ssl: Correct handling of bad input to premaster_secret calculation

alert records needs to be thrown from
ssl_handshake:premaster_secret/[2/3] so that operations will end up in
the catch clause of the invokation of certify_client_key_exchange/3 in
ssl_connection.erl, and hence terminate gracefully and not continue to try
and calculate the master secret with invalid inputs and crash.

1 files changed, 18 insertions, 16 deletions

diff --git a/lib/ssl/src/ssl_handshake.erl b/lib/ssl/src/ssl_handshake.erl
index 88ccb94e0b..29b64f7a81 100644
--- a/lib/ssl/src/ssl_handshake.erl
+++ b/lib/ssl/src/ssl_handshake.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2013-2014. All Rights Reserved.
+%% Copyright Ericsson AB 2013-2015. All Rights Reserved.
 %%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -500,19 +500,27 @@ update_handshake_history({Handshake0, _Prev}, Data) ->
 %%     end.
 
 premaster_secret(OtherPublicDhKey, MyPrivateKey, #'DHParameter'{} = Params) ->
-    public_key:compute_key(OtherPublicDhKey, MyPrivateKey, Params);
-
+    try 
+	public_key:compute_key(OtherPublicDhKey, MyPrivateKey, Params)  
+    catch 
+	error:computation_failed -> 
+	    throw(?ALERT_REC(?FATAL, ?ILLEGAL_PARAMETER))
+    end;	   
 premaster_secret(PublicDhKey, PrivateDhKey, #server_dh_params{dh_p = Prime, dh_g = Base}) ->
-    crypto:compute_key(dh, PublicDhKey, PrivateDhKey, [Prime, Base]);
+    try 
+	crypto:compute_key(dh, PublicDhKey, PrivateDhKey, [Prime, Base])
+    catch 
+	error:computation_failed -> 
+	    throw(?ALERT_REC(?FATAL, ?ILLEGAL_PARAMETER))
+    end;
 premaster_secret(#client_srp_public{srp_a = ClientPublicKey}, ServerKey, #srp_user{prime = Prime,
 										   verifier = Verifier}) ->
     case crypto:compute_key(srp, ClientPublicKey, ServerKey, {host, [Verifier, Prime, '6a']}) of
 	error ->
-	    ?ALERT_REC(?FATAL, ?ILLEGAL_PARAMETER);
+	    throw(?ALERT_REC(?FATAL, ?ILLEGAL_PARAMETER));
 	PremasterSecret ->
 	    PremasterSecret
     end;
-
 premaster_secret(#server_srp_params{srp_n = Prime, srp_g = Generator, srp_s = Salt, srp_b = Public},
 		 ClientKeys, {Username, Password}) ->
     case ssl_srp_primes:check_srp_params(Generator, Prime) of
@@ -520,21 +528,19 @@ premaster_secret(#server_srp_params{srp_n = Prime, srp_g = Generator, srp_s = Sa
 	    DerivedKey = crypto:hash(sha, [Salt, crypto:hash(sha, [Username, <<$:>>, Password])]),
 	    case crypto:compute_key(srp, Public, ClientKeys, {user, [DerivedKey, Prime, Generator, '6a']}) of
 		error ->
-		    ?ALERT_REC(?FATAL, ?ILLEGAL_PARAMETER);
+		    throw(?ALERT_REC(?FATAL, ?ILLEGAL_PARAMETER));
 		PremasterSecret ->
 		    PremasterSecret
 	    end;
 	_ ->
-	    ?ALERT_REC(?FATAL, ?ILLEGAL_PARAMETER)
+	    throw(?ALERT_REC(?FATAL, ?ILLEGAL_PARAMETER))
     end;
-
 premaster_secret(#client_rsa_psk_identity{
 		    identity = PSKIdentity,
 		    exchange_keys = #encrypted_premaster_secret{premaster_secret = EncPMS}
 		   }, #'RSAPrivateKey'{} = Key, PSKLookup) ->
     PremasterSecret = premaster_secret(EncPMS, Key),
     psk_secret(PSKIdentity, PSKLookup, PremasterSecret);
-
 premaster_secret(#server_dhe_psk_params{
 		    hint = IdentityHint,
 		    dh_params =  #server_dh_params{dh_y = PublicDhKey} = Params},
@@ -542,7 +548,6 @@ premaster_secret(#server_dhe_psk_params{
 		    LookupFun) ->
     PremasterSecret = premaster_secret(PublicDhKey, PrivateDhKey, Params),
     psk_secret(IdentityHint, LookupFun, PremasterSecret);
-
 premaster_secret({rsa_psk, PSKIdentity}, PSKLookup, RSAPremasterSecret) ->
     psk_secret(PSKIdentity, PSKLookup, RSAPremasterSecret).
 
@@ -551,13 +556,10 @@ premaster_secret(#client_dhe_psk_identity{
 		    dh_public = PublicDhKey}, PrivateKey, #'DHParameter'{} = Params, PSKLookup) ->
     PremasterSecret = premaster_secret(PublicDhKey, PrivateKey, Params),
     psk_secret(PSKIdentity, PSKLookup, PremasterSecret).
-
 premaster_secret(#client_psk_identity{identity = PSKIdentity}, PSKLookup) ->
     psk_secret(PSKIdentity, PSKLookup);
-
 premaster_secret({psk, PSKIdentity}, PSKLookup) ->
     psk_secret(PSKIdentity, PSKLookup);
-
 premaster_secret(#'ECPoint'{} = ECPoint, #'ECPrivateKey'{} = ECDHKeys) ->
     public_key:compute_key(ECPoint, ECDHKeys);
 premaster_secret(EncSecret, #'RSAPrivateKey'{} = RSAPrivateKey) ->
@@ -1933,7 +1935,7 @@ psk_secret(PSKIdentity, PSKLookup) ->
 	#alert{} = Alert ->
 	    Alert;
 	_ ->
-	    ?ALERT_REC(?FATAL, ?ILLEGAL_PARAMETER)
+	    throw(?ALERT_REC(?FATAL, ?ILLEGAL_PARAMETER))
     end.
 
 psk_secret(PSKIdentity, PSKLookup, PremasterSecret) ->
@@ -1945,7 +1947,7 @@ psk_secret(PSKIdentity, PSKLookup, PremasterSecret) ->
 	#alert{} = Alert ->
 	    Alert;
 	_ ->
-	    ?ALERT_REC(?FATAL, ?ILLEGAL_PARAMETER)
+	    throw(?ALERT_REC(?FATAL, ?ILLEGAL_PARAMETER))
     end.
 
 handle_psk_identity(_PSKIdentity, LookupFun)