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  • How do I use multiple settings file in Django with multiple sites on one server?

    - by William Bing Hua
    I have an ec2 instance running Ubuntu 14.04 and I want to host two sites from it. On my first site I have two settings file, production_settings.py and settings.py (for local development). I import the local settings into the production settings and override any settings with the production settings file. Since my production settings file is not the default settings.py name, I have to create an environment variable DJANGO_SETTINGS_MODULE='site1.production_settings' However because of this whenever I try to start my second site it says No module named site1.production_settings I am assuming that this is due to me setting the environment variable. Another problem is that I won't be able to use different settings file for different sites. How do I start use two different settings file for two different websites?

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  • Is SHA sufficient for checking file duplication? (sha1_file in PHP)

    - by wag2639
    Suppose you wanted to make a file hosting site for people to upload their files and send a link to their friends to retrieve it later and you want to insure files are duplicated where we store them, is PHP's sha1_file good enough for the task? Is there any reason to not use md5_file instead? For the frontend, it'll be obscured using the original file name store in a database but some additional concerns would be if this would reveal anything about the original poster. Does a file inherit any meta information with it like last modified or who posted it or is this stuff based in the file system? Also, is using a salt frivolous since security in regards of rainbow table attack mean nothing to this and the hash could later be used as a checksum? One last thing, scalability? initially, it's only going to be used for small files a couple of megs big but eventually... Edit 1: The point of the hash is primarily to avoid file duplication, not to create obscurity.

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  • How to load a resource bundle from a file resource in Java?

    - by user143794
    I have a file called mybundle.txt in c:/temp - c:/temp/mybundle.txt how do I load this file into a java.util.resource bundle? The file is a valid resource bundle. This does not seem to work: java.net.URL resourceURL = null; String path = "c:/temp/mybundle.txt"; java.io.File fl = new java.io.File(path); try { resourceURL = fl.toURI().toURL(); } catch (MalformedURLException e) { } URLClassLoader urlLoader = new URLClassLoader(new java.net.URL[]{resourceURL}); java.util.ResourceBundle bundle = java.util.ResourceBundle.getBundle( path , java.util.Locale.getDefault(), urlLoader ); What is the best way to do this?

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  • C# move file as soon as it becomes available.

    - by m0s
    Hi, I need to accomplish the following task: Attempt to move a file. If file is locked schedule for moving as soon as it becomes available. I am using File.Move which is sufficient for my program. Now the problems are that: 1) I can't find a good way to check if the file I need to move is locked. I am catching System.IO.IOException but reading other posts around I discovered that the same exception may be thrown for different reasons as well. 2) Determining when the file gets unlocked. One way of doing this is probably using a timer/thread and checking the scheduled files lets say every 30 seconds and attempting to move them. But I hope there is a better way using FileSystemWatcher. This is a .net 3.5 winforms application. Any comments/suggestions are appreciated. Thanks for attention.

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  • Hudson: where to download file and stop specific builds running ?

    - by Kim Jong Woo
    I have a file that is generated inside (hudson server) /var/lib/hudson/jobs/jobtitle/1/out.txt I need to fetch this file, but doing a GET request for http://myhudson:8090/job/jobtitle/1/out.txt doesn't actually locate the file. Basically, I have another box that will grab this file from the hudson server. This box will make the out.txt file available for download. Another challenge is the build number directories. How would I be able to use the hudson API to stop or delete the specific builds running ? I am forced to do iterate through all build numbers to send STOP or DELETE api call in php using wget to do the REST API call. This is not very efficient. for ($i=0; $i < 3000; $i++){ exec('wget -O /dev/null "http://myhudson:8090/job/' . 'jobtitle' . '/$i/stop"'); }

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  • How do you tell git to permanently ignore changes in a file?

    - by Malvineous
    Hi all, I'm working with a git repository that's storing data for a website. It contains a .htaccess file, with some values that are suitable for the production server. In order for me to work on the site, I have to change some values in the file, but I never want to commit these changes or I will break the server. Since .gitignore doesn't work for tracked files, I was using "git update-index --assume-unchanged .htaccess" to ignore my changes in the file, however this only works until you switch branches. Once you change back to your original branch, your changes are lost. Is there some way of telling git to ignore changes in a file and leave it alone when changing branches? (Just as if the file was untracked.)

