif
+
 #if defined(ENABLE_WWW)
 extern void www_init();
 extern void *www_logger(void *cls, const char *uri, struct MHD_Connection *con);

src/bluewave.c

@@ -591,9 +591,9 @@ int bwave_add_message(int confr, int area, unsigned int dwritten, char *to, char
 	jmh.DateWritten = dwritten;
 	jmh.Attribute |= JAM_MSG_LOCAL;
 	if (conf.mail_conferences[confr]->realnames == 0) {
-		strcpy(buffer, gUser->loginname);
+		strlcpy(buffer, gUser->loginname, sizeof buffer);
 	} else {
-		sprintf(buffer, "%s %s", gUser->firstname, gUser->lastname);
+		snprintf(buffer, sizeof buffer, "%s %s", gUser->firstname, gUser->lastname);
 	}
 
 	jsp = JAM_NewSubPacket();

src/chat_system.c

@@ -432,8 +432,8 @@ void chat_system(struct user_record *user) {
 					return;
 				}
 
-				strncat(partmessage, readbuffer, len);
+				strlcat(partmessage, readbuffer, sizeof(partmessage));
-				strcpy(readbuffer, partmessage);
+				strlcpy(readbuffer, partmessage, sizeof(readbuffer));
 
 				y = 0;
 				for (z = 0; z < strlen(readbuffer); z++) {

src/doors.c

@@ -91,7 +91,7 @@ int write_door32sys(struct user_record *user) {
 		return 1;
 	}
 
-	strcpy(buffer, conf.sysop_name);
+	strlcpy(buffer, conf.sysop_name, sizeof(buffer));
 
 	ptr = NULL;
 

src/email.c

@@ -170,7 +170,7 @@ void show_email(struct user_record *user, int msgno, int email_count, struct ema
 				if (z == start_line) {
 					line[0] = '\0';
 				} else {
-					strncpy(line, &emails[msgno]->body[start_line], z - start_line);
+					strlcpy(line, &emails[msgno]->body[start_line], z - start_line + 1);
 					line[z - start_line] = '\0';
 				}
 				if (emails[msgno]->body[z] == '\r') {

src/mail_menu.c

@@ -531,10 +531,10 @@ char *external_editor(struct user_record *user, char *to, char *from, char *quot
 
 			if (!sig) {
 				if (user->autosig) {
-					strcat(body2, "\r");
+					strlcat(body2, "\r", totlen + 1);
-					strcat(body2, user->signature);
+					strlcat(body2, user->signature, totlen + 1);
 				}
-				strcat(body2, buffer);
+				strlcat(body2, buffer, totlen + 1);
 			}
 
 			free(body);
@@ -594,7 +594,7 @@ char *editor(struct user_record *user, char *quote, int quotelen, char *from, in
 
 	while (!doquit) {
 		s_printf(get_string(88), lines, "");
-		strcpy(linebuffer, next_line_buffer);
+		strlcpy(linebuffer, next_line_buffer, sizeof(linebuffer));
 		s_readstring_inject(linebuffer, 70, next_line_buffer);
 		memset(next_line_buffer, 0, 70);
 
@@ -602,7 +602,7 @@ char *editor(struct user_record *user, char *quote, int quotelen, char *from, in
 			for (i = strlen(linebuffer) - 1; i > 15; i--) {
 				if (linebuffer[i] == ' ') {
 					linebuffer[i] = '\0';
-					strcpy(next_line_buffer, &linebuffer[i + 1]);
+					strlcpy(next_line_buffer, &linebuffer[i + 1], sizeof next_line_buffer);
 					s_printf("\e[%dD\e[0K", 70 - i);
 					break;
 				}
@@ -654,18 +654,18 @@ char *editor(struct user_record *user, char *quote, int quotelen, char *from, in
 
 				msg = (char *)malloz(size);
 				for (i = 0; i < ptr_vector_len(&content); i++) {
-					strcat(msg, ptr_vector_get(&content, i));
+					strlcat(msg, ptr_vector_get(&content, i), size);
-					strcat(msg, "\r");
+					strlcat(msg, "\r", size);
 				}
 				ptr_vector_apply(&content, free);
 				destroy_ptr_vector(&content);
 
 				if (!sig) {
 					if (user->autosig) {
-						strcat(msg, "\r");
+						strlcat(msg, "\r", size);
-						strcat(msg, user->signature);
+						strlcat(msg, user->signature, size);
 					}
-					strcat(msg, buffer);
+					strlcat(msg, buffer, size);
 				}
 
 				if (quote != NULL) {
@@ -1520,7 +1520,7 @@ int read_message(struct user_record *user, struct msg_headers *msghs, int mailno
 				if (z == start_line) {
 					msg_line[0] = '\0';
 				} else {
-					strncpy(msg_line, &body[start_line], z - start_line);
+					strlcpy(msg_line, &body[start_line], z - start_line + 1);
 					msg_line[z - start_line] = '\0';
 				}
 				if (body[z] == '\r') {
@@ -1634,7 +1634,7 @@ int read_message(struct user_record *user, struct msg_headers *msghs, int mailno
 				s_printf("\r\n");
 
