【发布时间】：2015-06-19 04:45:23
【问题描述】：
这个问题几乎是this的副本。但是由于它没有得到解决，我想问一下是否有其他人想出解决 JSCH java 库的方法？？
问题再次是我可以使用 JSCH 库连接到大多数 SSH 服务器，但我遇到的这台服务器似乎无法使用 JSCH 连接。在建立连接时，它会抛出一个异常说明：
INFO: Connecting to xxxx.xxxxx.com port 22
INFO: Connection established
INFO: Remote version string: SSH-2.0-2.0
INFO: Local version string: SSH-2.0-JSCH-0.1.53
INFO: CheckCiphers: aes256-ctr,aes192-ctr,aes128-ctr,aes256-cbc,aes192-cbc,aes128-cbc,3des-ctr,arcfour,arcfour128,arcfour256
INFO: CheckKexes: diffie-hellman-group14-sha1,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521
INFO: CheckSignatures: ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521
INFO: SSH_MSG_KEXINIT sent
INFO: SSH_MSG_KEXINIT received
INFO: kex: server: diffie-hellman-group1-sha1,diffie-hellman-group14-sha1
INFO: kex: server: ssh-dss
INFO: kex: server: aes128-cbc,rijndael128-cbc,3des-cbc,blowfish-cbc,aes192-cbc,rijndael192-cbc,aes256-cbc,rijndael256-cbc,rijndael-cbc@lysator.liu.se,cast128-cbc,rijndael-cbc@lysator.liu.se,aes128-ctr,aes192-ctr,aes256-ctr
INFO: kex: server: aes128-cbc,rijndael128-cbc,3des-cbc,blowfish-cbc,aes192-cbc,rijndael192-cbc,aes256-cbc,rijndael256-cbc,rijndael-cbc@lysator.liu.se,cast128-cbc,rijndael-cbc@lysator.liu.se,aes128-ctr,aes192-ctr,aes256-ctr
INFO: kex: server: hmac-md5,hmac-sha1,hmac-sha1-96,hmac-sha2-256,hmac-sha2-256-96,hmac-sha2-512,hmac-sha2-512-96
INFO: kex: server: hmac-md5,hmac-sha1,hmac-sha1-96,hmac-sha2-256,hmac-sha2-256-96,hmac-sha2-512,hmac-sha2-512-96
INFO: kex: server: zlib,none
INFO: kex: server: zlib,none
INFO: kex: server:
INFO: kex: server:
INFO: kex: client: 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
INFO: kex: client: ssh-rsa,ssh-dss,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521
INFO: kex: client: aes128-ctr,aes128-cbc,3des-ctr,3des-cbc,blowfish-cbc,aes192-ctr,aes192-cbc,aes256-ctr,aes256-cbc
INFO: kex: client: aes128-ctr,aes128-cbc,3des-ctr,3des-cbc,blowfish-cbc,aes192-ctr,aes192-cbc,aes256-ctr,aes256-cbc
INFO: kex: client: hmac-md5,hmac-sha1,hmac-sha2-256,hmac-sha1-96,hmac-md5-96
INFO: kex: client: hmac-md5,hmac-sha1,hmac-sha2-256,hmac-sha1-96,hmac-md5-96
INFO: kex: client: none
INFO: kex: client: none
INFO: kex: client:
INFO: kex: client:
INFO: kex: server->client aes128-ctr hmac-md5 none
INFO: kex: client->server aes128-ctr hmac-md5 none
INFO: SSH_MSG_KEXDH_INIT sent
INFO: expecting SSH_MSG_KEXDH_REPLY
INFO: Disconnecting from xxxxx.xxxxx.com port 22
com.jcraft.jsch.JSchException: Session.connect: java.security.InvalidKeyException: Key is too long for this algorithm
at com.jcraft.jsch.Session.connect(Session.java:558)
at com.jcraft.jsch.Session.connect(Session.java:183)
at com.test.filetransfer.SftpDownload.main(SftpDownload.java:29)
Exception occurred : Session.connect: java.security.InvalidKeyException: Key is too long for this algorithm
我已经安装了无限加密策略，但是
这似乎是支持 DH 和 DSA 生成到 1024 位的默认 Java JCE 提供程序的问题。这个堆栈支持我的主张：
com.jcraft.jsch.JSchException: Session.connect failed
at com.jcraft.jsch.Session.connect(Session.java:560)
at com.jcraft.jsch.Session.connect(Session.java:184)
at com.test.filetransfer.SftpDownload.main(SftpDownload.java:28)
Caused by: java.security.InvalidKeyException: Key is too long for this algorithm
at sun.security.provider.DSA$LegacyDSA.checkKey(DSA.java:487)
at sun.security.provider.DSA.engineInitVerify(DSA.java:152)
at java.security.Signature$Delegate.init(Signature.java:1124)
at java.security.Signature$Delegate.chooseProvider(Signature.java:1087)
at java.security.Signature$Delegate.engineInitVerify(Signature.java:1142)
at java.security.Signature.initVerify(Signature.java:452)
at com.jcraft.jsch.jce.SignatureDSA.setPubKey(SignatureDSA.java:52)
at com.jcraft.jsch.KeyExchange.verify(KeyExchange.java:269)
at com.jcraft.jsch.DHG1.next(DHG1.java:187)
at com.jcraft.jsch.Session.connect(Session.java:327)
我真的不想放弃 JSCH 库，因为它具有丰富的功能、受欢迎程度和文档，而且服务器不在我们的管辖范围内。
那么有没有人想出使用 JSCH 库的解决方法？？？
【问题讨论】：
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@MartinPrikryl 谢谢，我现在启用了日志记录并使用详细的连接消息编辑了帖子，但无法找出问题！！！！
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你能找到
java.security.InvalidKeyException的调用栈吗？在Session.java:558放置一个断点并检查e。 -
@MartinPrikryl 抱歉不能这样做。断点可能意味着在 IDE 中，但我通过在我的云实例中构建一个 jar 来部署此代码，该 jar 必须由客户端拥有的 sftp 服务器列入白名单。如果还有其他方法，请务必提及？？
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好的，所以将
throw new JSchException("Session.connect: "+e)更改为throw new JSchException("Session.connect failed", e)。以便保留有关内部异常/原因的所有信息。 -
@MartinPrikryl 完成！！！我已经粘贴了上面的堆栈，这似乎是由于 DSA 生成器造成的。现在我们能做什么????
标签： java bouncycastle jsch jce