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  • use file or class for documenting classes in doxygen?

    - by AlejandroVK
    Hi all, This surely is a noob question, but I can't find an answer in Doxygen documentation. I'm not sure whether using: @file or @class when documenting my header files. The reason is that if I put file, then all the comments appear in the Files tab only, but not in the Classes tab (per each). For cpp it's ok, I just use file and it's good, but if I use both file and class in the header (file at the beginning and class right before the start of the class declaration) then I get duplicated entries for the class in the generated documentation... What I'm doing wrong? Any suggestions? Ideas? Regards, Alex

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  • In Python, how do I search a flat file for the closest match to a particular numeric value?

    - by kaushik
    have file data of format 3.343445 1 3.54564 1 4.345535 1 2.453454 1 and so on upto 1000 lines and i have number given such as a=2.44443 for the given file i need to find the row number of the numbers in file which is most close to the given number "a" how can i do this i am presently doing by loading whole file into list and comparing each element and finding the closest one any other better faster method? my code:i need to ru this for different file each time around 20000 times so want a fast method p=os.path.join("c:/begpython/wavnk/",str(str(str(save_a[1]).replace('phone','text'))+'.pm')) x=open(p , 'r') for i in range(6): x.readline() j=0 o=[] for line in x: oj=str(str(line).rstrip('\n')).split(' ') o=o+[oj] j=j+1 temp=long(1232332) end_time=save_a[4] for i in range((j-1)): diff=float(o[i][0])-float(end_time) if diff<0: diff=diff*(-1) if temp>diff: temp=diff pm_row=i

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  • How to open a file with chinese name in python.

    - by mahendraliya
    I am trying to open a file in "w" mode with "open()" function in python. The filename is : ?????.jpg. The open function fails with this filename but succeeds with normal files. How can I open a file with names which are not in English in python? My code is as follows: try: filename = urllib.quote(filename.encode('utf-8')) destination = open(filename, 'w') yield("<br>Obtained the file reference") except: yield("<br>Error while opening the file") I always get "Error while opening the file" for non-english filenames. Thanks in advance.

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  • Defining a static array into a C or C++ source file.

    - by VansFannel
    Hello. I know this is a question that every programmer should know, but I do not know. Long time no C programming and I've forgotten a lot of things. My question is: I have three huge static arrays defined inside a header file. Someone told me that It's much better to declare them as extern in the header file, and define them in a single C or C++ source file. How can I do that? Here is my header file: #ifndef _TEMPLE_OBJECT_H_ #define _TEMPLE_OBJECT_H_ #define NUM_TEMPLE_OBJECT_VERTEX 10818 static const float TEMPLEVertices[NUM_TEMPLE_OBJECT_VERTEX * 3] = {...}; static const float TEMPLENormals[NUM_TEMPLE_OBJECT_VERTEX * 3] = {...}; static const float TEMPLETexCoords[NUM_TEMPLE_OBJECT_VERTEX * 3] = {...}; #endif If a use a C++ source file, may I need to define a class? Thank you.

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  • indexing for faster search of lists in a file??

    - by kaushik
    i have a file having around 1 lakh lists and have a another file with again a list of around an average of 50.. I want to compare 2nd item of list in second file with the 2nd element of 1st file and repeat this for each of the 50 lists in 2nd file and get the result of all the matching element. I have written the code for all this,but this is taking a lot of time as it need to check the whole the 1lakh list some 50 times..i want to improve the speed... please tell me how can i do this.... i cant not post my code as it is part of big code and will be difficult to infer anything from that... please tell what can be done to improve the speed?? thank u,

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  • Why a revert a file in EGit, but the dirty symbol '<' still exist in the project view?

    - by Happier
    I try EGit revert for several days, It's very confuse that when I revert the file following the user guide, and I still got the file dirty symbol in the related file. http://wiki.eclipse.org/EGit/User_Guide#Reverting_Changes I choose 'Replace with' - 'File in Git Index', it works, the content has been revert, but the symbol stays the same, sometimes, the symbol will disappear after a while, but sometimes, it didn't disappear. I'm using eclipse on windows, I'm not sure it's about the '\r\n' character. But I use 'Compare with ' - 'File in Git Index', two files look the same. Hope someone can tell me why, I think it can be a bug? Thank you in advance.

