From patchwork Thu Sep 29 01:56:34 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Enzo Matsumiya X-Patchwork-Id: 12993384 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5814EC32771 for ; Thu, 29 Sep 2022 01:57:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234551AbiI2B5W (ORCPT ); Wed, 28 Sep 2022 21:57:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51986 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231419AbiI2B5U (ORCPT ); Wed, 28 Sep 2022 21:57:20 -0400 Received: from smtp-out1.suse.de (smtp-out1.suse.de [IPv6:2001:67c:2178:6::1c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1ADBA74B8A for ; Wed, 28 Sep 2022 18:57:18 -0700 (PDT) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id B88EF21C9D; Thu, 29 Sep 2022 01:57:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1664416636; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=aWMJO9ORUZOdWWz+swf+noR54h06GAmjBgjkO+LChN4=; b=wzLuL06u0ZKXG6wMFoMipD9iOPn+J+8mwFmueMyy5sILrKMxLBzXttsgEbe5M5tmdXK4Ht SSJY4jmrTqsGu74D9HrYKWAJf/hF7Ow/w0ezEfSMcznBGvOcZva8mGVUCGqQpWmsizWEWe pOfEMzXpgwg+cEIcbsVQjuVgHpUJQX8= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1664416636; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=aWMJO9ORUZOdWWz+swf+noR54h06GAmjBgjkO+LChN4=; b=eCsCfZSyqB4D8OwRdj52zJQ0cpvLGgOXlSf4lmBLsm7qVcd43Rd3hPsayI416AQJGRvOy0 HIIXOFLQQNXtrbBA== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id AA765139B3; Thu, 29 Sep 2022 01:57:15 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id n2e8F3v7NGOQeQAAMHmgww (envelope-from ); Thu, 29 Sep 2022 01:57:15 +0000 From: Enzo Matsumiya To: linux-cifs@vger.kernel.org Cc: smfrench@gmail.com, pc@cjr.nz, ronniesahlberg@gmail.com, nspmangalore@gmail.com, tom@talpey.com, metze@samba.org Subject: [PATCH v3 5/8] cifs: introduce AES-GMAC signing support for SMB 3.1.1 Date: Wed, 28 Sep 2022 22:56:34 -0300 Message-Id: <20220929015637.14400-6-ematsumiya@suse.de> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20220929015637.14400-1-ematsumiya@suse.de> References: <20220929015637.14400-1-ematsumiya@suse.de> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org Implement support for AES-GMAC message signing, as specified in MS-SMB2 3.1.4.1 "Signing An Outgoing Message". The core function is smb311_calc_signature(), which will be used as the ->calc_signature op when SIGNING_ALG_AES_GMAC has been negotiated with the server. If "enable_negotiate_signing" is false (default) or if SIGNING_ALG_AES_GMAC was not negotiated, use AES-CMAC. Changes: - convert cifs_secmech sign/verify to unions, where .aead is for AES-GMAC TFM and .shash for all the others signing algorithms - init_sg(): rename to smb3_init_sg(), make it non-static, remove skip variable. This makes it fit for both crypt_message() and smb311_calc_signature() - crypt_message(): advance the 20 bytes of rqst[0].rq_iov[0] that are not part of the encrypted blob before calling smb3_init_sg(). Rewind it back right after the call. (this was done in init_sg() via the skip variable) Other smaller modifications: - smb2_setup_request(): check if the request has a transform header as we must not sign an encrypted message (MS-SMB2 3.2.4.1.1) - smb2_verify_signature(): * check if MessageId is 0xFFFFFFFFFFFFFFFF or if status is STATUS_PENDING (MS-SMB2 3.2.5.1.3) * remove extra call to zero the header signature as this is already done by all ->calc_signature implementations * remove useless call to check for "BSRSPYL" signature (SMB1 only), and from smb2_sign_rqst() as well Signed-off-by: Enzo Matsumiya --- fs/cifs/cifsencrypt.c | 23 ++- fs/cifs/cifsglob.h | 40 +++-- fs/cifs/smb2ops.c | 36 ++--- fs/cifs/smb2pdu.c | 82 +++++----- fs/cifs/smb2proto.h | 9 +- fs/cifs/smb2transport.c | 331 ++++++++++++++++++++++++++++++---------- 6 files changed, 354 insertions(+), 167 deletions(-) diff --git a/fs/cifs/cifsencrypt.c