libcli/auth Make the source3/ implementation of the NTLMSSP server common
[amitay/samba.git] / libcli / auth / ntlmssp_server.c
index 30b5541880966aa9be093ed3a246418df9df0cbe..844a0b4a5d1e193fc727b4cdff3dab23a9ee2389 100644 (file)
 #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;
+}