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-rw-r--r--lib/ssh/src/ssh_transport.erl187
1 files changed, 127 insertions, 60 deletions
diff --git a/lib/ssh/src/ssh_transport.erl b/lib/ssh/src/ssh_transport.erl
index a6438e69d4..8b65806dc6 100644
--- a/lib/ssh/src/ssh_transport.erl
+++ b/lib/ssh/src/ssh_transport.erl
@@ -44,6 +44,7 @@
handle_kexdh_reply/2,
handle_kex_ecdh_init/2,
handle_kex_ecdh_reply/2,
+ extract_public_key/1,
unpack/3, decompress/2, ssh_packet/2, pack/2, msg_data/1,
sign/3, verify/4]).
@@ -65,8 +66,8 @@ default_algorithms() -> [{K,default_algorithms(K)} || K <- algo_classes()].
algo_classes() -> [kex, public_key, cipher, mac, compression].
-default_algorithms(kex) ->
- supported_algorithms(kex, []); %% Just to have a call to supported_algorithms/2
+%% default_algorithms(kex) -> % Example of how to disable an algorithm
+%% supported_algorithms(kex, ['ecdh-sha2-nistp521']);
default_algorithms(Alg) ->
supported_algorithms(Alg).
@@ -117,11 +118,11 @@ supported_algorithms(compression) ->
'zlib'
]).
-supported_algorithms(Key, [{client2server,BL1},{server2client,BL2}]) ->
- [{client2server,As1},{server2client,As2}] = supported_algorithms(Key),
- [{client2server,As1--BL1},{server2client,As2--BL2}];
-supported_algorithms(Key, BlackList) ->
- supported_algorithms(Key) -- BlackList.
+%% Dialyzer complains when not called...supported_algorithms(Key, [{client2server,BL1},{server2client,BL2}]) ->
+%% Dialyzer complains when not called... [{client2server,As1},{server2client,As2}] = supported_algorithms(Key),
+%% Dialyzer complains when not called... [{client2server,As1--BL1},{server2client,As2--BL2}];
+%% Dialyzer complains when not called...supported_algorithms(Key, BlackList) ->
+%% Dialyzer complains when not called... supported_algorithms(Key) -- BlackList.
select_crypto_supported(L) ->
Sup = [{ec_curve,crypto_supported_curves()} | crypto:supports()],
@@ -328,9 +329,7 @@ verify_algorithm(#alg{encrypt = undefined}) -> false;
verify_algorithm(#alg{decrypt = undefined}) -> false;
verify_algorithm(#alg{compress = undefined}) -> false;
verify_algorithm(#alg{decompress = undefined}) -> false;
-
-verify_algorithm(#alg{kex = Kex}) -> lists:member(Kex, supported_algorithms(kex));
-verify_algorithm(_) -> false.
+verify_algorithm(#alg{kex = Kex}) -> lists:member(Kex, supported_algorithms(kex)).
%%%----------------------------------------------------------------
%%%
@@ -380,13 +379,15 @@ handle_kexdh_init(#ssh_msg_kexdh_init{e = E},
1=<E, E=<(P-1) ->
{Public, Private} = generate_key(dh, [P,G]),
K = compute_key(dh, E, Private, [P,G]),
- Key = get_host_key(Ssh0),
- H = kex_h(Ssh0, Key, E, Public, K),
- H_SIG = sign_host_key(Ssh0, Key, H),
- {SshPacket, Ssh1} = ssh_packet(#ssh_msg_kexdh_reply{public_host_key = Key,
- f = Public,
- h_sig = H_SIG
- }, Ssh0),
+ MyPrivHostKey = get_host_key(Ssh0),
+ MyPubHostKey = extract_public_key(MyPrivHostKey),
+ H = kex_h(Ssh0, MyPubHostKey, E, Public, K),
+ H_SIG = sign_host_key(Ssh0, MyPrivHostKey, H),
+ {SshPacket, Ssh1} =
+ ssh_packet(#ssh_msg_kexdh_reply{public_host_key = MyPubHostKey,
+ f = Public,
+ h_sig = H_SIG
+ }, Ssh0),
{ok, SshPacket, Ssh1#ssh{keyex_key = {{Private, Public}, {G, P}},
shared_secret = K,
exchanged_hash = H,
@@ -401,7 +402,7 @@ handle_kexdh_init(#ssh_msg_kexdh_init{e = E},
})
end.