 				if (msghs->msgs[mailno]->from != NULL) {
-					strcpy(buffer, msghs->msgs[mailno]->from);
+					strlcpy(buffer, msghs->msgs[mailno]->from, sizeof buffer);
 				}
 				if (conf.mail_conferences[user->cur_mail_conf]->realnames == 0) {
 					from = strdup(user->loginname);
@@ -1643,8 +1643,7 @@ int read_message(struct user_record *user, struct msg_headers *msghs, int mailno
 				}
 				if (conf.mail_conferences[user->cur_mail_conf]->mail_areas[user->cur_mail_area]->type == TYPE_NEWSGROUP_AREA) {
 					free(to);
-					to = (char *)malloz(4);
+					to = strdup("ALL");
-					strcpy(to, "ALL");
 				}
 				replybody = external_editor(user, to, from, body, z2, msghs->msgs[mailno]->from, subject, 0, 0);
 				if (replybody != NULL) {
@@ -2064,7 +2063,7 @@ void post_message(struct user_record *user) {
 		s_readstring(buffer, 32);
 	}
 	if (strlen(buffer) == 0) {
-		strcpy(buffer, "ALL");
+		strlcpy(buffer, "ALL", sizeof(buffer));
 	}
 
 	if (conf.mail_conferences[user->cur_mail_conf]->mail_areas[user->cur_mail_area]->type == TYPE_NETMAIL_AREA) {
@@ -2129,9 +2128,9 @@ void post_message(struct user_record *user) {
 		jmh.DateWritten = (uint32_t)utc_to_local(time(NULL));
 		jmh.Attribute |= JAM_MSG_LOCAL;
 		if (conf.mail_conferences[user->cur_mail_conf]->realnames == 0) {
-			strcpy(buffer, user->loginname);
+			strlcpy(buffer, user->loginname, sizeof(buffer));
 		} else {
-			sprintf(buffer, "%s %s", user->firstname, user->lastname);
+			snprintf(buffer, sizeof buffer, "%s %s", user->firstname, user->lastname);
 		}
 
 		jsp = JAM_NewSubPacket();

src/strlcpy/strlcat.c

@@ -0,0 +1,55 @@
+/*	$OpenBSD: strlcat.c,v 1.18 2016/10/16 17:37:39 dtucker Exp $	*/
+
+/*
+ * Copyright (c) 1998, 2015 Todd C. Miller <Todd.Miller@courtesan.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/types.h>
+#include <string.h>
+
+/*
+ * Appends src to string dst of size dsize (unlike strncat, dsize is the
+ * full size of dst, not space left).  At most dsize-1 characters
+ * will be copied.  Always NUL terminates (unless dsize <= strlen(dst)).
+ * Returns strlen(src) + MIN(dsize, strlen(initial dst)).
+ * If retval >= dsize, truncation occurred.
+ */
+size_t
+strlcat(char *dst, const char *src, size_t dsize)
+{
+	const char *odst = dst;
+	const char *osrc = src;
+	size_t n = dsize;
+	size_t dlen;
+
+	/* Find the end of dst and adjust bytes left but don't go past end. */
+	while (n-- != 0 && *dst != '\0')
+		dst++;
+	dlen = dst - odst;
+	n = dsize - dlen;
+
+	if (n-- == 0)
+		return(dlen + strlen(src));
+	while (*src != '\0') {
+		if (n != 0) {
+			*dst++ = *src;
+			n--;
+		}
+		src++;
+	}
+	*dst = '\0';
+
+	return(dlen + (src - osrc));	/* count does not include NUL */
+}

src/strlcpy/strlcpy.c

@@ -0,0 +1,50 @@
+/*	$OpenBSD: strlcpy.c,v 1.15 2016/10/16 17:37:39 dtucker Exp $	*/
+
+/*
+ * Copyright (c) 1998, 2015 Todd C. Miller <Todd.Miller@courtesan.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/types.h>
+#include <string.h>
+
+/*
+ * Copy string src to buffer dst of size dsize.  At most dsize-1
+ * chars will be copied.  Always NUL terminates (unless dsize == 0).
+ * Returns strlen(src); if retval >= dsize, truncation occurred.
+ */
+size_t
+strlcpy(char *dst, const char *src, size_t dsize)
+{
+	const char *osrc = src;
+	size_t nleft = dsize;
+
+	/* Copy as many bytes as will fit. */
+	if (nleft != 0) {
+		while (--nleft != 0) {
+			if ((*dst++ = *src++) == '\0')
+				break;
+		}
+	}
+
+	/* Not enough room in dst, add NUL and traverse rest of src. */
+	if (nleft == 0) {
+		if (dsize != 0)
+			*dst = '\0';		/* NUL-terminate dst */
+		while (*src++)
+			;
+	}
+
+	return(src - osrc - 1);	/* count does not include NUL */
+}

src/www_msgs.c

@@ -870,9 +870,9 @@ int www_send_msg(struct user_record *user, char *to, char *subj, int conference,
 		jmh.Attribute |= JAM_MSG_LOCAL;
 
 		if (conf.mail_conferences[conference]->realnames == 0) {
-			strcpy(buffer, user->loginname);
+			strlcpy(buffer, user->loginname, sizeof buffer);
 		} else {
-			sprintf(buffer, "%s %s", user->firstname, user->lastname);
+			snprintf(buffer, sizeof buffer, "%s %s", user->firstname, user->lastname);
 		}
 		jsp = JAM_NewSubPacket();