Split SMB1-specific message signing into smb1encrypt.c. Signed-off-by: David Howells cc: Steve French cc: Paulo Alcantara cc: Enzo Matsumiya cc: linux-cifs@vger.kernel.org cc: linux-fsdevel@vger.kernel.org cc: linux-kernel@vger.kernel.org --- fs/smb/client/Makefile | 1 + fs/smb/client/cifsencrypt.c | 123 ------------------------------- fs/smb/client/cifsproto.h | 5 -- fs/smb/client/smb1encrypt.c | 139 ++++++++++++++++++++++++++++++++++++ fs/smb/client/smb1proto.h | 9 +++ 5 files changed, 149 insertions(+), 128 deletions(-) create mode 100644 fs/smb/client/smb1encrypt.c diff --git a/fs/smb/client/Makefile b/fs/smb/client/Makefile index 82ad4bccb131..a66e3b5b5912 100644 --- a/fs/smb/client/Makefile +++ b/fs/smb/client/Makefile @@ -35,6 +35,7 @@ cifs-$(CONFIG_CIFS_ROOT) += cifsroot.o cifs-$(CONFIG_CIFS_ALLOW_INSECURE_LEGACY) += \ cifssmb.o \ smb1debug.o \ + smb1encrypt.o \ smb1maperror.o \ smb1misc.o \ smb1ops.o \ diff --git a/fs/smb/client/cifsencrypt.c b/fs/smb/client/cifsencrypt.c index 661c7b8dc602..50b7ec39053c 100644 --- a/fs/smb/client/cifsencrypt.c +++ b/fs/smb/client/cifsencrypt.c @@ -115,129 +115,6 @@ int __cifs_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server, return rc; } -/* - * Calculate and return the CIFS signature based on the mac key and SMB PDU. - * The 16 byte signature must be allocated by the caller. Note we only use the - * 1st eight bytes and that the smb header signature field on input contains - * the sequence number before this function is called. Also, this function - * should be called with the server->srv_mutex held. - */ -static int cifs_calc_signature(struct smb_rqst *rqst, - struct TCP_Server_Info *server, char *signature) -{ - struct md5_ctx ctx; - - if (!rqst->rq_iov || !signature || !server) - return -EINVAL; - if (fips_enabled) { - cifs_dbg(VFS, - "MD5 signature support is disabled due to FIPS\n"); - return -EOPNOTSUPP; - } - - md5_init(&ctx); - md5_update(&ctx, server->session_key.response, server->session_key.len); - - return __cifs_calc_signature( - rqst, server, signature, - &(struct cifs_calc_sig_ctx){ .md5 = &ctx }); -} - -/* must be called with server->srv_mutex held */ -int cifs_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server, - __u32 *pexpected_response_sequence_number) -{ - int rc = 0; - char smb_signature[20]; - struct smb_hdr *cifs_pdu = (struct smb_hdr *)rqst->rq_iov[0].iov_base; - - if ((cifs_pdu == NULL) || (server == NULL)) - return -EINVAL; - - spin_lock(&server->srv_lock); - if (!(cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) || - server->tcpStatus == CifsNeedNegotiate) { - spin_unlock(&server->srv_lock); - return rc; - } - spin_unlock(&server->srv_lock); - - if (!server->session_estab) { - memcpy(cifs_pdu->Signature.SecuritySignature, "BSRSPYL", 8); - return rc; - } - - cifs_pdu->Signature.Sequence.SequenceNumber = - cpu_to_le32(server->sequence_number); - cifs_pdu->Signature.Sequence.Reserved = 0; - - *pexpected_response_sequence_number = ++server->sequence_number; - ++server->sequence_number; - - rc = cifs_calc_signature(rqst, server, smb_signature); - if (rc) - memset(cifs_pdu->Signature.SecuritySignature, 0, 8); - else - memcpy(cifs_pdu->Signature.SecuritySignature, smb_signature, 8); - - return rc; -} - -int cifs_verify_signature(struct smb_rqst *rqst, - struct TCP_Server_Info *server, - __u32 expected_sequence_number) -{ - unsigned int rc; - char server_response_sig[8]; - char what_we_think_sig_should_be[20]; - struct smb_hdr *cifs_pdu = (struct smb_hdr *)rqst->rq_iov[0].iov_base; - - if (cifs_pdu == NULL || server == NULL) - return -EINVAL; - - if (!server->session_estab) - return 0; - - if (cifs_pdu->Command == SMB_COM_LOCKING_ANDX) { - struct smb_com_lock_req *pSMB = - (struct smb_com_lock_req *)cifs_pdu; - if (pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE) - return 0; - } - - /* BB what if signatures are supposed to be on for session but - server does not send one? BB */ - - /* Do not need to verify session setups with signature "BSRSPYL " */ - if (memcmp(cifs_pdu->Signature.SecuritySignature, "BSRSPYL ", 8) == 0) - cifs_dbg(FYI, "dummy signature received for smb command 0x%x\n", - cifs_pdu->Command); - - /* save off the original signature so we can modify the smb and check - its signature against what the server sent */ - memcpy(server_response_sig, cifs_pdu->Signature.SecuritySignature, 8); - - cifs_pdu->Signature.Sequence.SequenceNumber = - cpu_to_le32(expected_sequence_number); - cifs_pdu->Signature.Sequence.Reserved = 0; - - cifs_server_lock(server); - rc = cifs_calc_signature(rqst, server, what_we_think_sig_should_be); - cifs_server_unlock(server); - - if (rc) - return rc; - -/* cifs_dump_mem("what we think it should be: ", - what_we_think_sig_should_be, 16); */ - - if (memcmp(server_response_sig, what_we_think_sig_should_be, 8)) - return -EACCES; - else - return 0; - -} - /* Build a proper attribute value/target info pairs blob. * Fill in netbios and dns domain name and workstation name * and client time (total five av pairs and + one end of fields indicator. diff --git a/fs/smb/client/cifsproto.h b/fs/smb/client/cifsproto.h index 884a66b6bd34..ba571cc7453a 100644 --- a/fs/smb/client/cifsproto.h +++ b/fs/smb/client/cifsproto.h @@ -326,11 +326,6 @@ struct cifs_tcon *tcon_info_alloc(bool dir_leases_enabled, enum smb3_tcon_ref_trace trace); void tconInfoFree(struct cifs_tcon *tcon, enum smb3_tcon_ref_trace trace); -int cifs_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server, - __u32 *pexpected_response_sequence_number); -int cifs_verify_signature(struct smb_rqst *rqst, - struct TCP_Server_Info *server, - __u32 expected_sequence_number); int setup_ntlmv2_rsp(struct cifs_ses *ses, const struct nls_table *nls_cp); void cifs_crypto_secmech_release(struct TCP_Server_Info *server); int calc_seckey(struct cifs_ses *ses); diff --git a/fs/smb/client/smb1encrypt.c b/fs/smb/client/smb1encrypt.c new file mode 100644 index 000000000000..0dbbce2431ff --- /dev/null +++ b/fs/smb/client/smb1encrypt.c @@ -0,0 +1,139 @@ +// SPDX-License-Identifier: LGPL-2.1 +/* + * + * Encryption and hashing operations relating to NTLM, NTLMv2. See MS-NLMP + * for more detailed information + * + * Copyright (C) International Business Machines Corp., 2005,2013 + * Author(s): Steve French (sfrench@us.ibm.com) + * + */ + +#include +#include +#include "cifsproto.h" +#include "smb1proto.h" +#include "cifs_debug.h" + +/* + * Calculate and return the CIFS signature based on the mac key and SMB PDU. + * The 16 byte signature must be allocated by the caller. Note we only use the + * 1st eight bytes and that the smb header signature field on input contains + * the sequence number before this function is called. Also, this function + * should be called with the server->srv_mutex held. + */ +static int cifs_calc_signature(struct smb_rqst *rqst, + struct TCP_Server_Info *server, char *signature) +{ + struct md5_ctx ctx; + + if (!rqst->rq_iov || !signature || !server) + return -EINVAL; + if (fips_enabled) { + cifs_dbg(VFS, + "MD5 signature support is disabled due to FIPS\n"); + return -EOPNOTSUPP; + } + + md5_init(&ctx); + md5_update(&ctx, server->session_key.response, server->session_key.len); + + return __cifs_calc_signature( + rqst, server, signature, + &(struct cifs_calc_sig_ctx){ .md5 = &ctx }); +} + +/* must be called with server->srv_mutex held */ +int cifs_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server, + __u32 *pexpected_response_sequence_number) +{ + int rc = 0; + char smb_signature[20]; + struct smb_hdr *cifs_pdu = (struct smb_hdr *)rqst->rq_iov[0].iov_base; + + if ((cifs_pdu == NULL) || (server == NULL)) + return -EINVAL; + + spin_lock(&server->srv_lock); + if (!(cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) || + server->tcpStatus == CifsNeedNegotiate) { + spin_unlock(&server->srv_lock); + return rc; + } + spin_unlock(&server->srv_lock); + + if (!server->session_estab) { + memcpy(cifs_pdu->Signature.SecuritySignature, "BSRSPYL", 8); + return rc; + } + + cifs_pdu->Signature.Sequence.SequenceNumber = + cpu_to_le32(server->sequence_number); + cifs_pdu->Signature.Sequence.Reserved = 0; + + *pexpected_response_sequence_number = ++server->sequence_number; + ++server->sequence_number; + + rc = cifs_calc_signature(rqst, server, smb_signature); + if (rc) + memset(cifs_pdu->Signature.SecuritySignature, 0, 8); + else + memcpy(cifs_pdu->Signature.SecuritySignature, smb_signature, 8); + + return rc; +} + +int cifs_verify_signature(struct smb_rqst *rqst, + struct TCP_Server_Info *server, + __u32 expected_sequence_number) +{ + unsigned int rc; + char server_response_sig[8]; + char what_we_think_sig_should_be[20]; + struct smb_hdr *cifs_pdu = (struct smb_hdr *)rqst->rq_iov[0].iov_base; + + if (cifs_pdu == NULL || server == NULL) + return -EINVAL; + + if (!server->session_estab) + return 0; + + if (cifs_pdu->Command == SMB_COM_LOCKING_ANDX) { + struct smb_com_lock_req *pSMB = + (struct smb_com_lock_req *)cifs_pdu; + if (pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE) + return 0; + } + + /* BB what if signatures are supposed to be on for session but + server does not send one? BB */ + + /* Do not need to verify session setups with signature "BSRSPYL " */ + if (memcmp(cifs_pdu->Signature.SecuritySignature, "BSRSPYL ", 8) == 0) + cifs_dbg(FYI, "dummy signature received for smb command 0x%x\n", + cifs_pdu->Command); + + /* save off the original signature so we can modify the smb and check + its signature against what the server sent */ + memcpy(server_response_sig, cifs_pdu->Signature.SecuritySignature, 8); + + cifs_pdu->Signature.Sequence.SequenceNumber = + cpu_to_le32(expected_sequence_number); + cifs_pdu->Signature.Sequence.Reserved = 0; + + cifs_server_lock(server); + rc = cifs_calc_signature(rqst, server, what_we_think_sig_should_be); + cifs_server_unlock(server); + + if (rc) + return rc; + +/* cifs_dump_mem("what we think it should be: ", + what_we_think_sig_should_be, 16); */ + + if (memcmp(server_response_sig, what_we_think_sig_should_be, 8)) + return -EACCES; + else + return 0; + +} diff --git a/fs/smb/client/smb1proto.h b/fs/smb/client/smb1proto.h index f5760af58999..0f54c0740da1 100644 --- a/fs/smb/client/smb1proto.h +++ b/fs/smb/client/smb1proto.h @@ -220,6 +220,15 @@ int CIFSSMBSetEA(const unsigned int xid, struct cifs_tcon *tcon, void cifs_dump_detail(void *buf, size_t buf_len, struct TCP_Server_Info *server); +/* + * smb1encrypt.c + */ +int cifs_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server, + __u32 *pexpected_response_sequence_number); +int cifs_verify_signature(struct smb_rqst *rqst, + struct TCP_Server_Info *server, + __u32 expected_sequence_number); + /* * smb1maperror.c */