-handle_kexdh_reply(#ssh_msg_kexdh_reply{public_host_key = HostKey,
+handle_kexdh_reply(#ssh_msg_kexdh_reply{public_host_key = PeerPubHostKey,
f = F,
h_sig = H_SIG},
#ssh{keyex_key = {{Private, Public}, {G, P}}} = Ssh0) ->
@@ -409,9 +410,9 @@ handle_kexdh_reply(#ssh_msg_kexdh_reply{public_host_key = HostKey,
if
1=<F, F=<(P-1)->
K = compute_key(dh, F, Private, [P,G]),
- H = kex_h(Ssh0, HostKey, Public, F, K),
+ H = kex_h(Ssh0, PeerPubHostKey, Public, F, K),
- case verify_host_key(Ssh0, HostKey, H, H_SIG) of
+ case verify_host_key(Ssh0, PeerPubHostKey, H, H_SIG) of
ok ->
{SshPacket, Ssh} = ssh_packet(#ssh_msg_newkeys{}, Ssh0),
{ok, SshPacket, Ssh#ssh{shared_secret = K,
@@ -480,11 +481,12 @@ handle_kex_dh_gex_init(#ssh_msg_kex_dh_gex_init{e = E},
K = compute_key(dh, E, Private, [P,G]),
if
1<K, K<(P-1) ->
- HostKey = get_host_key(Ssh0),
- H = kex_h(Ssh0, HostKey, Min, NBits, Max, P, G, E, Public, K),
- H_SIG = sign_host_key(Ssh0, HostKey, H),
+ MyPrivHostKey = get_host_key(Ssh0),
+ MyPubHostKey = extract_public_key(MyPrivHostKey),
+ H = kex_h(Ssh0, MyPubHostKey, Min, NBits, Max, P, G, E, Public, K),
+ H_SIG = sign_host_key(Ssh0, MyPrivHostKey, H),
{SshPacket, Ssh} =
- ssh_packet(#ssh_msg_kex_dh_gex_reply{public_host_key = HostKey,
+ ssh_packet(#ssh_msg_kex_dh_gex_reply{public_host_key = MyPubHostKey,
f = Public,
h_sig = H_SIG}, Ssh0),
{ok, SshPacket, Ssh#ssh{shared_secret = K,
@@ -508,7 +510,7 @@ handle_kex_dh_gex_init(#ssh_msg_kex_dh_gex_init{e = E},
})
end.
-handle_kex_dh_gex_reply(#ssh_msg_kex_dh_gex_reply{public_host_key = HostKey,
+handle_kex_dh_gex_reply(#ssh_msg_kex_dh_gex_reply{public_host_key = PeerPubHostKey,
f = F,
h_sig = H_SIG},
#ssh{keyex_key = {{Private, Public}, {G, P}},
@@ -520,9 +522,9 @@ handle_kex_dh_gex_reply(#ssh_msg_kex_dh_gex_reply{public_host_key = HostKey,
K = compute_key(dh, F, Private, [P,G]),
if
1<K, K<(P-1) ->
- H = kex_h(Ssh0, HostKey, Min, NBits, Max, P, G, Public, F, K),
+ H = kex_h(Ssh0, PeerPubHostKey, Min, NBits, Max, P, G, Public, F, K),
- case verify_host_key(Ssh0, HostKey, H, H_SIG) of
+ case verify_host_key(Ssh0, PeerPubHostKey, H, H_SIG) of
ok ->
{SshPacket, Ssh} = ssh_packet(#ssh_msg_newkeys{}, Ssh0),
{ok, SshPacket, Ssh#ssh{shared_secret = K,
@@ -565,11 +567,12 @@ handle_kex_ecdh_init(#ssh_msg_kex_ecdh_init{q_c = PeerPublic},
true ->
{MyPublic, MyPrivate} = generate_key(ecdh, Curve),
K = compute_key(ecdh, PeerPublic, MyPrivate, Curve),
- HostKey = get_host_key(Ssh0),
- H = kex_h(Ssh0, Curve, HostKey, PeerPublic, MyPublic, K),
- H_SIG = sign_host_key(Ssh0, HostKey, H),
+ MyPrivHostKey = get_host_key(Ssh0),
+ MyPubHostKey = extract_public_key(MyPrivHostKey),
+ H = kex_h(Ssh0, Curve, MyPubHostKey, PeerPublic, MyPublic, K),
+ H_SIG = sign_host_key(Ssh0, MyPrivHostKey, H),
{SshPacket, Ssh1} =
- ssh_packet(#ssh_msg_kex_ecdh_reply{public_host_key = HostKey,
+ ssh_packet(#ssh_msg_kex_ecdh_reply{public_host_key = MyPubHostKey,
q_s = MyPublic,
h_sig = H_SIG},
Ssh0),
@@ -587,7 +590,7 @@ handle_kex_ecdh_init(#ssh_msg_kex_ecdh_init{q_c = PeerPublic},
})
end.
