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author | Hans Nilsson <[email protected]> | 2015-05-11 10:53:00 +0200 |
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committer | Hans Nilsson <[email protected]> | 2015-05-11 10:53:00 +0200 |
commit | 4fc828ad916a5f3eedeea55ec7a6e7ea169fa46b (patch) | |
tree | 036caddc1ba73d7eb4dfa374144bb2c107efedba /lib/ssh | |
parent | 5e27065ab2d3f12f84b07fd547d4cc44de410954 (diff) | |
parent | 1dbb97809d0d4cafab45cf0f0281f88ed777cae3 (diff) | |
download | otp-4fc828ad916a5f3eedeea55ec7a6e7ea169fa46b.tar.gz otp-4fc828ad916a5f3eedeea55ec7a6e7ea169fa46b.tar.bz2 otp-4fc828ad916a5f3eedeea55ec7a6e7ea169fa46b.zip |
Merge branch 'hans/ssh/check_kex_e_f_in_range/OTP-12649'
* hans/ssh/check_kex_e_f_in_range/OTP-12649:
ssh: Check e and f parameters in kexdh
Diffstat (limited to 'lib/ssh')
-rw-r--r-- | lib/ssh/src/ssh_transport.erl | 50 |
1 files changed, 34 insertions, 16 deletions
diff --git a/lib/ssh/src/ssh_transport.erl b/lib/ssh/src/ssh_transport.erl index 8669be570e..d6414bab6c 100644 --- a/lib/ssh/src/ssh_transport.erl +++ b/lib/ssh/src/ssh_transport.erl @@ -240,20 +240,30 @@ key_exchange_first_msg('diffie-hellman-group-exchange-sha1', Ssh0) -> handle_kexdh_init(#ssh_msg_kexdh_init{e = E}, Ssh0) -> {G, P} = dh_group1(), - {Private, Public} = dh_gen_key(G, P, 1024), - K = ssh_math:ipow(E, Private, P), - 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), - - {ok, SshPacket, Ssh1#ssh{keyex_key = {{Private, Public}, {G, P}}, - shared_secret = K, - exchanged_hash = H, - session_id = sid(Ssh1, H)}}. + if + 1=<E, E=<(P-1) -> + {Private, Public} = dh_gen_key(G, P, 1024), + K = ssh_math:ipow(E, Private, P), + 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), + + {ok, SshPacket, Ssh1#ssh{keyex_key = {{Private, Public}, {G, P}}, + shared_secret = K, + exchanged_hash = H, + session_id = sid(Ssh1, H)}}; + true -> + Error = {error,bad_e_from_peer}, + Disconnect = #ssh_msg_disconnect{ + code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, + description = "Key exchange failed, 'f' out of bounds", + language = "en"}, + throw({Error, Disconnect}) + end. handle_kex_dh_gex_group(#ssh_msg_kex_dh_gex_group{p = P, g = G}, Ssh0) -> {Private, Public} = dh_gen_key(G,P,1024), @@ -277,7 +287,7 @@ handle_new_keys(#ssh_msg_newkeys{}, Ssh0) -> %% %% Select algorithms handle_kexdh_reply(#ssh_msg_kexdh_reply{public_host_key = HostKey, f = F, h_sig = H_SIG}, - #ssh{keyex_key = {{Private, Public}, {_G, P}}} = Ssh0) -> + #ssh{keyex_key = {{Private, Public}, {_G, P}}} = Ssh0) when 1=<F, F=<(P-1)-> K = ssh_math:ipow(F, Private, P), H = kex_h(Ssh0, HostKey, Public, F, K), @@ -293,7 +303,15 @@ handle_kexdh_reply(#ssh_msg_kexdh_reply{public_host_key = HostKey, f = F, description = "Key exchange failed", language = "en"}, throw({Error, Disconnect}) - end. + end; +handle_kexdh_reply(#ssh_msg_kexdh_reply{}, _SSH) -> + Error = {error,bad_f_from_peer}, + Disconnect = #ssh_msg_disconnect{ + code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, + description = "Key exchange failed, 'f' out of bounds", + language = "en"}, + throw({Error, Disconnect}). + handle_kex_dh_gex_request(#ssh_msg_kex_dh_gex_request{min = _Min, n = _NBits, |