From 373512ec5c105ed09e3738196dcb257dfab65cba Mon Sep 17 00:00:00 2001 From: Steve French Date: Fri, 18 Dec 2015 13:05:30 -0600 Subject: [PATCH] Prepare for encryption support (first part). Add decryption and encryption key generation. Thanks to Metze for helping with this. Reviewed-by: Stefan Metzmacher Signed-off-by: Steve French --- fs/cifs/cifsglob.h | 8 +++- fs/cifs/cifsproto.h | 5 +- fs/cifs/connect.c | 2 +- fs/cifs/misc.c | 2 +- fs/cifs/smb2misc.c | 36 +++++++++++--- fs/cifs/smb2ops.c | 13 +++-- fs/cifs/smb2pdu.c | 10 ++-- fs/cifs/smb2pdu.h | 8 ++-- fs/cifs/smb2proto.h | 3 +- fs/cifs/smb2transport.c | 102 +++++++++++++++++++++++++++++++++++++--- 10 files changed, 156 insertions(+), 33 deletions(-) diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index 9d14926531ba..a25b2513f146 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -227,7 +227,7 @@ struct smb_version_operations { void (*print_stats)(struct seq_file *m, struct cifs_tcon *); void (*dump_share_caps)(struct seq_file *, struct cifs_tcon *); /* verify the message */ - int (*check_message)(char *, unsigned int); + int (*check_message)(char *, unsigned int, struct TCP_Server_Info *); bool (*is_oplock_break)(char *, struct TCP_Server_Info *); void (*downgrade_oplock)(struct TCP_Server_Info *, struct cifsInodeInfo *, bool); @@ -630,6 +630,7 @@ struct TCP_Server_Info { #ifdef CONFIG_CIFS_SMB2 unsigned int max_read; unsigned int max_write; + __u8 preauth_hash[512]; #endif /* CONFIG_CIFS_SMB2 */ unsigned long echo_interval; }; @@ -813,7 +814,10 @@ struct cifs_ses { bool need_reconnect:1; /* connection reset, uid now invalid */ #ifdef CONFIG_CIFS_SMB2 __u16 session_flags; - char smb3signingkey[SMB3_SIGN_KEY_SIZE]; /* for signing smb3 packets */ + __u8 smb3signingkey[SMB3_SIGN_KEY_SIZE]; + __u8 smb3encryptionkey[SMB3_SIGN_KEY_SIZE]; + __u8 smb3decryptionkey[SMB3_SIGN_KEY_SIZE]; + __u8 preauth_hash[512]; #endif /* CONFIG_CIFS_SMB2 */ }; diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h index c63fd1dde25b..eed7ff50faf0 100644 --- a/fs/cifs/cifsproto.h +++ b/fs/cifs/cifsproto.h @@ -102,7 +102,7 @@ extern int SendReceiveBlockingLock(const unsigned int xid, struct smb_hdr *out_buf, int *bytes_returned); extern int cifs_reconnect(struct TCP_Server_Info *server); -extern int checkSMB(char *buf, unsigned int length); +extern int checkSMB(char *buf, unsigned int len, struct TCP_Server_Info *srvr); extern bool is_valid_oplock_break(char *, struct TCP_Server_Info *); extern bool backup_cred(struct cifs_sb_info *); extern bool is_size_safe_to_change(struct cifsInodeInfo *, __u64 eof); @@ -439,7 +439,8 @@ extern int setup_ntlm_response(struct cifs_ses *, const struct nls_table *); extern int setup_ntlmv2_rsp(struct cifs_ses *, const struct nls_table *); extern void cifs_crypto_shash_release(struct TCP_Server_Info *); extern int calc_seckey(struct cifs_ses *); -extern int generate_smb3signingkey(struct cifs_ses *); +extern int generate_smb30signingkey(struct cifs_ses *); +extern int generate_smb311signingkey(struct cifs_ses *); #ifdef CONFIG_CIFS_WEAK_PW_HASH extern int calc_lanman_hash(const char *password, const char *cryptkey, diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index