b/fs/cifs/cifsencrypt.c index 4ae58ab29458..3a78efc45a23 100644 --- a/fs/cifs/cifsencrypt.c +++ b/fs/cifs/cifsencrypt.c @@ -23,6 +23,7 @@ #include #include "../smbfs_common/arc4.h" #include +#include "smb2proto.h" int __cifs_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server, char *signature, @@ -105,9 +106,9 @@ static int cifs_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *se return -EINVAL; if (verify) - shash = server->secmech.verify; + shash = server->secmech.verify.shash; else - shash = server->secmech.sign; + shash = server->secmech.sign.shash; rc = crypto_shash_init(shash); if (rc) { @@ -703,16 +704,14 @@ calc_seckey(struct cifs_ses *ses) void cifs_crypto_secmech_release(struct TCP_Server_Info *server) { - cifs_free_hash(&server->secmech.sign); - cifs_free_hash(&server->secmech.verify); - - if (server->secmech.enc) { - crypto_free_aead(server->secmech.enc); - server->secmech.enc = NULL; + if (server->signing_algorithm == SIGNING_ALG_AES_GMAC) { + smb3_crypto_aead_free(&server->secmech.sign.aead); + smb3_crypto_aead_free(&server->secmech.verify.aead); + } else { + cifs_free_hash(&server->secmech.sign.shash); + cifs_free_hash(&server->secmech.verify.shash); } - if (server->secmech.dec) { - crypto_free_aead(server->secmech.dec); - server->secmech.dec = NULL; - } + smb3_crypto_aead_free(&server->secmech.enc); + smb3_crypto_aead_free(&server->secmech.dec); } diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index 30b3fadb4b06..81a8eff06467 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -153,24 +153,48 @@ struct session_key { char *response; }; +struct smb_rqst; +struct TCP_Server_Info; /** * cifs_secmech - Crypto hashing related structure/fields, not specific to one mechanism - * @sign: SHASH descriptor to allocate a hashing TFM for signing requests - * @verify: SHASH descriptor to allocate a hashing TFM for verifying requests' signatures + * @sign.shash: SHASH descriptor for signing TFM + * @sign.aead: AEAD TFM for signing + * @sign_wait: Completion struct for signing operations + * @verify.shash: SHASH descriptor for verifying TFM + * @verify.aead: AEAD TFM for verifying + * @verify_wait: Completion struct for verifying operations + * @calc_signature: Signature calculation function to be used. * @enc: AEAD TFM for SMB3+ encryption * @dec: AEAD TFM for SMB3+ decryption * - * @sign and @verify are allocated per-server, and the negotiated connection dialect will dictate - * which algorithm to use: + * @sign and @verify TFMs are allocated per-server, and the negotiated dialect will dictate which + * algorithm to use: * - MD5 for SMB1 * - HMAC-SHA256 for SMB2 * - AES-CMAC for SMB3 + * - AES-GMAC for SMB3.1.1 + * + * The completion structs @sign_wait and @verify_wait are required so that we can serialize access + * to the AEAD TFMs, since they're asynchronous by design. Using a stack-allocated structure could + * cause concurrent access to the TFMs to overwrite the completion status of a previous operation. * - * @enc and @dec holds the encryption/decryption TFMs, where it'll be either AES-CCM or AES-GCM. + * @enc and @dec holds the encryption/decryption TFMs, also allocated per server, where each will + * be either AES-CCM or AES-GCM. */ struct cifs_secmech { - struct shash_desc *sign; - struct shash_desc *verify; + union { + struct shash_desc *shash; + struct crypto_aead *aead; + } sign; + struct crypto_wait sign_wait; + + union { + struct shash_desc *shash; + struct crypto_aead *aead; + } verify; + struct crypto_wait verify_wait; + + int (*calc_signature)(struct smb_rqst *rqst, struct TCP_Server_Info *server, bool verify); struct crypto_aead *enc; struct crypto_aead *dec; @@ -445,8 +469,6 @@ struct smb_version_operations { void (*new_lease_key)(struct cifs_fid *); int (*generate_signingkey)(struct cifs_ses *ses, struct TCP_Server_Info *server); - int (*calc_signature)(struct smb_rqst *, struct TCP_Server_Info *, - bool allocate_crypto); int (*set_integrity)(const unsigned int, struct cifs_tcon *tcon, struct cifsFileInfo *src_file); int (*enum_snapshots)(const unsigned int xid, struct cifs_tcon *tcon, diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index 0aaad18e1ec8..22b40d181bba 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -4234,21 +4234,14 @@ static inline void smb2_sg_set_buf(struct scatterlist *sg, const void *buf, sg_set_page(sg, addr, buflen, offset_in_page(buf)); } -/* Assumes the first rqst has a transform header as the first iov. - * I.e. - * rqst[0].rq_iov[0] is transform header - * rqst[0].rq_iov[1+] data to be encrypted/decrypted - * rqst[1+].rq_iov[0+] data to be encrypted/decrypted - */ -static struct scatterlist * -init_sg(int num_rqst, struct smb_rqst *rqst, u8 *sign) +struct scatterlist * +smb3_init_sg(int num_rqst, struct smb_rqst *rqst, u8 *sign) { unsigned int sg_len; struct scatterlist *sg; unsigned int i; unsigned int j; unsigned int idx = 0; - int skip; sg_len = 1; for (i = 0; i < num_rqst; i++) @@ -4261,15 +4254,10 @@ init_sg(int num_rqst, struct smb_rqst *rqst, u8 *sign) sg_init_table(sg, sg_len); for (i = 0; i < num_rqst; i++) { for (j = 0; j < rqst[i].rq_nvec; j++) { - /* - * The first rqst has a transform header where the - * first 20 bytes are not part of the encrypted blob - */ - skip = (i == 0) && (j == 0) ? 20 : 0; smb2_sg_set_buf(&sg[idx++], - rqst[i].rq_iov[j].iov_base + skip, - rqst[i].rq_iov[j].iov_len - skip); - } + rqst[i].rq_iov[j].iov_base, + rqst[i].rq_iov[j].iov_len); + } for (j = 0; j < rqst[i].rq_npages; j++) { unsigned int len, offset; @@ -4325,7 +4313,15 @@ crypt_message(struct TCP_Server_Info *server, int num_rqst, crypt_len += SMB2_SIGNATURE_SIZE; } - sg = init_sg(num_rqst, rqst, sign); + /* Skip the first 20 bytes of the first iov of the first request as they're not part of the + * encrypted blob */ + rqst[0].rq_iov[0].iov_base += 20; + rqst[0].rq_iov[0].iov_len -= 20; + sg = smb3_init_sg(num_rqst, rqst, sign); + /* Rewind those 20 bytes before going any further */ + rqst[0].rq_iov[0].iov_base -= 20; + rqst[0].rq_iov[0].iov_len += 20; + if (!sg) { cifs_server_dbg(VFS, "%s: Failed to init sg\n", __func__); rc = -ENOMEM; @@ -5213,7 +5209,6 @@ struct smb_version_operations smb20_operations = { .get_lease_key = smb2_get_lease_key, .set_lease_key = smb2_set_lease_key, .new_lease_key = smb2_new_lease_key, - .calc_signature = smb2_calc_signature, .is_read_op = smb2_is_read_op, .set_oplock_level = smb2_set_oplock_level, .create_lease_buf = smb2_create_lease_buf, @@ -5314,7 +5309,6 @@ struct smb_version_operations smb21_operations = { .get_lease_key = smb2_get_lease_key, .set_lease_key = smb2_set_lease_key, .new_lease_key = smb2_new_lease_key, - .calc_signature = smb2_calc_signature, .is_read_op = smb21_is_read_op, .set_oplock_level = smb21_set_oplock_level, .create_lease_buf = smb2_create_lease_buf, @@ -5421,7 +5415,6 @@ struct smb_version_operations smb30_operations = { .set_lease_key = smb2_set_lease_key, .new_lease_key = smb2_new_lease_key, .generate_signingkey = generate_smb30signingkey, - .calc_signature = smb2_calc_signature, .set_integrity = smb3_set_integrity, .is_read_op = smb21_is_read_op, .set_oplock_level = smb3_set_oplock_level, @@ -5535,7 +5528,6 @@ struct smb_version_operations smb311_operations = { .set_lease_key = smb2_set_lease_key, .new_lease_key = smb2_new_lease_key, .generate_signingkey = generate_smb311signingkey, - .calc_signature = smb2_calc_signature, .set_integrity = smb3_set_integrity, .is_read_op = smb21_is_read_op, .set_oplock_level = smb3_set_oplock_level, diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index e5939c374c35..2c2bf28382bc 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -460,7 +460,7 @@ static unsigned int build_signing_ctxt(struct