cifs: secmech: use shash_desc directly, remove sdesc

The struct sdesc is just a wrapper around shash_desc, with exact same
memory layout. Replace the hashing TFMs with shash_desc as it's what's
passed to the crypto API anyway.

Also remove the crypto_shash pointers as they can be accessed via
shash_desc->tfm (and are actually only used in the setkey calls).

Adapt cifs_{alloc,free}_hash functions to this change.

Signed-off-by: Enzo Matsumiya <[email protected]>
Reviewed-by: Paulo Alcantara (SUSE) <[email protected]>
Signed-off-by: Steve French <[email protected]>

Author: ematsumiya

fs/cifs/cifsencrypt.c

@@ -103,26 +103,24 @@ static int cifs_calc_signature(struct smb_rqst *rqst,
 	if (!rqst->rq_iov || !signature || !server)
 		return -EINVAL;
 
-	rc = cifs_alloc_hash("md5", &server->secmech.md5,
-			     &server->secmech.sdescmd5);
+	rc = cifs_alloc_hash("md5", &server->secmech.md5);
 	if (rc)
 		return -1;
 
-	rc = crypto_shash_init(&server->secmech.sdescmd5->shash);
+	rc = crypto_shash_init(server->secmech.md5);
 	if (rc) {
 		cifs_dbg(VFS, "%s: Could not init md5\n", __func__);
 		return rc;
 	}
 
-	rc = crypto_shash_update(&server->secmech.sdescmd5->shash,
+	rc = crypto_shash_update(server->secmech.md5,
 		server->session_key.response, server->session_key.len);
 	if (rc) {
 		cifs_dbg(VFS, "%s: Could not update with response\n", __func__);
 		return rc;
 	}
 
-	return __cifs_calc_signature(rqst, server, signature,
-				     &server->secmech.sdescmd5->shash);
+	return __cifs_calc_signature(rqst, server, signature, server->secmech.md5);
 }
 
 /* must be called with server->srv_mutex held */
@@ -412,22 +410,22 @@ static int calc_ntlmv2_hash(struct cifs_ses *ses, char *ntlmv2_hash,
 	wchar_t *domain;
 	wchar_t *server;
 
-	if (!ses->server->secmech.sdeschmacmd5) {
+	if (!ses->server->secmech.hmacmd5) {
 		cifs_dbg(VFS, "%s: can't generate ntlmv2 hash\n", __func__);
 		return -1;
 	}
 
 	/* calculate md4 hash of password */
 	E_md4hash(ses->password, nt_hash, nls_cp);
 
-	rc = crypto_shash_setkey(ses->server->secmech.hmacmd5, nt_hash,
+	rc = crypto_shash_setkey(ses->server->secmech.hmacmd5->tfm, nt_hash,
 				CIFS_NTHASH_SIZE);
 	if (rc) {
 		cifs_dbg(VFS, "%s: Could not set NT Hash as a key\n", __func__);
 		return rc;
 	}
 
-	rc = crypto_shash_init(&ses->server->secmech.sdeschmacmd5->shash);
+	rc = crypto_shash_init(ses->server->secmech.hmacmd5);
 	if (rc) {
 		cifs_dbg(VFS, "%s: Could not init hmacmd5\n", __func__);
 		return rc;
@@ -448,7 +446,7 @@ static int calc_ntlmv2_hash(struct cifs_ses *ses, char *ntlmv2_hash,
 		memset(user, '\0', 2);
 	}
 
