s3:ntlmssp: inline ntlmssp_weaken_keys()

metze

Signed-off-by: Günther Deschner <gd@samba.org>

diff --git a/source3/libsmb/ntlmssp.c b/source3/libsmb/ntlmssp.c
index 1ca9810b5d09d33920829d3e2b5befaae737c4a8..4c1fd24e3b8e27622c1f52a0e3a4368b40fc69c0 100644 (file)
--- a/source3/libsmb/ntlmssp.c
+++ b/source3/libsmb/ntlmssp.c
@@ -438,47 +438,6 @@ static void ntlmssp_handle_neg_flags(struct ntlmssp_state *ntlmssp_state,
        }
 }
 
-/**
- Weaken NTLMSSP keys to cope with down-level clients and servers.
-
- We probably should have some parameters to control this, but as
- it only occours for LM_KEY connections, and this is controlled
- by the client lanman auth/lanman auth parameters, it isn't too bad.
-*/
-
-DATA_BLOB ntlmssp_weaken_keys(struct ntlmssp_state *ntlmssp_state, TALLOC_CTX *mem_ctx)
-{
-       DATA_BLOB weakened_key = data_blob_talloc(mem_ctx,
-                                       ntlmssp_state->session_key.data,
-                                       ntlmssp_state->session_key.length);
-
-       /* Nothing to weaken.  We certainly don't want to 'extend' the length... */
-       if (weakened_key.length < 16) {
-               /* perhaps there was no key? */
-               return weakened_key;
-       }
-
-       /* Key weakening not performed on the master key for NTLM2
-          and does not occour for NTLM1.  Therefore we only need
-          to do this for the LM_KEY.
-       */
-
-       if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_LM_KEY) {
-               /* LM key doesn't support 128 bit crypto, so this is
-                * the best we can do.  If you negotiate 128 bit, but
-                * not 56, you end up with 40 bit... */
-               if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_56) {
-                       weakened_key.data[7] = 0xa0;
-               } else { /* forty bits */
-                       weakened_key.data[5] = 0xe5;
-                       weakened_key.data[6] = 0x38;
-                       weakened_key.data[7] = 0xb0;
-               }
-               weakened_key.length = 8;
-       }
-       return weakened_key;
-}
-
 /**
  * Next state function for the Negotiate packet
  *

diff --git a/source3/libsmb/ntlmssp_sign.c b/source3/libsmb/ntlmssp_sign.c
index e3d53ab137945561ea3b122ec0c792a61fe3a07e..26d35f99805943bde0bf3179882a22111c3be237 100644 (file)
--- a/source3/libsmb/ntlmssp_sign.c
+++ b/source3/libsmb/ntlmssp_sign.c
@@ -331,18 +331,10 @@ NTSTATUS ntlmssp_unseal_packet(struct ntlmssp_state *ntlmssp_state,
 */
 NTSTATUS ntlmssp_sign_init(struct ntlmssp_state *ntlmssp_state)
 {
-       TALLOC_CTX *mem_ctx;
-
-       mem_ctx = talloc_init("weak_keys");
-       if (!mem_ctx) {
-               return NT_STATUS_NO_MEMORY;
-       }
-
        DEBUG(3, ("NTLMSSP Sign/Seal - Initialising with flags:\n"));
        debug_ntlmssp_flags(ntlmssp_state->neg_flags);
 
        if (ntlmssp_state->session_key.length < 8) {
-               TALLOC_FREE(mem_ctx);
                DEBUG(3, ("NO session key, cannot intialise signing\n"));
                return NT_STATUS_NO_USER_SESSION_KEY;
        }
@@ -374,7 +366,6 @@ NTSTATUS ntlmssp_sign_init(struct ntlmssp_state *ntlmssp_state)
                        recv_seal_const = CLI_SEAL;
                        break;
                default:
-                       TALLOC_FREE(mem_ctx);
                        return NT_STATUS_INTERNAL_ERROR;
                }
 
@@ -434,33 +425,50 @@ NTSTATUS ntlmssp_sign_init(struct ntlmssp_state *ntlmssp_state)
 
 
        } else {
-#if 0
-               /* Hmmm. Shouldn't we also weaken keys for ntlmv1 ? JRA. */
+               uint8_t weak_session_key[8];
+               DATA_BLOB seal_session_key = ntlmssp_state->session_key;
+               bool do_weak = false;
 
-               DATA_BLOB weak_session_key = ntlmssp_state->session_key;
-               /**
-                 Weaken NTLMSSP keys to cope with down-level clients, servers and export restrictions.
-                 We probably should have some parameters to control this, once we get NTLM2 working.
-               */
+               DEBUG(5, ("NTLMSSP Sign/Seal - using NTLM1\n"));
 
-               if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_128) {
-                       ;
-               } else if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_56) {
-                       weak_session_key.length = 6;
-               } else { /* forty bits */
-                       weak_session_key.length = 5;
+               /*
+                * Key weakening not performed on the master key for NTLM2
+                * and does not occour for NTLM1. Therefore we only need
+                * to do this for the LM_KEY.
+                */
+               if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_LM_KEY) {
+                       do_weak = true;
                }
-               dump_data_pw("NTLMSSP weakend master key:\n",
-                               weak_session_key.data,
-                               weak_session_key.length);
-#endif
 
-               DATA_BLOB weak_session_key = ntlmssp_weaken_keys(ntlmssp_state, mem_ctx);
+               /*
+                * Nothing to weaken.
+                * We certainly don't want to 'extend' the length...
+                */
+               if (seal_session_key.length < 16) {
+                       /* TODO: is this really correct? */
+                       do_weak = false;
+               }
 
-               DEBUG(5, ("NTLMSSP Sign/Seal - using NTLM1\n"));
+               if (do_weak) {
+                       memcpy(weak_session_key, seal_session_key.data, 8);
+                       seal_session_key = data_blob_const(weak_session_key, 8);
+
+                       /*
+                        * LM key doesn't support 128 bit crypto, so this is
+                        * the best we can do. If you negotiate 128 bit, but
+                        * not 56, you end up with 40 bit...
+                        */
+                       if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_56) {
+                               weak_session_key[7] = 0xa0;
+                       } else { /* forty bits */
+                               weak_session_key[5] = 0xe5;
+                               weak_session_key[6] = 0x38;
+                               weak_session_key[7] = 0xb0;
+                       }
+               }
 
                arcfour_init(&ntlmssp_state->ntlmv1_arc4_state,
-                            &weak_session_key);
+                            &seal_session_key);
 
                 dump_arc4_state("NTLMv1 arc4 state:\n",
                                &ntlmssp_state->ntlmv1_arc4_state);
@@ -468,6 +476,5 @@ NTSTATUS ntlmssp_sign_init(struct ntlmssp_state *ntlmssp_state)
                ntlmssp_state->ntlmv1_seq_num = 0;
        }
 
-       TALLOC_FREE(mem_ctx);
        return NT_STATUS_OK;
 }