smb2_signing_capabilities *pneg_ctxt) { unsigned int ctxt_len = sizeof(struct smb2_signing_capabilities); - unsigned short num_algs = 1; /* number of signing algorithms sent */ + unsigned short num_algs = 2; /* number of signing algorithms sent */ pneg_ctxt->ContextType = SMB2_SIGNING_CAPABILITIES; /* @@ -471,12 +471,18 @@ build_signing_ctxt(struct smb2_signing_capabilities *pneg_ctxt) sizeof(struct smb2_neg_context) + (num_algs * 2 /* sizeof u16 */), 8) * 8); pneg_ctxt->SigningAlgorithmCount = cpu_to_le16(num_algs); - pneg_ctxt->SigningAlgorithms[0] = cpu_to_le16(SIGNING_ALG_AES_CMAC); + + /* + * Set AES-GMAC as preferred, but will fall back to AES-CMAC if server doesn't support it. + * MS-SMB2 2.2.3.1.7 + */ + pneg_ctxt->SigningAlgorithms[0] = SIGNING_ALG_AES_GMAC_LE; + pneg_ctxt->SigningAlgorithms[1] = SIGNING_ALG_AES_CMAC_LE; + /* SMB 3.1.1 doesn't accept HMAC-SHA256, so no need to send it */ ctxt_len += 2 /* sizeof le16 */ * num_algs; ctxt_len = DIV_ROUND_UP(ctxt_len, 8) * 8; return ctxt_len; - /* TBD add SIGNING_ALG_AES_GMAC and/or SIGNING_ALG_HMAC_SHA256 */ } static void @@ -927,22 +933,6 @@ SMB2_negotiate(const unsigned int xid, else req->SecurityMode = 0; - if (req->SecurityMode) { - /* - * Allocate HMAC-SHA256 regardless of dialect requested, change to AES-CMAC later, - * if SMB3+ is negotiated - */ - rc = cifs_alloc_hash("hmac(sha256)", &server->secmech.sign); - if (rc) - goto neg_exit; - - rc = cifs_alloc_hash("hmac(sha256)", &server->secmech.verify); - if (rc) { - cifs_free_hash(&server->secmech.sign); - goto neg_exit; - } - } - req->Capabilities = cpu_to_le32(server->vals->req_capabilities); if (ses->chan_max > 1) req->Capabilities |= cpu_to_le32(SMB2_GLOBAL_CAP_MULTI_CHANNEL); @@ -1087,22 +1077,6 @@ SMB2_negotiate(const unsigned int xid, rc = cifs_enable_signing(server, ses->sign); if (rc) goto neg_exit; - - if (server->sign && server->dialect >= SMB30_PROT_ID) { - /* free HMAC-SHA256 allocated earlier for negprot */ - cifs_free_hash(&server->secmech.sign); - cifs_free_hash(&server->secmech.verify); - rc = cifs_alloc_hash("cmac(aes)", &server->secmech.sign); - if (rc) - goto neg_exit; - - rc = cifs_alloc_hash("cmac(aes)", &server->secmech.verify); - if (rc) { - cifs_free_hash(&server->secmech.sign); - goto neg_exit; - } - } - if (blob_length) { rc = decode_negTokenInit(security_blob, blob_length, server); if (rc == 1) @@ -1112,12 +1086,35 @@ SMB2_negotiate(const unsigned int xid, } if (rsp->DialectRevision == cpu_to_le16(SMB311_PROT_ID)) { + server->signing_algorithm = SIGNING_ALG_AES_CMAC; + server->signing_negotiated = false; + if (rsp->NegotiateContextCount) rc = smb311_decode_neg_context(rsp, server, rsp_iov.iov_len); else cifs_server_dbg(VFS, "Missing expected negotiate contexts\n"); + + /* + * Some servers will not send a SMB2_SIGNING_CAPABILITIES context response (*), + * so use AES-CMAC signing algorithm as it is expected to be accepted. + * See MS-SMB2 note <125> Section 3.2.4.2.2.2 + */ + if (!server->signing_negotiated) + cifs_dbg(VFS, "signing capabilities were not negotiated, using " + "AES-CMAC for message signing\n"); + } else if (server->dialect >= SMB30_PROT_ID) { + server->signing_algorithm = SIGNING_ALG_AES_CMAC; + } else if (server->dialect >= SMB20_PROT_ID) { + server->signing_algorithm = SIGNING_ALG_HMAC_SHA256; } + + rc = smb2_init_secmechs(server); + if (rc) { + cifs_dbg(VFS, "Failed to initialize secmechs, rc=%d\n", rc); + goto neg_exit; + } + neg_exit: free_rsp_buf(resp_buftype, rsp); return rc; @@ -1677,18 +1674,13 @@ SMB2_sess_auth_rawntlmssp_authenticate(struct SMB2_sess_data *sess_data) goto out; if (ses->server->dialect < SMB30_PROT_ID) { - rc = crypto_shash_setkey(server->secmech.sign->tfm, - ses->auth_key.response, SMB2_NTLMV2_SESSKEY_SIZE); - if (rc) { - cifs_dbg(VFS, "%s: Failed to set HMAC-SHA256 signing key, rc=%d\n", - __func__, rc); - goto