-handle_kex_ecdh_reply(#ssh_msg_kex_ecdh_reply{public_host_key = HostKey,
+handle_kex_ecdh_reply(#ssh_msg_kex_ecdh_reply{public_host_key = PeerPubHostKey,
q_s = PeerPublic,
h_sig = H_SIG},
#ssh{keyex_key = {{MyPublic,MyPrivate}, Curve}} = Ssh0
@@ -596,8 +599,8 @@ handle_kex_ecdh_reply(#ssh_msg_kex_ecdh_reply{public_host_key = HostKey,
case ecdh_validate_public_key(PeerPublic, Curve) of
true ->
K = compute_key(ecdh, PeerPublic, MyPrivate, Curve),
- H = kex_h(Ssh0, Curve, HostKey, MyPublic, PeerPublic, K),
- case verify_host_key(Ssh0, HostKey, H, H_SIG) of
+ H = kex_h(Ssh0, Curve, PeerPubHostKey, MyPublic, PeerPublic, K),
+ case verify_host_key(Ssh0, PeerPubHostKey, H, H_SIG) of
ok ->
{SshPacket, Ssh} = ssh_packet(#ssh_msg_newkeys{}, Ssh0),
{ok, SshPacket, Ssh#ssh{shared_secret = K,
@@ -622,7 +625,61 @@ handle_kex_ecdh_reply(#ssh_msg_kex_ecdh_reply{public_host_key = HostKey,
end.
-ecdh_validate_public_key(_, _) -> true. % FIXME: Far too many false positives :)
+%%%----------------------------------------------------------------
+%%%
+%%% 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) ->
@@ -659,13 +716,20 @@ get_host_key(SSH) ->
sign_host_key(_Ssh, PrivateKey, H) ->
sign(H, sign_host_key_sha(PrivateKey), PrivateKey).
-sign_host_key_sha(#'ECPrivateKey'{parameters = {namedCurve, ?'secp256r1'}}) -> sha256;
-sign_host_key_sha(#'ECPrivateKey'{parameters = {namedCurve, ?'secp384r1'}}) -> sha384;
-sign_host_key_sha(#'ECPrivateKey'{parameters = {namedCurve, ?'secp521r1'}}) -> sha512;
+sign_host_key_sha(#'ECPrivateKey'{parameters = {namedCurve,OID}}) -> sha(OID);
sign_host_key_sha(#'RSAPrivateKey'{}) -> sha;
sign_host_key_sha(#'DSAPrivateKey'{}) -> sha.
+extract_public_key(#'RSAPrivateKey'{modulus = N, publicExponent = E}) ->
+ #'RSAPublicKey'{modulus = N, publicExponent = E};
+extract_public_key(#'DSAPrivateKey'{y = Y, p = P, q = Q, g = G}) ->
+ {Y, #'Dss-Parms'{p=P, q=Q, g=G}};
+extract_public_key(#'ECPrivateKey'{parameters = {namedCurve,OID},
+ publicKey = Q}) ->
+ {#'ECPoint'{point=Q}, {namedCurve,OID}}.
+
+
verify_host_key(SSH, PublicKey, Digest, Signature) ->
case verify(Digest, host_key_sha(PublicKey), Signature, PublicKey) of
false ->
@@ -674,14 +738,16 @@ verify_host_key(SSH, PublicKey, Digest, Signature) ->
known_host_key(SSH, PublicKey, public_algo(PublicKey))
end.
-host_key_sha(#'RSAPublicKey'{}) -> sha;
-host_key_sha({_, #'Dss-Parms'{}}) -> sha;
-host_key_sha({#'ECPoint'{},Id}) -> sha(list_to_atom(binary_to_list(Id))).
+host_key_sha(#'RSAPublicKey'{}) -> sha;
+host_key_sha({_, #'Dss-Parms'{}}) -> sha;
+host_key_sha({#'ECPoint'{},{namedCurve,OID}}) -> sha(OID).
public_algo(#'RSAPublicKey'{}) -> 'ssh-rsa';
public_algo({_, #'Dss-Parms'{}}) -> 'ssh-dss';
-public_algo({#'ECPoint'{},Id}) -> list_to_atom("ecdsa-sha2-" ++ binary_to_list(Id)).
+public_algo({#'ECPoint'{},{namedCurve,OID}}) ->
+ Curve = public_key:oid2ssh_curvename(OID),
+ list_to_atom("ecdsa-sha2-" ++ binary_to_list(Curve)).
