cifs: Assume passwords are encoded according to iocharset (try #2)

Re-posting a patch originally posted by Oskar Liljeblad after
rebasing on 3.2.

Modify cifs to assume that the supplied password is encoded according
to iocharset.  Before this patch passwords would be treated as
raw 8-bit data, which made authentication with Unicode passwords impossible
(at least passwords with characters > 0xFF).

The previous code would as a side effect accept passwords encoded with
ISO 8859-1, since Unicode < 0x100 basically is ISO 8859-1.  Software which
relies on that will no longer support password chars > 0x7F unless it also
uses iocharset=iso8859-1.  (mount.cifs does not care about the encoding so
it will work as expected.)

Signed-off-by: Oskar Liljeblad <oskar@osk.mine.nu>
Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru>
Tested-by: A <nimbus1_03087@yahoo.com>
Signed-off-by: Steve French <smfrench@gmail.com>

1 files changed, 12 insertions, 51 deletions

diff --git a/fs/cifs/smbencrypt.c b/fs/cifs/smbencrypt.c
index ac1221d969d6..7cacba12b8f1 100644
--- a/fs/cifs/smbencrypt.c
+++ b/fs/cifs/smbencrypt.c
@@ -199,75 +199,36 @@ SMBencrypt(unsigned char *passwd, const unsigned char *c8, unsigned char *p24)
 	return rc;
 }
 
-/* Routines for Windows NT MD4 Hash functions. */
-static int
-_my_wcslen(__u16 *str)
-{
-	int len = 0;
-	while (*str++ != 0)
-		len++;
-	return len;
-}
-
-/*
- * Convert a string into an NT UNICODE string.
- * Note that regardless of processor type
- * this must be in intel (little-endian)
- * format.
- */
-
-static int
-_my_mbstowcs(__u16 *dst, const unsigned char *src, int len)
-{	/* BB not a very good conversion routine - change/fix */
-	int i;
-	__u16 val;
-
-	for (i = 0; i < len; i++) {
-		val = *src;
-		SSVAL(dst, 0, val);
-		dst++;
-		src++;
-		if (val == 0)
-			break;
-	}
-	return i;
-}
-
 /*
  * Creates the MD4 Hash of the users password in NT UNICODE.
  */
 
 int
-E_md4hash(const unsigned char *passwd, unsigned char *p16)
+E_md4hash(const unsigned char *passwd, unsigned char *p16,
+	const struct nls_table *codepage)
 {
 	int rc;
 	int len;
 	__u16 wpwd[129];
 
 	/* Password cannot be longer than 128 characters */
-	if (passwd) {
-		len = strlen((char *) passwd);
-		if (len > 128)
-			len = 128;
-
-		/* Password must be converted to NT unicode */
-		_my_mbstowcs(wpwd, passwd, len);
-	} else
+	if (passwd) /* Password must be converted to NT unicode */
+		len = cifs_strtoUCS(wpwd, passwd, 128, codepage);
+	else {
 		len = 0;
+		*wpwd = 0; /* Ensure string is null terminated */
+	}
 
-	wpwd[len] = 0;	/* Ensure string is null terminated */
-	/* Calculate length in bytes */
-	len = _my_wcslen(wpwd) * sizeof(__u16);
-
-	rc = mdfour(p16, (unsigned char *) wpwd, len);
-	memset(wpwd, 0, 129 * 2);
+	rc = mdfour(p16, (unsigned char *) wpwd, len * sizeof(__u16));
+	memset(wpwd, 0, 129 * sizeof(__u16));
 
 	return rc;
 }
 
 /* Does the NT MD4 hash then des encryption. */
 int
-SMBNTencrypt(unsigned char *passwd, unsigned char *c8, unsigned char *p24)
+SMBNTencrypt(unsigned char *passwd, unsigned char *c8, unsigned char *p24,
+		const struct nls_table *codepage)
 {
 	int rc;
 	unsigned char p16[16], p21[21];
@@ -275,7 +236,7 @@ SMBNTencrypt(unsigned char *passwd, unsigned char *c8, unsigned char *p24)
 	memset(p16, '\0', 16);
 	memset(p21, '\0', 21);
 
-	rc = E_md4hash(passwd, p16);
+	rc = E_md4hash(passwd, p16, codepage);
 	if (rc) {
 		cFYI(1, "%s Can't generate NT hash, error: %d", __func__, rc);
 		return rc;