-	rc = crypto_shash_update(&ses->server->secmech.sdeschmacmd5->shash,
+	rc = crypto_shash_update(ses->server->secmech.hmacmd5,
 				(char *)user, 2 * len);
 	kfree(user);
 	if (rc) {
@@ -468,7 +466,7 @@ static int calc_ntlmv2_hash(struct cifs_ses *ses, char *ntlmv2_hash,
 		len = cifs_strtoUTF16((__le16 *)domain, ses->domainName, len,
 				      nls_cp);
 		rc =
-		crypto_shash_update(&ses->server->secmech.sdeschmacmd5->shash,
+		crypto_shash_update(ses->server->secmech.hmacmd5,
 					(char *)domain, 2 * len);
 		kfree(domain);
 		if (rc) {
@@ -488,7 +486,7 @@ static int calc_ntlmv2_hash(struct cifs_ses *ses, char *ntlmv2_hash,
 		len = cifs_strtoUTF16((__le16 *)server, ses->ip_addr, len,
 					nls_cp);
 		rc =
-		crypto_shash_update(&ses->server->secmech.sdeschmacmd5->shash,
+		crypto_shash_update(ses->server->secmech.hmacmd5,
 					(char *)server, 2 * len);
 		kfree(server);
 		if (rc) {
@@ -498,7 +496,7 @@ static int calc_ntlmv2_hash(struct cifs_ses *ses, char *ntlmv2_hash,
 		}
 	}
 
-	rc = crypto_shash_final(&ses->server->secmech.sdeschmacmd5->shash,
+	rc = crypto_shash_final(ses->server->secmech.hmacmd5,
 					ntlmv2_hash);
 	if (rc)
 		cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
@@ -518,20 +516,20 @@ CalcNTLMv2_response(const struct cifs_ses *ses, char *ntlmv2_hash)
 	hash_len = ses->auth_key.len - (CIFS_SESS_KEY_SIZE +
 		offsetof(struct ntlmv2_resp, challenge.key[0]));
 
-	if (!ses->server->secmech.sdeschmacmd5) {
+	if (!ses->server->secmech.hmacmd5) {
 		cifs_dbg(VFS, "%s: can't generate ntlmv2 hash\n", __func__);
 		return -1;
 	}
 
-	rc = crypto_shash_setkey(ses->server->secmech.hmacmd5,
+	rc = crypto_shash_setkey(ses->server->secmech.hmacmd5->tfm,
 				 ntlmv2_hash, CIFS_HMAC_MD5_HASH_SIZE);
 	if (rc) {
 		cifs_dbg(VFS, "%s: Could not set NTLMV2 Hash as a key\n",
 			 __func__);
 		return rc;
 	}
 
-	rc = crypto_shash_init(&ses->server->secmech.sdeschmacmd5->shash);
+	rc = crypto_shash_init(ses->server->secmech.hmacmd5);
 	if (rc) {
 		cifs_dbg(VFS, "%s: Could not init hmacmd5\n", __func__);
 		return rc;
@@ -543,15 +541,15 @@ CalcNTLMv2_response(const struct cifs_ses *ses, char *ntlmv2_hash)
 	else
 		memcpy(ntlmv2->challenge.key,
 		       ses->server->cryptkey, CIFS_SERVER_CHALLENGE_SIZE);
-	rc = crypto_shash_update(&ses->server->secmech.sdeschmacmd5->shash,
+	rc = crypto_shash_update(ses->server->secmech.hmacmd5,
 				 ntlmv2->challenge.key, hash_len);
 	if (rc) {
 		cifs_dbg(VFS, "%s: Could not update with response\n", __func__);
 		return rc;
 	}
 
 	/* Note that the MD5 digest over writes anon.challenge_key.key */
-	rc = crypto_shash_final(&ses->server->secmech.sdeschmacmd5->shash,
+	rc = crypto_shash_final(ses->server->secmech.hmacmd5,
 				ntlmv2->ntlmv2_hash);
 	if (rc)
 		cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
@@ -627,9 +625,7 @@ setup_ntlmv2_rsp(struct cifs_ses *ses, const struct nls_table *nls_cp)
 
 	cifs_server_lock(ses->server);
 
-	rc = cifs_alloc_hash("hmac(md5)",
-			     &ses->server->secmech.hmacmd5,
-			     &ses->server->secmech.sdeschmacmd5);
+	rc = cifs_alloc_hash("hmac(md5)", &ses->server->secmech.hmacmd5);
 	if (rc) {
 		goto unlock;
 	}
@@ -649,29 +645,29 @@ setup_ntlmv2_rsp(struct cifs_ses *ses, const struct nls_table *nls_cp)
 	}
 
