[CIFS] Use ecb des kernel crypto APIs instead of

 local cifs functions (repost)

Using kernel crypto APIs for DES encryption during LM and NT hash generation
instead of local functions within cifs.
Source file smbdes.c is deleted sans four functions, one of which
uses ecb des functionality provided by kernel crypto APIs.

Remove function SMBOWFencrypt.

Add return codes to various functions such as calc_lanman_hash,
SMBencrypt, and SMBNTencrypt.  Includes fix noticed by Dan Carpenter.
Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
CC: Dan Carpenter <error27@gmail.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

fs/cifs/Kconfig

@@ -7,6 +7,7 @@ config CIFS
 	select CRYPTO_MD5
 	select CRYPTO_HMAC
 	select CRYPTO_ARC4
+	select CRYPTO_DES
 	help
 	  This is the client VFS module for the Common Internet File System
 	  (CIFS) protocol which is the successor to the Server Message Block

fs/cifs/Makefile

@@ -4,7 +4,7 @@
 obj-$(CONFIG_CIFS) += cifs.o
 
 cifs-y := cifsfs.o cifssmb.o cifs_debug.o connect.o dir.o file.o inode.o \
-	  link.o misc.o netmisc.o smbdes.o smbencrypt.o transport.o asn1.o \
+	  link.o misc.o netmisc.o smbencrypt.o transport.o asn1.o \
 	  cifs_unicode.o nterr.o xattr.o cifsencrypt.o \
 	  readdir.o ioctl.o sess.o export.o
 

fs/cifs/cifsencrypt.c

@@ -268,10 +268,11 @@ int setup_ntlm_response(struct cifsSesInfo *ses)
 }
 
 #ifdef CONFIG_CIFS_WEAK_PW_HASH
-void calc_lanman_hash(const char *password, const char *cryptkey, bool encrypt,
+int calc_lanman_hash(const char *password, const char *cryptkey, bool encrypt,
 			char *lnm_session_key)
 {
 	int i;
+	int rc;
 	char password_with_pad[CIFS_ENCPWD_SIZE];
 
 	memset(password_with_pad, 0, CIFS_ENCPWD_SIZE);
@@ -282,7 +283,7 @@ void calc_lanman_hash(const char *password, const char *cryptkey, bool encrypt,
 		memset(lnm_session_key, 0, CIFS_SESS_KEY_SIZE);
 		memcpy(lnm_session_key, password_with_pad,
 			CIFS_ENCPWD_SIZE);
-		return;
+		return 0;
 	}
 
 	/* calculate old style session key */
@@ -299,10 +300,9 @@ void calc_lanman_hash(const char *password, const char *cryptkey, bool encrypt,
 	for (i = 0; i < CIFS_ENCPWD_SIZE; i++)
 		password_with_pad[i] = toupper(password_with_pad[i]);
 
-	SMBencrypt(password_with_pad, cryptkey, lnm_session_key);
+	rc = SMBencrypt(password_with_pad, cryptkey, lnm_session_key);
 
-	/* clear password before we return/free memory */
-	memset(password_with_pad, 0, CIFS_ENCPWD_SIZE);
+	return rc;
 }
 #endif /* CIFS_WEAK_PW_HASH */
 

fs/cifs/cifsproto.h

@@ -384,7 +384,7 @@ extern void cifs_crypto_shash_release(struct TCP_Server_Info *);
 extern int calc_seckey(struct cifsSesInfo *);
 
 #ifdef CONFIG_CIFS_WEAK_PW_HASH
-extern void calc_lanman_hash(const char *password, const char *cryptkey,
+extern int calc_lanman_hash(const char *password, const char *cryptkey,
 				bool encrypt, char *lnm_session_key);
 #endif /* CIFS_WEAK_PW_HASH */
 #ifdef CONFIG_CIFS_DNOTIFY_EXPERIMENTAL /* unused temporarily */
@@ -430,9 +430,6 @@ extern int CIFSCheckMFSymlink(struct cifs_fattr *fattr,
 		struct cifs_sb_info *cifs_sb, int xid);
 extern int mdfour(unsigned char *, unsigned char *, int);
 extern int E_md4hash(const unsigned char *passwd, unsigned char *p16);
-extern void SMBencrypt(unsigned char *passwd, const unsigned char *c8,
-			unsigned char *p24);
-extern void E_P16(unsigned char *p14, unsigned char *p16);
-extern void E_P24(unsigned char *p21, const unsigned char *c8,
+extern int SMBencrypt(unsigned char *passwd, const unsigned char *c8,
 			unsigned char *p24);
 #endif			/* _CIFSPROTO_H */

fs/cifs/sess.c

@@ -656,7 +656,7 @@ CIFS_SessSetup(unsigned int xid, struct cifsSesInfo *ses,
 		 * to use challenge/response method (i.e. Password bit is 1).
 		 */
 
-		calc_lanman_hash(ses->password, ses->server->cryptkey,
+		rc = calc_lanman_hash(ses->password, ses->server->cryptkey,
 				 ses->server->secMode & SECMODE_PW_ENCRYPT ?
 					true : false, lnm_session_key);
 

fs/cifs/smbencrypt.c

@@ -47,6 +47,88 @@
 #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)))
 
