From e97cf207fac5e4101376d2a10dd95a93a9a1e0fb Mon Sep 17 00:00:00 2001 From: Andrew Tridgell Date: Fri, 6 Jun 2008 22:10:30 -0700 Subject: added server side SMB2 signing (This used to be commit 8e919dcb0826a5b25d037ee6144af5f7cb21f3ae) --- source4/libcli/smb2/session.c | 8 +++-- source4/libcli/smb2/signing.c | 74 ++++++++++------------------------------- source4/libcli/smb2/transport.c | 32 ++++++++++++------ 3 files changed, 44 insertions(+), 70 deletions(-) (limited to 'source4/libcli') diff --git a/source4/libcli/smb2/session.c b/source4/libcli/smb2/session.c index 54915d8535..42fd4840a1 100644 --- a/source4/libcli/smb2/session.c +++ b/source4/libcli/smb2/session.c @@ -188,11 +188,13 @@ static void session_request_handler(struct smb2_request *req) } if (session->transport->signing.doing_signing) { - c->status = smb2_start_signing(session->transport); - if (!NT_STATUS_IS_OK(c->status)) { - composite_error(c, c->status); + if (session->transport->signing.session_key.length != 16) { + DEBUG(2,("Wrong session key length %u for SMB2 signing\n", + (unsigned)session->transport->signing.session_key.length)); + composite_error(c, NT_STATUS_ACCESS_DENIED); return; } + session->transport->signing.signing_started = true; } composite_done(c); diff --git a/source4/libcli/smb2/signing.c b/source4/libcli/smb2/signing.c index 16c0ff99c1..fb2c22db4e 100644 --- a/source4/libcli/smb2/signing.c +++ b/source4/libcli/smb2/signing.c @@ -25,42 +25,14 @@ #include "libcli/smb2/smb2_calls.h" #include "lib/crypto/crypto.h" -/* - NOTE: this code does not yet interoperate with the windows SMB2 - implementation. We are waiting on feedback on the docs to find out - why - */ - - -/* - setup signing on a transport - */ -NTSTATUS smb2_start_signing(struct smb2_transport *transport) -{ - if (transport->signing.session_key.length != 16) { - DEBUG(2,("Wrong session key length %u for SMB2 signing\n", - (unsigned)transport->signing.session_key.length)); - return NT_STATUS_ACCESS_DENIED; - } - - transport->signing.signing_started = true; - return NT_STATUS_OK; -} - /* sign an outgoing message */ -NTSTATUS smb2_sign_message(struct smb2_request *req) +NTSTATUS smb2_sign_message(struct smb2_request_buffer *buf, DATA_BLOB session_key) { - struct smb2_request_buffer *buf = &req->out; - uint64_t session_id; struct HMACSHA256Context m; uint8_t res[32]; - - if (!req->transport->signing.doing_signing || - !req->transport->signing.signing_started) { - return NT_STATUS_OK; - } + uint64_t session_id; if (buf->size < NBT_HDR_SIZE + SMB2_HDR_SIGNATURE + 16) { /* can't sign non-SMB2 messages */ @@ -74,9 +46,9 @@ NTSTATUS smb2_sign_message(struct smb2_request *req) return NT_STATUS_OK; } - if (req->transport->signing.session_key.length != 16) { + if (session_key.length != 16) { DEBUG(2,("Wrong session key length %u for SMB2 signing\n", - (unsigned)req->transport->signing.session_key.length)); + (unsigned)session_key.length)); return NT_STATUS_ACCESS_DENIED; } @@ -85,7 +57,7 @@ NTSTATUS smb2_sign_message(struct smb2_request *req) SIVAL(buf->hdr, SMB2_HDR_FLAGS, IVAL(buf->hdr, SMB2_HDR_FLAGS) | SMB2_HDR_FLAG_SIGNED); ZERO_STRUCT(m); - hmac_sha256_init(req->transport->signing.session_key.data, 16, &m); + hmac_sha256_init(session_key.data, 16, &m); hmac_sha256_update(buf->buffer+NBT_HDR_SIZE, buf->size-NBT_HDR_SIZE, &m); hmac_sha256_final(res, &m); @@ -93,66 +65,56 @@ NTSTATUS smb2_sign_message(struct smb2_request *req) memcpy(buf->hdr + SMB2_HDR_SIGNATURE, res, 16); - if (DEBUGLVL(5)) { - /* check our own signature */ - smb2_check_signature(req->transport, buf->buffer, buf->size); - } - return NT_STATUS_OK; } /* check an incoming signature */ -NTSTATUS smb2_check_signature(struct smb2_transport *transport, - uint8_t *buffer, uint_t