Description: Include patch for moving the cache directory to a safe location.
Origin: https://fedorahosted.org/coolkey/changeset/67
Author: rrelyea
Reviewed-by: Jack Magne <jmagne@fedoraproject.org>
Date:   Thu Sep 27 23:32:51 2007 +0000
 http://pkgs.fedoraproject.org/gitweb/?p=coolkey.git;a=commit;h=ad9b6d26933ab3dfd88d42a571f7958c5b9588f8

--- a/src/coolkey/machdep.cpp
+++ b/src/coolkey/machdep.cpp
@@ -185,12 +185,20 @@
 #define MAP_INHERIT 0
 #endif
 
+#ifndef BASEPATH
+#ifdef MAC
+#define BASEPATH "/var"
+#else
+#define BASEPATH "/var/cache"
+#endif
+#endif
+
 #ifdef FULL_CLEANUP
 #define RESERVED_OFFSET 256
-#define MEMSEGPATH "/tmp/.pk11ipc"
+#define MEMSEGPATH BASEPATH"/coolkey-lock"
 #else 
 #define RESERVED_OFFSET 0
-#define MEMSEGPATH "/tmp/.pk11ipc1"
+#define MEMSEGPATH BASEPATH"/coolkey"
 #endif
 
 struct SHMemData {
@@ -208,11 +216,6 @@
 #ifdef FULL_CLEANUP
 	flock(fd,LOCK_EX);
 	unsigned long ref = --(*(unsigned long *)addr); 
-#ifdef notdef
-	if (ref == 0) {
-	    unlink(path);
-	}
-#endif
 	flock(fd, LOCK_UN);
 #endif
 	munmap(addr,size+RESERVED_OFFSET);
@@ -225,6 +228,73 @@
     }
 }
 
+/*
+ * The cache directory is shared and accessible by anyone, make
+ * sure the cache file we are opening is really a valid cache file.
+ */
+int safe_open(char *path, int flags, int mode, int size)
+{
+    struct stat buf;
+    int fd, ret;
+
+    fd = open (path, flags|O_NOFOLLOW, mode);
+
+    if (fd < 0) {
+	return fd;
+    }
+
+    ret = fstat(fd, &buf);
+    if (ret < 0) {
+	close (fd);
+	return ret;
+    }
+
+    /* our cache files are pretty specific, make sure we are looking
+     * at the correct one */
+
+    /* first, we should own the file ourselves, don't open a file
+     * that someone else wanted us to see. */
+    if (buf.st_uid != getuid()) {
+	close(fd);
+	errno = EACCES;
+	return -1;
+    }
+
+    /* next, there should only be one link in this file. Don't
+     * use this code to trash another file */
+    if (buf.st_nlink != 1) {
+	close(fd);
+	errno = EMLINK;
+	return -1;
+    }
+
+    /* next, This better be a regular file */
+    if (!S_ISREG(buf.st_mode)) {
+	close(fd);
+	errno = EACCES;
+	return -1;
+    }
+
+    /* if the permissions don't match, something is wrong */
+    if ((buf.st_mode & 03777) != mode) {
+	close(fd);
+	errno = EACCES;
+	return -1;
+    }
+
+    /* finally the file should be the correct size. This 
+     * check isn't so much to protect from an attack, as it is to
+     * detect a corrupted cache file */
+    if (buf.st_size != size) {
+	close(fd);
+	errno = EACCES;
+	return -1;
+    }
+
+    /* OK, the file checked out, ok to continue */
+    return fd;
+}
+
 SHMem::SHMem(): shmemData(0) {}
 
 SHMem *
@@ -248,7 +318,7 @@
 	return NULL;
     }
     int mask = umask(0);
-    int ret = mkdir (MEMSEGPATH, 0777);
+    int ret = mkdir (MEMSEGPATH, 01777);
     umask(mask);
     if ((ret == -1) && (errno != EEXIST)) {
 	delete shmemData;
@@ -264,21 +334,16 @@
     shmemData->path[sizeof(MEMSEGPATH)-1] = '/';
     strcpy(&shmemData->path[sizeof(MEMSEGPATH)],name);
 
-    int mode = 0777;
-    if (strcmp(name,"token_names") != 0) {
-	/* each user gets his own uid array */
-    	sprintf(uid_str, "-%u",getuid());
-    	strcat(shmemData->path,uid_str);
-	mode = 0700;
-    } 
+    sprintf(uid_str, "-%u",getuid());
+    strcat(shmemData->path,uid_str);
+    int mode = 0600;
+
     shmemData->fd = open(shmemData->path, 
 		O_CREAT|O_RDWR|O_EXCL|O_APPEND|O_EXLOCK, mode);
-    if (shmemData->fd  < 0) {
-	needInit = false;
-	shmemData->fd = open(shmemData->path,O_RDWR|O_EXLOCK, mode);
-    }  else {
+    if (shmemData->fd >= 0) {
 	char *buf;
 	int len = size+RESERVED_OFFSET;
+	int ret;
 
 	buf = (char *)calloc(1,len);
 	if (!buf) {
@@ -289,8 +354,22 @@
 	    delete shmemData;
 	    return NULL;
 	}
-	write(shmemData->fd,buf,len);
+	ret = write(shmemData->fd,buf,len);
+	if (ret != len) {
+	    unlink(shmemData->path);
+#ifdef FULL_CLEANUP
+	    flock(shmemData->fd, LOCK_UN);
+#endif
+	    delete shmemData;
+	    return NULL;
+	}
+	
 	free(buf);
+    } else if (errno == EEXIST) {
+	needInit = false;
+
+	shmemData->fd = safe_open(shmemData->path,O_RDWR|O_EXLOCK, mode,
+				  size+RESERVED_OFFSET);
     }
     if (shmemData->fd < 0) {
 	delete shmemData;
