最近接触jsch这个包，发现在默认情况下，jsch登录ssh的时候，协商的加密算法和mac算法都不是最高优先级的，这个时候需要手动配置一下算法列表，将强度高的调整在算法列表的前面，这样ssh链接的时候，如果双方都，就会协商成高优先级算法。代码参数jsch的示例，只是添加了一个配置文件，通过wireshark抓包来观测配置前后的变化。
测试结果：
默认不配置：
配置算法列表：
代码：
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importjava.io.InputStream;
importjava.util.Properties;
importcom.jcraft.jsch.*;
publicclassjschSample{
publicstaticvoidmain(String[]args){
// TODO Auto-generated method stub
Propertiesp=newProperties();
p.setProperty("cipher.s2c","aes256-ctr,aes192-ctr,aes128-ctr");
p.setProperty("cipher.c2s","aes256-ctr,aes192-ctr,aes128-ctr");
p.setProperty("mac.s2c","hmac-sha2,hmac-sha1");
p.setProperty("mac.c2s","hmac-sha2,hmac-sha1");
p.setProperty("kex","ecdh-sha2-nistp256");
p.setProperty("StrictHostKeyChecking","no");
try{
JSchjsch=newJSch();
Sessionsession=jsch.getSession("pi","192.168.1.7",22);
session.setConfig(p);
session.setPassword("raspberry");
session.connect();
Channelchannel=session.openChannel("exec");
((ChannelExec)channel).setCommand("pwd");
channel.setInputStream(null);
InputStreamin=channel.getInputStream();
channel.connect();
byte[]tmp=newbyte[1024];
while(true){
while(in.available()>0){
inti=in.read(tmp,0,1024);
if(i<0)break;
System.out.print(newString(tmp,0,i));
}
if(channel.isClosed()){
if(in.available()>0)continue;
System.out.println("exit-status: "+channel.getExitStatus());
break;
}
try{Thread.sleep(1000);}catch(Exceptionee){}
}
channel.disconnect();
session.disconnect();
}
catch(Exceptione)
{
System.out.println(e);
}
}
}
捕获到的jsch0.1.55版本消息算法列表如下(encryption_algorithms/mac_algorithms算法s2c和c2s是一样的)：
kex_algorithms string:
ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group14-sha1,diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group1-sha1
server_host_key_algorithms string:
ssh-rsa,ssh-dss,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521
encryption_algorithms_client_to_server string:
aes128-ctr,aes128-cbc,3des-ctr,3des-cbc,blowfish-cbc,aes192-ctr,aes192-cbc,aes256-ctr,aes256-cbc
mac_algorithms_client_to_server string:
hmac-md5,hmac-sha1,hmac-sha2-256,hmac-sha1-96,hmac-md5-96
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