length) +NTSTATUS smb2_check_signature(struct smb2_request_buffer *buf, DATA_BLOB session_key) { uint64_t session_id; struct HMACSHA256Context m; uint8_t res[SHA256_DIGEST_LENGTH]; uint8_t sig[16]; - if (!transport->signing.signing_started || - !transport->signing.doing_signing) { - return NT_STATUS_OK; - } - - if (length < NBT_HDR_SIZE + SMB2_HDR_SIGNATURE + 16) { + if (buf->size < NBT_HDR_SIZE + SMB2_HDR_SIGNATURE + 16) { /* can't check non-SMB2 messages */ return NT_STATUS_OK; } - session_id = BVAL(buffer+NBT_HDR_SIZE, SMB2_HDR_SESSION_ID); + session_id = BVAL(buf->hdr, SMB2_HDR_SESSION_ID); if (session_id == 0) { /* don't sign messages with a zero session_id. See MS-SMB2 3.2.4.1.1 */ return NT_STATUS_OK; } - if (transport->signing.session_key.length == 0) { + if (session_key.length == 0) { /* we don't have the session key yet */ return NT_STATUS_OK; } - if (transport->signing.session_key.length != 16) { + if (session_key.length != 16) { DEBUG(2,("Wrong session key length %u for SMB2 signing\n", - (unsigned)transport->signing.session_key.length)); + (unsigned)session_key.length)); return NT_STATUS_ACCESS_DENIED; } - memcpy(sig, buffer+NBT_HDR_SIZE+SMB2_HDR_SIGNATURE, 16); + memcpy(sig, buf->hdr+SMB2_HDR_SIGNATURE, 16); - memset(buffer + NBT_HDR_SIZE + SMB2_HDR_SIGNATURE, 0, 16); + memset(buf->hdr + SMB2_HDR_SIGNATURE, 0, 16); ZERO_STRUCT(m); - hmac_sha256_init(transport->signing.session_key.data, 16, &m); - hmac_sha256_update(buffer+NBT_HDR_SIZE, length-NBT_HDR_SIZE, &m); + hmac_sha256_init(session_key.data, 16, &m); + hmac_sha256_update(buf->hdr, buf->size-NBT_HDR_SIZE, &m); hmac_sha256_final(res, &m); - memcpy(buffer+NBT_HDR_SIZE+SMB2_HDR_SIGNATURE, sig, 16); + memcpy(buf->hdr+SMB2_HDR_SIGNATURE, sig, 16); if (memcmp(res, sig, 16) != 0) { - DEBUG(0,("Bad SMB2 signature for message of size %u\n", length)); + DEBUG(0,("Bad SMB2 signature for message of size %u\n", + (unsigned)buf->size-NBT_HDR_SIZE)); dump_data(0, sig, 16); dump_data(0, res, 16); return NT_STATUS_ACCESS_DENIED; diff --git a/source4/libcli/smb2/transport.c b/source4/libcli/smb2/transport.c index 561b6e528e..a9a9efb3aa 100644 --- a/source4/libcli/smb2/transport.c +++ b/source4/libcli/smb2/transport.c @@ -205,12 +205,6 @@ static NTSTATUS smb2_transport_finish_recv(void *private, DATA_BLOB blob) goto error; } - status = smb2_check_signature(transport, buffer, len); - if (!NT_STATUS_IS_OK(status)) { - talloc_free(buffer); - return status; - } - flags = IVAL(hdr, SMB2_HDR_FLAGS); seqnum = BVAL(hdr, SMB2_HDR_MESSAGE_ID); @@ -241,6 +235,18 @@ static NTSTATUS smb2_transport_finish_recv(void *private, DATA_BLOB blob) req->in.body_size = req->in.size - (SMB2_HDR_BODY+NBT_HDR_SIZE); req->status = NT_STATUS(IVAL(hdr, SMB2_HDR_STATUS)); + if (transport->signing.signing_started && + transport->signing.doing_signing) { + status = smb2_check_signature(&req->in, + transport->signing.session_key); + if (!NT_STATUS_IS_OK(status)) { + /* the spec says to ignore packets with a bad signature */ + talloc_free(buffer); + return status; + } + } + + if (NT_STATUS_EQUAL(req->status, STATUS_PENDING)) { if (flags & 0x00000002) { req->cancel.can_cancel = true; @@ -346,11 +352,15 @@ void smb2_transport_send(struct smb2_request *req) return; } - status = smb2_sign_message(req); - if (!NT_STATUS_IS_OK(status)) { - req->state = SMB2_REQUEST_ERROR; - req->status = status; - return; + /* possibly sign the message */ + if (req->transport->signing.doing_signing && + req->transport->signing.signing_started) { + status = smb2_sign_message(&req->out, req->transport->signing.session_key); + if (!NT_STATUS_IS_OK(status)) { + req->state = SMB2_REQUEST_ERROR; + req->status = status; + return; + } } blob = data_blob_const(req->out.buffer, req->out.size); -- cgit