I use gpg-agent also as an ssh agent, or at least, that was my intention. However, I can only conclude that ssh-support is completely broken as ssh-add does't work with with gpg-agent, and ssh can't use gpg-agent for authentication.
Here is the proof:
As you can see, gpg-agent is configured correctly as an ssh-agent:
echo $GPG_AGENT_INFO /home/jeroen/.gnupg/S.gpg-agent:0:1 echo $SSH_AUTH_SOCK /home/jeroen/.gnupg/S.gpg-agent.ssh
ssh-add even picks up the authentication subkey in my keyring:
$ ssh-add -l 2048 SHA256:vqxRmLYNTdgXVm92f5WLoOpMYYU4k+Bun0aqnxU2FVY (none) (RSA)
However, ssh fails miserably when trying to authenticate:
ssh 192.168.60.10 sign_and_send_pubkey: signing failed: agent refused operation
I don't get even prompted for my password.
adding existing ssh keys doesn't work either:
ssh-add ~/.ssh/datacenter-hic-deploy Enter passphrase for /home/jeroen/.ssh/datacenter-hic-deploy: Could not add identity "/home/jeroen/.ssh/datacenter-hic-deploy": agent refused operation
Additional info:
- I'm not using a smartcard at the moment.
- No other ssh agent is active
Here is a full ssh connection log, in case you need it:
ssh -vv 192.168.60.10 OpenSSH_7.2p2 Ubuntu-4ubuntu2.2, OpenSSL 1.0.2g 1 Mar 2016 debug1: Reading configuration data /home/jeroen/.ssh/config debug1: Reading configuration data /etc/ssh/ssh_config debug1: /etc/ssh/ssh_config line 19: Applying options for * debug2: resolving "192.168.60.10" port 22 debug2: ssh_connect_direct: needpriv 0 debug1: Connecting to 192.168.60.10 [192.168.60.10] port 22. debug1: Connection established. debug1: key_load_public: No such file or directory debug1: identity file /home/jeroen/.ssh/id_rsa type -1 debug1: key_load_public: No such file or directory debug1: identity file /home/jeroen/.ssh/id_rsa-cert type -1 debug1: key_load_public: No such file or directory debug1: identity file /home/jeroen/.ssh/id_dsa type -1 debug1: key_load_public: No such file or directory debug1: identity file /home/jeroen/.ssh/id_dsa-cert type -1 debug1: key_load_public: No such file or directory debug1: identity file /home/jeroen/.ssh/id_ecdsa type -1 debug1: key_load_public: No such file or directory debug1: identity file /home/jeroen/.ssh/id_ecdsa-cert type -1 debug1: key_load_public: No such file or directory debug1: identity file /home/jeroen/.ssh/id_ed25519 type -1 debug1: key_load_public: No such file or directory debug1: identity file /home/jeroen/.ssh/id_ed25519-cert type -1 debug1: Enabling compatibility mode for protocol 2.0 debug1: Local version string SSH-2.0-OpenSSH_7.2p2 Ubuntu-4ubuntu2.2 debug1: Remote protocol version 2.0, remote software version OpenSSH_6.6.1 debug1: match: OpenSSH_6.6.1 pat OpenSSH_6.6.1* compat 0x04000000 debug2: fd 3 setting O_NONBLOCK debug1: Authenticating to 192.168.60.10:22 as 'jeroen' debug1: SSH2_MSG_KEXINIT sent debug1: SSH2_MSG_KEXINIT received debug2: local client KEXINIT proposal debug2: KEX algorithms: curve25519-sha256@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,ext-info-c debug2: host key algorithms: ecdsa-sha2-nistp256-cert-v01@openssh.com,ecdsa-sha2-nistp384-cert-v01@openssh.com,ecdsa-sha2-nistp521-cert-v01@openssh.com,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,ssh-ed25519-cert-v01@openssh.com,ssh-rsa-cert-v01@openssh.com,ssh-ed25519,rsa-sha2-512,rsa-sha2-256,ssh-rsa debug2: ciphers ctos: chacha20-poly1305@openssh.com,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com,aes128-cbc,aes192-cbc,aes256-cbc,3des-cbc debug2: ciphers stoc: chacha20-poly1305@openssh.com,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com,aes128-cbc,aes192-cbc,aes256-cbc,3des-cbc debug2: MACs ctos: umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1 debug2: MACs stoc: umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1 debug2: compression ctos: none,zlib@openssh.com,zlib debug2: compression stoc: none,zlib@openssh.com,zlib debug2: languages ctos: debug2: languages stoc: debug2: first_kex_follows 