From 2e55f44545504aa1ba109e072e6833f5c045b58f Mon Sep 17 00:00:00 2001 From: Hans Nilsson Date: Wed, 19 Apr 2017 14:10:29 +0200 Subject: ssh: Implement signature algorithms rsa-sha2-*. draft-ietf-curdle-rsa-sha2 --- lib/ssh/src/ssh_transport.erl | 205 ++++++++++++++++++++++-------------------- 1 file changed, 109 insertions(+), 96 deletions(-) (limited to 'lib/ssh/src/ssh_transport.erl') diff --git a/lib/ssh/src/ssh_transport.erl b/lib/ssh/src/ssh_transport.erl index 3c2c345261..3cf1e60634 100644 --- a/lib/ssh/src/ssh_transport.erl +++ b/lib/ssh/src/ssh_transport.erl @@ -48,6 +48,7 @@ parallell_gen_key/1, extract_public_key/1, ssh_packet/2, pack/2, + valid_key_sha_alg/2, sha/1, sign/3, verify/4]). %%% For test suites @@ -117,6 +118,9 @@ supported_algorithms(public_key) -> {'ecdsa-sha2-nistp384', [{public_keys,ecdsa}, {hashs,sha384}, {ec_curve,secp384r1}]}, {'ecdsa-sha2-nistp521', [{public_keys,ecdsa}, {hashs,sha512}, {ec_curve,secp521r1}]}, {'ecdsa-sha2-nistp256', [{public_keys,ecdsa}, {hashs,sha256}, {ec_curve,secp256r1}]}, + {'rsa-sha2-256', [{public_keys,rsa}, {hashs,sha256} ]}, + {'rsa-sha2-384', [{public_keys,rsa}, {hashs,sha384} ]}, + {'rsa-sha2-512', [{public_keys,rsa}, {hashs,sha512} ]}, {'ssh-rsa', [{public_keys,rsa}, {hashs,sha} ]}, {'ssh-dss', [{public_keys,dss}, {hashs,sha} ]} % Gone in OpenSSH 7.3.p1 ]); @@ -377,7 +381,8 @@ key_exchange_first_msg(Kex, Ssh0) when Kex == 'ecdh-sha2-nistp256' ; %%% diffie-hellman-group18-sha512 %%% handle_kexdh_init(#ssh_msg_kexdh_init{e = E}, - Ssh0 = #ssh{algorithms = #alg{kex=Kex} = Algs}) -> + Ssh0 = #ssh{algorithms = #alg{kex=Kex, + hkey=SignAlg} = Algs}) -> %% server {G, P} = dh_group(Kex), if @@ -385,12 +390,12 @@ handle_kexdh_init(#ssh_msg_kexdh_init{e = E}, Sz = dh_bits(Algs), {Public, Private} = generate_key(dh, [P,G,2*Sz]), K = compute_key(dh, E, Private, [P,G]), - MyPrivHostKey = get_host_key(Ssh0), + MyPrivHostKey = get_host_key(Ssh0, SignAlg), MyPubHostKey = extract_public_key(MyPrivHostKey), - H = kex_h(Ssh0, MyPubHostKey, E, Public, K), - H_SIG = sign_host_key(Ssh0, MyPrivHostKey, H), + H = kex_hash(Ssh0, MyPubHostKey, SignAlg, sha(Kex), {E,Public,K}), + H_SIG = sign(H, sha(SignAlg), MyPrivHostKey), {SshPacket, Ssh1} = - ssh_packet(#ssh_msg_kexdh_reply{public_host_key = MyPubHostKey, + ssh_packet(#ssh_msg_kexdh_reply{public_host_key = {MyPubHostKey,SignAlg}, f = Public, h_sig = H_SIG }, Ssh0), @@ -411,13 +416,14 @@ handle_kexdh_init(#ssh_msg_kexdh_init{e = E}, 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) -> + #ssh{keyex_key = {{Private, Public}, {G, P}}, + algorithms = #alg{kex=Kex, + hkey=SignAlg}} = Ssh0) -> %% client if 1= K = compute_key(dh, F, Private, [P,G]), - H = kex_h(Ssh0, PeerPubHostKey, Public, F, K), - + H = kex_hash(Ssh0, PeerPubHostKey, SignAlg, sha(Kex), {Public,F,K}), case verify_host_key(Ssh0, PeerPubHostKey, H, H_SIG) of ok -> {SshPacket, Ssh} = ssh_packet(#ssh_msg_newkeys{}, Ssh0), @@ -493,7 +499,7 @@ handle_kex_dh_gex_request(#ssh_msg_kex_dh_gex_request_old{n = NBits}, ssh_packet(#ssh_msg_kex_dh_gex_group{p = P, g = G}, Ssh0), {ok, SshPacket, Ssh#ssh{keyex_key = {x, {G, P}}, - keyex_info = {-1, -1, NBits} % flag for kex_h hash calc + keyex_info = {-1, -1, NBits} % flag for kex_hash calc }}; {error,_} -> ssh_connection_handler:disconnect( @@ -539,20 +545,21 @@ handle_kex_dh_gex_group(#ssh_msg_kex_dh_gex_group{p = P, g = G}, Ssh0) -> handle_kex_dh_gex_init(#ssh_msg_kex_dh_gex_init{e = E}, #ssh{keyex_key = {{Private, Public}, {G, P}}, - keyex_info = {Min, Max, NBits}} = - Ssh0) -> + keyex_info = {Min, Max, NBits}, + algorithms = #alg{kex=Kex, + hkey=SignAlg}} = Ssh0) -> %% server if 1= K = compute_key(dh, E, Private, [P,G]), if 1 - MyPrivHostKey = get_host_key(Ssh0), + MyPrivHostKey = get_host_key(Ssh0, SignAlg), 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), + H = kex_hash(Ssh0, MyPubHostKey, SignAlg, sha(Kex), {Min,NBits,Max,P,G,E,Public,K}), + H_SIG = sign(H, sha(SignAlg), MyPrivHostKey), {SshPacket, Ssh} = - ssh_packet(#ssh_msg_kex_dh_gex_reply{public_host_key = MyPubHostKey, + ssh_packet(#ssh_msg_kex_dh_gex_reply{public_host_key = {MyPubHostKey,SignAlg}, f = Public, h_sig = H_SIG}, Ssh0), {ok, SshPacket, Ssh#ssh{shared_secret = ssh_bits:mpint(K), @@ -578,7 +585,9 @@ handle_kex_dh_gex_reply(#ssh_msg_kex_dh_gex_reply{public_host_key = PeerPubHostK f = F, h_sig = H_SIG}, #ssh{keyex_key = {{Private, Public}, {G, P}}, - keyex_info = {Min, Max, NBits}} = + keyex_info = {Min, Max, NBits}, + algorithms = #alg{kex=Kex, + hkey=SignAlg}} = Ssh0) -> %% client if @@ -586,8 +595,7 @@ handle_kex_dh_gex_reply(#ssh_msg_kex_dh_gex_reply{public_host_key = PeerPubHostK K = compute_key(dh, F, Private, [P,G]), if 1 - H = kex_h(Ssh0, PeerPubHostKey, Min, NBits, Max, P, G, Public, F, K), - + H = kex_hash(Ssh0, PeerPubHostKey, SignAlg, sha(Kex), {Min,NBits,Max,P,G,Public,F,K}), case verify_host_key(Ssh0, PeerPubHostKey, H, H_SIG) of ok -> {SshPacket, Ssh} = ssh_packet(#ssh_msg_newkeys{}, Ssh0), @@ -623,7 +631,8 @@ handle_kex_dh_gex_reply(#ssh_msg_kex_dh_gex_reply{public_host_key = PeerPubHostK %%% diffie-hellman-ecdh-sha2-* %%% handle_kex_ecdh_init(#ssh_msg_kex_ecdh_init{q_c = PeerPublic}, - Ssh0 = #ssh{algorithms = #alg{kex=Kex}}) -> + Ssh0 = #ssh{algorithms = #alg{kex=Kex, + hkey=SignAlg}}) -> %% at server Curve = ecdh_curve(Kex), {MyPublic, MyPrivate} = generate_key(ecdh, Curve), @@ -631,12 +640,12 @@ handle_kex_ecdh_init(#ssh_msg_kex_ecdh_init{q_c = PeerPublic}, compute_key(ecdh, PeerPublic, MyPrivate, Curve) of K -> - MyPrivHostKey = get_host_key(Ssh0), + MyPrivHostKey = get_host_key(Ssh0, SignAlg), MyPubHostKey = extract_public_key(MyPrivHostKey), - H = kex_h(Ssh0, Curve, MyPubHostKey, PeerPublic, MyPublic, K), - H_SIG = sign_host_key(Ssh0, MyPrivHostKey, H), + H = kex_hash(Ssh0, MyPubHostKey, SignAlg, sha(Curve), {PeerPublic, MyPublic, K}), + H_SIG = sign(H, sha(SignAlg), MyPrivHostKey), {SshPacket, Ssh1} = - ssh_packet(#ssh_msg_kex_ecdh_reply{public_host_key = MyPubHostKey, + ssh_packet(#ssh_msg_kex_ecdh_reply{public_host_key = {MyPubHostKey,SignAlg}, q_s = MyPublic, h_sig = H_SIG}, Ssh0), @@ -656,14 +665,15 @@ handle_kex_ecdh_init(#ssh_msg_kex_ecdh_init{q_c = PeerPublic}, 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 + #ssh{keyex_key = {{MyPublic,MyPrivate}, Curve}, + algorithms = #alg{hkey=SignAlg}} = Ssh0 ) -> %% at client try compute_key(ecdh, PeerPublic, MyPrivate, Curve) of