 	/* now calculate the session key for NTLMv2 */
-	rc = crypto_shash_setkey(ses->server->secmech.hmacmd5,
+	rc = crypto_shash_setkey(ses->server->secmech.hmacmd5->tfm,
 		ntlmv2_hash, CIFS_HMAC_MD5_HASH_SIZE);
 	if (rc) {
 		cifs_dbg(VFS, "%s: Could not set NTLMV2 Hash as a key\n",
 			 __func__);
 		goto unlock;
 	}
 
-	rc = crypto_shash_init(&ses->server->secmech.sdeschmacmd5->shash);
+	rc = crypto_shash_init(ses->server->secmech.hmacmd5);
 	if (rc) {
 		cifs_dbg(VFS, "%s: Could not init hmacmd5\n", __func__);
 		goto unlock;
 	}
 
-	rc = crypto_shash_update(&ses->server->secmech.sdeschmacmd5->shash,
+	rc = crypto_shash_update(ses->server->secmech.hmacmd5,
 		ntlmv2->ntlmv2_hash,
 		CIFS_HMAC_MD5_HASH_SIZE);
 	if (rc) {
 		cifs_dbg(VFS, "%s: Could not update with response\n", __func__);
 		goto unlock;
 	}
 
-	rc = crypto_shash_final(&ses->server->secmech.sdeschmacmd5->shash,
+	rc = crypto_shash_final(ses->server->secmech.hmacmd5,
 		ses->auth_key.response);
 	if (rc)
 		cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
@@ -718,30 +714,11 @@ calc_seckey(struct cifs_ses *ses)
 void
 cifs_crypto_secmech_release(struct TCP_Server_Info *server)
 {
-	if (server->secmech.cmacaes) {
-		crypto_free_shash(server->secmech.cmacaes);
-		server->secmech.cmacaes = NULL;
-	}
-
-	if (server->secmech.hmacsha256) {
-		crypto_free_shash(server->secmech.hmacsha256);
-		server->secmech.hmacsha256 = NULL;
-	}
-
-	if (server->secmech.md5) {
-		crypto_free_shash(server->secmech.md5);
-		server->secmech.md5 = NULL;
-	}
-
-	if (server->secmech.sha512) {
-		crypto_free_shash(server->secmech.sha512);
-		server->secmech.sha512 = NULL;
-	}
-
-	if (server->secmech.hmacmd5) {
-		crypto_free_shash(server->secmech.hmacmd5);
-		server->secmech.hmacmd5 = NULL;
-	}
+	cifs_free_hash(&server->secmech.aes_cmac);
+	cifs_free_hash(&server->secmech.hmacsha256);
+	cifs_free_hash(&server->secmech.md5);
+	cifs_free_hash(&server->secmech.sha512);
+	cifs_free_hash(&server->secmech.hmacmd5);
 
 	if (server->secmech.enc) {
 		crypto_free_aead(server->secmech.enc);
@@ -752,15 +729,4 @@ cifs_crypto_secmech_release(struct TCP_Server_Info *server)
 		crypto_free_aead(server->secmech.dec);
 		server->secmech.dec = NULL;
 	}
-
-	kfree_sensitive(server->secmech.sdesccmacaes);
-	server->secmech.sdesccmacaes = NULL;
-	kfree_sensitive(server->secmech.sdeschmacsha256);
-	server->secmech.sdeschmacsha256 = NULL;
-	kfree_sensitive(server->secmech.sdeschmacmd5);
-	server->secmech.sdeschmacmd5 = NULL;
-	kfree_sensitive(server->secmech.sdescmd5);
-	server->secmech.sdescmd5 = NULL;
-	kfree_sensitive(server->secmech.sdescsha512);
-	server->secmech.sdescsha512 = NULL;
 }

fs/cifs/cifsglob.h

@@ -153,26 +153,16 @@ struct session_key {
 	char *response;
 };
 
