cifs: More crypto cleanup (try #2)

Replaced md4 hashing function local to cifs module with kernel crypto APIs.
As a result, md4 hashing function and its supporting functions in
file md4.c are not needed anymore.

Cleaned up function declarations, removed forward function declarations,
and removed a header file that is being deleted from being included.

Verified that sec=ntlm/i, sec=ntlmv2/i, and sec=ntlmssp/i work correctly.

Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

fs/cifs/Makefile

@@ -5,7 +5,7 @@ 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 \
-	  md4.o cifs_unicode.o nterr.o xattr.o cifsencrypt.o \
+	  cifs_unicode.o nterr.o xattr.o cifsencrypt.o \
 	  readdir.o ioctl.o sess.o export.o
 
 cifs-$(CONFIG_CIFS_ACL) += cifsacl.o

fs/cifs/cifsencrypt.c

@@ -36,11 +36,6 @@
 /* Note that the smb header signature field on input contains the
 	sequence number before this function is called */
 
-extern void mdfour(unsigned char *out, unsigned char *in, int n);
-extern void E_md4hash(const unsigned char *passwd, unsigned char *p16);
-extern void SMBencrypt(unsigned char *passwd, const unsigned char *c8,
-		       unsigned char *p24);
-
 static int cifs_calculate_signature(const struct smb_hdr *cifs_pdu,
 				struct TCP_Server_Info *server, char *signature)
 {
@@ -233,6 +228,7 @@ int cifs_verify_signature(struct smb_hdr *cifs_pdu,
 /* first calculate 24 bytes ntlm response and then 16 byte session key */
 int setup_ntlm_response(struct cifsSesInfo *ses)
 {
+	int rc = 0;
 	unsigned int temp_len = CIFS_SESS_KEY_SIZE + CIFS_AUTH_RESP_SIZE;
 	char temp_key[CIFS_SESS_KEY_SIZE];
 
@@ -246,13 +242,26 @@ int setup_ntlm_response(struct cifsSesInfo *ses)
 	}
 	ses->auth_key.len = temp_len;
 
-	SMBNTencrypt(ses->password, ses->server->cryptkey,
+	rc = SMBNTencrypt(ses->password, ses->server->cryptkey,
 			ses->auth_key.response + CIFS_SESS_KEY_SIZE);
+	if (rc) {
+		cFYI(1, "%s Can't generate NTLM response, error: %d",
+			__func__, rc);
+		return rc;
+	}
+
+	rc = E_md4hash(ses->password, temp_key);
+	if (rc) {
+		cFYI(1, "%s Can't generate NT hash, error: %d", __func__, rc);
+		return rc;
+	}
 
-	E_md4hash(ses->password, temp_key);
-	mdfour(ses->auth_key.response, temp_key, CIFS_SESS_KEY_SIZE);
+	rc = mdfour(ses->auth_key.response, temp_key, CIFS_SESS_KEY_SIZE);
+	if (rc)
+		cFYI(1, "%s Can't generate NTLM session key, error: %d",
+			__func__, rc);
 
-	return 0;
+	return rc;
 }
 
 #ifdef CONFIG_CIFS_WEAK_PW_HASH
@@ -699,14 +708,13 @@ cifs_crypto_shash_allocate(struct TCP_Server_Info *server)
 	unsigned int size;
 
 	server->secmech.hmacmd5 = crypto_alloc_shash("hmac(md5)", 0, 0);
-	if (!server->secmech.hmacmd5 ||
-			IS_ERR(server->secmech.hmacmd5)) {
+	if (IS_ERR(server->secmech.hmacmd5)) {
 		cERROR(1, "could not allocate crypto hmacmd5\n");
 		return PTR_ERR(server->secmech.hmacmd5);
 	}
 
 	server->secmech.md5 = crypto_alloc_shash("md5", 0, 0);
-	if (!server->secmech.md5 || IS_ERR(server->secmech.md5)) {
+	if (IS_ERR(server->secmech.md5)) {
 		cERROR(1, "could not allocate crypto md5\n");
 		rc = PTR_ERR(server->secmech.md5);
 		goto crypto_allocate_md5_fail;

fs/cifs/cifsproto.h

@@ -375,7 +375,7 @@ extern int cifs_sign_smb2(struct kvec *iov, int n_vec, struct TCP_Server_Info *,
 extern int cifs_verify_signature(struct smb_hdr *,
 				 struct TCP_Server_Info *server,
 				__u32 expected_sequence_number);
-extern void SMBNTencrypt(unsigned char *, unsigned char *, unsigned char *);
+extern int SMBNTencrypt(unsigned char *, unsigned char *, unsigned char *);
 extern int setup_ntlm_response(struct cifsSesInfo *);
 extern int setup_ntlmv2_rsp(struct cifsSesInfo *, const struct nls_table *);
 extern int cifs_crypto_shash_allocate(struct TCP_Server_Info *);
@@ -425,4 +425,11 @@ extern bool CIFSCouldBeMFSymlink(const struct cifs_fattr *fattr);
 extern int CIFSCheckMFSymlink(struct cifs_fattr *fattr,
 		const unsigned char *path,
 		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,
+			unsigned char *p24);
 #endif			/* _CIFSPROTO_H */

fs/cifs/connect.c

@@ -55,9 +55,6 @@
 /* SMB echo "timeout" -- FIXME: tunable? */
 #define SMB_ECHO_INTERVAL (60 * HZ)
 
-extern void SMBNTencrypt(unsigned char *passwd, unsigned char *c8,
-			 unsigned char *p24);
-
 extern mempool_t *cifs_req_poolp;
 
 struct smb_vol {
@@ -2990,7 +2987,8 @@ CIFSTCon(unsigned int xid, struct cifsSesInfo *ses,
 					 bcc_ptr);
 		else
 #endif /* CIFS_WEAK_PW_HASH */
-		SMBNTencrypt(tcon->password, ses->server->cryptkey, bcc_ptr);
+		rc = SMBNTencrypt(tcon->password, ses->server->cryptkey,
+					bcc_ptr);
 
 		bcc_ptr += CIFS_AUTH_RESP_SIZE;
 		if (ses->capabilities & CAP_UNICODE) {

fs/cifs/link.c

@@ -54,10 +54,9 @@ symlink_hash(unsigned int link_len, const char *link_str, u8 *md5_hash)
 	struct sdesc *sdescmd5;
 
 	md5 = crypto_alloc_shash("md5", 0, 0);
-	if (!md5 || IS_ERR(md5)) {
-		rc = PTR_ERR(md5);
+	if (IS_ERR(md5)) {
 		cERROR(1, "%s: Crypto md5 allocation error %d\n", __func__, rc);
-		return rc;
+		return PTR_ERR(md5);
 	}
 	size = sizeof(struct shash_desc) + crypto_shash_descsize(md5);
 	sdescmd5 = kmalloc(size, GFP_KERNEL);

fs/cifs/smbdes.c

@@ -45,7 +45,6 @@
    up with a different answer to the one above)
 */
 #include <linux/slab.h>
-#include "cifsencrypt.h"
 #define uchar unsigned char
 
 static uchar perm1[56] = { 57, 49, 41, 33, 25, 17, 9,