+static void
+str_to_key(unsigned char *str, unsigned char *key)
+{
+	int i;
+
+	key[0] = str[0] >> 1;
+	key[1] = ((str[0] & 0x01) << 6) | (str[1] >> 2);
+	key[2] = ((str[1] & 0x03) << 5) | (str[2] >> 3);
+	key[3] = ((str[2] & 0x07) << 4) | (str[3] >> 4);
+	key[4] = ((str[3] & 0x0F) << 3) | (str[4] >> 5);
+	key[5] = ((str[4] & 0x1F) << 2) | (str[5] >> 6);
+	key[6] = ((str[5] & 0x3F) << 1) | (str[6] >> 7);
+	key[7] = str[6] & 0x7F;
+	for (i = 0; i < 8; i++)
+		key[i] = (key[i] << 1);
+}
+
+static int
+smbhash(unsigned char *out, const unsigned char *in, unsigned char *key)
+{
+	int rc;
+	unsigned char key2[8];
+	struct crypto_blkcipher *tfm_des;
+	struct scatterlist sgin, sgout;
+	struct blkcipher_desc desc;
+
+	str_to_key(key, key2);
+
+	tfm_des = crypto_alloc_blkcipher("ecb(des)", 0, CRYPTO_ALG_ASYNC);
+	if (IS_ERR(tfm_des)) {
+		rc = PTR_ERR(tfm_des);
+		cERROR(1, "could not allocate des crypto API\n");
+		goto smbhash_err;
+	}
+
+	desc.tfm = tfm_des;
+
+	crypto_blkcipher_setkey(tfm_des, key2, 8);
+
+	sg_init_one(&sgin, in, 8);
+	sg_init_one(&sgout, out, 8);
+
+	rc = crypto_blkcipher_encrypt(&desc, &sgout, &sgin, 8);
+	if (rc) {
+		cERROR(1, "could not encrypt crypt key rc: %d\n", rc);
+		crypto_free_blkcipher(tfm_des);
+		goto smbhash_err;
+	}
+
+smbhash_err:
+	return rc;
+}
+
+static int
+E_P16(unsigned char *p14, unsigned char *p16)
+{
+	int rc;
+	unsigned char sp8[8] =
+	    { 0x4b, 0x47, 0x53, 0x21, 0x40, 0x23, 0x24, 0x25 };
+
+	rc = smbhash(p16, sp8, p14);
+	if (rc)
+		return rc;
+	rc = smbhash(p16 + 8, sp8, p14 + 7);
+	return rc;
+}
+
+static int
+E_P24(unsigned char *p21, const unsigned char *c8, unsigned char *p24)
+{
+	int rc;
+
+	rc = smbhash(p24, c8, p21);
+	if (rc)
+		return rc;
+	rc = smbhash(p24 + 8, c8, p21 + 7);
+	if (rc)
+		return rc;
+	rc = smbhash(p24 + 16, c8, p21 + 14);
+	return rc;
+}
+
 /* produce a md4 message digest from data of length n bytes */
 int
 mdfour(unsigned char *md4_hash, unsigned char *link_str, int link_len)
@@ -87,40 +169,30 @@ mdfour(unsigned char *md4_hash, unsigned char *link_str, int link_len)
 	return rc;
 }
 
-/* Does the des encryption from the NT or LM MD4 hash. */
-static void
-SMBOWFencrypt(unsigned char passwd[16], const unsigned char *c8,
-	      unsigned char p24[24])
-{
-	unsigned char p21[21];
-
-	memset(p21, '\0', 21);
-
-	memcpy(p21, passwd, 16);
-	E_P24(p21, c8, p24);
-}
-
 /*
    This implements the X/Open SMB password encryption
    It takes a password, a 8 byte "crypt key" and puts 24 bytes of
    encrypted password into p24 */
 /* Note that password must be uppercased and null terminated */
-void
+int
 SMBencrypt(unsigned char *passwd, const unsigned char *c8, unsigned char *p24)
 {
-	unsigned char p14[15], p21[21];
+	int rc;
+	unsigned char p14[14], p16[16], p21[21];
 
-	memset(p21, '\0', 21);
 	memset(p14, '\0', 14);
-	strncpy((char *) p14, (char *) passwd, 14);
+	memset(p16, '\0', 16);
+	memset(p21, '\0', 21);
 
-/*	strupper((char *)p14); *//* BB at least uppercase the easy range */
-	E_P16(p14, p21);
+	memcpy(p14, passwd, 14);
+	rc = E_P16(p14, p16);
+	if (rc)
+		return rc;
 
-	SMBOWFencrypt(p21, c8, p24);
+	memcpy(p21, p16, 16);
+	rc = E_P24(p21, c8, p24);
 
-	memset(p14, 0, 15);
-	memset(p21, 0, 21);
+	return rc;
 }
 
 /* Routines for Windows NT MD4 Hash functions. */
@@ -279,16 +351,18 @@ int
 SMBNTencrypt(unsigned char *passwd, unsigned char *c8, unsigned char *p24)
 {
 	int rc;
-	unsigned char p21[21];
+	unsigned char p16[16], p21[21];
 
+	memset(p16, '\0', 16);
 	memset(p21, '\0', 21);
 
-	rc = E_md4hash(passwd, p21);
+	rc = E_md4hash(passwd, p16);
 	if (rc) {
 		cFYI(1, "%s Can't generate NT hash, error: %d", __func__, rc);
 		return rc;
 	}
-	SMBOWFencrypt(p21, c8, p24);
+	memcpy(p21, p16, 16);
+	rc = E_P24(p21, c8, p24);
 	return rc;
 }