-/* crypto security descriptor definition */
-struct sdesc {
-	struct shash_desc shash;
-	char ctx[];
-};
-
 /* crypto hashing related structure/fields, not specific to a sec mech */
 struct cifs_secmech {
-	struct crypto_shash *hmacmd5; /* hmac-md5 hash function */
-	struct crypto_shash *md5; /* md5 hash function */
-	struct crypto_shash *hmacsha256; /* hmac-sha256 hash function */
-	struct crypto_shash *cmacaes; /* block-cipher based MAC function */
-	struct crypto_shash *sha512; /* sha512 hash function */
-	struct sdesc *sdeschmacmd5;  /* ctxt to generate ntlmv2 hash, CR1 */
-	struct sdesc *sdescmd5; /* ctxt to generate cifs/smb signature */
-	struct sdesc *sdeschmacsha256;  /* ctxt to generate smb2 signature */
-	struct sdesc *sdesccmacaes;  /* ctxt to generate smb3 signature */
-	struct sdesc *sdescsha512; /* ctxt to generate smb3.11 signing key */
-	struct crypto_aead *enc; /* smb3 AEAD encryption TFM (AES-CCM and AES-GCM) */
-	struct crypto_aead *dec; /* smb3 AEAD decryption TFM (AES-CCM and AES-GCM) */
+	struct shash_desc *hmacmd5; /* hmacmd5 hash function, for NTLMv2/CR1 hashes */
+	struct shash_desc *md5; /* md5 hash function, for CIFS/SMB1 signatures */
+	struct shash_desc *hmacsha256; /* hmac-sha256 hash function, for SMB2 signatures */
+	struct shash_desc *sha512; /* sha512 hash function, for SMB3.1.1 preauth hash */
+	struct shash_desc *aes_cmac; /* block-cipher based MAC function, for SMB3 signatures */
+
+	struct crypto_aead *enc; /* smb3 encryption AEAD TFM (AES-CCM and AES-GCM) */
+	struct crypto_aead *dec; /* smb3 decryption AEAD TFM (AES-CCM and AES-GCM) */
 };
 
 /* per smb session structure/fields */

fs/cifs/cifsproto.h

@@ -598,9 +598,8 @@ struct cifs_aio_ctx *cifs_aio_ctx_alloc(void);
 void cifs_aio_ctx_release(struct kref *refcount);
 int setup_aio_ctx_iter(struct cifs_aio_ctx *ctx, struct iov_iter *iter, int rw);
 
-int cifs_alloc_hash(const char *name, struct crypto_shash **shash,
-		    struct sdesc **sdesc);
-void cifs_free_hash(struct crypto_shash **shash, struct sdesc **sdesc);
+int cifs_alloc_hash(const char *name, struct shash_desc **sdesc);
+void cifs_free_hash(struct shash_desc **sdesc);
 
 extern void rqst_page_get_length(struct smb_rqst *rqst, unsigned int page,
 				unsigned int *len, unsigned int *offset);

fs/cifs/link.c

@@ -38,29 +38,28 @@ static int
 symlink_hash(unsigned int link_len, const char *link_str, u8 *md5_hash)
 {
 	int rc;
-	struct crypto_shash *md5 = NULL;
-	struct sdesc *sdescmd5 = NULL;
+	struct shash_desc *md5 = NULL;
 
-	rc = cifs_alloc_hash("md5", &md5, &sdescmd5);
+	rc = cifs_alloc_hash("md5", &md5);
 	if (rc)
 		goto symlink_hash_err;
 
