SSH-Agent forwarding not working
<p>I'm trying to ssh from a server into a Mac (mac1) and then from that mac into another (Mac2) using agent forwarding. Both are accessible through the server but don't have the keys to access each other. </p>

<p>I have this config file in the server's ~/.ssh/config:</p>

<pre><code>Host *
ForwardAgent yes
</code></pre>

<p>And then this file in mac1's /etc/sshd_config:</p>

<pre><code>AllowAgentForwarding yes
</code></pre>

<p>Then I log into mac1 with agent-forwarding option:</p>

<pre><code>[brandon's_server]$ ssh -Av root@mac1
OpenSSH_5.3p1, OpenSSL 1.0.1e-fips 11 Feb 2013
debug1: Reading configuration data /home/brandon/.ssh/config
debug1: Applying options for *
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug1: Applying options for *
debug1: Connecting to mac1 [171.67.128.45] port 22.
debug1: Connection established.
debug1: identity file /home/brandon/.ssh/identity type -1
debug1: identity file /home/brandon/.ssh/identity-cert type -1
debug1: identity file /home/brandon/.ssh/id_rsa type -1
debug1: identity file /home/brandon/.ssh/id_rsa-cert type -1
debug1: identity file /home/brandon/.ssh/id_dsa type -1
debug1: identity file /home/brandon/.ssh/id_dsa-cert type -1
debug1: identity file /home/brandon/.ssh/id_ecdsa type -1
debug1: identity file /home/brandon/.ssh/id_ecdsa-cert type -1
debug1: Remote protocol version 2.0, remote software version OpenSSH_6.2
debug1: match: OpenSSH_6.2 pat OpenSSH*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_5.3
debug1: Unspecified GSS failure.  Minor code may provide more information
Server not found in Kerberos database

debug1: Unspecified GSS failure.  Minor code may provide more information
Server not found in Kerberos database

debug1: Unspecified GSS failure.  Minor code may provide more information


debug1: Offering GSSAPI proposal: gss-group1-sha1-eipGX3TCiQSrx573bT1o1Q==,gss-group14-sha1-eipGX3TCiQSrx573bT1o1Q==,gss-gex-sha1-eipGX3TCiQSrx573bT1o1Q==
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: server-&gt;client aes128-ctr hmac-md5 none
debug1: kex: client-&gt;server aes128-ctr hmac-md5 none
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024&lt;1024&lt;8192) sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
debug1: Host 'mac1' is known and matches the RSA host key.
debug1: Found key in /home/brandon/.ssh/known_hosts:10
debug1: ssh_rsa_verify: signature correct
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey
debug1: Next authentication method: publickey
debug1: Offering public key: /home/brandon/.ssh/image_admin_dsa
debug1: Authentications that can continue: publickey
debug1: Offering public key: /home/brandon/.ssh/acts-key-2010
debug1: Server accepts key: pkalg ssh-dss blen 434
debug1: Authentication succeeded (publickey).
debug1: channel 0: new [client-session]
debug1: Requesting no-more-sessions@openssh.com
debug1: Entering interactive session.
debug1: Requesting authentication agent forwarding.
debug1: Sending environment.
debug1: Sending env LANG = en_US.UTF-8
Last login: Fri Jul  1 11:34:39 2016 from
</code></pre>

<p>I seem to have a socket:</p>

<pre><code>mac1&gt;echo $SSH_AUTH_SOCK
/tmp/ssh-0cpmpDpPo9/agent.1941
</code></pre>

<p>Then I run ssh-add with no arguments.
The ssh agent gives me this on mac1:</p>

<pre><code>mac1:~ root# ssh-agent
SSH_AUTH_SOCK=/var/folders/zz/zyxvpxvq6csfxvn_n0000000000000/T//ssh-QOl0KPFzqDTK/agent.4209; export SSH_AUTH_SOCK;
SSH_AGENT_PID=4211; export SSH_AGENT_PID;
echo Agent pid 4211;
</code></pre>