K -> - H = kex_h(Ssh0, Curve, PeerPubHostKey, MyPublic, PeerPublic, K), + H = kex_hash(Ssh0, PeerPubHostKey, SignAlg, sha(Curve), {MyPublic,PeerPublic,K}), case verify_host_key(Ssh0, PeerPubHostKey, H, H_SIG) of ok -> {SshPacket, Ssh} = ssh_packet(#ssh_msg_newkeys{}, Ssh0), @@ -735,25 +745,14 @@ sid(#ssh{session_id = Id}, _) -> Id. %% %% The host key should be read from storage %% -get_host_key(SSH) -> - #ssh{key_cb = {KeyCb,KeyCbOpts}, opts = Opts, algorithms = ALG} = SSH, +get_host_key(SSH, SignAlg) -> + #ssh{key_cb = {KeyCb,KeyCbOpts}, opts = Opts} = SSH, UserOpts = ?GET_OPT(user_options, Opts), - case KeyCb:host_key(ALG#alg.hkey, [{key_cb_private,KeyCbOpts}|UserOpts]) of - {ok, #'RSAPrivateKey'{} = Key} -> Key; - {ok, #'DSAPrivateKey'{} = Key} -> Key; - {ok, #'ECPrivateKey'{} = Key} -> Key; - Result -> - exit({error, {Result, unsupported_key_type}}) + case KeyCb:host_key(SignAlg, [{key_cb_private,KeyCbOpts}|UserOpts]) of + {ok, PrivHostKey} -> PrivHostKey; + Result -> exit({error, {Result, unsupported_key_type}}) end. -sign_host_key(_Ssh, PrivateKey, H) -> - sign(H, sign_host_key_sha(PrivateKey), PrivateKey). - -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}) -> @@ -763,8 +762,8 @@ extract_public_key(#'ECPrivateKey'{parameters = {namedCurve,OID}, {#'ECPoint'{point=Q}, {namedCurve,OID}}. -verify_host_key(SSH, PublicKey, Digest, Signature) -> - case verify(Digest, host_key_sha(PublicKey), Signature, PublicKey) of +verify_host_key(#ssh{algorithms=Alg}=SSH, PublicKey, Digest, Signature) -> + case verify(Digest, sha(Alg#alg.hkey), Signature, PublicKey) of false -> {error, bad_signature}; true -> @@ -772,16 +771,6 @@ verify_host_key(SSH, PublicKey, Digest, Signature) -> end. -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'{},{namedCurve,OID}}) -> - Curve = public_key:oid2ssh_curvename(OID), - list_to_atom("ecdsa-sha2-" ++ binary_to_list(Curve)). - accepted_host(Ssh, PeerName, Public, Opts) -> case ?GET_OPT(silently_accept_hosts, Opts) of @@ -1201,29 +1190,29 @@ payload(<>) -> <> = PayloadAndPadding, Payload. -sign(SigData, Hash, #'DSAPrivateKey'{} = Key) -> - DerSignature = public_key:sign(SigData, Hash, Key), +sign(SigData, HashAlg, #'DSAPrivateKey'{} = Key) -> + DerSignature = public_key:sign(SigData, HashAlg, Key), #'Dss-Sig-Value'{r = R, s = S} = public_key:der_decode('Dss-Sig-Value', DerSignature), <>; -sign(SigData, Hash, Key = #'ECPrivateKey'{}) -> - DerEncodedSign = public_key:sign(SigData, Hash, Key), +sign(SigData, HashAlg, Key = #'ECPrivateKey'{}) -> + DerEncodedSign = public_key:sign(SigData, HashAlg, Key), #'ECDSA-Sig-Value'{r=R, s=S} = public_key:der_decode('ECDSA-Sig-Value', DerEncodedSign), <>; -sign(SigData, Hash, Key) -> - public_key:sign(SigData, Hash, Key). +sign(SigData, HashAlg, Key) -> + public_key:sign(SigData, HashAlg, Key). -verify(PlainText, Hash, Sig, {_, #'Dss-Parms'{}} = Key) -> +verify(PlainText, HashAlg, Sig, {_, #'Dss-Parms'{}} = Key) -> <> = 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'{},_} = Key) -> + public_key:verify(PlainText, HashAlg, Signature, Key); +verify(PlainText, HashAlg, Sig, {#'ECPoint'{},_} = Key) -> <> = Sig, Sval = #'ECDSA-Sig-Value'{r=R, s=S}, DerEncodedSig = public_key:der_encode('ECDSA-Sig-Value',Sval), - public_key:verify(PlainText, Hash, DerEncodedSig, Key); -verify(PlainText, Hash, Sig, Key) -> - public_key:verify(PlainText, Hash, Sig, Key). + public_key:verify(PlainText, HashAlg, DerEncodedSig, Key); +verify(PlainText, HashAlg, Sig, Key) -> + public_key:verify(PlainText, HashAlg, Sig, Key). %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% @@ -1730,39 +1719,63 @@ hash(K, H, Ki, N, HashAlg) -> hash(K, H, <>, N-128, HashAlg). %%%---------------------------------------------------------------- -kex_h(SSH, Key, E, F, K) -> - KeyBin = public_key:ssh_encode(Key, ssh2_pubkey), - L = <>, - crypto:hash(sha((SSH#ssh.algorithms)#alg.kex), L). - -kex_h(SSH, Curve, Key, Q_c, Q_s, K) -> - KeyBin = public_key:ssh_encode(Key, ssh2_pubkey), - L = <>, - crypto:hash(sha(Curve), L). - -kex_h(SSH, Key, Min, NBits, Max, Prime, Gen, E, F, K) -> - KeyBin = public_key:ssh_encode(Key, ssh2_pubkey), - L = if Min==-1; Max==-1 -> - %% flag from 'ssh_msg_kex_dh_gex_request_old' - %% It was like this before that message was supported, - %% why? - <>; - true -> - <> - end, - crypto:hash(sha((SSH#ssh.algorithms)#alg.kex), L). - +kex_hash(SSH, Key, SignAlg, HashAlg, Args) -> + crypto:hash(HashAlg, kex_plaintext(SSH,Key,SignAlg,Args)). + +kex_plaintext(SSH, Key, SignAlg, Args) -> + EncodedKey = public_key:ssh_encode({Key,SignAlg}, ssh2_pubkey), + <>. + +kex_alg_dependent({E, F, K}) -> + %% diffie-hellman and ec diffie-hellman (with E = Q_c, F = Q_s) + <>; + +kex_alg_dependent({-1, _, -1, _, _, E, F, K}) -> + %% ssh_msg_kex_dh_gex_request_old + <>; + +kex_alg_dependent({Min, NBits, Max, Prime, Gen, E, F, K}) -> + %% diffie-hellman group exchange + <>. + +%%%---------------------------------------------------------------- + +valid_key_sha_alg(#'RSAPublicKey'{}, 'rsa-sha2-512') -> true; +valid_key_sha_alg(#'RSAPublicKey'{}, 'rsa-sha2-384') -> true; +valid_key_sha_alg(#'RSAPublicKey'{}, 'rsa-sha2-256') -> true; +valid_key_sha_alg(#'RSAPublicKey'{}, 'ssh-rsa' ) -> true; + +valid_key_sha_alg(#'RSAPrivateKey'{}, 'rsa-sha2-512') -> true; +valid_key_sha_alg(#'RSAPrivateKey'{}, 'rsa-sha2-384') -> true; +valid_key_sha_alg(#'RSAPrivateKey'{}, 'rsa-sha2-256') -> true; +valid_key_sha_alg(#'RSAPrivateKey'{}, 'ssh-rsa' ) -> true; + +valid_key_sha_alg({_, #'Dss-Parms'{}}, 'ssh-dss') -> true; +valid_key_sha_alg(#'DSAPrivateKey'{}, 'ssh-dss') -> true; + +valid_key_sha_alg({#'ECPoint'{},{namedCurve,OID}}, Alg) -> sha(OID) == sha(Alg); +valid_key_sha_alg(#'ECPrivateKey'{parameters = {namedCurve,OID}}, Alg) -> sha(OID) == sha(Alg); +valid_key_sha_alg(_, _) -> false. + + + +public_algo(#'RSAPublicKey'{}) -> 'ssh-rsa'; % FIXME: Not right with draft-curdle-rsa-sha2 +public_algo({_, #'Dss-Parms'{}}) -> 'ssh-dss'; +public_algo({#'ECPoint'{},{namedCurve,OID}}) -> + Curve = public_key:oid2ssh_curvename(OID), + list_to_atom("ecdsa-sha2-" ++ binary_to_list(Curve)). + + + sha('ssh-rsa') -> sha; +sha('rsa-sha2-256') -> sha256; +sha('rsa-sha2-384') -> sha384; +sha('rsa-sha2-512') -> sha512; sha('ssh-dss') -> sha; sha('ecdsa-sha2-nistp256') -> sha(secp256r1); sha('ecdsa-sha2-nistp384') -> sha(secp384r1); -- cgit v1.2.3