View source for Honeycomb/Releases/1609/Honeycomb and ODL

== Honeycomb and ODL ==

Honeycomb can be managed using ODL as any NETCONF-enabled device.
Please follow https://wiki.opendaylight.org/view/OpenDaylight_Controller:Config:Examples:Netconf
for detailed instructions how to mount and connect to a NETCONF device

== Troubleshooting ==

=== Unable to open SSH session due to invalid crypto configuration ===

If ODL fails to open ssh session due to InvalidAlgorithmParameterException, e.g.:

  2016-09-13 13:52:34,852 | WARN  | NioProcessor-3   | ClientSessionImpl | 180 -
  org.apache.sshd.core - 0.14.0 | Exception caught
  java.security.InvalidAlgorithmParameterException: Prime size must be multiple of 64,
    and can only range from 512 to 2048 (inclusive)
      at com.sun.crypto.provider.DHKeyPairGenerator.initialize(DHKeyPairGenerator.java:120)
        [sunjce_provider.jar:1.8.0_45]
      at java.security.KeyPairGenerator$Delegate.initialize(KeyPairGenerator.java:674)
        [:1.8.0_45-internal]
      at java.security.KeyPairGenerator.initialize(KeyPairGenerator.java:411)
        [:1.8.0_45-internal]
      at org.apache.sshd.common.kex.DH.getE(DH.java:65)[180:org.apache.sshd.core:0.14.0]
  [...]
  2016-09-13 13:52:34,852 | DEBUG | NioProcessor-3   | ClientSessionImpl | 180 -
  org.apache.sshd.core - 0.14.0 | Closing ClientSessionImpl[admin@/127.0.0.1:2835] immediately

It probably means BouncyCastle provider is not properly configured/loaded on the ODL side.

There are 2 solutions to this problem:

==== Solution 1, HC side, less secure ====

First solution is to not use BouncyCastle in Honeycomb. This limits its capabilities in terms of security (using just default Java stuff), but makes it compatible with Opendaylight:

As a workaround start honeycomb with (must be placed into Honeycomb's startup script)

  -Dorg.apache.sshd.registerBouncyCastle=false

As a result 1024 bit DH group will be used for SSH key exchange.

==== Solution 2, ODL side, more secure ====

Second solution is to locate mina sshd jar in ODL distribution's system folder. For Boron it is:

  system/org/apache/sshd/sshd-core/0.14.0/sshd-core-0.14.0.jar

Open the jar (it's just a zip archive), locate ''META-INF/MANIFEST.MF'' file, open it and update the ''Import-Package'' section.
Find this piece:

  org.bouncycast.openssl;version="[1.51,2)";resolution:=optional

and replace it with:

  org.bouncycast.openssl;version="[1.51,2)"

This needs to be done before ODL is started the first time or it needs to be started with "clean" parameter.

===== Background =====

* ODL and HC both use mina-sshd 0.14 for SSH.
* mina-sshd relies partially on bouncy-castle as a security provider
* mina-sshd only defines bouncy-castle dependencies as optional for OSGi environment (which is not correct since there are bugs in the mina-sshd where missing bouncy-castle is just not expected, causing various problems... but that's a different topic)
* netconf features in ODL make sure to first load bouncy-castle bundles and only then mina-sshd (in addition, bouncy-castle provider is placed in karaf's lib/ext and marked to be a security provider in karaf's etc/custom.properties)
* however, when loading netconf features as initial features, there seems to be some sort of race condition in karaf and mina is started without bouncy-castle available making, it work only partially
* but so far so good, everything loads and mina should just use less secure provider from Java
* however when an SSH connection is started from ODL to e.g. Honeycomb. Mina-sshd is picking key size that's only supported by bouncy-castle (not by Java) during negotiation
* this means that if remote supports such size, mina-sshd in ODL subsequently fails, since it finds out bouncy-castle is not present and Java is unable to handle it