out; - } - - rc = crypto_shash_setkey(server->secmech.verify->tfm, + rc = crypto_shash_setkey(server->secmech.sign.shash->tfm, ses->auth_key.response, SMB2_NTLMV2_SESSKEY_SIZE); + if (!rc) + rc = crypto_shash_setkey(server->secmech.verify.shash->tfm, + ses->auth_key.response, SMB2_NTLMV2_SESSKEY_SIZE); if (rc) { - cifs_dbg(VFS, "%s: Failed to set HMAC-SHA256 verify key, rc=%d\n", + cifs_dbg(VFS, "%s: Failed to set HMAC-SHA256 signing keys, rc=%d\n", __func__, rc); goto out; } diff --git a/fs/cifs/smb2proto.h b/fs/cifs/smb2proto.h index 33af35b6e586..e4db59e6cee6 100644 --- a/fs/cifs/smb2proto.h +++ b/fs/cifs/smb2proto.h @@ -14,6 +14,7 @@ struct statfs; struct smb_rqst; +struct crypto_aead; /* ***************************************************************** @@ -37,6 +38,7 @@ extern struct mid_q_entry *smb2_setup_request(struct cifs_ses *ses, struct smb_rqst *rqst); extern struct mid_q_entry *smb2_setup_async_request( struct TCP_Server_Info *server, struct smb_rqst *rqst); +extern int smb2_init_secmechs(struct TCP_Server_Info *server); extern struct cifs_ses *smb2_find_smb_ses(struct TCP_Server_Info *server, __u64 ses_id); extern struct cifs_tcon *smb2_find_smb_tcon(struct TCP_Server_Info *server, @@ -44,6 +46,10 @@ extern struct cifs_tcon *smb2_find_smb_tcon(struct TCP_Server_Info *server, extern int smb2_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server, bool verify); +extern int smb311_calc_signature(struct smb_rqst *rqst, + struct TCP_Server_Info *server, + bool verify); +extern struct scatterlist *smb3_init_sg(int num_rqst, struct smb_rqst *rqst, u8 *sign); extern void smb2_echo_request(struct work_struct *work); extern __le32 smb2_get_lease_state(struct cifsInodeInfo *cinode); extern bool smb2_is_valid_oplock_break(char *buffer, @@ -99,7 +105,8 @@ extern int smb2_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock, const unsigned int xid); extern int smb2_push_mandatory_locks(struct cifsFileInfo *cfile); extern void smb2_reconnect_server(struct work_struct *work); -extern int smb3_crypto_aead_allocate(struct TCP_Server_Info *server); +extern int smb3_crypto_aead_allocate(const char *name, struct crypto_aead **tfm); +extern void smb3_crypto_aead_free(struct crypto_aead **tfm); extern unsigned long smb_rqst_len(struct TCP_Server_Info *server, struct smb_rqst *rqst); extern void smb2_set_next_command(struct cifs_tcon *tcon, diff --git a/fs/cifs/smb2transport.c b/fs/cifs/smb2transport.c index cf319fc25161..ded7144d1578 100644 --- a/fs/cifs/smb2transport.c +++ b/fs/cifs/smb2transport.c @@ -26,6 +26,63 @@ #include "smb2status.h" #include "smb2glob.h" +int +smb2_init_secmechs(struct TCP_Server_Info *server) +{ + int rc = 0; + + if (server->dialect >= SMB30_PROT_ID && + (server->capabilities & SMB2_GLOBAL_CAP_ENCRYPTION)) { + if (server->cipher_type == SMB2_ENCRYPTION_AES128_GCM || + server->cipher_type == SMB2_ENCRYPTION_AES256_GCM) { + rc = smb3_crypto_aead_allocate("gcm(aes)", &server->secmech.enc); + if (!rc) + rc = smb3_crypto_aead_allocate("gcm(aes)", &server->secmech.dec); + } else { + rc = smb3_crypto_aead_allocate("ccm(aes)", &server->secmech.enc); + if (!rc) + rc = smb3_crypto_aead_allocate("ccm(aes)", &server->secmech.dec); + } + + if (rc) + return rc; + } + + if (server->signing_algorithm == SIGNING_ALG_AES_GMAC) { + cifs_free_hash(&server->secmech.sign.shash); + cifs_free_hash(&server->secmech.verify.shash); + + rc = smb3_crypto_aead_allocate("gcm(aes)", &server->secmech.sign.aead); + if (!rc) + rc = smb3_crypto_aead_allocate("gcm(aes)", &server->secmech.verify.aead); + if (rc) { + smb3_crypto_aead_free(&server->secmech.sign.aead); + return rc; + } + + server->secmech.calc_signature = smb311_calc_signature; + } else { + char *shash_alg; + + if (server->dialect >= SMB30_PROT_ID) + shash_alg = "cmac(aes)"; + else + shash_alg = "hmac(sha256)"; + + rc = cifs_alloc_hash(shash_alg, &server->secmech.sign.shash); + if (!rc) + rc = cifs_alloc_hash(shash_alg, &server->secmech.verify.shash); + if (rc) { + cifs_free_hash(&server->secmech.sign.shash); + return rc; + } + + server->secmech.calc_signature = smb2_calc_signature; + } + + return rc; +} + static int smb3_setup_keys(struct TCP_Server_Info *server, u8 *sign_key, u8 *enc_key, u8 *dec_key) { @@ -42,44 +99,51 @@ smb3_setup_keys(struct TCP_Server_Info *server, u8 *sign_key, u8 *enc_key, u8 *d crypt_keylen = SMB3_GCM128_CRYPTKEY_SIZE; rc = crypto_aead_setkey(server->secmech.enc, enc_key, crypt_keylen); + if (!rc) + rc = crypto_aead_setkey(server->secmech.dec, dec_key, crypt_keylen); if (rc) { - cifs_server_dbg(VFS, "%s: Failed to set AEAD encryption key, rc=%d\n", + cifs_server_dbg(VFS, "%s: Failed to set encryption/decryption key, rc=%d\n", __func__, rc); return rc; } rc = crypto_aead_setauthsize(server->secmech.enc, SMB2_SIGNATURE_SIZE); + if (!rc) + rc = crypto_aead_setauthsize(server->secmech.dec, SMB2_SIGNATURE_SIZE); if (rc) { - cifs_server_dbg(VFS, "%s: Failed to set AEAD encryption authsize, rc=%d\n", - __func__, rc); - return rc; - } - - rc = crypto_aead_setkey(server->secmech.dec, dec_key, crypt_keylen); - if (rc) { - cifs_server_dbg(VFS, "%s: Failed to set AEAD decryption key, rc=%d\n", - __func__, rc); - return rc; - } - - rc = crypto_aead_setauthsize(server->secmech.dec, SMB2_SIGNATURE_SIZE); - if (rc) { - cifs_server_dbg(VFS, "%s: Failed to set AEAD decryption authsize, rc=%d\n", + cifs_server_dbg(VFS, "%s: Failed to set encryption/decryption authsize, rc=%d\n", __func__, rc); return rc; } setup_sign: - rc = crypto_shash_setkey(server->secmech.sign->tfm, sign_key, SMB3_SIGN_KEY_SIZE); - if (rc) { - cifs_server_dbg(VFS, "%s: Failed to set AES-CMAC signing key, rc=%d\n", - __func__, rc); - return rc; - } + if (server->signing_algorithm == SIGNING_ALG_AES_GMAC) { + rc = crypto_aead_setkey(server->secmech.sign.aead, sign_key, SMB3_SIGN_KEY_SIZE); + if (!rc) + rc = crypto_aead_setkey(server->secmech.verify.aead, sign_key, + SMB3_SIGN_KEY_SIZE); + if (rc) { + cifs_server_dbg(VFS, "%s: Failed to set AES-GMAC key, rc=%d\n", + __func__, rc); + return rc; + } - rc = crypto_shash_setkey(server->secmech.verify->tfm, sign_key, SMB3_SIGN_KEY_SIZE); - if (rc) - cifs_server_dbg(VFS, "%s: Failed to set AES-CMAC verify key, rc=%d\n", - __func__, rc); + rc = crypto_aead_setauthsize(server->secmech.sign.aead, SMB2_SIGNATURE_SIZE); + if (!rc) + rc = crypto_aead_setauthsize(server->secmech.verify.aead, + SMB2_SIGNATURE_SIZE); + if (rc) + cifs_server_dbg(VFS, "%s: Failed to set AES-GMAC authsize, rc=%d\n", + __func__, rc); + } else { + rc = crypto_shash_setkey(server->secmech.sign.shash->tfm, sign_key, + SMB3_SIGN_KEY_SIZE); + if (!rc) + rc = crypto_shash_setkey(server->secmech.verify.shash->tfm, sign_key, + SMB3_SIGN_KEY_SIZE); + if (rc) + cifs_server_dbg(VFS, "%s: Failed to set %s signing key, rc=%d\n", __func__, + crypto_shash_alg_name(server->secmech.sign.shash->tfm), rc); + } return rc; } @@ -171,9 +235,9 @@ smb2_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server, bool memset(shdr->Signature, 0x0, SMB2_SIGNATURE_SIZE); if (verify) - shash = server->secmech.verify; + shash = server->secmech.verify.shash; else - shash = server->secmech.sign; + shash = server->secmech.sign.shash; rc = crypto_shash_init(shash); if (rc) { @@ -360,10 +424,6 @@ generate_smb3signingkey(struct cifs_ses *ses, if (rc) goto out_zero_keys; - rc = smb3_crypto_aead_allocate(server); - if (rc) - goto out_zero_keys; - rc = smb3_setup_keys(ses->server, sign_key, enc_key, dec_key); if (rc) goto out_zero_keys; @@ -471,6 +531,125 @@ generate_smb311signingkey(struct cifs_ses *ses, return generate_smb3signingkey(ses, server, &triplet); } +/* + * This function implements AES-GMAC signing for SMB2 messages as described