OpenSSH升级中断scp

Question

最近，我将OpenSSH 4服务器中的一个服务器(将RHEL作为5运行)升级为OpenSSH 5.2服务器。

由于升级，客户无法从机器scp文件了。他们使用来自http://ssh.com/的ssh客户机。我可以使用openssh从机器到机器的scp文件，没有问题。

我们使用“公钥身份验证”，它们仍然能够对机器进行ssh，但不能使用scp文件。

这种不相容有什么明显的原因吗？如果不是，我如何才能更深入地研究这个问题？

下面是客户端的日志：

user@srv/home/user> /usr/local/bin/scp -v cdr@xxx.xxx.xxx.51:/home/cdr/test .
scp:SshAppCommon/sshappcommon.c:133: Allocating global SshRegex context.
scp:Scp2/scp2.c:499: Received error "SSH_FC_OK"., msg: Globbing successful.
scp:Scp2/scp2.c:564: Starting transfer...
scp:/home/cdr/test
scp:SshFCTransfer/sshfc_transfer.c:3018: File list has 2 files.
scp:SshFCTransfer/sshfc_transfer.c:2567: Not yet connected, or connection down, waiting...
scp:SshFileCopy/sshfilecopy.c:940: Connecting to remote host. (host = xxx.xxx.xxx.51, user = cdr, port = NULL)
scp:Scp2/scp2.c:1679: argv[0] = /usr/local/bin/ssh2
scp:Scp2/scp2.c:1679: argv[1] = -l
scp:Scp2/scp2.c:1679: argv[2] = cdr
scp:Scp2/scp2.c:1679: argv[3] = -v
scp:Scp2/scp2.c:1679: argv[4] = -x
scp:Scp2/scp2.c:1679: argv[5] = -a
scp:Scp2/scp2.c:1679: argv[6] = -o
scp:Scp2/scp2.c:1679: argv[7] = clearallforwardings yes
scp:Scp2/scp2.c:1679: argv[8] = -o
scp:Scp2/scp2.c:1679: argv[9] = passwordprompt %U@%H's password: 
scp:Scp2/scp2.c:1679: argv[10] = -o
scp:Scp2/scp2.c:1679: argv[11] = nodelay yes
scp:Scp2/scp2.c:1679: argv[12] = -o
scp:Scp2/scp2.c:1679: argv[13] = authenticationnotify yes
scp:Scp2/scp2.c:1679: argv[14] = xxx.xxx.xxx.51
scp:Scp2/scp2.c:1679: argv[15] = -s
scp:Scp2/scp2.c:1679: argv[16] = sftp
debug: Connecting to xxx.xxx.xxx.51, port 22... (SOCKS not used)
debug: Ssh2/ssh2.c:2121: Entering event loop.
debug: Ssh2Client/sshclient.c:1403: Creating transport protocol.
debug: SshAuthMethodClient/sshauthmethodc.c:83: Added "publickey" to usable methods.
debug: SshAuthMethodClient/sshauthmethodc.c:83: Added "password" to usable methods.
debug: Ssh2Client/sshclient.c:1444: Creating userauth protocol.
debug: client supports 2 auth methods: 'publickey,password'
debug: Ssh2Common/sshcommon.c:559: local ip = xxx.xxx.xxx.35, local port = 56985
debug: Ssh2Common/sshcommon.c:561: remote ip = xxx.xxx.xxx.51, remote port = 22
debug: SshConnection/sshconn.c:1930: Wrapping...
debug: Ssh2/ssh2.c:899: Opening /dev/tty for queries.
debug: Remote version: SSH-2.0-OpenSSH_5.2
debug: Ssh2Transport/trcommon.c:1306: Remote version has rekey incompatibility bug.
debug: Ssh2Transport/trcommon.c:1308: Remote version is OpenSSH, KEX guesses disabled.
debug: Ssh2Transport/trcommon.c:1647: lang s to c: `', lang c to s: `'
debug: Ssh2Transport/trcommon.c:1712: c_to_s: cipher aes128-cbc, mac hmac-sha1, compression none
debug: Ssh2Transport/trcommon.c:1715: s_to_c: cipher aes128-cbc, mac hmac-sha1, compression none
debug: Remote host key found from database.
debug: Ssh2Common/sshcommon.c:317: Received SSH_CROSS_STARTUP packet from connection protocol.
debug: Ssh2Common/sshcommon.c:367: Received SSH_CROSS_ALGORITHMS packet from connection protocol.
debug: server offers auth methods 'publickey,password,keyboard-interactive'.
debug: Ssh2AuthPubKeyClient/authc-pubkey.c:1535: adding keyfile "/devapp_users/nsdtest/.ssh2/nsdau187" to candidates
debug: Ssh2AuthPubKeyClient/authc-pubkey.c:1535: adding keyfile "/devapp_users/nsdtest/.ssh2/id_dsa_1024_a" to candidates
debug: Ssh2AuthPubKeyClient/authc-pubkey.c:1535: adding keyfile "/devapp_users/nsdtest/.ssh2/id_dsa_1024_b" to candidates
debug: Constructing and sending signature in publickey authentication.
debug: Ssh2AuthPubKeyClient/authc-pubkey.c:772: ssh_client_auth_pubkey_send_signature: reading /devapp_users/nsdtest/.ssh2/nsdau187
debug: Ssh2AuthPubKeyClient/authc-pubkey.c:1751: Public key authentication was successful.
debug: Ssh2Common/sshcommon.c:285: Received SSH_CROSS_AUTHENTICATED packet from connection protocol.
debug: Ssh2/ssh2.c:650: Returning user input stream to original values.
debug: Ssh2Common/sshcommon.c:829: num_channels now 1
scp:SshFCTransfer/sshfc_transfer.c:130: Source file is "raw", and it needs to be parsed.
debug: SshTtyFlags/sshttyflags.c:354: Not a tty. (fd = 0)
scp:SshFCTransfer/sshfc_transfer.c:1319: No connection yet. Waiting...
scp:SshFileXferClient/sshfilexferc.c:981: ssh_file_client_receive_proc: bad VERSION
scp:SshFCTransfer/sshfc_transfer.c:1319: No connection yet. Waiting...
scp:SshFCTransfer/sshfc_transfer.c:1319: No connection yet. Waiting...
scp:SshFCTransfer/sshfc_transfer.c:1319: No connection yet. Waiting...
scp:SshFCTransfer/sshfc_transfer.c:1319: No connection yet. Waiting...
scp:SshFCTransfer/sshfc_transfer.c:1319: No connection yet. Waiting...
[...] same until the user presses Ctrl+C

