Don't copy auth states on receipt of a COMMIT message

Similarly to the previous commit, if we receive a COMMIT message, we
should just use it to start a new SIGMA protocol, rather than comparing
it against the old COMMIT message we may have still lying around.  This
completely removes the need for the otrl_auth_copy_on_commit function.

src/auth.c

@@ -1426,41 +1426,6 @@ err:
     return err;
 }
 
-/*
- * Copy relevant information from the master OtrlAuthInfo to an
- * instance OtrlAuthInfo in response to a D-H Commit with a new
- * instance. The fields copied will depend on the state of the
- * master auth.
- */
-void otrl_auth_copy_on_commit(OtrlAuthInfo *m_auth, OtrlAuthInfo *auth)
-{
-    switch(m_auth->authstate) {
-	case OTRL_AUTHSTATE_NONE:
-	case OTRL_AUTHSTATE_AWAITING_REVEALSIG:
-	    auth->authstate = OTRL_AUTHSTATE_NONE;
-	    break;
-	case OTRL_AUTHSTATE_AWAITING_DHKEY:
-	    /* We sent a D-H Commit Message, and we also received one.
-	     *  Copy our D_H Commit and auth state */
-	    otrl_dh_keypair_free(&(auth->our_dh));
-	    auth->initiated = m_auth->initiated;
-	    otrl_dh_keypair_copy(&(auth->our_dh), &(m_auth->our_dh));
-	    auth->our_keyid = m_auth->our_keyid;
-	    memmove(auth->r, m_auth->r, 16);
-	    if (auth->encgx) free(auth->encgx);
-	    auth->encgx = malloc(m_auth->encgx_len);
-	    memmove(auth->encgx, m_auth->encgx, m_auth->encgx_len);
-	    memmove(auth->hashgx, m_auth->hashgx, 32);
-
-	    auth->authstate = OTRL_AUTHSTATE_AWAITING_DHKEY;
-	    break;
-
-	default:
-	    /* This bad state will be detected and handled later */
-	    break;
-    }
-}
-
 /*
  * Copy relevant information from the master OtrlAuthInfo to an
  * instance OtrlAuthInfo in response to a D-H Key with a new

src/auth.h

@@ -159,14 +159,6 @@ gcry_error_t otrl_auth_handle_v1_key_exchange(OtrlAuthInfo *auth,
 	gcry_error_t (*auth_succeeded)(const OtrlAuthInfo *auth, void *asdata),
 	void *asdata);
 
-/*
- * Copy relevant information from the master OtrlAuthInfo to an
- * instance OtrlAuthInfo in response to a D-H Commit with a new
- * instance. The fields copied will depend on the state of the
- * master auth.
- */
-void otrl_auth_copy_on_commit(OtrlAuthInfo *m_auth, OtrlAuthInfo *auth);
-
 /*
  * Copy relevant information from the master OtrlAuthInfo to an
  * instance OtrlAuthInfo in response to a D-H Key with a new

src/message.c

@@ -1051,11 +1051,9 @@ int otrl_message_receiving(OtrlUserState us, const OtrlMessageAppOps *ops,
 		context->msgstate = m_context->msgstate;
 	    }
 
-	    if (msgtype == OTRL_MSGTYPE_DH_COMMIT) {
-		otrl_auth_copy_on_commit(&(m_context->auth), &(context->auth));
-	    } else if (msgtype == OTRL_MSGTYPE_DH_KEY) {
+	    if (msgtype == OTRL_MSGTYPE_DH_KEY) {
 		otrl_auth_copy_on_key(&(m_context->auth), &(context->auth));
-	    } else {
+	    } else if (msgtype != OTRL_MSGTYPE_DH_COMMIT) {
 		return 1;  /* Ignore unexpected message */
 	    }
 
@@ -1073,14 +1071,6 @@ int otrl_message_receiving(OtrlUserState us, const OtrlMessageAppOps *ops,
 		context->auth.protocol_version = 3;
 		context->protocol_version = 3;
 		otrl_auth_copy_on_key(&(m_context->auth), &(context->auth));
-	    } else if (msgtype == OTRL_MSGTYPE_DH_COMMIT &&
-		    m_context->auth.authstate == OTRL_AUTHSTATE_AWAITING_DHKEY
-		    && !(context->auth.authstate ==
-		    OTRL_AUTHSTATE_AWAITING_DHKEY)) {
-		context->msgstate = m_context->msgstate;
-		context->auth.protocol_version = 3;
-		context->protocol_version = 3;
-		otrl_auth_copy_on_commit(&(m_context->auth), &(context->auth));
 	    }
 	}
     }