From 8da6f7108cc9a49e7d7ccb07fa6382e293b19a4a Mon Sep 17 00:00:00 2001 From: Kenneth Lakin Date: Sat, 30 Apr 2016 20:17:03 -0700 Subject: ssl: Use cipher suite's PRF in prf/5 Use the negotiated cipher suite's PRF algorithm in calls to ssl:prf/5, rather than a hard-coded one. For TLS 1.0 the PRF algorithm was hard-coded to MD5/SHA1. This was correct 100% of the time. For TLS 1.1 and 1.2 the PRF algorithm was hard-coded to SHA256. This was correct only some of the time for TLS 1.2 and none of the time for TLS 1.1. Because the TLS handshake code calls tls_v1:prf/5 through another path, the handshaking process used the negotiated PRF and did not encounter this bug. A new test (prf) has been added to ssl_basic_SUITE to guard against future breakage. --- lib/ssl/src/ssl_connection.erl | 5 +++-- lib/ssl/src/ssl_handshake.erl | 12 +++++------- 2 files changed, 8 insertions(+), 9 deletions(-) (limited to 'lib/ssl/src') diff --git a/lib/ssl/src/ssl_connection.erl b/lib/ssl/src/ssl_connection.erl index 57fa1b904e..5bb43725e3 100644 --- a/lib/ssl/src/ssl_connection.erl +++ b/lib/ssl/src/ssl_connection.erl @@ -927,7 +927,8 @@ handle_call({prf, Secret, Label, Seed, WantedLength}, From, _, SecParams = ConnectionState#connection_state.security_parameters, #security_parameters{master_secret = MasterSecret, client_random = ClientRandom, - server_random = ServerRandom} = SecParams, + server_random = ServerRandom, + prf_algorithm = PRFAlgorithm} = SecParams, Reply = try SecretToUse = case Secret of _ when is_binary(Secret) -> Secret; @@ -938,7 +939,7 @@ handle_call({prf, Secret, Label, Seed, WantedLength}, From, _, (client_random, Acc) -> [ClientRandom|Acc]; (server_random, Acc) -> [ServerRandom|Acc] end, [], Seed)), - ssl_handshake:prf(Version, SecretToUse, Label, SeedToUse, WantedLength) + ssl_handshake:prf(Version, PRFAlgorithm, SecretToUse, Label, SeedToUse, WantedLength) catch exit:_ -> {error, badarg}; error:Reason -> {error, Reason} diff --git a/lib/ssl/src/ssl_handshake.erl b/lib/ssl/src/ssl_handshake.erl index 2a2a7b7d25..598d4e4112 100644 --- a/lib/ssl/src/ssl_handshake.erl +++ b/lib/ssl/src/ssl_handshake.erl @@ -74,7 +74,7 @@ ]). %% MISC --export([select_version/3, prf/5, select_hashsign/5, +-export([select_version/3, prf/6, select_hashsign/5, select_hashsign_algs/3, premaster_secret/2, premaster_secret/3, premaster_secret/4]). @@ -564,17 +564,15 @@ server_key_exchange_hash(md5sha, Value) -> server_key_exchange_hash(Hash, Value) -> crypto:hash(Hash, Value). %%-------------------------------------------------------------------- --spec prf(ssl_record:ssl_version(), binary(), binary(), [binary()], non_neg_integer()) -> +-spec prf(ssl_record:ssl_version(), non_neg_integer(), binary(), binary(), [binary()], non_neg_integer()) -> {ok, binary()} | {error, undefined}. %% %% Description: use the TLS PRF to generate key material %%-------------------------------------------------------------------- -prf({3,0}, _, _, _, _) -> +prf({3,0}, _, _, _, _, _) -> {error, undefined}; -prf({3,1}, Secret, Label, Seed, WantedLength) -> - {ok, tls_v1:prf(?MD5SHA, Secret, Label, Seed, WantedLength)}; -prf({3,_N}, Secret, Label, Seed, WantedLength) -> - {ok, tls_v1:prf(?SHA256, Secret, Label, Seed, WantedLength)}. +prf({3,_N}, PRFAlgo, Secret, Label, Seed, WantedLength) -> + {ok, tls_v1:prf(PRFAlgo, Secret, Label, Seed, WantedLength)}. %%-------------------------------------------------------------------- -- cgit v1.2.3