lseek(2) may return -1 when getting the public/private key lenght.

Simplify the code and check for errors using fstat(2).

Problem reported by Mauricio Sanchez, markus@ ok.

1 files changed, 16 insertions, 5 deletions

diff --git a/usr.bin/ssh/authfile.c b/usr.bin/ssh/authfile.c
index 9cdd528442c..33217bf3b68 100644
--- a/usr.bin/ssh/authfile.c
+++ b/usr.bin/ssh/authfile.c
@@ -36,7 +36,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: authfile.c,v 1.50 2002/06/24 14:55:38 markus Exp $");
+RCSID("$OpenBSD: authfile.c,v 1.51 2002/11/15 10:03:09 fgsch Exp $");
 
 #include <openssl/err.h>
 #include <openssl/evp.h>
@@ -232,12 +232,17 @@ key_load_public_rsa1(int fd, const char *filename, char **commentp)
 {
 	Buffer buffer;
 	Key *pub;
+	struct stat st;
 	char *cp;
 	int i;
 	off_t len;
 
-	len = lseek(fd, (off_t) 0, SEEK_END);
-	lseek(fd, (off_t) 0, SEEK_SET);
+	if (fstat(fd, &st) < 0) {
+		error("fstat for key file %.200s failed: %.100s",
+		    filename, strerror(errno));
+		return NULL;
+	}
+	len = st.st_size;
 
 	buffer_init(&buffer);
 	cp = buffer_append_space(&buffer, len);
@@ -318,9 +323,15 @@ key_load_private_rsa1(int fd, const char *filename, const char *passphrase,
 	CipherContext ciphercontext;
 	Cipher *cipher;
 	Key *prv = NULL;
+	struct stat st;
 
-	len = lseek(fd, (off_t) 0, SEEK_END);
-	lseek(fd, (off_t) 0, SEEK_SET);
+	if (fstat(fd, &st) < 0) {
+		error("fstat for key file %.200s failed: %.100s",
+		    filename, strerror(errno));
+		close(fd);
+		return NULL;
+	}
+	len = st.st_size;
 
 	buffer_init(&buffer);
 	cp = buffer_append_space(&buffer, len);