title: ssh2_connect(): Error startingup SSH connection(-8): Unable to exchange encryption keys
body: <p>I'm doing some coding with libssh2 to connect to Huawei routers. On some routers works fine, on others just echo this error: </p>
  
  <p>"Warning: ssh2_connect(): Error startingup SSH connection(-8): Unable to exchange encryption keys in (...)". </p>
  
  <p>I used putty on same routers and the sessions logs are identical:</p>
  
  <pre><code>2015-05-27 12:02:19 Server version: SSH-2.0-HUAWEI-1.5
  2015-05-27 12:02:19 Using SSH protocol version 2
  2015-05-27 12:02:19 We claim version: SSH-2.0-PuTTY_Release_0.63
  2015-05-27 12:02:19 Doing Diffie-Hellman group exchange
  2015-05-27 12:02:19 Doing Diffie-Hellman key exchange with hash SHA-1
  2015-05-27 12:02:32 Host key fingerprint is:
  2015-05-27 12:02:32 ssh-rsa 512 8a:07:9a:28:1d:4d:22:4c:18:35:4f:18:eb:ba:9e:b3
  2015-05-27 12:02:32 Initialised AES-128 CBC client-&gt;server encryption
  2015-05-27 12:02:32 Initialised HMAC-SHA1 client-&gt;server MAC algorithm
  2015-05-27 12:02:32 Initialised AES-128 CBC server-&gt;client encryption
  2015-05-27 12:02:32 Initialised HMAC-SHA1 server-&gt;client MAC algorithm
  </code></pre>
  
  <p>Can you help me?
  Thanks!</p>