Skip to content

server gave bad signature for RSA key 0: incorrect signature on connect #4

@un-def

Description

@un-def

The following warning is printed after successful authentication:

client_global_hostkeys_prove_confirm: server gave bad signature for RSA key 0: incorrect signature

DEBUG3 log with relevant messages:

debug3: receive packet: type 80
debug1: client_input_global_request: rtype hostkeys-00@openssh.com want_reply 0
debug3: client_input_hostkeys: received RSA key SHA256:pBfV4Mkhk33j52vy5/K0n4S6rAeZl+3KWpI7RlKjR8Y
debug3: client_input_hostkeys: received ECDSA key SHA256:ZC/9S8peKtRgAfiHNSrRvH34ZsB+f1XoRh2NlBTjmGg
debug3: client_input_hostkeys: received ED25519 key SHA256:HwSlQTKh/PnjJMKSNqBv4JlPcKRtWTGLOeBlYlkw8fE
debug3: client_input_hostkeys: asking server to prove ownership for 3 keys
debug3: send packet: type 80
debug3: receive packet: type 91
debug3: receive packet: type 81
debug3: client_global_hostkeys_prove_confirm: verify RSA key 0 using sigalg rsa-sha2-512
client_global_hostkeys_prove_confirm: server gave bad signature for RSA key 0: incorrect signature

hostkeys-00@openssh.com request in the log is part of host key update mechanism:

On success, the server returns the following message:

   byte             SSH_MSG_REQUEST_SUCCESS
   string[]         signatures

Each signature is made by signing the following structure with the corresponding key[...]

   string           "hostkeys-prove-0"
   string           session identifier
   string           hostkey

As client-sshproxy and sshproxy-upstream connections has different sessions identifiers, the signature check always fails.

Metadata

Metadata

Assignees

Labels

bugSomething isn't working

Type

No type

Projects

No projects

Milestone

No milestone

Relationships

None yet

Development

No branches or pull requests

Issue actions