From 75adca63f21ab4b415e0f909a54972d8dd57a153 Mon Sep 17 00:00:00 2001 From: Andrew Bartlett Date: Fri, 6 Aug 2010 21:31:21 +1000 Subject: libcli/auth Make the source3/ implementation of the NTLMSSP server common MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This means that the core logic (but not the initialisation) of the NTLMSSP server is in common, but uses different authentication backends. Andrew Bartlett Signed-off-by: Günther Deschner --- libcli/auth/ntlmssp_server.c | 524 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 524 insertions(+) (limited to 'libcli/auth/ntlmssp_server.c') diff --git a/libcli/auth/ntlmssp_server.c b/libcli/auth/ntlmssp_server.c index 30b5541880..844a0b4a5d 100644 --- a/libcli/auth/ntlmssp_server.c +++ b/libcli/auth/ntlmssp_server.c @@ -23,6 +23,10 @@ #include "includes.h" #include "../libcli/auth/ntlmssp.h" #include "../libcli/auth/ntlmssp_private.h" +#include "../librpc/gen_ndr/ndr_ntlmssp.h" +#include "../libcli/auth/ntlmssp_ndr.h" +#include "../libcli/auth/libcli_auth.h" +#include "../lib/crypto/crypto.h" /** * Determine correct target name flags for reply, given server role @@ -51,3 +55,523 @@ const char *ntlmssp_target_name(struct ntlmssp_state *ntlmssp_state, return ""; } } + +/** + * Next state function for the Negotiate packet + * + * @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. + */ + +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; + uint32_t neg_flags = 0; + uint32_t ntlmssp_command, chal_flags; + uint8_t cryptkey[8]; + const char *target_name; + NTSTATUS status; + + /* parse the NTLMSSP packet */ +#if 0 + file_save("ntlmssp_negotiate.dat", request.data, request.length); +#endif + + if (request.length) { + if ((request.length < 16) || !msrpc_parse(ntlmssp_state, &request, "Cdd", + "NTLMSSP", + &ntlmssp_command, + &neg_flags)) { + DEBUG(1, ("ntlmssp_server_negotiate: failed to parse NTLMSSP Negotiate of length %u\n", + (unsigned int)request.length)); + dump_data(2, request.data, request.length); + return NT_STATUS_INVALID_PARAMETER; + } + debug_ntlmssp_flags(neg_flags); + + if (DEBUGLEVEL >= 10) { + struct NEGOTIATE_MESSAGE *negotiate = talloc( + ntlmssp_state, struct NEGOTIATE_MESSAGE); + if (negotiate != NULL) { + status = ntlmssp_pull_NEGOTIATE_MESSAGE( + &request, negotiate, negotiate); + if (NT_STATUS_IS_OK(status)) { + NDR_PRINT_DEBUG(NEGOTIATE_MESSAGE, + negotiate); + } + TALLOC_FREE(negotiate); + } + } + } + + ntlmssp_handle_neg_flags(ntlmssp_state, neg_flags, ntlmssp_state->allow_lm_key); + + /* Ask our caller what challenge they would like in the packet */ + status = ntlmssp_state->get_challenge(ntlmssp_state, cryptkey); + if (!NT_STATUS_IS_OK(status)) { + DEBUG(1, ("ntlmssp_server_negotiate: backend doesn't give a challenge: %s\n", + nt_errstr(status))); + return status; + } + + /* Check if we may set the challenge */ + if (!ntlmssp_state->may_set_challenge(ntlmssp_state)) { + ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_NTLM2; + } + + /* The flags we send back are not just the negotiated flags, + * they are also 'what is in this packet'. Therfore, we + * operate on 'chal_flags' from here on + */ + + chal_flags = ntlmssp_state->neg_flags; + + /* get the right name to fill in as 'target' */ + target_name = ntlmssp_target_name(ntlmssp_state, + neg_flags, &chal_flags); + if (target_name == NULL) + return NT_STATUS_INVALID_PARAMETER; + + ntlmssp_state->chal = data_blob_talloc(ntlmssp_state, cryptkey, 8); + ntlmssp_state->internal_chal = data_blob_talloc(ntlmssp_state, + cryptkey, 8); + + /* This creates the 'blob' of names that appears at the end of the packet */ + if (chal_flags & NTLMSSP_NEGOTIATE_TARGET_INFO) + { + msrpc_gen(ntlmssp_state, &struct_blob, "aaaaa", + MsvAvNbDomainName, target_name, + MsvAvNbComputerName, ntlmssp_state->server.netbios_name, + MsvAvDnsDomainName, ntlmssp_state->server.dns_domain, + MsvAvDnsComputerName, ntlmssp_state->server.dns_name, + MsvAvEOL, ""); + } else { + struct_blob = data_blob_null; + } + + { + /* Marshal the packet in the right format, be it unicode or ASCII */ + const char *gen_string; + DATA_BLOB version_blob = data_blob_null; + + if (chal_flags & NTLMSSP_NEGOTIATE_VERSION) { + enum ndr_err_code err; + struct VERSION vers; + + /* "What Windows returns" as a version number. */ + ZERO_STRUCT(vers); + vers.ProductMajorVersion = NTLMSSP_WINDOWS_MAJOR_VERSION_6; + vers.ProductMinorVersion = NTLMSSP_WINDOWS_MINOR_VERSION_1; + vers.ProductBuild = 0; + vers.NTLMRevisionCurrent = NTLMSSP_REVISION_W2K3; + + err = ndr_push_struct_blob(&version_blob, + ntlmssp_state, + &vers, + (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; + } + } + + if (ntlmssp_state->unicode) { + gen_string = "CdUdbddBb"; + } else { + gen_string = "CdAdbddBb"; + } + + msrpc_gen(out_mem_ctx, reply, gen_string, + "NTLMSSP", + NTLMSSP_CHALLENGE, + target_name, + chal_flags, + cryptkey, 8, + 0, 0, + struct_blob.data, struct_blob.length, + version_blob.data, version_blob.length); + + data_blob_free(&version_blob); + + if (DEBUGLEVEL >= 10) { + struct CHALLENGE_MESSAGE *challenge = talloc( + ntlmssp_state, struct CHALLENGE_MESSAGE); + if (challenge != NULL) { + challenge->NegotiateFlags = chal_flags; + status = ntlmssp_pull_CHALLENGE_MESSAGE( + reply, challenge, challenge); + if (NT_STATUS_IS_OK(status)) { + NDR_PRINT_DEBUG(CHALLENGE_MESSAGE, + challenge); + } + TALLOC_FREE(challenge); + } + } + } + + data_blob_free(&struct_blob); + + ntlmssp_state->expected_state = NTLMSSP_AUTH; + + 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 + * @return Errors or NT_STATUS_OK. + */ + +static NTSTATUS ntlmssp_server_preauth(struct ntlmssp_state *ntlmssp_state, + struct ntlmssp_server_auth_state *state, + const DATA_BLOB request) +{ + uint32_t ntlmssp_command, auth_flags; + NTSTATUS nt_status; + + uint8_t session_nonce_hash[16]; + + const char *parse_string; + +#if 0 + file_save("ntlmssp_auth.dat", request.data, request.length); +#endif + + if (ntlmssp_state->unicode) { + parse_string = "CdBBUUUBd"; + } else { + 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, + "NTLMSSP", + &ntlmssp_command, + &ntlmssp_state->lm_resp, + &ntlmssp_state->nt_resp, + &ntlmssp_state->domain, + &ntlmssp_state->user, + &ntlmssp_state->client.netbios_name, + &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) */ + if (ntlmssp_state->unicode) { + parse_string = "CdBBUUU"; + } else { + parse_string = "CdBBAAA"; + } + + /* now the NTLMSSP encoded auth hashes */ + if (!msrpc_parse(ntlmssp_state, &request, parse_string, + "NTLMSSP", + &ntlmssp_command, + &ntlmssp_state->lm_resp, + &ntlmssp_state->nt_resp, + &ntlmssp_state->domain, + &ntlmssp_state->user, + &ntlmssp_state->client.netbios_name)) { + DEBUG(1, ("ntlmssp_server_auth: failed to parse NTLMSSP (tried both formats):\n")); + dump_data(2, request.data, request.length); + + return NT_STATUS_INVALID_PARAMETER; + } + } + + talloc_steal(state, state->encrypted_session_key.data); + + if (auth_flags) + ntlmssp_handle_neg_flags(ntlmssp_state, auth_flags, ntlmssp_state->allow_lm_key); + + if (DEBUGLEVEL >= 10) { + struct AUTHENTICATE_MESSAGE *authenticate = talloc( + ntlmssp_state, struct AUTHENTICATE_MESSAGE); + if (authenticate != NULL) { + NTSTATUS status; + authenticate->NegotiateFlags = auth_flags; + status = ntlmssp_pull_AUTHENTICATE_MESSAGE( + &request, authenticate, authenticate); + if (NT_STATUS_IS_OK(status)) { + NDR_PRINT_DEBUG(AUTHENTICATE_MESSAGE, + authenticate); + } + TALLOC_FREE(authenticate); + } + } + + DEBUG(3,("Got user=[%s] domain=[%s] workstation=[%s] len1=%lu len2=%lu\n", + ntlmssp_state->user, ntlmssp_state->domain, + ntlmssp_state->client.netbios_name, + (unsigned long)ntlmssp_state->lm_resp.length, + (unsigned long)ntlmssp_state->nt_resp.length)); + +#if 0 + file_save("nthash1.dat", &ntlmssp_state->nt_resp.data, &ntlmssp_state->nt_resp.length); + file_save("lmhash1.dat", &ntlmssp_state->lm_resp.data, &ntlmssp_state->lm_resp.length); +#endif + + /* NTLM2 uses a 'challenge' that is made of up both the server challenge, and a + client challenge + + However, the NTLM2 flag may still be set for the real NTLMv2 logins, be careful. + */ + 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; + state->doing_ntlm2 = true; + + memcpy(state->session_nonce, ntlmssp_state->internal_chal.data, 8); + memcpy(&state->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, state->session_nonce, 16); + MD5Final(session_nonce_hash, &md5_session_nonce_ctx); + + ntlmssp_state->chal = data_blob_talloc( + ntlmssp_state, session_nonce_hash, 8); + + /* LM response is no longer useful */ + data_blob_free(&ntlmssp_state->lm_resp); + + /* We changed the effective challenge - set it */ + if (!NT_STATUS_IS_OK(nt_status = ntlmssp_state->set_challenge(ntlmssp_state, &ntlmssp_state->chal))) { + return nt_status; + } + + /* LM Key is incompatible. */ + ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_LM_KEY; + } + } + return NT_STATUS_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. + */ + +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 (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, 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); + + } else { + DEBUG(10,("ntlmssp_server_auth: Failed to create NTLM2 session key.\n")); + session_key = data_blob_null; + } + } else if ((ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_LM_KEY) + /* Ensure we can never get here on NTLMv2 */ + && (ntlmssp_state->nt_resp.length == 0 || ntlmssp_state->nt_resp.length == 24)) { + + if (lm_session_key.data && lm_session_key.length >= 8) { + if (ntlmssp_state->lm_resp.data && ntlmssp_state->lm_resp.length == 24) { + session_key = data_blob_talloc(ntlmssp_state, + NULL, 16); + if (session_key.data == NULL) { + return NT_STATUS_NO_MEMORY; + } + SMBsesskeygen_lm_sess_key(lm_session_key.data, ntlmssp_state->lm_resp.data, + session_key.data); + DEBUG(10,("ntlmssp_server_auth: Created NTLM session key.\n")); + } else { + static const uint8_t zeros[24] = {0, }; + session_key = data_blob_talloc( + ntlmssp_state, NULL, 16); + if (session_key.data == NULL) { + return NT_STATUS_NO_MEMORY; + } + SMBsesskeygen_lm_sess_key(zeros, zeros, + session_key.data); + DEBUG(10,("ntlmssp_server_auth: Created NTLM session key.\n")); + } + dump_data_pw("LM session key:\n", session_key.data, + session_key.length); + } else { + /* LM Key not selected */ + ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_LM_KEY; + + 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")); + dump_data_pw("unmodified session key:\n", session_key.data, session_key.length); + + /* LM Key not selected */ + ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_LM_KEY; + + } else if (lm_session_key.data) { + /* Very weird to have LM key, but no user session key, but anyway.. */ + session_key = lm_session_key; + DEBUG(10,("ntlmssp_server_auth: Using unmodified lm session key.\n")); + dump_data_pw("unmodified session key:\n", session_key.data, session_key.length); + + /* LM Key not selected */ + ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_LM_KEY; + + } else { + DEBUG(10,("ntlmssp_server_auth: Failed to create unmodified session key.\n")); + session_key = data_blob_null; + + /* LM Key not selected */ + ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_LM_KEY; + } + + /* 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 (!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)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", + 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; + } + + if (ntlmssp_state->session_key.length) { + nt_status = ntlmssp_sign_init(ntlmssp_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 + */ + +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; +} -- cgit