diff options
Diffstat (limited to 'lib/net/ssh/transport/packet_stream.rb')
| -rw-r--r-- | lib/net/ssh/transport/packet_stream.rb | 90 |
1 files changed, 57 insertions, 33 deletions
diff --git a/lib/net/ssh/transport/packet_stream.rb b/lib/net/ssh/transport/packet_stream.rb index a4120d4..9466096 100644 --- a/lib/net/ssh/transport/packet_stream.rb +++ b/lib/net/ssh/transport/packet_stream.rb @@ -144,31 +144,36 @@ module Net padding = Array.new(padding_length) { rand(256) }.pack("C*") - if client.hmac.etm - debug { "using encrypt-then-mac" } + if client.cipher.name == "chacha20-poly1305@openssh.com" + unencrypted_data = [padding_length, payload, padding].pack("CA*A*") + message = client.cipher.update_cipher_mac(unencrypted_data, client.sequence_number) + else + if client.hmac.etm + debug { "using encrypt-then-mac" } - # Encrypt padding_length, payload, and padding. Take MAC - # from the unencrypted packet_lenght and the encrypted - # data. - length_data = [packet_length].pack("N") + # Encrypt padding_length, payload, and padding. Take MAC + # from the unencrypted packet_lenght and the encrypted + # data. + length_data = [packet_length].pack("N") - unencrypted_data = [padding_length, payload, padding].pack("CA*A*") + unencrypted_data = [padding_length, payload, padding].pack("CA*A*") - encrypted_data = client.update_cipher(unencrypted_data) << client.final_cipher + encrypted_data = client.update_cipher(unencrypted_data) << client.final_cipher - mac_data = length_data + encrypted_data + mac_data = length_data + encrypted_data - mac = client.hmac.digest([client.sequence_number, mac_data].pack("NA*")) + mac = client.hmac.digest([client.sequence_number, mac_data].pack("NA*")) - message = mac_data + mac - else - unencrypted_data = [packet_length, padding_length, payload, padding].pack("NCA*A*") + message = mac_data + mac + else + unencrypted_data = [packet_length, padding_length, payload, padding].pack("NCA*A*") - mac = client.hmac.digest([client.sequence_number, unencrypted_data].pack("NA*")) + mac = client.hmac.digest([client.sequence_number, unencrypted_data].pack("NA*")) - encrypted_data = client.update_cipher(unencrypted_data) << client.final_cipher + encrypted_data = client.update_cipher(unencrypted_data) << client.final_cipher - message = encrypted_data + mac + message = encrypted_data + mac + end end debug { "queueing packet nr #{client.sequence_number} type #{payload.getbyte(0)} len #{packet_length}" } @@ -225,44 +230,63 @@ module Net data = read_available(minimum + aad_length) # decipher it - if server.hmac.etm - @packet_length = data.unpack("N").first + if server.cipher.name == "chacha20-poly1305@openssh.com" + @packet_length = server.cipher.read_length(data[0...4], server.sequence_number) + @packet = Net::SSH::Buffer.new() @mac_data = data - @packet = Net::SSH::Buffer.new(server.update_cipher(data[aad_length..-1])) else - @packet = Net::SSH::Buffer.new(server.update_cipher(data)) - @packet_length = @packet.read_long + if server.hmac.etm + @packet_length = data.unpack("N").first + @mac_data = data + @packet = Net::SSH::Buffer.new(server.update_cipher(data[aad_length..-1])) + else + @packet = Net::SSH::Buffer.new(server.update_cipher(data)) + @packet_length = @packet.read_long + end end end need = @packet_length + 4 - aad_length - server.block_size raise Net::SSH::Exception, "padding error, need #{need} block #{server.block_size}" if need % server.block_size != 0 - return nil if available < need + server.hmac.mac_length + if server.cipher.name == "chacha20-poly1305@openssh.com" + return nil if available < need + server.cipher.mac_length + else + return nil if available < need + server.hmac.mac_length + end if need > 0 # read the remainder of the packet and decrypt it. data = read_available(need) - @mac_data += data if server.hmac.etm - @packet.append(server.update_cipher(data)) + @mac_data += data if server.hmac.etm || (server.cipher.name == "chacha20-poly1305@openssh.com") + if server.cipher.name != "chacha20-poly1305@openssh.com" + @packet.append(server.update_cipher(data)) + end end - # get the hmac from the tail of the packet (if one exists), and - # then validate it. - real_hmac = read_available(server.hmac.mac_length) || "" + if server.cipher.name != "chacha20-poly1305@openssh.com" + # get the hmac from the tail of the packet (if one exists), and + # then validate it. + real_hmac = read_available(server.hmac.mac_length) || "" - @packet.append(server.final_cipher) - padding_length = @packet.read_byte + @packet.append(server.final_cipher) + padding_length = @packet.read_byte - payload = @packet.read(@packet_length - padding_length - 1) + payload = @packet.read(@packet_length - padding_length - 1) + - my_computed_hmac = if server.hmac.etm + my_computed_hmac = if server.hmac.etm server.hmac.digest([server.sequence_number, @mac_data].pack("NA*")) else server.hmac.digest([server.sequence_number, @packet.content].pack("NA*")) end - raise Net::SSH::Exception, "corrupted hmac detected #{server.hmac.class}" if real_hmac != my_computed_hmac - + raise Net::SSH::Exception, "corrupted hmac detected #{server.hmac.class}" if real_hmac != my_computed_hmac + else + real_hmac = read_available(server.cipher.mac_length) || "" + @packet = Net::SSH::Buffer.new(server.cipher.read_and_mac(@mac_data, real_hmac, server.sequence_number)) + padding_length = @packet.read_byte + payload = @packet.read(@packet_length - padding_length - 1) + end # try to decompress the payload, in case compression is active payload = server.decompress(payload) |