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  • how to read hindi text from a file in c++ ??

    - by yogeshbablu
    A file contains hindi text. I want to read this file and perform some operations on text it contains. So, if anyone could please explain how to read it from file and handle it(or just print it). Ex: if file contains ?? ?? ?????? ???? then my program should read this content from file and print above text on standard output. I want to perform it on Linux. Direct code will be more beneficial.

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  • In C++, how can I make typedefs visible to every file in my project?

    - by user231536
    I have a typedef typedef unsigned int my_type; used in a file. I would like to make it visible across all my files, without putting it in a header file included by everything. I don't want to go the header file route because as it stands this will be the only declaration in the header file (and it seems unnecessary to add a file just for this). Is there a way to do this? If instead I had: typedef X my_type; where X was a class, would I need to include X.h everywhere and have the typedef at the end of X.h ?

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  • How do I create a sqlite 3 (.sl3) database file?

    - by BC
    I have a *.sqlite file... but I need the database in *.sl3 format? What software/tool can I us to create that? What are the steps? This is to be used in an iPhone app. Original developer used an .sl3 file, now that I have updated the DB - I can't seem to export/generate a .sl3 file I have tried just changing the extension - all the way to inserting the *.sqlite file in XCode and pointing the app delegates to the new DB file format... doesn't work. Thanks in advance...

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  • Nginx + PHP - No input file specified for 1 server block. Other server block works fine

    - by F21
    I am running Ubuntu Desktop 12.04 with nginx 1.2.6. PHP is PHP-FPM 5.4.9. This is the relevant part of my nginx.conf: http { include mime.types; default_type application/octet-stream; sendfile on; keepalive_timeout 65; server { server_name testapp.com; root /www/app/www/; index index.php index.html index.htm; location ~ \.php$ { fastcgi_intercept_errors on; fastcgi_pass 127.0.0.1:9000; fastcgi_index index.php; fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name; include fastcgi_params; } } server { listen 80 default_server; root /www index index.html index.php; location ~ \.php$ { fastcgi_intercept_errors on; fastcgi_pass 127.0.0.1:9000; fastcgi_index index.php; fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name; include fastcgi_params; } } } Relevant bits from php-fpm.conf: ; Chroot to this directory at the start. This value must be defined as an ; absolute path. When this value is not set, chroot is not used. ; Note: you can prefix with '$prefix' to chroot to the pool prefix or one ; of its subdirectories. If the pool prefix is not set, the global prefix ; will be used instead. ; Note: chrooting is a great security feature and should be used whenever ; possible. However, all PHP paths will be relative to the chroot ; (error_log, sessions.save_path, ...). ; Default Value: not set ;chroot = ; Chdir to this directory at the start. ; Note: relative path can be used. ; Default Value: current directory or / when chroot chdir = /www In my hosts file, I redirect 2 domains: testapp.com and test.com to 127.0.0.1. My web files are all stored in /www. From the above settings, if I visit test.com/phpinfo.php and test.com/app/www, everything works as expected and I get output from PHP. However, if I visit testapp.com, I get the dreaded No input file specified. error. So, at this point, I pull out the log files and have a look: 2012/12/19 16:00:53 [error] 12183#0: *17 FastCGI sent in stderr: "Unable to open primary script: /www/app/www/index.php (No such file or directory)" while reading response header from upstream, client: 127.0.0.1, server: testapp.com, request: "GET / HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "testapp.com" This baffles me because I have checked again and again and /www/app/www/index.php definitely exists! This is also validated by the fact that test.com/app/www/index.php works which means the file exists and the permissions are correct. Why is this happening and what are the root causes of things breaking for just the testapp.com v-host? Just an update to my investigation: I have commented out chroot and chdir in php-fpm.conf to narrow down the problem If I remove the location ~ \.php$ block for testapp.com, then nginx will send me a bin file which contains the PHP code. This means that on nginx's side, things are fine. The problem is that something must be mangling the file paths when passing it to PHP-FPM. Having said that, it is quite strange that the default_server v-host works fine because its root is /www, where as things just won't work for the testapp.com v-host because the root is /www/app/www.

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  • In Haskell, I want to read a file and then write to it. Do I need strictness annotation?

    - by Steve
    Hi, Still quite new to Haskell.. I want to read the contents of a file, do something with it possibly involving IO (using putStrLn for now) and then write new contents to the same file. I came up with: doit :: String -> IO () doit file = do contents <- withFile tagfile ReadMode $ \h -> hGetContents h putStrLn contents withFile tagfile WriteMode $ \h -> hPutStrLn h "new content" However this doesn't work due to laziness. The file contents are not printed. I found this post which explains it well. The solution proposed there is to include putStrLn within the withFile: doit :: String -> IO () doit file = do withFile tagfile ReadMode $ \h -> do contents <- hGetContents h putStrLn contents withFile tagfile WriteMode $ \h -> hPutStrLn h "new content" This works, but it's not what I want to do. The operation in I will eventually replace putStrLn might be long, I don't want to keep the file open the whole time. In general I just want to be able to get the file content out and then close it before working with that content. The solution I came up with is the following: doit :: String -> IO () doit file = do c <- newIORef "" withFile tagfile ReadMode $ \h -> do a <- hGetContents h writeIORef c $! a d <- readIORef c putStrLn d withFile tagfile WriteMode $ \h -> hPutStrLn h "Test" However, I find this long and a bit obfuscated. I don't think I should need an IORef just to get a value out, but I needed "place" to put the file contents. Also, it still didn't work without the strictness annotation $! for writeIORef. I guess IORefs are not strict by nature? Can anyone recommend a better, shorter way to do this while keeping my desired semantics? Thanks!

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  • No module named sqlalchemy when installing ckanext-viewhelpers