<p>However when I run the second ssh from mac1 to mac2 I get:</p>

<pre><code>&lt;mac1&gt;:~ root# ssh -vvv root@mac2
OpenSSH_6.2p2, OSSLShim 0.9.8r 8 Dec 2011
debug1: Reading configuration data /etc/ssh_config
debug1: /etc/ssh_config line 20: Applying options for *
debug2: ssh_connect: needpriv 0
debug1: Connecting to mac1 [171.67.131.191] port 22.
debug1: Connection established.
debug1: permanently_set_uid: 0/0
debug1: identity file /var/root/.ssh/id_rsa type -1
debug1: identity file /var/root/.ssh/id_rsa-cert type -1
debug1: identity file /var/root/.ssh/id_dsa type -1
debug1: identity file /var/root/.ssh/id_dsa-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_6.2
debug1: Remote protocol version 2.0, remote software version OpenSSH_6.2
debug1: match: OpenSSH_6.2 pat OpenSSH*
debug2: fd 3 setting O_NONBLOCK
debug3: load_hostkeys: loading entries for host "mac2" from file "/var/root/.ssh/known_hosts"
debug3: load_hostkeys: found key type RSA in file /var/root/.ssh/known_hosts:1
debug3: load_hostkeys: loaded 1 keys
debug3: order_hostkeyalgs: prefer hostkeyalgs: ssh-rsa-cert-v01@openssh.com,ssh-rsa-cert-v00@openssh.com,ssh-rsa
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug2: kex_parse_kexinit: diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
debug2: kex_parse_kexinit: ssh-rsa-cert-v01@openssh.com,ssh-rsa-cert-v00@openssh.com,ssh-rsa,ssh-dss-cert-v01@openssh.com,ssh-dss-cert-v00@openssh.com,ssh-dss
debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-gcm@openssh.com,aes256-gcm@openssh.com,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-cbc@lysator.liu.se
debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-gcm@openssh.com,aes256-gcm@openssh.com,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-cbc@lysator.liu.se
debug2: kex_parse_kexinit: 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: kex_parse_kexinit: 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: kex_parse_kexinit: none,zlib@openssh.com,zlib
debug2: kex_parse_kexinit: none,zlib@openssh.com,zlib
debug2: kex_parse_kexinit: 
debug2: kex_parse_kexinit: 
debug2: kex_parse_kexinit: first_kex_follows 0 
debug2: kex_parse_kexinit: reserved 0 
debug2: kex_parse_kexinit: diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
debug2: kex_parse_kexinit: ssh-rsa,ssh-dss
debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-gcm@openssh.com,aes256-gcm@openssh.com,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-cbc@lysator.liu.se
debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-gcm@openssh.com,aes256-gcm@openssh.com,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-cbc@lysator.liu.se
debug2: kex_parse_kexinit: 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: kex_parse_kexinit: 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: kex_parse_kexinit: none,zlib@openssh.com
debug2: kex_parse_kexinit: none,zlib@openssh.com
debug2: kex_parse_kexinit: 
debug2: kex_parse_kexinit: 
debug2: kex_parse_kexinit: first_kex_follows 0 
debug2: kex_parse_kexinit: reserved 0 
debug2: mac_setup: found hmac-md5-etm@openssh.com
debug1: kex: server-&gt;client aes128-ctr hmac-md5-etm@openssh.com none
debug2: mac_setup: found hmac-md5-etm@openssh.com
debug1: kex: client-&gt;server aes128-ctr hmac-md5-etm@openssh.com none
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024&lt;1024&lt;8192) sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
debug2: dh_gen_key: priv key bits set: 137/256
debug2: bits set: 489/1024
debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
debug1: Server host key: RSA 3d:e7:79:12:c0:49:3d:88:e8:b2:6c:18:88:a2:c1:d4
debug3: load_hostkeys: loading entries for host "mac2" from file "/var/root/.ssh/known_hosts"
debug3: load_hostkeys: found key type RSA in file /var/root/.ssh/known_hosts:1
debug3: load_hostkeys: loaded 1 keys
debug3: load_hostkeys: loading entries for host "171.67.131.191" from file "/var/root/.ssh/known_hosts"
debug3: load_hostkeys: found key type RSA in file /var/root/.ssh/known_hosts:1
debug3: load_hostkeys: loaded 1 keys
debug1: Host 'mac2' is known and matches the RSA host key.
debug1: Found key in /var/root/.ssh/known_hosts:1
debug2: bits set: 532/1024
debug1: ssh_rsa_verify: signature correct
debug2: kex_derive_keys
debug2: set_newkeys: mode 1
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug2: set_newkeys: mode 0
debug1: SSH2_MSG_NEWKEYS received
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug2: service_accept: ssh-userauth
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug2: key: /home/brandon/.ssh/image_admin_dsa (0x7fcc73c17420),
debug2: key: /home/brandon/.ssh/acts-key-2010 (0x7fcc73c177d0),
debug2: key: /var/root/.ssh/id_rsa (0x0),
debug2: key: /var/root/.ssh/id_dsa (0x0),
debug1: Authentications that can continue: publickey
debug3: start over, passed a different list publickey
debug3: preferred publickey,keyboard-interactive,password
debug3: authmethod_lookup publickey
debug3: remaining preferred: keyboard-interactive,password
debug3: authmethod_is_enabled publickey
debug1: Next authentication method: publickey
debug1: Offering DSA public key: /home/brandon/.ssh/image_admin_dsa
debug3: send_pubkey_test
debug2: we sent a publickey packet, wait for reply
debug1: Authentications that can continue: publickey
debug1: Offering DSA public key: /home/brandon/.ssh/acts-key-2010
debug3: send_pubkey_test
debug2: we sent a publickey packet, wait for reply
debug1: Authentications that can continue: publickey
debug1: Trying private key: /var/root/.ssh/id_rsa
debug3: no such identity: /var/root/.ssh/id_rsa: No such file or directory
debug1: Trying private key: /var/root/.ssh/id_dsa
debug3: no such identity: /var/root/.ssh/id_dsa: No such file or directory
debug2: we did not send a packet, disable method
debug1: No more authentication methods to try.
Permission denied (publicly).
</code></pre>

<p>I believe I got it to work once. But I can't figure out how I did it. Thoughts?</p>