Visual Studio基于密钥的SSH远程连接失败问题求助

问题描述 #

尝试在Visual Studio（非VS Code）中配置基于密钥的SSH远程调试，在「连接到远程系统」对话框添加新连接时第一步就失败。

已验证的信息：

• 私钥为PEM格式（以-----BEGIN RSA PRIVATE KEY-----开头）。
• 终端执行ssh -v -i id_rsa user@host_ip，可通过该PEM密钥成功SSH登录，无需密码。
• 目标主机可通过Visual Studio的密码SSH方式正常调试，说明远程调试功能整体可用。

点击连接按钮后出现「连接失败」错误，跨平台日志跟踪信息如下：

10:52:20.2991235 [Info, Thread 1]   liblinux.RemoteSystemBase: Connecting over SSH to 192.168.20.2:22
10:52:20.4114885 [Info, Thread 36]  liblinux.HostKeyVerifier: Connection failed.
10:52:20.4114885 [Info, Thread 36]  liblinux.HostKeyVerifier: System.Security.Cryptography.CryptographicException: Specified padding mode is not valid for this algorithm.
at System.Security.Cryptography.RSACryptoServiceProvider.SignHash(Byte[] hash, HashAlgorithmName hashAlgorithm, RSASignaturePadding padding)
at System.Security.Cryptography.RSA.SignData(Byte[] data, Int32 offset, Int32 count, HashAlgorithmName hashAlgorithm, RSASignaturePadding padding)
at System.Security.Cryptography.RSA.SignData(Byte[] data, HashAlgorithmName hashAlgorithm, RSASignaturePadding padding)
at Renci.SshNet.Security.KeyHostAlgorithm.Sign(Byte[] data)
at Renci.SshNet.PrivateKeyAuthenticationMethod.Authenticate(Session session)
at Renci.SshNet.ClientAuthentication.TryAuthenticate(ISession session, AuthenticationState authenticationState, String[] allowedAuthenticationMethods, SshAuthenticationException& authenticationException)
at Renci.SshNet.ClientAuthentication.Authenticate(IConnectionInfoInternal connectionInfo, ISession session)
at Renci.SshNet.ConnectionInfo.Authenticate(ISession session, IServiceFactory serviceFactory)
at Renci.SshNet.Session.<ConnectAsync>d__180.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Renci.SshNet.BaseClient.<CreateAndConnectSessionAsync>d__56.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Renci.SshNet.BaseClient.<ConnectAsync>d__36.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at liblinux.HostKeyVerifier.<ConnectAsync>d__24.MoveNext()
10:52:20.4114885 [Error, Thread 36] liblinux.RemoteSystemBase: Connection failure over SSH to 192.168.20.2:22
10:52:20.4114885 [Error, Thread 36] liblinux.RemoteSystemBase: System.Security.Cryptography.CryptographicException: Specified padding mode is not valid for this algorithm.
at System.Security.Cryptography.RSACryptoServiceProvider.SignHash(Byte[] hash, HashAlgorithmName hashAlgorithm, RSASignaturePadding padding)
at System.Security.Cryptography.RSA.SignData(Byte[] data, Int32 offset, Int32 count, HashAlgorithmName hashAlgorithm, RSASignaturePadding padding)
at System.Security.Cryptography.RSA.SignData(Byte[] data, HashAlgorithmName hashAlgorithm, RSASignaturePadding padding)
at Renci.SshNet.Security.KeyHostAlgorithm.Sign(Byte[] data)
at Renci.SshNet.PrivateKeyAuthenticationMethod.Authenticate(Session session)
at Renci.SshNet.ClientAuthentication.TryAuthenticate(ISession session, AuthenticationState authenticationState, String[] allowedAuthenticationMethods, SshAuthenticationException& authenticationException)
at Renci.SshNet.ClientAuthentication.Authenticate(IConnectionInfoInternal connectionInfo, ISession session)
at Renci.SshNet.ConnectionInfo.Authenticate(ISession session, IServiceFactory serviceFactory)
at Renci.SshNet.Session.<ConnectAsync>d__180.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Renci.SshNet.BaseClient.<CreateAndConnectSessionAsync>d__56.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Renci.SshNet.BaseClient.<ConnectAsync>d__36.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at liblinux.HostKeyVerifier.<ConnectAsync>d__24.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at liblinux.HostKeyVerifier.<ConnectAsync>d__24.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at liblinux.RemoteSystemBase.<ConnectCoreAsync>d__68.MoveNext()

解决方案 #

1. 重新生成兼容的RSA密钥 #

Visual Studio依赖的Renci.SshNet库对密钥签名填充模式要求严格，终端SSH客户端兼容性更强。重新生成适配的RSA密钥：

ssh-keygen -t rsa -b 2048 -m PEM -f id_rsa_vs

• -m PEM 指定输出格式为PEM
• 将生成的公钥id_rsa_vs.pub添加到远程主机的~/.ssh/authorized_keys文件中，私钥id_rsa_vs用于Visual Studio连接。

2. 转换现有密钥格式 #

若不想重新生成，可通过ssh-keygen转换现有密钥为兼容格式：

ssh-keygen -p -m PEM -f id_rsa

执行后按提示操作（可留空密码），转换完成后再尝试在Visual Studio中使用该密钥。

3. 更新Visual Studio版本 #

部分旧版本Visual Studio的Renci.SshNet库存在加密算法兼容bug，更新到最新稳定版可能解决该问题。

4. 检查密钥权限 #

确保本地私钥文件权限为600（Windows下右键设置权限，仅当前用户可读写）；远程主机~/.ssh目录权限为700，authorized_keys文件权限为600，权限异常也会导致连接失败。

内容的提问来源于stack exchange，提问作者jackhab