From 979b672dcb013ed38a312b280fa6c0642469649b Mon Sep 17 00:00:00 2001 From: Andrew Bartlett Date: Fri, 6 Aug 2010 20:53:39 +1000 Subject: s3:ntlmssp Split the NTLMSSP server into before and after authentication MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This allows for a future where the auth subsystem is async, and the session key generation needs to happen in a callback. This code is originally reworked into this style by metze for the source4/ implementation. The other change here is to introduce an 'out_mem_ctx', which makes the API match that used in source4. Andrew Bartlett Signed-off-by: Günther Deschner --- source3/libsmb/ntlmssp.c | 210 +++++++++++++++++++++++++++++++++-------------- 1 file changed, 148 insertions(+), 62 deletions(-) diff --git a/source3/libsmb/ntlmssp.c b/source3/libsmb/ntlmssp.c index 6815358447..d393404c1e 100644 --- a/source3/libsmb/ntlmssp.c +++ b/source3/libsmb/ntlmssp.c @@ -4,8 +4,8 @@ handle NLTMSSP, server side Copyright (C) Andrew Tridgell 2001 - Copyright (C) Andrew Bartlett 2001-2003 - Copyright (C) Andrew Bartlett 2005 (Updated from gensec). + Copyright (C) Andrew Bartlett 2001-2010 + Copyright (C) Stefan Metzmacher 2005 This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -32,12 +32,16 @@ #include "../lib/crypto/hmacmd5.h" static NTSTATUS ntlmssp_client_initial(struct ntlmssp_state *ntlmssp_state, + TALLOC_CTX *out_mem_ctx, /* Unused at this time */ DATA_BLOB reply, DATA_BLOB *next_request); static NTSTATUS ntlmssp_server_negotiate(struct ntlmssp_state *ntlmssp_state, + TALLOC_CTX *out_mem_ctx, const DATA_BLOB in, DATA_BLOB *out); static NTSTATUS ntlmssp_client_challenge(struct ntlmssp_state *ntlmssp_state, + TALLOC_CTX *out_mem_ctx, /* Unused at this time */ const DATA_BLOB reply, DATA_BLOB *next_request); static NTSTATUS ntlmssp_server_auth(struct ntlmssp_state *ntlmssp_state, + TALLOC_CTX *out_mem_ctx, const DATA_BLOB request, DATA_BLOB *reply); /** @@ -49,6 +53,7 @@ static const struct ntlmssp_callbacks { enum ntlmssp_role role; enum ntlmssp_message_type ntlmssp_command; NTSTATUS (*fn)(struct ntlmssp_state *ntlmssp_state, + TALLOC_CTX *out_mem_ctx, DATA_BLOB in, DATA_BLOB *out); } ntlmssp_callbacks[] = { {NTLMSSP_CLIENT, NTLMSSP_INITIAL, ntlmssp_client_initial}, @@ -264,7 +269,7 @@ NTSTATUS ntlmssp_update(struct ntlmssp_state *ntlmssp_state, for (i=0; ntlmssp_callbacks[i].fn; i++) { if (ntlmssp_callbacks[i].role == ntlmssp_state->role && ntlmssp_callbacks[i].ntlmssp_command == ntlmssp_command) { - return ntlmssp_callbacks[i].fn(ntlmssp_state, input, out); + return ntlmssp_callbacks[i].fn(ntlmssp_state, ntlmssp_state, input, out); } } @@ -277,13 +282,15 @@ NTSTATUS ntlmssp_update(struct ntlmssp_state *ntlmssp_state, /** * Next state function for the Negotiate packet * - * @param ntlmssp_state NTLMSSP State - * @param request The request, as a DATA_BLOB - * @param request The reply, as an allocated DATA_BLOB, caller to free. - * @return Errors or MORE_PROCESSING_REQUIRED if a reply is sent. + * @param ntlmssp_state NTLMSSP state + * @param out_mem_ctx Memory context for *out + * @param in The request, as a DATA_BLOB. reply.data must be NULL + * @param out The reply, as an allocated DATA_BLOB, caller to free. + * @return Errors or MORE_PROCESSING_REQUIRED if (normal) a reply is required. */ static NTSTATUS ntlmssp_server_negotiate(struct ntlmssp_state *ntlmssp_state, + TALLOC_CTX *out_mem_ctx, const DATA_BLOB request, DATA_BLOB *reply) { DATA_BLOB struct_blob; @@ -312,7 +319,7 @@ static NTSTATUS ntlmssp_server_negotiate(struct ntlmssp_state *ntlmssp_state, if (DEBUGLEVEL >= 10) { struct NEGOTIATE_MESSAGE *negotiate = talloc( - talloc_tos(), struct NEGOTIATE_MESSAGE); + ntlmssp_state, struct NEGOTIATE_MESSAGE); if (negotiate != NULL) { status = ntlmssp_pull_NEGOTIATE_MESSAGE( &request, negotiate, negotiate); @@ -392,6 +399,7 @@ static NTSTATUS ntlmssp_server_negotiate(struct ntlmssp_state *ntlmssp_state, (ndr_push_flags_fn_t)ndr_push_VERSION); if (!NDR_ERR_CODE_IS_SUCCESS(err)) { + data_blob_free(&struct_blob); return NT_STATUS_NO_MEMORY; } } @@ -402,7 +410,7 @@ static NTSTATUS ntlmssp_server_negotiate(struct ntlmssp_state *ntlmssp_state, gen_string = "CdAdbddBb"; } - msrpc_gen(ntlmssp_state, reply, gen_string, + msrpc_gen(out_mem_ctx, reply, gen_string, "NTLMSSP", NTLMSSP_CHALLENGE, target_name, @@ -437,36 +445,35 @@ static NTSTATUS ntlmssp_server_negotiate(struct ntlmssp_state *ntlmssp_state, return NT_STATUS_MORE_PROCESSING_REQUIRED; } +struct ntlmssp_server_auth_state { + DATA_BLOB user_session_key; + DATA_BLOB lm_session_key; + /* internal variables used by KEY_EXCH (client-supplied user session key */ + DATA_BLOB encrypted_session_key; + bool doing_ntlm2; + /* internal variables used by NTLM2 */ + uint8_t session_nonce[16]; +}; + /** * Next state function for the Authenticate packet * * @param ntlmssp_state NTLMSSP State * @param request The request, as a DATA_BLOB - * @param request The reply, as an allocated DATA_BLOB, caller to free. * @return Errors or NT_STATUS_OK. */ -static NTSTATUS ntlmssp_server_auth(struct ntlmssp_state *ntlmssp_state, - const DATA_BLOB request, DATA_BLOB *reply) +static NTSTATUS ntlmssp_server_preauth(struct ntlmssp_state *ntlmssp_state, + struct ntlmssp_server_auth_state *state, + const DATA_BLOB request) { - DATA_BLOB encrypted_session_key = data_blob_null; - DATA_BLOB user_session_key = data_blob_null; - DATA_BLOB lm_session_key = data_blob_null; - DATA_BLOB session_key = data_blob_null; uint32_t ntlmssp_command, auth_flags; - NTSTATUS nt_status = NT_STATUS_OK; + NTSTATUS nt_status; - /* used by NTLM2 */ - bool doing_ntlm2 = False; - - uint8_t session_nonce[16]; uint8_t session_nonce_hash[16]; const char *parse_string; - /* parse the NTLMSSP packet */ - *reply = data_blob_null; - #if 0 file_save("ntlmssp_auth.dat", request.data, request.length); #endif @@ -477,11 +484,14 @@ static NTSTATUS ntlmssp_server_auth(struct ntlmssp_state *ntlmssp_state, parse_string = "CdBBAAABd"; } + /* zero these out */ + data_blob_free(&ntlmssp_state->session_key); data_blob_free(&ntlmssp_state->lm_resp); data_blob_free(&ntlmssp_state->nt_resp); ntlmssp_state->user = NULL; ntlmssp_state->domain = NULL; + ntlmssp_state->client.netbios_name = NULL; /* now the NTLMSSP encoded auth hashes */ if (!msrpc_parse(ntlmssp_state, &request, parse_string, @@ -492,8 +502,13 @@ static NTSTATUS ntlmssp_server_auth(struct ntlmssp_state *ntlmssp_state, &ntlmssp_state->domain, &ntlmssp_state->user, &ntlmssp_state->client.netbios_name, - &encrypted_session_key, + &state->encrypted_session_key, &auth_flags)) { + DEBUG(10, ("ntlmssp_server_auth: failed to parse NTLMSSP (nonfatal):\n")); + dump_data(10, request.data, request.length); + + /* zero this out */ + data_blob_free(&state->encrypted_session_key); auth_flags = 0; /* Try again with a shorter string (Win9X truncates this packet) */ @@ -519,6 +534,8 @@ static NTSTATUS ntlmssp_server_auth(struct ntlmssp_state *ntlmssp_state, } } + talloc_steal(state, state->encrypted_session_key.data); + if (auth_flags) ntlmssp_handle_neg_flags(ntlmssp_state, auth_flags, ntlmssp_state->allow_lm_key); @@ -557,15 +574,15 @@ static NTSTATUS ntlmssp_server_auth(struct ntlmssp_state *ntlmssp_state, if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) { if (ntlmssp_state->nt_resp.length == 24 && ntlmssp_state->lm_resp.length == 24) { struct MD5Context md5_session_nonce_ctx; - SMB_ASSERT(ntlmssp_state->internal_chal.data && ntlmssp_state->internal_chal.length == 8); + state->doing_ntlm2 = true; - doing_ntlm2 = True; + memcpy(state->session_nonce, ntlmssp_state->internal_chal.data, 8); + memcpy(&state->session_nonce[8], ntlmssp_state->lm_resp.data, 8); - memcpy(session_nonce, ntlmssp_state->internal_chal.data, 8); - memcpy(&session_nonce[8], ntlmssp_state->lm_resp.data, 8); + SMB_ASSERT(ntlmssp_state->internal_chal.data && ntlmssp_state->internal_chal.length == 8); MD5Init(&md5_session_nonce_ctx); - MD5Update(&md5_session_nonce_ctx, session_nonce, 16); + MD5Update(&md5_session_nonce_ctx, state->session_nonce, 16); MD5Final(session_nonce_hash, &md5_session_nonce_ctx); ntlmssp_state->chal = data_blob_talloc( @@ -576,7 +593,6 @@ static NTSTATUS ntlmssp_server_auth(struct ntlmssp_state *ntlmssp_state, /* We changed the effective challenge - set it */ if (!NT_STATUS_IS_OK(nt_status = ntlmssp_state->set_challenge(ntlmssp_state, &ntlmssp_state->chal))) { - data_blob_free(&encrypted_session_key); return nt_status; } @@ -584,32 +600,35 @@ static NTSTATUS ntlmssp_server_auth(struct ntlmssp_state *ntlmssp_state, ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_LM_KEY; } } + return NT_STATUS_OK; +} - /* - * Note we don't check here for NTLMv2 auth settings. If NTLMv2 auth - * is required (by "ntlm auth = no" and "lm auth = no" being set in the - * smb.conf file) and no NTLMv2 response was sent then the password check - * will fail here. JRA. - */ - - /* Finally, actually ask if the password is OK */ +/** + * Next state function for the Authenticate packet + * (after authentication - figures out the session keys etc) + * + * @param ntlmssp_state NTLMSSP State + * @return Errors or NT_STATUS_OK. + */ - if (!NT_STATUS_IS_OK(nt_status = ntlmssp_state->check_password(ntlmssp_state, - &user_session_key, &lm_session_key))) { - data_blob_free(&encrypted_session_key); - return nt_status; - } +static NTSTATUS ntlmssp_server_postauth(struct ntlmssp_state *ntlmssp_state, + struct ntlmssp_server_auth_state *state) +{ + DATA_BLOB user_session_key = state->user_session_key; + DATA_BLOB lm_session_key = state->lm_session_key; + NTSTATUS nt_status; + DATA_BLOB session_key = data_blob(NULL, 0); dump_data_pw("NT session key:\n", user_session_key.data, user_session_key.length); dump_data_pw("LM first-8:\n", lm_session_key.data, lm_session_key.length); /* Handle the different session key derivation for NTLM2 */ - if (doing_ntlm2) { + if (state->doing_ntlm2) { if (user_session_key.data && user_session_key.length == 16) { session_key = data_blob_talloc(ntlmssp_state, NULL, 16); - hmac_md5(user_session_key.data, session_nonce, - sizeof(session_nonce), session_key.data); + hmac_md5(user_session_key.data, state->session_nonce, + sizeof(state->session_nonce), session_key.data); DEBUG(10,("ntlmssp_server_auth: Created NTLM2 session key.\n")); dump_data_pw("NTLM2 session key:\n", session_key.data, session_key.length); @@ -651,6 +670,7 @@ static NTSTATUS ntlmssp_server_auth(struct ntlmssp_state *ntlmssp_state, DEBUG(10,("ntlmssp_server_auth: Failed to create NTLM session key.\n")); session_key = data_blob_null; } + } else if (user_session_key.data) { session_key = user_session_key; DEBUG(10,("ntlmssp_server_auth: Using unmodified nt session key.\n")); @@ -679,25 +699,30 @@ static NTSTATUS ntlmssp_server_auth(struct ntlmssp_state *ntlmssp_state, /* With KEY_EXCH, the client supplies the proposed session key, but encrypts it with the long-term key */ if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_KEY_EXCH) { - if (!encrypted_session_key.data || encrypted_session_key.length != 16) { - data_blob_free(&encrypted_session_key); + if (!state->encrypted_session_key.data + || state->encrypted_session_key.length != 16) { + data_blob_free(&state->encrypted_session_key); DEBUG(1, ("Client-supplied KEY_EXCH session key was of invalid length (%u)!\n", - (unsigned int)encrypted_session_key.length)); + (unsigned)state->encrypted_session_key.length)); return NT_STATUS_INVALID_PARAMETER; } else if (!session_key.data || session_key.length != 16) { DEBUG(5, ("server session key is invalid (len == %u), cannot do KEY_EXCH!\n", (unsigned int)session_key.length)); ntlmssp_state->session_key = session_key; } else { - dump_data_pw("KEY_EXCH session key (enc):\n", encrypted_session_key.data, encrypted_session_key.length); - arcfour_crypt_blob(encrypted_session_key.data, - encrypted_session_key.length, - &session_key); - ntlmssp_state->session_key = data_blob_talloc( - ntlmssp_state, encrypted_session_key.data, - encrypted_session_key.length); - dump_data_pw("KEY_EXCH session key:\n", encrypted_session_key.data, - encrypted_session_key.length); + dump_data_pw("KEY_EXCH session key (enc):\n", + state->encrypted_session_key.data, + state->encrypted_session_key.length); + arcfour_crypt(state->encrypted_session_key.data, + session_key.data, + state->encrypted_session_key.length); + ntlmssp_state->session_key = data_blob_talloc(ntlmssp_state, + state->encrypted_session_key.data, + state->encrypted_session_key.length); + dump_data_pw("KEY_EXCH session key:\n", + state->encrypted_session_key.data, + state->encrypted_session_key.length); + talloc_free(session_key.data); } } else { ntlmssp_state->session_key = session_key; @@ -707,14 +732,73 @@ static NTSTATUS ntlmssp_server_auth(struct ntlmssp_state *ntlmssp_state, nt_status = ntlmssp_sign_init(ntlmssp_state); } - data_blob_free(&encrypted_session_key); - - /* Only one authentication allowed per server state. */ ntlmssp_state->expected_state = NTLMSSP_DONE; return nt_status; } + +/** + * Next state function for the Authenticate packet + * + * @param gensec_security GENSEC state + * @param out_mem_ctx Memory context for *out + * @param in The request, as a DATA_BLOB. reply.data must be NULL + * @param out The reply, as an allocated DATA_BLOB, caller to free. + * @return Errors or NT_STATUS_OK if authentication sucessful + */ + +static NTSTATUS ntlmssp_server_auth(struct ntlmssp_state *ntlmssp_state, + TALLOC_CTX *out_mem_ctx, + const DATA_BLOB in, DATA_BLOB *out) +{ + struct ntlmssp_server_auth_state *state; + NTSTATUS nt_status; + + /* zero the outbound NTLMSSP packet */ + *out = data_blob_null; + + state = talloc_zero(ntlmssp_state, struct ntlmssp_server_auth_state); + if (state == NULL) { + return NT_STATUS_NO_MEMORY; + } + + nt_status = ntlmssp_server_preauth(ntlmssp_state, state, in); + if (!NT_STATUS_IS_OK(nt_status)) { + TALLOC_FREE(state); + return nt_status; + } + + /* + * Note we don't check here for NTLMv2 auth settings. If NTLMv2 auth + * is required (by "ntlm auth = no" and "lm auth = no" being set in the + * smb.conf file) and no NTLMv2 response was sent then the password check + * will fail here. JRA. + */ + + /* Finally, actually ask if the password is OK */ + nt_status = ntlmssp_state->check_password(ntlmssp_state, + &state->user_session_key, + &state->lm_session_key); + if (!NT_STATUS_IS_OK(nt_status)) { + TALLOC_FREE(state); + return nt_status; + } + + /* When we get more async in the auth code behind + ntlmssp_state->check_password, the ntlmssp_server_postpath + can be done in a callback */ + + nt_status = ntlmssp_server_postauth(ntlmssp_state, state); + if (!NT_STATUS_IS_OK(nt_status)) { + TALLOC_FREE(state); + return nt_status; + } + + TALLOC_FREE(state); + return NT_STATUS_OK; +} + /** * Create an NTLMSSP state machine * @@ -814,6 +898,7 @@ NTSTATUS ntlmssp_server_start(TALLOC_CTX *mem_ctx, */ static NTSTATUS ntlmssp_client_initial(struct ntlmssp_state *ntlmssp_state, + TALLOC_CTX *out_mem_ctx, /* Unused at this time */ DATA_BLOB reply, DATA_BLOB *next_request) { if (ntlmssp_state->unicode) { @@ -864,6 +949,7 @@ static NTSTATUS ntlmssp_client_initial(struct ntlmssp_state *ntlmssp_state, */ static NTSTATUS ntlmssp_client_challenge(struct ntlmssp_state *ntlmssp_state, + TALLOC_CTX *out_mem_ctx, /* Unused at this time */ const DATA_BLOB reply, DATA_BLOB *next_request) { uint32_t chal_flags, ntlmssp_command, unkn1, unkn2; -- cgit