in MS-SMB2 + * specification. This algorithm is only supported on SMB 3.1.1. + * + * Note: even though Microsoft mentions RFC4543 in MS-SMB2, the mechanism used _must_ be the "raw" + * AES-128-GCM ("gcm(aes)"); RFC4543 is designed for IPsec and trying to use "rfc4543(gcm(aes)))" + * will fail the signature computation. + * + * MS-SMB2 3.1.4.1 + */ +int +smb311_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server, bool verify) +{ + union { + struct { + /* for MessageId (8 bytes) */ + __le64 mid; + /* for role (client or server) and if SMB2 CANCEL (4 bytes) */ + __le32 role; + }; + u8 buffer[12]; + } __packed nonce; + u8 sig[SMB2_SIGNATURE_SIZE] = { 0 }; + struct aead_request *aead_req = NULL; + struct crypto_aead *tfm = NULL; + struct scatterlist *sg = NULL; + unsigned long assoclen; + struct smb2_hdr *shdr = NULL; + struct crypto_wait *wait; + unsigned int save_npages = 0; + int rc = 0; + + if (verify) { + wait = &server->secmech.verify_wait; + tfm = server->secmech.verify.aead; + } else { + wait = &server->secmech.sign_wait; + tfm = server->secmech.sign.aead; + } + + if (completion_done(&wait->completion)) + reinit_completion(&wait->completion); + + shdr = (struct smb2_hdr *)rqst->rq_iov[0].iov_base; + + memset(shdr->Signature, 0, SMB2_SIGNATURE_SIZE); + memset(&nonce, 0, SMB3_AES_GCM_NONCE); + + /* note that nonce must always be little endian */ + nonce.mid = shdr->MessageId; + /* request is coming from the server, set LSB */ + nonce.role |= shdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR; + /* set penultimate LSB if SMB2_CANCEL command */ + if (shdr->Command == SMB2_CANCEL) + nonce.role |= cpu_to_le32(1UL << 1); + + aead_req = aead_request_alloc(tfm, GFP_KERNEL); + if (!aead_req) { + cifs_dbg(VFS, "%s: Failed to alloc AEAD request\n", __func__); + return -ENOMEM; + } + + /* skip page data if non-success error status, as it will compute an invalid signature */ + if (shdr->Status != 0 && rqst->rq_npages > 0) { + save_npages = rqst->rq_npages; + rqst->rq_npages = 0; + } + + assoclen = smb_rqst_len(server, rqst); + + sg = smb3_init_sg(1, rqst, sig); + if (!sg) { + cifs_dbg(VFS, "%s: Failed to init SG\n", __func__); + goto out_free_req; + } + + /* cryptlen == 0 because we're not encrypting anything */ + aead_request_set_crypt(aead_req, sg, sg, 0, nonce.buffer); + aead_request_set_ad(aead_req, assoclen); + aead_request_set_callback(aead_req, CRYPTO_TFM_REQ_MAY_BACKLOG, crypto_req_done, wait); + + /* + * Reminder: we must always use the encrypt function, as AES-GCM decrypt will internally + * try to match the authentication codes, where we pass a zeroed buffer, and the operation + * will fail with -EBADMSG (expectedly). + * + * Also note we can't use crypto_wait_req() here since it's not interruptible. + */ + rc = crypto_aead_encrypt(aead_req); + if (!rc) + goto out; + + if (rc == -EINPROGRESS || rc == -EBUSY) { + rc = wait_for_completion_interruptible(&wait->completion); + if (!rc) + /* wait->err is set by crypto_req_done callback above */ + rc = wait->err; + } + + if (rc) { + cifs_server_dbg(VFS, "%s: Failed to compute AES-GMAC signature, rc=%d\n", + __func__, rc); + goto out_free_sg; + } + +out: + memcpy(&shdr->Signature, sig, SMB2_SIGNATURE_SIZE); +out_free_sg: + kfree(sg); +out_free_req: + kfree(aead_req); + + /* restore rq_npages for further processing */ + if (shdr->Status != 0 && save_npages > 0) + rqst->rq_npages = save_npages; + + return rc; +} + /* must be called with server->srv_mutex held */ static int smb2_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server) @@ -497,12 +676,10 @@ smb2_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server) return 0; } spin_unlock(&server->srv_lock); - if (!is_binding && !server->session_estab) { - strncpy(shdr->Signature, "BSRSPYL", 8); + if (!is_binding && !server->session_estab) return 0; - } - rc = server->ops->calc_signature(rqst, server, false); + rc = server->secmech.calc_signature(rqst, server, false); return rc; } @@ -518,6 +695,8 @@ smb2_verify_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server) if ((shdr->Command == SMB2_NEGOTIATE) || (shdr->Command == SMB2_SESSION_SETUP) || (shdr->Command == SMB2_OPLOCK_BREAK) || + (shdr->MessageId == cpu_to_le64(0xFFFFFFFFFFFFFFFF)) || + (shdr->Status == STATUS_PENDING) || server->ignore_signature || (!server->session_estab)) return 0; @@ -527,20 +706,13 @@ smb2_verify_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server) * server does not send one? BB */ - /* Do not need to verify session setups with signature "BSRSPYL " */ - if (memcmp(shdr->Signature, "BSRSPYL ", 8) == 0) - cifs_dbg(FYI, "dummy signature received for smb command 0x%x\n", - shdr->Command); - /* * Save off the origiginal signature so we can modify the smb and check * our calculated signature against what the server sent. */ memcpy(server_response_sig, shdr->Signature, SMB2_SIGNATURE_SIZE); - memset(shdr->Signature, 0, SMB2_SIGNATURE_SIZE); - - rc = server->ops->calc_signature(rqst, server, true); + rc = server->secmech.calc_signature(rqst, server, true); if (rc) return rc; @@ -693,6 +865,8 @@ smb2_setup_request(struct cifs_ses *ses, struct TCP_Server_Info *server, int rc; struct smb2_hdr *shdr = (struct smb2_hdr *)rqst->rq_iov[0].iov_base; + struct smb2_transform_hdr *trhdr = + (struct smb2_transform_hdr *)rqst->rq_iov[0].iov_base; struct mid_q_entry *mid; smb2_seq_num_into_buf(server, shdr); @@ -703,11 +877,22 @@ smb2_setup_request(struct cifs_ses *ses, struct TCP_Server_Info *server, return ERR_PTR(rc); } - rc = smb2_sign_rqst(rqst, server); - if (rc) { - revert_current_mid_from_hdr(server, shdr); - delete_mid(mid); - return ERR_PTR(rc); + /* + * Client must not sign the request if it's encrypted. + * + * Note: we can't rely on SMB2_SESSION_FLAG_ENCRYPT_DATA or SMB2_GLOBAL_CAP_ENCRYPTION + * here because they might be set, but not being actively used (e.g. not mounted with + * "seal"), so just check if header is a transform header. + * + * MS-SMB2 3.2.4.1.1 + */ + if (trhdr->ProtocolId != SMB2_TRANSFORM_PROTO_NUM) { + rc = smb2_sign_rqst(rqst, server); + if (rc) { + revert_current_mid_from_hdr(server, shdr); + delete_mid(mid); + return ERR_PTR(rc); + } } return mid; @@ -748,39 +933,29 @@ smb2_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst) } int -smb3_crypto_aead_allocate(struct TCP_Server_Info *server) +smb3_crypto_aead_allocate(const char *name, struct crypto_aead **tfm) { - struct crypto_aead *tfm; + if (unlikely(!tfm)) + return -EIO; - if (!server->secmech.enc) { - if ((server->cipher_type == SMB2_ENCRYPTION_AES128_GCM) || - (server->cipher_type == SMB2_ENCRYPTION_AES256_GCM)) - tfm = crypto_alloc_aead("gcm(aes)", 0, 0); - else - tfm = crypto_alloc_aead("ccm(aes)", 0, 0); - if (IS_ERR(tfm)) { - cifs_server_dbg(VFS, "%s: Failed alloc encrypt aead\n", - __func__); - return PTR_ERR(tfm); - } - server->secmech.enc = tfm; - } + if (*tfm) + return 0; - if (!server->secmech.dec) { - if ((server->cipher_type == SMB2_ENCRYPTION_AES128_GCM) || - (server->cipher_type == SMB2_ENCRYPTION_AES256_GCM)) - tfm = crypto_alloc_aead("gcm(aes)", 0, 0); - else - tfm = crypto_alloc_aead("ccm(aes)", 0, 0); - if (IS_ERR(tfm)) { - crypto_free_aead(server->secmech.enc); - server->secmech.enc = NULL; - cifs_server_dbg(VFS, "%s: Failed to alloc decrypt aead\n", - __func__); - return PTR_ERR(tfm); - } - server->secmech.dec = tfm; + *tfm = crypto_alloc_aead(name, CRYPTO_ALG_TYPE_AEAD, 0); + if (IS_ERR(*tfm)) { + cifs_dbg(VFS, "%s: Failed to alloc %s crypto TFM, rc=%ld\n", + __func__, name, PTR_ERR(*tfm)); + return PTR_ERR(*tfm); } return 0; } + +void smb3_crypto_aead_free(struct crypto_aead **tfm) +{ + if (!tfm || !*tfm) + return; + + crypto_free_aead(*tfm); + *tfm = NULL; +}