Solved - Windows cannot access samba shares after linux upgrade

I encounter this issue after apt-get upgrade / dist-upgrade in Debian. It is solved now.
The cause was a change in samba between versions 3.3.2 and 3.4.0.

Error "failed to get a socket for (null)" after upgrading apache httpd

The symptom: After an regular Debian update, when I tried to start apache, it show me this error:

(22)Invalid argument: alloc_listener: failed to get a socket for (null)
...
Syntax error on line xx of /etc/apache2/ports.conf:

The line was
Listen 80

Status on verification of signed file

Table with Digital Signature Status Values

Counter-signatures and signing a file with multiple certificates

Counter-signing is the action of signing data that includes another signature.

Searching in default maven repository

http://repo1.maven.org/maven2/ is the default repository for Maven 2 & 3, but many times it is hard to find the project artifactId, groupId and version in it.

log4j in maven project

Adding support for log4j is realized via maven dependency. You have to edit pom.xml file, and add these lines:

Catching database resources leaks with Tomcat - howto

This it a solution of "Cannot get a connection, pool error Timeout waiting for idle object" error message. It guides how to find your resource leak.

Get console output in Tomcat

You need stdout.log & stderr.log in Tomcat in Windows? Here is a guide how to get it.

Client authentication with SSL certificates in Jetty in maven

Here is an example pom.xml fragment:

Client authentication with SSL certificates in Tomcat

Place something like this in server.xml file:

      <Connector port="8443" 
           protocol="HTTP/1.1" 
           SSLEnabled="true"
           maxThreads="150" 
           scheme="https" 
           secure="true"
           sslProtocol="TLS"
           keystorePass="pass"
           keystoreFile="/data/abcd/someserver/server1.jks"
           truststoreFile="/data/abcd/eshop/AbcdRootCa.jks"
           truststorePass="pass"
           keyAlias="www.miteff.com"
           clientAuth="want"
           SSLVerifyClient="optional"
           SSLCACertificateFile="/data/abcd/someserver/AbcdRootCA.pem"
       />


Attention: clientAuth parameter, in Tomcat 6.0 can get value "want", so it accepts connections with and wothout certificates. The application could decide what to do with the two types of clients internally. Take attention Tomcat 6.0 COULD NOT understand option clientAuth="optional". I suppose it was valid sometime, but now it is not.

Checking certificate validity via CRL with openssl


openssl verify -crl_check -CAfile miteff-root-ca-c.crt -untrusted signer-ca-c3-chain.crt https-miteff.com.chain.crt


Getting HTTPS SSL certificates from HttpRequest in Java

Such an easy solution:

java.security.cert.X509Certificate cert[] =
(java.security.cert.X509Certificate[]) httpServletRequest.getAttribute
("javax.servlet.request.X509Certificate");


The result is the whole certificate chain.

The client could or could not send its certificate. A client certificate can be send in SSL version 3 and in TLS. You have to set an option to the web application server to want ant to accept client certificates. In jetty, the option is named wantClientAuth. Later I will extend the article with the name for Tomcat.

Adding external jar libraries to maven project

You have to add something like this in your pom.xml:
    <dependency>
        <groupId>com.xxx.yyy.messages</groupId>
        <artifactId>xxxyyyMessages2</artifactId>
        <version>2.0-SNAPSHOT</version>
        <scope>system</scope>
        <systemPath>${project.basedir}/../xxxyyyMessages2/target/xxxyyyMessages2-2.0-SNAPSHOT.jar</systemPath>
    </dependency>


Making jar with dependency jars incorporated with maven

I want to start my program from the clear console. Here is the code, which has to be placed in pom.xml:

Redirecting output in MS DOS

I need to redirect the error output to file also. This can be done with

command > certpath.txt 2>&1


For example:

java -Djava.security.debug=certpath -jar target\xxx-2.0-SNAPSHOT-jar-with-dependencies.jar > certpath.txt 2>&1


Checking certificate validity via OCSP with OpenSSL

The certificate have to had a OCSP definition.


openssl
OpenSSL>
OpenSSL> ocsp -issuer G:\temp\1\XXXRootCA.pem -cert G:\temp\1\XXXRootCA.pem -CAfile G:\temp\1\XXXRootCA.pem -url http://ocsp.myserver.com:80 -text


Note: add full path to the files

Debugging classes without sources

I have to debug some classes, which are not provided with source code in NetBeans.

I have to choose from these options:
1. Switch to Eclipse and use JD-Eclipse. Many people indicates that they use it without problems.
2. Decompile the sources and add them to IDE. In this case we have to an another problem - line numbers. From Java bytecode, IDE knows the lines, where the operations are placed in source code. If lines mismatch, the debugger jumps to wrong numbers - fail.

Multiple vhosts with apache httpd

There are two major questions about that:
1. May an apache site has multiple https virtual hosts?
2. May an apache site has different certificates for different virtual hosts.

Answers:

java.lang.OutOfMemoryError: PermGen space - Cause and Solution

The error was (in maven):
java.lang.OutOfMemoryError: PermGen space

Solution:
If you build with maven:
MAVEN_OPTS="-Xms512m -Xmx768m -XX:PermSize=256m -XX:MaxPermSize=512m"
AND
JAVA_OPTS="-Xms512m -Xmx768m"

If you use other tools, check their OPTS configuration - may be there is analogue.

linux: Searching in command history

This is a great trick for everyone who uses linux console a lot.

1. Ctrl+R in console
2. Enter search string
3. OS suggests you a line from command history
4. If you want an older command with same search string, just hit Ctrl+R.
5. that's all folks

EJBCA with jboss

EJBCA 4.07 supports jBoss version 5.1 but not jboss 6.0 or jboss 7.0. I checked with jboss web profile and with full version too.

The error message is in ant command

ant bootstrap

The error was:

"package javax.ejb does not exist"


So how i resolved it? I returned to jboss 5.1. :(

Optimizing queries with EXPLAIN

The explain command gives information about indexes which are used for the query, so you could check, whether it is optimized as you expected.

Problem with WebDAV folders in debian linux

Here is my problem:

When I try to copy some files / folders to webdav folder, I get an error in Windows XP and this log in my Linux box:

[Tue Jan 03 13:49:35 2012] [error] [client 123.123.123.123] File does not exist: /the/webdav/folder/some-file.JPG
[Tue Jan 03 13:49:35 2012] [error] [client 123.123.123.123] The locks could not be queried for verification against a possible "If:" header. [500, #0]
[Tue Jan 03 13:49:35 2012] [error] [client 123.123.123.123] Could not open the lock database. [500, #400]
[Tue Jan 03 13:49:35 2012] [error] [client 123.123.123.123] (2)No such file or directory: Could not open property database. [500, #1]