    - by kean23
    I'm using CKAN as my open data portal and am trying to install the ckanext-viewhelpers Extension by following the instructions at https://github.com/ckan/ckanext-viewhelpers. /usr/lib/ckan/default/src/ckanext-viewhelpers-master$ sudo python setup.py installChecking .pth file support in /usr/local/lib/python2.7/dist-packages/ /usr/bin/python -E -c pass TEST PASSED: /usr/local/lib/python2.7/dist-packages/ appears to support .pth files running bdist_egg running egg_info writing ckanext_viewhelpers.egg-info/PKG-INFO writing namespace_packages to ckanext_viewhelpers.egg-info/namespace_packages.txt writing top-level names to ckanext_viewhelpers.egg-info/top_level.txt writing dependency_links to ckanext_viewhelpers.egg-info/dependency_links.txt writing entry points to ckanext_viewhelpers.egg-info/entry_points.txt reading manifest file 'ckanext_viewhelpers.egg-info/SOURCES.txt' reading manifest template 'MANIFEST.in' writing manifest file 'ckanext_viewhelpers.egg-info/SOURCES.txt' installing library code to build/bdist.linux-x86_64/egg running install_lib running build_py creating build/bdist.linux-x86_64/egg creating build/bdist.linux-x86_64/egg/ckanext copying build/lib.linux-x86_64-2.7/ckanext/__init__.py -> build/bdist.linux-x86_64/egg/ckanext creating build/bdist.linux-x86_64/egg/ckanext/viewhelpers copying build/lib.linux-x86_64-2.7/ckanext/viewhelpers/plugin.py -> build/bdist.linux-x86_64/egg/ckanext/viewhelpers copying build/lib.linux-x86_64-2.7/ckanext/viewhelpers/__init__.py -> build/bdist.linux-x86_64/egg/ckanext/viewhelpers creating build/bdist.linux-x86_64/egg/ckanext/viewhelpers/tests copying build/lib.linux-x86_64-2.7/ckanext/viewhelpers/tests/__init__.py -> build/bdist.linux-x86_64/egg/ckanext/viewhelpers/tests copying build/lib.linux-x86_64-2.7/ckanext/viewhelpers/tests/test_view.py -> build/bdist.linux-x86_64/egg/ckanext/viewhelpers/tests creating build/bdist.linux-x86_64/egg/ckanext/viewhelpers/public creating build/bdist.linux-x86_64/egg/ckanext/viewhelpers/public/vendor copying build/lib.linux-x86_64-2.7/ckanext/viewhelpers/public/vendor/queryStringToJSON.js -> build/bdist.linux-x86_64/egg/ckanext/viewhelpers/public/vendor copying build/lib.linux-x86_64-2.7/ckanext/viewhelpers/public/resource.config -> build/bdist.linux-x86_64/egg/ckanext/viewhelpers/public copying build/lib.linux-x86_64-2.7/ckanext/viewhelpers/public/filters_form.css -> build/bdist.linux-x86_64/egg/ckanext/viewhelpers/public copying build/lib.linux-x86_64-2.7/ckanext/viewhelpers/public/filters.js -> build/bdist.linux-x86_64/egg/ckanext/viewhelpers/public copying build/lib.linux-x86_64-2.7/ckanext/viewhelpers/public/filters_form.js -> build/bdist.linux-x86_64/egg/ckanext/viewhelpers/public byte-compiling build/bdist.linux-x86_64/egg/ckanext/__init__.py to __init__.pyc byte-compiling build/bdist.linux-x86_64/egg/ckanext/viewhelpers/plugin.py to plugin.pyc byte-compiling build/bdist.linux-x86_64/egg/ckanext/viewhelpers/__init__.py to __init__.pyc byte-compiling build/bdist.linux-x86_64/egg/ckanext/viewhelpers/tests/__init__.py to __init__.pyc byte-compiling build/bdist.linux-x86_64/egg/ckanext/viewhelpers/tests/test_view.py to test_view.pyc creating build/bdist.linux-x86_64/egg/EGG-INFO copying ckanext_viewhelpers.egg-info/PKG-INFO -> build/bdist.linux-x86_64/egg/EGG-INFO copying ckanext_viewhelpers.egg-info/SOURCES.txt -> build/bdist.linux-x86_64/egg/EGG-INFO copying ckanext_viewhelpers.egg-info/dependency_links.txt -> build/bdist.linux-x86_64/egg/EGG-INFO copying ckanext_viewhelpers.egg-info/entry_points.txt -> build/bdist.linux-x86_64/egg/EGG-INFO copying ckanext_viewhelpers.egg-info/namespace_packages.txt -> build/bdist.linux-x86_64/egg/EGG-INFO copying ckanext_viewhelpers.egg-info/not-zip-safe -> build/bdist.linux-x86_64/egg/EGG-INFO copying ckanext_viewhelpers.egg-info/top_level.txt -> build/bdist.linux-x86_64/egg/EGG-INFO creating 'dist/ckanext_viewhelpers-0.1-py2.7.egg' and adding 'build/bdist.linux-x86_64/egg' to it removing 'build/bdist.linux-x86_64/egg' (and everything under it) Processing ckanext_viewhelpers-0.1-py2.7.egg removing '/usr/local/lib/python2.7/dist-packages/ckanext_viewhelpers-0.1-py2.7.egg' (and everything under it) creating /usr/local/lib/python2.7/dist-packages/ckanext_viewhelpers-0.1-py2.7.egg Extracting ckanext_viewhelpers-0.1-py2.7.egg to /usr/local/lib/python2.7/dist-packages ckanext-viewhelpers 0.1 is already the active version in easy-install.pth Installed /usr/local/lib/python2.7/dist-packages/ckanext_viewhelpers-0.1-py2.7.egg Processing dependencies for ckanext-viewhelpers==0.1 Finished processing dependencies for ckanext-viewhelpers==0.1 However I am faced with this error which I could not solve after adding viewhelpers in my CKAN config file. paster serve /etc/ckan/default/development.ini Traceback (most recent call last): File "/usr/bin/paster", line 4, in <module> command.run() File "/usr/lib/python2.7/dist-packages/paste/script/command.py", line 104, in run invoke(command, command_name, options, args[1:]) File "/usr/lib/python2.7/dist-packages/paste/script/command.py", line 143, in invoke exit_code = runner.run(args) File "/usr/lib/python2.7/dist-packages/paste/script/command.py", line 238, in run result = self.command() File "/usr/lib/python2.7/dist-packages/paste/script/serve.py", line 284, in command relative_to=base, global_conf=vars) File "/usr/lib/python2.7/dist-packages/paste/script/serve.py", line 321, in loadapp **kw) File "/usr/lib/python2.7/dist-packages/paste/deploy/loadwsgi.py", line 247, in loadapp return loadobj(APP, uri, name=name, **kw) File "/usr/lib/python2.7/dist-packages/paste/deploy/loadwsgi.py", line 271, in loadobj global_conf=global_conf) File "/usr/lib/python2.7/dist-packages/paste/deploy/loadwsgi.py", line 296, in loadcontext global_conf=global_conf) File "/usr/lib/python2.7/dist-packages/paste/deploy/loadwsgi.py", line 320, in _loadconfig return loader.get_context(object_type, name, global_conf) File "/usr/lib/python2.7/dist-packages/paste/deploy/loadwsgi.py", line 454, in get_context section) File "/usr/lib/python2.7/dist-packages/paste/deploy/loadwsgi.py", line 476, in _context_from_use object_type, name=use, global_conf=global_conf) File "/usr/lib/python2.7/dist-packages/paste/deploy/loadwsgi.py", line 406, in get_context global_conf=global_conf) File "/usr/lib/python2.7/dist-packages/paste/deploy/loadwsgi.py", line 296, in loadcontext global_conf=global_conf) File "/usr/lib/python2.7/dist-packages/paste/deploy/loadwsgi.py", line 328, in _loadegg return loader.get_context(object_type, name, global_conf) File "/usr/lib/python2.7/dist-packages/paste/deploy/loadwsgi.py", line 620, in get_context object_type, name=name) File "/usr/lib/python2.7/dist-packages/paste/deploy/loadwsgi.py", line 646, in find_egg_entry_point possible.append((entry.load(), protocol, entry.name)) File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 1989, in load entry = __import__(self.module_name, globals(),globals(), ['__name__']) File "/usr/lib/ckan/default/src/ckan/ckan/config/middleware.py", line 9, in <module> import sqlalchemy as sa ImportError: No module named sqlalchemyckanext-viewhelpers