accepted_host(Ssh, PeerName, Opts) ->
@@ -933,17 +999,12 @@ verify(PlainText, Hash, Sig, {_, #'Dss-Parms'{}} = Key) ->
<<R:160/big-unsigned-integer, S:160/big-unsigned-integer>> = Sig,
Signature = public_key:der_encode('Dss-Sig-Value', #'Dss-Sig-Value'{r = R, s = S}),
public_key:verify(PlainText, Hash, Signature, Key);
-verify(PlainText, Hash, Sig, {ECPoint=#'ECPoint'{}, Param}) ->
- C = case Param of
- <<"nistp256">> -> {namedCurve, ?'secp256r1'};
- <<"nistp384">> -> {namedCurve, ?'secp384r1'};
- <<"nistp521">> -> {namedCurve, ?'secp521r1'}
- end,
+verify(PlainText, Hash, Sig, {#'ECPoint'{},_} = Key) ->
<<?UINT32(Rlen),R:Rlen/big-signed-integer-unit:8,
?UINT32(Slen),S:Slen/big-signed-integer-unit:8>> = Sig,
Sval = #'ECDSA-Sig-Value'{r=R, s=S},
DerEncodedSig = public_key:der_encode('ECDSA-Sig-Value',Sval),
- public_key:verify(PlainText, Hash, DerEncodedSig, {ECPoint,C});
+ public_key:verify(PlainText, Hash, DerEncodedSig, Key);
verify(PlainText, Hash, Sig, Key) ->
public_key:verify(PlainText, Hash, Sig, Key).
@@ -1336,52 +1397,58 @@ hash(K, H, Ki, N, HASH) ->
hash(K, H, <<Ki/binary, Kj/binary>>, N-128, HASH).
kex_h(SSH, Key, E, F, K) ->
+ KeyBin = public_key:ssh_encode(Key, ssh2_pubkey),
L = ssh_bits:encode([SSH#ssh.c_version, SSH#ssh.s_version,
SSH#ssh.c_keyinit, SSH#ssh.s_keyinit,
- ssh_message:encode_host_key(Key), E,F,K],
+ KeyBin, E,F,K],
[string,string,binary,binary,binary,
mpint,mpint,mpint]),
crypto:hash(sha((SSH#ssh.algorithms)#alg.kex), L).
%% crypto:hash(sha,L).
kex_h(SSH, Curve, Key, Q_c, Q_s, K) ->
+ KeyBin = public_key:ssh_encode(Key, ssh2_pubkey),
L = ssh_bits:encode([SSH#ssh.c_version, SSH#ssh.s_version,
SSH#ssh.c_keyinit, SSH#ssh.s_keyinit,
- ssh_message:encode_host_key(Key), Q_c, Q_s, K],
+ KeyBin, Q_c, Q_s, K],
[string,string,binary,binary,binary,
mpint,mpint,mpint]),
crypto:hash(sha(Curve), L).
kex_h(SSH, Key, Min, NBits, Max, Prime, Gen, E, F, K) ->
L = if Min==-1; Max==-1 ->
+ KeyBin = public_key:ssh_encode(Key, ssh2_pubkey),
Ts = [string,string,binary,binary,binary,
uint32,
mpint,mpint,mpint,mpint,mpint],
ssh_bits:encode([SSH#ssh.c_version,SSH#ssh.s_version,
SSH#ssh.c_keyinit,SSH#ssh.s_keyinit,
- ssh_message:encode_host_key(Key), NBits, Prime, Gen, E,F,K],
+ KeyBin, NBits, Prime, Gen, E,F,K],
Ts);
true ->
+ KeyBin = public_key:ssh_encode(Key, ssh2_pubkey),
Ts = [string,string,binary,binary,binary,
uint32,uint32,uint32,
mpint,mpint,mpint,mpint,mpint],
ssh_bits:encode([SSH#ssh.c_version,SSH#ssh.s_version,
SSH#ssh.c_keyinit,SSH#ssh.s_keyinit,
- ssh_message:encode_host_key(Key), Min, NBits, Max,
+ KeyBin, Min, NBits, Max,
Prime, Gen, E,F,K], Ts)
end,
crypto:hash(sha((SSH#ssh.algorithms)#alg.kex), L).
-sha('nistp256') -> sha256;
-sha('secp256r1')-> sha256;
-sha('nistp384') -> sha384;
-sha('secp384r1')-> sha384;
-sha('nistp521') -> sha512;
-sha('secp521r1')-> sha512;
+
+sha(secp256r1) -> sha256;
+sha(secp384r1) -> sha384;
+sha(secp521r1) -> sha512;
sha('diffie-hellman-group1-sha1') -> sha;
sha('diffie-hellman-group14-sha1') -> sha;
sha('diffie-hellman-group-exchange-sha1') -> sha;
-sha('diffie-hellman-group-exchange-sha256') -> sha256.
+sha('diffie-hellman-group-exchange-sha256') -> sha256;
+sha(?'secp256r1') -> sha(secp256r1);
+sha(?'secp384r1') -> sha(secp384r1);
+sha(?'secp521r1') -> sha(secp521r1).
+
mac_key_size('hmac-sha1') -> 20*8;
mac_key_size('hmac-sha1-96') -> 20*8;
generated by cgit v1.2.3 (git 2.25.1) at 2024-08-18 03:30:01 +0000