-	rc = crypto_shash_init(&sdescmd5->shash);
+	rc = crypto_shash_init(md5);
 	if (rc) {
 		cifs_dbg(VFS, "%s: Could not init md5 shash\n", __func__);
 		goto symlink_hash_err;
 	}
-	rc = crypto_shash_update(&sdescmd5->shash, link_str, link_len);
+	rc = crypto_shash_update(md5, link_str, link_len);
 	if (rc) {
 		cifs_dbg(VFS, "%s: Could not update with link_str\n", __func__);
 		goto symlink_hash_err;
 	}
-	rc = crypto_shash_final(&sdescmd5->shash, md5_hash);
+	rc = crypto_shash_final(md5, md5_hash);
 	if (rc)
 		cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
 
 symlink_hash_err:
-	cifs_free_hash(&md5, &sdescmd5);
+	cifs_free_hash(&md5);
 	return rc;
 }
 

fs/cifs/misc.c

@@ -1071,59 +1071,58 @@ setup_aio_ctx_iter(struct cifs_aio_ctx *ctx, struct iov_iter *iter, int rw)
 /**
  * cifs_alloc_hash - allocate hash and hash context together
  * @name: The name of the crypto hash algo
- * @shash: Where to put the pointer to the hash algo
- * @sdesc: Where to put the pointer to the hash descriptor
+ * @sdesc: SHASH descriptor where to put the pointer to the hash TFM
  *
  * The caller has to make sure @sdesc is initialized to either NULL or
- * a valid context. Both can be freed via cifs_free_hash().
+ * a valid context. It can be freed via cifs_free_hash().
  */
 int
-cifs_alloc_hash(const char *name,
-		struct crypto_shash **shash, struct sdesc **sdesc)
+cifs_alloc_hash(const char *name, struct shash_desc **sdesc)
 {
 	int rc = 0;
-	size_t size;
+	struct crypto_shash *alg = NULL;
 
-	if (*sdesc != NULL)
+	if (*sdesc)
 		return 0;
 
-	*shash = crypto_alloc_shash(name, 0, 0);
-	if (IS_ERR(*shash)) {
-		cifs_dbg(VFS, "Could not allocate crypto %s\n", name);
-		rc = PTR_ERR(*shash);
-		*shash = NULL;
+	alg = crypto_alloc_shash(name, 0, 0);
+	if (IS_ERR(alg)) {
+		cifs_dbg(VFS, "Could not allocate shash TFM '%s'\n", name);
+		rc = PTR_ERR(alg);
 		*sdesc = NULL;
 		return rc;
 	}
 
-	size = sizeof(struct shash_desc) + crypto_shash_descsize(*shash);
-	*sdesc = kmalloc(size, GFP_KERNEL);
+	*sdesc = kmalloc(sizeof(struct shash_desc) + crypto_shash_descsize(alg), GFP_KERNEL);
 	if (*sdesc == NULL) {
-		cifs_dbg(VFS, "no memory left to allocate crypto %s\n", name);
-		crypto_free_shash(*shash);
-		*shash = NULL;
+		cifs_dbg(VFS, "no memory left to allocate shash TFM '%s'\n", name);
+		crypto_free_shash(alg);
 		return -ENOMEM;
 	}
 
-	(*sdesc)->shash.tfm = *shash;
+	(*sdesc)->tfm = alg;
 	return 0;
 }
 
 /**
  * cifs_free_hash - free hash and hash context together
- * @shash: Where to find the pointer to the hash algo
- * @sdesc: Where to find the pointer to the hash descriptor
+ * @sdesc: Where to find the pointer to the hash TFM
  *
- * Freeing a NULL hash or context is safe.
+ * Freeing a NULL descriptor is safe.
  */
 void
-cifs_free_hash(struct crypto_shash **shash, struct sdesc **sdesc)
+cifs_free_hash(struct shash_desc **sdesc)
 {
+	if (unlikely(!sdesc) || !*sdesc)
+		return;
+
+	if ((*sdesc)->tfm) {
+		crypto_free_shash((*sdesc)->tfm);
+		(*sdesc)->tfm = NULL;
+	}
+
 	kfree_sensitive(*sdesc);
 	*sdesc = NULL;
-	if (*shash)
-		crypto_free_shash(*shash);
-	*shash = NULL;
 }
 
 /**