X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=src%2Fpasswd%2Fgetspnam_r.c;h=e488b67f5d850d33ae703dcfc0aa350611479c72;hb=2d7d05f031e014068a61d3076c6178513395d2ae;hp=1dd39ce01d973e5f8268cf6775fab909ce12fb49;hpb=0b44a0315b47dd8eced9f3b7f31580cf14bbfc01;p=musl

diff --git a/src/passwd/getspnam_r.c b/src/passwd/getspnam_r.c
index 1dd39ce0..e488b67f 100644
--- a/src/passwd/getspnam_r.c
+++ b/src/passwd/getspnam_r.c
@@ -1,5 +1,8 @@
 #include <fcntl.h>
 #include <unistd.h>
+#include <sys/stat.h>
+#include <ctype.h>
+#include <pthread.h>
 #include "pwf.h"
 
 /* This implementation support Openwall-style TCB passwords in place of
@@ -9,6 +12,52 @@
  * file. It also avoids any allocation to prevent memory-exhaustion
  * attacks via huge TCB shadow files. */
 
+static long xatol(char **s)
+{
+	long x;
+	if (**s == ':' || **s == '\n') return -1;
+	for (x=0; **s-'0'<10U; ++*s) x=10*x+(**s-'0');
+	return x;
+}
+
+int __parsespent(char *s, struct spwd *sp)
+{
+	sp->sp_namp = s;
+	if (!(s = strchr(s, ':'))) return -1;
+	*s = 0;
+
+	sp->sp_pwdp = ++s;
+	if (!(s = strchr(s, ':'))) return -1;
+	*s = 0;
+
+	s++; sp->sp_lstchg = xatol(&s);
+	if (*s != ':') return -1;
+
+	s++; sp->sp_min = xatol(&s);
+	if (*s != ':') return -1;
+
+	s++; sp->sp_max = xatol(&s);
+	if (*s != ':') return -1;
+
+	s++; sp->sp_warn = xatol(&s);
+	if (*s != ':') return -1;
+
+	s++; sp->sp_inact = xatol(&s);
+	if (*s != ':') return -1;
+
+	s++; sp->sp_expire = xatol(&s);
+	if (*s != ':') return -1;
+
+	s++; sp->sp_flag = xatol(&s);
+	if (*s != '\n') return -1;
+	return 0;
+}
+
+static void cleanup(void *p)
+{
+	fclose(p);
+}
+
 int getspnam_r(const char *name, struct spwd *sp, char *buf, size_t size, struct spwd **res)
 {
 	char path[20+NAME_MAX];
@@ -16,36 +65,41 @@ int getspnam_r(const char *name, struct spwd *sp, char *buf, size_t size, struct
 	int rv = 0;
 	int fd;
 	size_t k, l = strlen(name);
-	char *s;
 	int skip = 0;
+	int cs;
 
 	*res = 0;
 
 	/* Disallow potentially-malicious user names */
 	if (*name=='.' || strchr(name, '/') || !l)
-		return EINVAL;
+		return errno = EINVAL;
 
 	/* Buffer size must at least be able to hold name, plus some.. */
-	if (size < l+100) return ERANGE;
+	if (size < l+100)
+		return errno = EINVAL;
 
 	/* Protect against truncation */
 	if (snprintf(path, sizeof path, "/etc/tcb/%s/shadow", name) >= sizeof path)
-		return EINVAL;
+		return errno = EINVAL;
 
-	fd = open(path, O_RDONLY|O_NOFOLLOW|O_NONBLOCK);
+	fd = open(path, O_RDONLY|O_NOFOLLOW|O_NONBLOCK|O_CLOEXEC);
 	if (fd >= 0) {
-		f = fdopen(fd, "rb");
-		if (!f) {
+		struct stat st = { 0 };
+		errno = EINVAL;
+		if (fstat(fd, &st) || !S_ISREG(st.st_mode) || !(f = fdopen(fd, "rb"))) {
+			pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
 			close(fd);
+			pthread_setcancelstate(cs, 0);
 			return errno;
 		}
 	} else {
-		f = fopen("/etc/shadow", "rb");
+		f = fopen("/etc/shadow", "rbe");
 		if (!f) return errno;
 	}
 
+	pthread_cleanup_push(cleanup, f);
 	while (fgets(buf, size, f) && (k=strlen(buf))>0) {
-		if (skip || strncmp(name, buf, l)) {
+		if (skip || strncmp(name, buf, l) || buf[l]!=':') {
 			skip = buf[k-1] != '\n';
 			continue;
 		}
@@ -53,37 +107,12 @@ int getspnam_r(const char *name, struct spwd *sp, char *buf, size_t size, struct
 			rv = ERANGE;
 			break;
 		}
-		buf[k-1] = 0;
-
-		s = buf;
-		sp->sp_namp = s;
-		if (!(s = strchr(s, ':'))) continue;
-
-		*s++ = 0; sp->sp_pwdp = s;
-		if (!(s = strchr(s, ':'))) continue;
-
-		*s++ = 0; sp->sp_lstchg = atol(s);
-		if (!(s = strchr(s, ':'))) continue;
-
-		*s++ = 0; sp->sp_min = atol(s);
-		if (!(s = strchr(s, ':'))) continue;
-
-		*s++ = 0; sp->sp_max = atol(s);
-		if (!(s = strchr(s, ':'))) continue;
-
-		*s++ = 0; sp->sp_warn = atol(s);
-		if (!(s = strchr(s, ':'))) continue;
-
-		*s++ = 0; sp->sp_inact = atol(s);
-		if (!(s = strchr(s, ':'))) continue;
-
-		*s++ = 0; sp->sp_expire = atol(s);
-		if (!(s = strchr(s, ':'))) continue;
 
-		*s++ = 0; sp->sp_flag = atol(s);
+		if (__parsespent(buf, sp) < 0) continue;
 		*res = sp;
 		break;
 	}
-	fclose(f);
+	pthread_cleanup_pop(1);
+	if (rv) errno = rv;
 	return rv;
 }