NO-JIRA: refresh test keystores, fix failures on new OS/JDK combos where the old signature algs fail updated constraints

(cherry picked from commit 45a400b37d)

activemq-amqp/src/test/resources/README.txt

@@ -0,0 +1,17 @@
+# The various keystores/truststores here were created with the following commands.
+# You can source this file to run it as a sript to regenerate them.
+
+# NOTE: This module isnt a good example of how to generate keypairs and use keystores. This should be replaced,
+#       but needs various module-wide changes to the tests and their client/brokers use of keys/certs/trust.
+
+# Clean up existing files:
+# ------------------------
+rm -f keystore alternative.keystore
+
+# Create a key pair
+# -----------------
+keytool -storetype jks -keystore keystore -storepass password -keypass password -alias activemq -genkey -keyalg "RSA" -keysize 2048 -dname "O=ActiveMQ,CN=localhost" -validity 9999
+
+# Create an alternative keypair, to allow use in provoking 'failure to trust' it when matched against the above
+# ----------------------------------------------------------------------------------------------------------------------
+keytool -storetype jks -keystore alternative.keystore -storepass password -keypass password -alias alternative -genkey -keyalg "RSA" -keysize 2048 -dname "O=Alternative,CN=localhost" -validity 9999