de53c5558fe3..6ab9e83b899e 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -831,7 +831,7 @@ standard_receive3(struct TCP_Server_Info *server, struct mid_q_entry *mid) * 48 bytes is enough to display the header and a little bit * into the payload for debugging purposes. */ - length = server->ops->check_message(buf, server->total_read); + length = server->ops->check_message(buf, server->total_read, server); if (length != 0) cifs_dump_mem("Bad SMB: ", buf, min_t(unsigned int, server->total_read, 48)); diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c index 8442b8b8e0be..813fe13c2ae1 100644 --- a/fs/cifs/misc.c +++ b/fs/cifs/misc.c @@ -310,7 +310,7 @@ check_smb_hdr(struct smb_hdr *smb) } int -checkSMB(char *buf, unsigned int total_read) +checkSMB(char *buf, unsigned int total_read, struct TCP_Server_Info *server) { struct smb_hdr *smb = (struct smb_hdr *)buf; __u32 rfclen = be32_to_cpu(smb->smb_buf_length); diff --git a/fs/cifs/smb2misc.c b/fs/cifs/smb2misc.c index 1c5907019045..389fb9f8c84e 100644 --- a/fs/cifs/smb2misc.c +++ b/fs/cifs/smb2misc.c @@ -38,7 +38,7 @@ check_smb2_hdr(struct smb2_hdr *hdr, __u64 mid) * Make sure that this really is an SMB, that it is a response, * and that the message ids match. */ - if ((*(__le32 *)hdr->ProtocolId == SMB2_PROTO_NUMBER) && + if ((hdr->ProtocolId == SMB2_PROTO_NUMBER) && (mid == wire_mid)) { if (hdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR) return 0; @@ -50,9 +50,9 @@ check_smb2_hdr(struct smb2_hdr *hdr, __u64 mid) cifs_dbg(VFS, "Received Request not response\n"); } } else { /* bad signature or mid */ - if (*(__le32 *)hdr->ProtocolId != SMB2_PROTO_NUMBER) + if (hdr->ProtocolId != SMB2_PROTO_NUMBER) cifs_dbg(VFS, "Bad protocol string signature header %x\n", - *(unsigned int *) hdr->ProtocolId); + le32_to_cpu(hdr->ProtocolId)); if (mid != wire_mid) cifs_dbg(VFS, "Mids do not match: %llu and %llu\n", mid, wire_mid); @@ -93,11 +93,11 @@ static const __le16 smb2_rsp_struct_sizes[NUMBER_OF_SMB2_COMMANDS] = { }; int -smb2_check_message(char *buf, unsigned int length) +smb2_check_message(char *buf, unsigned int length, struct TCP_Server_Info *srvr) { struct smb2_hdr *hdr = (struct smb2_hdr *)buf; struct smb2_pdu *pdu = (struct smb2_pdu *)hdr; - __u64 mid = le64_to_cpu(hdr->MessageId); + __u64 mid; __u32 len = get_rfc1002_length(buf); __u32 clc_len; /* calculated length */ int command; @@ -111,6 +111,30 @@ smb2_check_message(char *buf, unsigned int length) * ie Validate the wct via smb2_struct_sizes table above */ + if (hdr->ProtocolId == SMB2_TRANSFORM_PROTO_NUM) { + struct smb2_transform_hdr *thdr = + (struct smb2_transform_hdr *)buf; + struct cifs_ses *ses = NULL; + struct list_head *tmp; + + /* decrypt frame now that it is completely read in */ + spin_lock(&cifs_tcp_ses_lock); + list_for_each(tmp, &srvr->smb_ses_list) { + ses = list_entry(tmp, struct cifs_ses, smb_ses_list); + if (ses->Suid == thdr->SessionId) + break; + + ses = NULL; + } + spin_unlock(&cifs_tcp_ses_lock); + if (ses == NULL) { + cifs_dbg(VFS, "no decryption - session id not found\n"); + return 1; + } + } + + + mid = le64_to_cpu(hdr->MessageId); if (length < sizeof(struct smb2_pdu)) { if ((length >= sizeof(struct