user@srv/home/user> debug: SshConnection/sshconn.c:405: EOF from channel stream
debug: Ssh2ChannelSession/sshchsession.c:1721: received exit status : 0
debug: Ssh2Common/sshcommon.c:803: num_channels now 0
debug: Got session close with exit_status=0
debug: destroying client struct...
debug: Ssh2Client/sshclient.c:1478: Destroying client.
debug: SshConfig/sshconfig.c:555: Freeing pki. (host_pki != NULL, user_pki = NULL)
debug: SshConnection/sshconn.c:1982: Destroying SshConn object.
debug: Ssh2Client/sshclient.c:1540: Destroying client completed.
debug: SshAuthMethodClient/sshauthmethodc.c:88: Destroying authentication method array.
debug: SshAppCommon/sshappcommon.c:146: Freeing global SshRegex context.
debug: SshConfig/sshconfig.c:555: Freeing pki. (host_pki = NULL, user_pki = NULL)

以下是服务器日志中的条目

Jun 3 07:22:36 localhost sshd[19898]: Accepted publickey for cdr from xxx.xxx.xx.x port 53119 ssh2
Jun 3 07:22:36 localhost sshd[19900]: subsystem request for sftp
Jun 3 07:22:58 localhost snmpd[8500]: netsnmp_assert index == tmp failed if-mib/data_access/interface.c:467 _access_interface_entry_save_name()
Jun 3 07:23:58 localhost last message repeated 4 times

编辑："Subsystem sftp in sftp“已经在conf文件中启用，并且我可以在没有问题的情况下从服务器中生成sftp文件。

编辑:通过指定用户名/密码尝试在没有密钥的情况下也不起作用。返回到旧版本的工作，所以这是我们现在所做的。

顺便说一下，我们怀疑这条线

debug: SshTtyFlags/sshttyflags.c:354: Not a tty. (fd = 0)

这可能意味着shell发送的东西显示在ssh控制台上，却破坏了scp，但似乎没有在ssh上发送(而且.bashrc看起来很干净)，而且我无法查看解密的scp通信量，以查看是否错误地发送了什么。

Answer 1

“无法scp文件”意味着什么？他们得到的错误信息是什么？

检查您的日志(/var/log/syslog、/var/log/messages、/var/log/daemon.log)，看看SSH服务器是否抛出了任何错误。它们应该很有描述性。有了日志和客户的错误，我们应该能够缩小问题的范围。

编辑

您发布的日志显示了最有可能出现的问题：

scp 2/scp2.c:1679: argv16 = sftp ... scp:SshFileXferClient/sshfilexferc.c:981: ssh_file_client_receive_proc:坏版本

看起来这件事是试图使用sftp协议，而不是scp直接。默认情况下，OpenSSH禁用sftp子系统。我不知道这个变化是什么时候做的，但听起来很有可能。将其添加到您的sshd_config中，看看它是否会更改：

子系统sftp内部

Answer 2

有很多潜在的问题。首先，您是否检查了服务器上的日志，以确定是否有任何线索？是否可能升级更改了客户端无法使用或未设置为使用的设置。例如，您的服务器现在是否需要SSH2，但是客户机只使用SSH1？

日志文件可能会提供找到答案的方法。如果SCP客户端可以进行任何日志记录，这也会很有帮助。

Answer 3

这与已修复的openssh键漏洞有关。所有易受攻击的钥匙都被列入黑名单，应该重新创建。检查一下他们是否可以删除你服务器缓存的指纹。Ons这样做了，客户端应该向用户展示新指纹，并询问他们是否接受。他们认为SSH可能有效，因为应用程序可能会询问用户是否接受新的密钥，或者在升级后与用户进行了初步联系。