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  • C#/.NET Little Wonders: The Concurrent Collections (1 of 3)

    - by James Michael Hare
    Once again we consider some of the lesser known classes and keywords of C#.  In the next few weeks, we will discuss the concurrent collections and how they have changed the face of concurrent programming. This week’s post will begin with a general introduction and discuss the ConcurrentStack<T> and ConcurrentQueue<T>.  Then in the following post we’ll discuss the ConcurrentDictionary<T> and ConcurrentBag<T>.  Finally, we shall close on the third post with a discussion of the BlockingCollection<T>. For more of the "Little Wonders" posts, see the index here. A brief history of collections In the beginning was the .NET 1.0 Framework.  And out of this framework emerged the System.Collections namespace, and it was good.  It contained all the basic things a growing programming language needs like the ArrayList and Hashtable collections.  The main problem, of course, with these original collections is that they held items of type object which means you had to be disciplined enough to use them correctly or you could end up with runtime errors if you got an object of a type you weren't expecting. Then came .NET 2.0 and generics and our world changed forever!  With generics the C# language finally got an equivalent of the very powerful C++ templates.  As such, the System.Collections.Generic was born and we got type-safe versions of all are favorite collections.  The List<T> succeeded the ArrayList and the Dictionary<TKey,TValue> succeeded the Hashtable and so on.  The new versions of the library were not only safer because they checked types at compile-time, in many cases they were more performant as well.  So much so that it's Microsoft's recommendation that the System.Collections original collections only be used for backwards compatibility. So we as developers came to know and love the generic collections and took them into our hearts and embraced them.  The problem is, thread safety in both the original collections and the generic collections can be problematic, for very different reasons. Now, if you are only doing single-threaded development you may not care – after all, no locking is required.  Even if you do have multiple threads, if a collection is “load-once, read-many” you don’t need to do anything to protect that container from multi-threaded access, as illustrated below: 1: public static class OrderTypeTranslator 2: { 3: // because this dictionary is loaded once before it is ever accessed, we don't need to synchronize 4: // multi-threaded read access 5: private static readonly Dictionary<string, char> _translator = new Dictionary<string, char> 6: { 7: {"New", 'N'}, 8: {"Update", 'U'}, 9: {"Cancel", 'X'} 10: }; 11:  12: // the only public interface into the dictionary is for reading, so inherently thread-safe 13: public static char? Translate(string orderType) 14: { 15: char charValue; 16: if (_translator.TryGetValue(orderType, out charValue)) 17: { 18: return charValue; 19: } 20:  21: return null; 22: } 23: } Unfortunately, most of our computer science problems cannot get by with just single-threaded applications or with multi-threading in a load-once manner.  Looking at  today's trends, it's clear to see that computers are not so much getting faster because of faster processor speeds -- we've nearly reached the limits we can push through with today's technologies -- but more because we're adding more cores to the boxes.  With this new hardware paradigm, it is even more important to use multi-threaded applications to take full advantage of parallel processing to achieve higher application speeds. So let's look at how to use collections in a thread-safe manner. Using historical collections in a concurrent fashion The early .NET collections (System.Collections) had a Synchronized() static method that could be used to wrap the early collections to make them completely thread-safe.  This paradigm was dropped in the generic collections (System.Collections.Generic) because having a synchronized wrapper resulted in atomic locks for all operations, which could prove overkill in many multithreading situations.  Thus the paradigm shifted to having the user of the collection specify their own locking, usually with an external object: 1: public class OrderAggregator 2: { 3: private static readonly Dictionary<string, List<Order>> _orders = new Dictionary<string, List<Order>>(); 4: private static readonly _orderLock = new object(); 5:  6: public void Add(string accountNumber, Order newOrder) 7: { 8: List<Order> ordersForAccount; 9:  10: // a complex operation like this should all be protected 11: lock (_orderLock) 12: { 13: if (!_orders.TryGetValue(accountNumber, out ordersForAccount)) 14: { 15: _orders.Add(accountNumber, ordersForAccount = new List<Order>()); 16: } 17:  18: ordersForAccount.Add(newOrder); 19: } 20: } 21: } Notice how we’re performing several operations on the dictionary under one lock.  With the Synchronized() static methods of the early collections, you wouldn’t be able to specify this level of locking (a more macro-level).  So in the generic collections, it was decided that if a user needed synchronization, they could implement their own locking scheme instead so that they could provide synchronization as needed. The need for better concurrent access to collections Here’s the problem: it’s relatively easy to write a collection that locks itself down completely for access, but anything more complex than that can be difficult and error-prone to write, and much less to make it perform efficiently!  For example, what if you have a Dictionary that has frequent reads but in-frequent updates?  Do you want to lock down the entire Dictionary for every access?  This would be overkill and would prevent concurrent reads.  In such cases you could use something like a ReaderWriterLockSlim which allows for multiple readers in a lock, and then once a writer grabs the lock it blocks all further readers until the writer is done (in a nutshell).  This is all very complex stuff to consider. Fortunately, this is where the Concurrent Collections come in.  