aboutsummaryrefslogtreecommitdiffstats
path: root/lib/ssh/src/ssh_transport.erl
diff options
context:
space:
mode:
Diffstat (limited to 'lib/ssh/src/ssh_transport.erl')
-rw-r--r--lib/ssh/src/ssh_transport.erl176
1 files changed, 59 insertions, 117 deletions
diff --git a/lib/ssh/src/ssh_transport.erl b/lib/ssh/src/ssh_transport.erl
index d622ec27fc..0c999b96cc 100644
--- a/lib/ssh/src/ssh_transport.erl
+++ b/lib/ssh/src/ssh_transport.erl
@@ -441,19 +441,29 @@ handle_kexdh_reply(#ssh_msg_kexdh_reply{public_host_key = PeerPubHostKey,
%%%
%%% diffie-hellman-group-exchange-sha1
%%%
-handle_kex_dh_gex_request(#ssh_msg_kex_dh_gex_request{min = Min,
+handle_kex_dh_gex_request(#ssh_msg_kex_dh_gex_request{min = Min0,
n = NBits,
- max = Max},
- Ssh0=#ssh{opts=Opts}) when Min=<NBits, NBits=<Max ->
+ max = Max0},
+ Ssh0=#ssh{opts=Opts}) when Min0=<NBits, NBits=<Max0 ->
%% server
- {G, P} = dh_gex_group(Min, NBits, Max, proplists:get_value(dh_gex_groups,Opts)),
- {Public, Private} = generate_key(dh, [P,G]),
- {SshPacket, Ssh} =
- ssh_packet(#ssh_msg_kex_dh_gex_group{p = P, g = G}, Ssh0),
- {ok, SshPacket,
- Ssh#ssh{keyex_key = {{Private, Public}, {G, P}},
- keyex_info = {Min, Max, NBits}
- }};
+ {Min, Max} = adjust_gex_min_max(Min0, Max0, Opts),
+ case public_key:dh_gex_group(Min, NBits, Max,
+ proplists:get_value(dh_gex_groups,Opts)) of
+ {ok, {_Sz, {G,P}}} ->
+ {Public, Private} = generate_key(dh, [P,G]),
+ {SshPacket, Ssh} =
+ ssh_packet(#ssh_msg_kex_dh_gex_group{p = P, g = G}, Ssh0),
+ {ok, SshPacket,
+ Ssh#ssh{keyex_key = {{Private, Public}, {G, P}},
+ keyex_info = {Min, Max, NBits}
+ }};
+ {error,_} ->
+ throw(#ssh_msg_disconnect{
+ code = ?SSH_DISCONNECT_PROTOCOL_ERROR,
+ description = "No possible diffie-hellman-group-exchange group found",
+ language = ""})
+ end;
+
handle_kex_dh_gex_request(_, _) ->
throw({{error,bad_ssh_msg_kex_dh_gex_request},
#ssh_msg_disconnect{
@@ -462,6 +472,26 @@ handle_kex_dh_gex_request(_, _) ->
language = ""}
}).
+
+adjust_gex_min_max(Min0, Max0, Opts) ->
+ case proplists:get_value(dh_gex_limits, Opts) of
+ undefined ->
+ {Min0, Max0};
+ {Min1, Max1} ->
+ Min2 = max(Min0, Min1),
+ Max2 = min(Max0, Max1),
+ if
+ Min2 =< Max2 ->
+ {Min2, Max2};
+ Max2 < Min2 ->
+ throw(#ssh_msg_disconnect{
+ code = ?SSH_DISCONNECT_PROTOCOL_ERROR,
+ description = "No possible diffie-hellman-group-exchange group possible",
+ language = ""})
+ end
+ end.
+
+
handle_kex_dh_gex_group(#ssh_msg_kex_dh_gex_group{p = P, g = G}, Ssh0) ->
%% client
{Public, Private} = generate_key(dh, [P,G]),
@@ -563,10 +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),
@@ -579,9 +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,
@@ -596,9 +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 ->
@@ -613,9 +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,
@@ -626,62 +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 ->
@@ -1482,44 +1458,10 @@ peer_name({Host, _}) ->
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-dh_group('diffie-hellman-group1-sha1') -> element(2, ?dh_group1);
-dh_group('diffie-hellman-group14-sha1') -> element(2, ?dh_group14).
-
-dh_gex_default_groups() -> ?dh_default_groups.
-
-
-dh_gex_group(Min, N, Max, undefined) ->
- dh_gex_group(Min, N, Max, dh_gex_default_groups());
-dh_gex_group(Min, N, Max, Groups) ->
- %% First try to find an exact match. If not an exact match, select the largest possible.
- {_Size,Group} =
- lists:foldl(
- fun(_, {I,G}) when I==N ->
- %% If we have an exact match already: use that one
- {I,G};
- ({I,G}, _) when I==N ->
- %% If we now found an exact match: use that very one
- {I,G};
- ({I,G}, {Imax,_Gmax}) when Min=<I,I=<Max, % a) {I,G} fullfills the requirements
- I>Imax -> % b) {I,G} is larger than current max
- %% A group within the limits and better than the one we have
- {I,G};
- (_, IGmax) ->
- %% Keep the one we have
- IGmax
- end, {-1,undefined}, Groups),
-
- case Group of
- undefined ->
- throw(#ssh_msg_disconnect{
- code = ?SSH_DISCONNECT_PROTOCOL_ERROR,
- description = "No possible diffie-hellman-group-exchange group found",
- language = ""});
- _ ->
- Group
- end.
-
+dh_group('diffie-hellman-group1-sha1') -> ?dh_group1;
+dh_group('diffie-hellman-group14-sha1') -> ?dh_group14.
+%%%----------------------------------------------------------------
generate_key(Algorithm, Args) ->
{Public,Private} = crypto:generate_key(Algorithm, Args),
{crypto:bytes_to_integer(Public), crypto:bytes_to_integer(Private)}.
generated by cgit v1.2.3 (git 2.25.1) at 2024-08-05 15:45:12 +0000