fs/smb/client/smbencrypt.c

Source file repositories/reference/linux-study-clean/fs/smb/client/smbencrypt.c

File Facts

System
Linux kernel
Corpus path
fs/smb/client/smbencrypt.c
Extension
.c
Size
2124 bytes
Lines
84
Domain
Core OS
Bucket
VFS And Filesystem Core
Inferred role
Core OS: implementation source
Status
source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0-or-later
/*
   Unix SMB/Netbios implementation.
   Version 1.9.
   SMB parameters and setup
   Copyright (C) Andrew Tridgell 1992-2000
   Copyright (C) Luke Kenneth Casson Leighton 1996-2000
   Modified by Jeremy Allison 1995.
   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2002-2003
   Modified by Steve French (sfrench@us.ibm.com) 2002-2003

*/

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/fips.h>
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/random.h>
#include "cifs_fs_sb.h"
#include "cifs_unicode.h"
#include "cifsglob.h"
#include "cifs_debug.h"
#include "cifsproto.h"
#include "../common/md4.h"

/* following came from the other byteorder.h to avoid include conflicts */
#define CVAL(buf,pos) (((unsigned char *)(buf))[pos])
#define SSVALX(buf,pos,val) (CVAL(buf,pos)=(val)&0xFF,CVAL(buf,pos+1)=(val)>>8)
#define SSVAL(buf,pos,val) SSVALX((buf),(pos),((__u16)(val)))

/* produce a md4 message digest from data of length n bytes */
static int
mdfour(unsigned char *md4_hash, unsigned char *link_str, int link_len)
{
	int rc;
	struct md4_ctx mctx;

	rc = cifs_md4_init(&mctx);
	if (rc) {
		cifs_dbg(VFS, "%s: Could not init MD4\n", __func__);
		goto mdfour_err;
	}
	rc = cifs_md4_update(&mctx, link_str, link_len);
	if (rc) {
		cifs_dbg(VFS, "%s: Could not update MD4\n", __func__);
		goto mdfour_err;
	}
	rc = cifs_md4_final(&mctx, md4_hash);
	if (rc)
		cifs_dbg(VFS, "%s: Could not finalize MD4\n", __func__);


mdfour_err:
	return rc;
}

/*
 * Creates the MD4 Hash of the users password in NT UNICODE.
 */

int
E_md4hash(const unsigned char *passwd, unsigned char *p16,
	const struct nls_table *codepage)
{
	int rc;
	int len;
	__le16 wpwd[129];

	/* Password cannot be longer than 128 characters */
	if (passwd) /* Password must be converted to NT unicode */
		len = cifs_strtoUTF16(wpwd, passwd, 128, codepage);
	else {
		len = 0;
		*wpwd = 0; /* Ensure string is null terminated */
	}

	rc = mdfour(p16, (unsigned char *) wpwd, len * sizeof(__le16));
	memzero_explicit(wpwd, sizeof(wpwd));

	return rc;
}

Annotation

Implementation Notes