Technology Insights

JTR – John The Ripper Compile Error – /usr/bin/ld: cannot find -lOpenCL

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The article below describes an error received while attempting to compile John The Ripper with GPU support via OpenCL on Ubuntu Linux version 12.04 LTS also known as Precise Pangolin. Many compile errors are related to necessary packages not being installed on Linux though other errors could be related to all sorts of different issues such as incorrect Library versions or files in the incorrect locations. In this case the specific error states that ld cannot locate the OpenCL library so below we describe the error in more detail, how to search to see if the proper libraries are installed, and the resolution by simply creating a symbolic link to the proper OpenCL library.

Technology Insights

JTR – John The Ripper Compile Error – common-opencl.h:8:19: fatal error: CL/cl.h: No such file or directory

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Recently while attempting to get John The Ripper 1.7.9 jumbo-7 working on a Ubuntu 12.04 LTS Linux server with multiple AMD GPU cards in it I ran across an error during the compile process. The error complained about the VL/cl.h file not being installed and thus could not finishing compiling. Below I describe the compile error, how to locate the Ubuntu package that installs the necessary file to move past the previously mentioned compile error, and then how to install the correct package.

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JTR – John The Ripper Compile Error – sha.h:4:25: fatal error: openssl/sha.h: No such file or directory

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Earlier while compiling JTR or John The Ripper password cracker on a new Ubuntu 12.04 LTS server I received a compile error. The error compiling JTR, which is noted in more detail below, pointed to the sha.h file not being found which likely means there is a missing package though I have seen other causes for file versions being incorrect. Below I explain the initial compile error in more detail, how to track down the package that provides the necessary file or files, and how to install the necessary package on Ubuntu.

Information Security

PCRE Regex Filters For Kismet On Backtrack Linux

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If you decide to remove the default kismet install on Backtrack Linux so you can then compile kismet from source you will be missing some functionality. One of the bits of functionality not installed by default on Backtrack 5 release 3 is the PCRE Regex Filters. You can easily enable this functionality by installing a single package before you run the kismet configure command when compiling the source.

Information Security

btscanner Brute Force Bluetooth Crashes On Backtrack 5 R3

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I have been playing around with some of the bluetooth tools within Backtrack recently and btscanner is one of the main tools I have bene using. The btscanner application in Backtrack Linux provides two bluetooth scanning functions it calls inquiry scanning and brute force scanning. Unfortunately the package installed with Backtrack 5 release 3 will crash when attempting to use it for brute force scanning however I was able to create a fix that isn’t too messy to accomplish. Below we describe the btscanner crash in more detail and provide a way to get btscanner bluetooth brute forcing operating properly.