smb2_hdr)) && (hdr->Status != 0)) { pdu->StructureSize2 = 0; @@ -322,7 +346,7 @@ smb2_get_data_area_len(int *off, int *len, struct smb2_hdr *hdr) /* return pointer to beginning of data area, ie offset from SMB start */ if ((*off != 0) && (*len != 0)) - return (char *)(&hdr->ProtocolId[0]) + *off; + return (char *)(&hdr->ProtocolId) + *off; else return NULL; } diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index 53ccdde6ff18..3525ed756173 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -182,6 +182,11 @@ smb2_find_mid(struct TCP_Server_Info *server, char *buf) struct smb2_hdr *hdr = (struct smb2_hdr *)buf; __u64 wire_mid = le64_to_cpu(hdr->MessageId); + if (hdr->ProtocolId == SMB2_TRANSFORM_PROTO_NUM) { + cifs_dbg(VFS, "encrypted frame parsing not supported yet"); + return NULL; + } + spin_lock(&GlobalMid_Lock); list_for_each_entry(mid, &server->pending_mid_q, qhead) { if ((mid->mid == wire_mid) && @@ -1692,7 +1697,7 @@ struct smb_version_operations smb30_operations = { .get_lease_key = smb2_get_lease_key, .set_lease_key = smb2_set_lease_key, .new_lease_key = smb2_new_lease_key, - .generate_signingkey = generate_smb3signingkey, + .generate_signingkey = generate_smb30signingkey, .calc_signature = smb3_calc_signature, .set_integrity = smb3_set_integrity, .is_read_op = smb21_is_read_op, @@ -1779,7 +1784,7 @@ struct smb_version_operations smb311_operations = { .get_lease_key = smb2_get_lease_key, .set_lease_key = smb2_set_lease_key, .new_lease_key = smb2_new_lease_key, - .generate_signingkey = generate_smb3signingkey, + .generate_signingkey = generate_smb311signingkey, .calc_signature = smb3_calc_signature, .set_integrity = smb3_set_integrity, .is_read_op = smb21_is_read_op, @@ -1838,7 +1843,7 @@ struct smb_version_values smb21_values = { struct smb_version_values smb30_values = { .version_string = SMB30_VERSION_STRING, .protocol_id = SMB30_PROT_ID, - .req_capabilities = SMB2_GLOBAL_CAP_DFS | SMB2_GLOBAL_CAP_LEASING | SMB2_GLOBAL_CAP_LARGE_MTU | SMB2_GLOBAL_CAP_PERSISTENT_HANDLES, + .req_capabilities = SMB2_GLOBAL_CAP_DFS | SMB2_GLOBAL_CAP_LEASING | SMB2_GLOBAL_CAP_LARGE_MTU | SMB2_GLOBAL_CAP_PERSISTENT_HANDLES | SMB2_GLOBAL_CAP_ENCRYPTION, .large_lock_type = 0, .exclusive_lock_type = SMB2_LOCKFLAG_EXCLUSIVE_LOCK, .shared_lock_type = SMB2_LOCKFLAG_SHARED_LOCK, @@ -1858,7 +1863,7 @@ struct smb_version_values smb30_values = { struct smb_version_values smb302_values = { .version_string = SMB302_VERSION_STRING, .protocol_id = SMB302_PROT_ID, - .req_capabilities = SMB2_GLOBAL_CAP_DFS | SMB2_GLOBAL_CAP_LEASING | SMB2_GLOBAL_CAP_LARGE_MTU | SMB2_GLOBAL_CAP_PERSISTENT_HANDLES, + .req_capabilities = SMB2_GLOBAL_CAP_DFS | SMB2_GLOBAL_CAP_LEASING | SMB2_GLOBAL_CAP_LARGE_MTU | SMB2_GLOBAL_CAP_PERSISTENT_HANDLES | SMB2_GLOBAL_CAP_ENCRYPTION, .large_lock_type = 0, .exclusive_lock_type = SMB2_LOCKFLAG_EXCLUSIVE_LOCK, .shared_lock_type = SMB2_LOCKFLAG_SHARED_LOCK, diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index 767555518d40..10f8d5cf5681 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -97,10 +97,7 @@ smb2_hdr_assemble(struct smb2_hdr *hdr, __le16 smb2_cmd /* command */ , hdr->smb2_buf_length = cpu_to_be32(parmsize + sizeof(struct smb2_hdr) - 4 /* RFC 1001 length field itself not counted */); - hdr->ProtocolId[0] = 0xFE; - hdr->ProtocolId[1] = 'S'; - hdr->ProtocolId[2] = 'M'; - hdr->ProtocolId[3] = 'B'; + hdr->ProtocolId = SMB2_PROTO_NUMBER; hdr->StructureSize = cpu_to_le16(64); hdr->Command = smb2_cmd; hdr->CreditRequest = cpu_to_le16(2); /* BB make this dynamic */ @@ -1573,7 +1570,8 @@ SMB2_ioctl(const unsigned int xid, struct cifs_tcon *tcon, u64 persistent_fid, goto ioctl_exit; } - memcpy(*out_data, rsp->hdr.ProtocolId + le32_to_cpu(rsp->OutputOffset), + memcpy(*out_data, + (char *)&rsp->hdr.ProtocolId + le32_to_cpu(rsp->OutputOffset), *plen); ioctl_exit: free_rsp_buf(resp_buftype, rsp); @@ -2093,7 +2091,7 @@ SMB2_read(const unsigned int xid, struct cifs_io_parms *io_parms, } if (*buf) { - memcpy(*buf, (char *)rsp->hdr.ProtocolId + rsp->DataOffset, + memcpy(*buf, (char *)&rsp->hdr.ProtocolId + rsp->DataOffset, *nbytes); free_rsp_buf(resp_buftype, iov[0].iov_base); } else if (resp_buftype != CIFS_NO_BUFFER) { diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h index 4af52780ec35..ff88d9feb01e 100644 --- a/fs/cifs/smb2pdu.h +++ b/fs/cifs/smb2pdu.h @@ -86,6 +86,7 @@ #define MAX_SMB2_HDR_SIZE 0x78 /* 4 len + 64 hdr + (2*24 wct) + 2 bct + 2 pad */ #define SMB2_PROTO_NUMBER cpu_to_le32(0x424d53fe) +#define SMB2_TRANSFORM_PROTO_NUM cpu_to_le32(0x424d53fd) /* * SMB2 Header Definition @@ -102,7 +103,7 @@ struct smb2_hdr { __be32 smb2_buf_length; /* big endian on wire */ /* length is only two or three bytes - with one or two byte type preceding it that MBZ */ - __u8 ProtocolId[4]; /* 0xFE 'S' 'M' 'B' */ + __le32 ProtocolId; /* 0xFE 'S' 'M' 'B' */ __le16 StructureSize; /* 64 */ __le16 CreditCharge; /* MBZ */ __le32 Status; /* Error from server */ @@ -128,11 +129,10 @@ struct smb2_transform_hdr { one or two byte type preceding it that MBZ */ __u8 ProtocolId[4]; /* 0xFD 'S' 'M' 'B' */ __u8 Signature[16]; - __u8 Nonce[11]; - __u8 Reserved[5]; + __u8 Nonce[16]; __le32 OriginalMessageSize; __u16 Reserved1; - __le16 EncryptionAlgorithm; + __le16 Flags; /* EncryptionAlgorithm */ __u64 SessionId; } __packed; diff --git a/fs/cifs/smb2proto.h b/fs/cifs/smb2proto.h index 79dc650c18b2..4f07dc93608d 100644 --- a/fs/cifs/smb2proto.h +++ b/fs/cifs/smb2proto.h @@ -34,7 +34,8 @@ struct smb_rqst; ***************************************************************** */ extern int map_smb2_to_linux_error(char *buf, bool log_err); -extern int smb2_check_message(char *buf, unsigned int length); +extern int smb2_check_message(char *buf, unsigned int length, + struct TCP_Server_Info *server); extern unsigned int smb2_calc_size(void *buf); extern char *smb2_get_data_area_len(int *off, int *len, struct smb2_hdr *hdr); extern __le16 *cifs_convert_path_to_utf16(const char *from, diff --git a/fs/cifs/smb2transport.c b/fs/cifs/smb2transport.c index d4c5b6f109a7..8732a43b1008 100644 --- a/fs/cifs/smb2transport.c +++ b/fs/cifs/smb2transport.c @@ -222,8 +222,8 @@ smb2_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server) return rc; } -int -generate_smb3signingkey(struct cifs_ses *ses) +static int generate_key(struct cifs_ses *ses, struct kvec label, + struct kvec context, __u8 *key, unsigned int key_size) { unsigned char