tFTP Connection (SFTP) fails with an 'Algorithm negotiation fail' error

[TalendSolutionExpert]

Problem Description

tFTP Connection with SFTP support, fails with the following error:

tFTPConnection_1 Algorithm negotiation fail
 Exception in component tFTPConnection_1
 com.jcraft.jsch.JSchException: Algorithm negotiation fail

Root Cause

By default, Java provides only a restricted list of algorithms.

Due to import control restrictions, the version of JCE policy files that are bundled in the JDK(TM) environment allow "strong" but limited cryptography to be used.
 The JCE download bundle provides "unlimited strength" policy files which contain no restrictions on cryptographic strengths.

NOTE : This restriction / limitation no more exists in Java 8 updates >=162

https://www.jvmhost.com/articles/jce-unlimited-cipher-policy-different-jdk-versions/
JDK >= 8u162
Unlimited policy files are included and unlimited cipher strength is enabled by default.

The update 162 was released in January 2018 :
https://www.java.com/download/help/release_dates.html

This restriction / limitation does not exist in Java 11
https://help.talend.com/r/en-US/7.3/installation-guide-real-time-big-data-platform-mac/compatible-ja...

Solution

1. Download the Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files, according to your JDK version, from the Oracle Java Archive Download page.

2. Extract the local_policy.jar and US_export_policy.jar, and replace them in the following locations:

   {jdk home}\jre\lib\security\local_policy.jar

   {jdk home}\jre\lib\security\US_export_policy.jar

For more information, see the SAP blog B2B Adapters – Updating to JCE Unlimited Strength Jurisdiction Policy page.