0 debug2: reserved 0 debug2: peer server KEXINIT proposal debug2: KEX algorithms: curve25519-sha256@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1 debug2: host key algorithms: ssh-rsa,ecdsa-sha2-nistp256,ssh-ed25519 debug2: ciphers ctos: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-gcm@openssh.com,aes256-gcm@openssh.com,chacha20-poly1305@openssh.com,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-cbc@lysator.liu.se debug2: ciphers stoc: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-gcm@openssh.com,aes256-gcm@openssh.com,chacha20-poly1305@openssh.com,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-cbc@lysator.liu.se debug2: MACs ctos: hmac-md5-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-ripemd160-etm@openssh.com,hmac-sha1-96-etm@openssh.com,hmac-md5-96-etm@openssh.com,hmac-md5,hmac-sha1,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-ripemd160,hmac-ripemd160@openssh.com,hmac-sha1-96,hmac-md5-96 debug2: MACs stoc: hmac-md5-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-ripemd160-etm@openssh.com,hmac-sha1-96-etm@openssh.com,hmac-md5-96-etm@openssh.com,hmac-md5,hmac-sha1,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-ripemd160,hmac-ripemd160@openssh.com,hmac-sha1-96,hmac-md5-96 debug2: compression ctos: none,zlib@openssh.com debug2: compression stoc: none,zlib@openssh.com debug2: languages ctos: debug2: languages stoc: debug2: first_kex_follows 0 debug2: reserved 0 debug1: kex: algorithm: curve25519-sha256@libssh.org debug1: kex: host key algorithm: ecdsa-sha2-nistp256 debug1: kex: server->client cipher: chacha20-poly1305@openssh.com MAC: <implicit> compression: none debug1: kex: client->server cipher: chacha20-poly1305@openssh.com MAC: <implicit> compression: none debug1: expecting SSH2_MSG_KEX_ECDH_REPLY debug1: Server host key: ecdsa-sha2-nistp256 SHA256:Er8J4FdvgSXTmA8mGGi1+myV/xwGPAtfaeUvwf7SheY debug1: Host '192.168.60.10' is known and matches the ECDSA host key. debug1: Found key in /home/jeroen/.ssh/known_hosts:213 debug2: set_newkeys: mode 1 debug1: rekey after 134217728 blocks debug1: SSH2_MSG_NEWKEYS sent debug1: expecting SSH2_MSG_NEWKEYS debug2: set_newkeys: mode 0 debug1: rekey after 134217728 blocks debug1: SSH2_MSG_NEWKEYS received debug2: key: (none) (0x55c09da53cb0), agent debug2: key: /home/jeroen/.ssh/id_rsa ((nil)) debug2: key: /home/jeroen/.ssh/id_dsa ((nil)) debug2: key: /home/jeroen/.ssh/id_ecdsa ((nil)) debug2: key: /home/jeroen/.ssh/id_ed25519 ((nil)) debug2: service_accept: ssh-userauth debug1: SSH2_MSG_SERVICE_ACCEPT received debug1: Authentications that can continue: publickey,gssapi-keyex,gssapi-with-mic,password debug1: Next authentication method: gssapi-keyex debug1: No valid Key exchange context debug2: we did not send a packet, disable method debug1: Next authentication method: gssapi-with-mic debug1: Unspecified GSS failure. Minor code may provide more information No Kerberos credentials available debug1: Unspecified GSS failure. Minor code may provide more information No Kerberos credentials available debug1: Unspecified GSS failure. Minor code may provide more information debug1: Unspecified GSS failure. Minor code may provide more information No Kerberos credentials available debug2: we did not send a packet, disable method debug1: Next authentication method: publickey debug1: Offering RSA public key: (none) debug2: we sent a publickey packet, wait for reply debug1: Server accepts key: pkalg ssh-rsa blen 279 debug2: input_userauth_pk_ok: fp SHA256:vqxRmLYNTdgXVm92f5WLoOpMYYU4k+Bun0aqnxU2FVY sign_and_send_pubkey: signing failed: agent refused operation debug1: Trying private key: /home/jeroen/.ssh/id_rsa debug1: Trying private key: /home/jeroen/.ssh/id_dsa debug1: Trying private key: /home/jeroen/.ssh/id_ecdsa debug1: Trying private key: /home/jeroen/.ssh/id_ed25519 debug2: we did not send a packet, disable method debug1: Next authentication method: password jeroen@192.168.60.10's password: