diff options
Diffstat (limited to 'lib/ssh/src/ssh_transport.erl')
| -rw-r--r-- | lib/ssh/src/ssh_transport.erl | 84 |
1 files changed, 15 insertions, 69 deletions
diff --git a/lib/ssh/src/ssh_transport.erl b/lib/ssh/src/ssh_transport.erl index d61fc76c0a..0c999b96cc 100644 --- a/lib/ssh/src/ssh_transport.erl +++ b/lib/ssh/src/ssh_transport.erl @@ -593,10 +593,11 @@ handle_kex_ecdh_init(#ssh_msg_kex_ecdh_init{q_c = PeerPublic}, Ssh0 = #ssh{algorithms = #alg{kex=Kex}}) -> %% at server Curve = ecdh_curve(Kex), - case ecdh_validate_public_key(PeerPublic, Curve) of - true -> - {MyPublic, MyPrivate} = generate_key(ecdh, Curve), - K = compute_key(ecdh, PeerPublic, MyPrivate, Curve), + {MyPublic, MyPrivate} = generate_key(ecdh, Curve), + try + compute_key(ecdh, PeerPublic, MyPrivate, Curve) + of + K -> MyPrivHostKey = get_host_key(Ssh0), MyPubHostKey = extract_public_key(MyPrivHostKey), H = kex_h(Ssh0, Curve, MyPubHostKey, PeerPublic, MyPublic, K), @@ -609,9 +610,9 @@ handle_kex_ecdh_init(#ssh_msg_kex_ecdh_init{q_c = PeerPublic}, {ok, SshPacket, Ssh1#ssh{keyex_key = {{MyPublic,MyPrivate},Curve}, shared_secret = K, exchanged_hash = H, - session_id = sid(Ssh1, H)}}; - - false -> + session_id = sid(Ssh1, H)}} + catch + _:_ -> throw({{error,invalid_peer_public_key}, #ssh_msg_disconnect{ code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, @@ -626,9 +627,10 @@ handle_kex_ecdh_reply(#ssh_msg_kex_ecdh_reply{public_host_key = PeerPubHostKey, #ssh{keyex_key = {{MyPublic,MyPrivate}, Curve}} = Ssh0 ) -> %% at client - case ecdh_validate_public_key(PeerPublic, Curve) of - true -> - K = compute_key(ecdh, PeerPublic, MyPrivate, Curve), + try + compute_key(ecdh, PeerPublic, MyPrivate, Curve) + of + K -> H = kex_h(Ssh0, Curve, PeerPubHostKey, MyPublic, PeerPublic, K), case verify_host_key(Ssh0, PeerPubHostKey, H, H_SIG) of ok -> @@ -643,9 +645,9 @@ handle_kex_ecdh_reply(#ssh_msg_kex_ecdh_reply{public_host_key = PeerPubHostKey, description = "Key exchange failed", language = ""} }) - end; - - false -> + end + catch + _:_ -> throw({{error,invalid_peer_public_key}, #ssh_msg_disconnect{ code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, @@ -656,62 +658,6 @@ handle_kex_ecdh_reply(#ssh_msg_kex_ecdh_reply{public_host_key = PeerPubHostKey, %%%---------------------------------------------------------------- -%%% -%%% Standards for Efficient Cryptography Group, "Elliptic Curve Cryptography", SEC 1 -%%% Section 3.2.2.1 -%%% - -ecdh_validate_public_key(Key, Curve) -> - case key_size(Curve) of - undefined -> - false; - - Sz -> - case dec_key(Key, Sz) of - {ok,Q} -> - case crypto:ec_curve(Curve) of - {{prime_field,P}, {A, B, _Seed}, - _P0Bin, _OrderBin, _CoFactorBin} -> - on_curve(Q, bin2int(A), bin2int(B), bin2int(P)) - end; - - {error,compressed_not_implemented} -> % Be a bit generous... - true; - - _Error -> - false - end - end. - - -on_curve({X,Y}, A, B, P) when 0 =< X,X =< (P-1), - 0 =< Y,Y =< (P-1) -> - %% Section 3.2.2.1, point 2 - (Y*Y) rem P == (X*X*X + A*X + B) rem P; -on_curve(_, _, _, _) -> - false. - - -bin2int(B) -> - Sz = erlang:bit_size(B), - <<I:Sz/big-unsigned-integer>> = B, - I. - -key_size(secp256r1) -> 256; -key_size(secp384r1) -> 384; -key_size(secp521r1) -> 528; % Round 521 up to closest 8-bits. -key_size(_) -> undefined. - - -dec_key(Key, NBits) -> - Size = 8 + 2*NBits, - case <<Key:Size>> of - <<4:8, X:NBits, Y:NBits>> -> {ok,{X,Y}}; - <<4:8, _/binary>> -> {error,bad_format}; - _ -> {error,compressed_not_implemented} - end. - -%%%---------------------------------------------------------------- handle_new_keys(#ssh_msg_newkeys{}, Ssh0) -> try install_alg(Ssh0) of #ssh{} = Ssh -> |