zero = 0x0; __u8 i[4] = {0, 0, 0, 1}; @@ -233,7 +233,7 @@ generate_smb3signingkey(struct cifs_ses *ses) unsigned char *hashptr = prfhash; memset(prfhash, 0x0, SMB2_HMACSHA256_SIZE); - memset(ses->smb3signingkey, 0x0, SMB3_SIGNKEY_SIZE); + memset(key, 0x0, key_size); rc = smb3_crypto_shash_allocate(ses->server); if (rc) { @@ -262,7 +262,7 @@ generate_smb3signingkey(struct cifs_ses *ses) } rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash, - "SMB2AESCMAC", 12); + label.iov_base, label.iov_len); if (rc) { cifs_dbg(VFS, "%s: Could not update with label\n", __func__); goto smb3signkey_ret; @@ -276,7 +276,7 @@ generate_smb3signingkey(struct cifs_ses *ses) } rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash, - "SmbSign", 8); + context.iov_base, context.iov_len); if (rc) { cifs_dbg(VFS, "%s: Could not update with context\n", __func__); goto smb3signkey_ret; @@ -296,12 +296,102 @@ generate_smb3signingkey(struct cifs_ses *ses) goto smb3signkey_ret; } - memcpy(ses->smb3signingkey, hashptr, SMB3_SIGNKEY_SIZE); + memcpy(key, hashptr, key_size); smb3signkey_ret: return rc; } +struct derivation { + struct kvec label; + struct kvec context; +}; + +struct derivation_triplet { + struct derivation signing; + struct derivation encryption; + struct derivation decryption; +}; + +static int +generate_smb3signingkey(struct cifs_ses *ses, + const struct derivation_triplet *ptriplet) +{ + int rc; + + rc = generate_key(ses, ptriplet->signing.label, + ptriplet->signing.context, ses->smb3signingkey, + SMB3_SIGN_KEY_SIZE); + if (rc) + return rc; + + rc = generate_key(ses, ptriplet->encryption.label, + ptriplet->encryption.context, ses->smb3encryptionkey, + SMB3_SIGN_KEY_SIZE); + if (rc) + return rc; + + return generate_key(ses, ptriplet->decryption.label, + ptriplet->decryption.context, + ses->smb3decryptionkey, SMB3_SIGN_KEY_SIZE); +} + +int +generate_smb30signingkey(struct cifs_ses *ses) + +{ + struct derivation_triplet triplet; + struct derivation *d; + + d = &triplet.signing; + d->label.iov_base = "SMB2AESCMAC"; + d->label.iov_len = 12; + d->context.iov_base = "SmbSign"; + d->context.iov_len = 8; + + d = &triplet.encryption; + d->label.iov_base = "SMB2AESCCM"; + d->label.iov_len = 11; + d->context.iov_base = "ServerIn "; + d->context.iov_len = 10; + + d = &triplet.decryption; + d->label.iov_base = "SMB2AESCCM"; + d->label.iov_len = 11; + d->context.iov_base = "ServerOut"; + d->context.iov_len = 10; + + return generate_smb3signingkey(ses, &triplet); +} + +int +generate_smb311signingkey(struct cifs_ses *ses) + +{ + struct derivation_triplet triplet; + struct derivation *d; + + d = &triplet.signing; + d->label.iov_base = "SMB2AESCMAC"; + d->label.iov_len = 12; + d->context.iov_base = "SmbSign"; + d->context.iov_len = 8; + + d = &triplet.encryption; + d->label.iov_base = "SMB2AESCCM"; + d->label.iov_len = 11; + d->context.iov_base = "ServerIn "; + d->context.iov_len = 10; + + d = &triplet.decryption; + d->label.iov_base = "SMB2AESCCM"; + d->label.iov_len = 11; + d->context.iov_base = "ServerOut"; + d->context.iov_len = 10; + + return generate_smb3signingkey(ses, &triplet); +} + int smb3_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server) { -- GitLab