The Parallel Computing Platform team at Microsoft went through great pains to determine how to make a set of concurrent collections that would have the best performance characteristics for general case multi-threaded use. Now, as in all things involving threading, you should always make sure you evaluate all your container options based on the particular usage scenario and the degree of parallelism you wish to acheive. This article should not be taken to understand that these collections are always supperior to the generic collections. Each fills a particular need for a particular situation. Understanding what each container is optimized for is key to the success of your application whether it be single-threaded or multi-threaded. General points to consider with the concurrent collections The MSDN points out that the concurrent collections all support the ICollection interface. However, since the collections are already synchronized, the IsSynchronized property always returns false, and SyncRoot always returns null.  Thus you should not attempt to use these properties for synchronization purposes. Note that since the concurrent collections also may have different operations than the traditional data structures you may be used to.  Now you may ask why they did this, but it was done out of necessity to keep operations safe and atomic.  For example, in order to do a Pop() on a stack you have to know the stack is non-empty, but between the time you check the stack’s IsEmpty property and then do the Pop() another thread may have come in and made the stack empty!  This is why some of the traditional operations have been changed to make them safe for concurrent use. In addition, some properties and methods in the concurrent collections achieve concurrency by creating a snapshot of the collection, which means that some operations that were traditionally O(1) may now be O(n) in the concurrent models.  I’ll try to point these out as we talk about each collection so you can be aware of any potential performance impacts.  Finally, all the concurrent containers are safe for enumeration even while being modified, but some of the containers support this in different ways (snapshot vs. dirty iteration).  Once again I’ll highlight how thread-safe enumeration works for each collection. ConcurrentStack<T>: The thread-safe LIFO container The ConcurrentStack<T> is the thread-safe counterpart to the System.Collections.Generic.Stack<T>, which as you may remember is your standard last-in-first-out container.  If you think of algorithms that favor stack usage (for example, depth-first searches of graphs and trees) then you can see how using a thread-safe stack would be of benefit. The ConcurrentStack<T> achieves thread-safe access by using System.Threading.Interlocked operations.  This means that the multi-threaded access to the stack requires no traditional locking and is very, very fast! For the most part, the ConcurrentStack<T> behaves like it’s Stack<T> counterpart with a few differences: Pop() was removed in favor of TryPop() Returns true if an item existed and was popped and false if empty. PushRange() and TryPopRange() were added Allows you to push multiple items and pop multiple items atomically. Count takes a snapshot of the stack and then counts the items. This means it is a O(n) operation, if you just want to check for an empty stack, call IsEmpty instead which is O(1). ToArray() and GetEnumerator() both also take snapshots. This means that iteration over a stack will give you a static view at the time of the call and will not reflect updates. Pushing on a ConcurrentStack<T> works just like you’d expect except for the aforementioned PushRange() method that was added to allow you to push a range of items concurrently. 1: var stack = new ConcurrentStack<string>(); 2:  3: // adding to stack is much the same as before 4: stack.Push("First"); 5:  6: // but you can also push multiple items in one atomic operation (no interleaves) 7: stack.PushRange(new [] { "Second", "Third", "Fourth" }); For looking at the top item of the stack (without removing it) the Peek() method has been removed in favor of a TryPeek().  This is because in order to do a peek the stack must be non-empty, but between the time you check for empty and the time you execute the peek the stack contents may have changed.  Thus the TryPeek() was created to be an atomic check for empty, and then peek if not empty: 1: // to look at top item of stack without removing it, can use TryPeek. 2: // Note that there is no Peek(), this is because you need to check for empty first. TryPeek does. 3: string item; 4: if (stack.TryPeek(out item)) 5: { 6: Console.WriteLine("Top item was " + item); 7: } 8: else 9: { 10: Console.WriteLine("Stack was empty."); 11: } Finally, to remove items from the stack, we have the TryPop() for single, and TryPopRange() for multiple items.  Just like the TryPeek(), these operations replace Pop() since we need to ensure atomically that the stack is non-empty before we pop from it: 1: // to remove items, use TryPop or TryPopRange to get multiple items atomically (no interleaves) 2: if (stack.TryPop(out item)) 3: { 4: Console.WriteLine("Popped " + item); 5: } 6:  7: // TryPopRange will only pop up to the number of spaces in the array, the actual number popped is returned. 8: var poppedItems = new string[2]; 9: int numPopped = stack.TryPopRange(poppedItems); 10:  11: foreach (var theItem in poppedItems.Take(numPopped)) 12: { 13: Console.WriteLine("Popped " + theItem); 14: } Finally, note that as stated before, GetEnumerator() and ToArray() gets a snapshot of the data at the time of the call.  That means if you are enumerating the stack you will get a snapshot of the stack at the time of the call.  This is illustrated below: 1: var stack = new ConcurrentStack<string>(); 2:  3: // adding to stack is much the same as before 4: stack.Push("First"); 5:  6: var results = stack.GetEnumerator(); 7:  8: // but you can also push multiple items in one atomic operation (no interleaves) 9: stack.PushRange(new [] { "Second", "Third", "Fourth" }); 10:  11: while(results.MoveNext()) 12: { 13: Console.WriteLine("Stack only has: " + results.Current); 14: } The only item that will be printed out in the above code is "First" because the snapshot was taken before the other items were added. This may sound like an issue, but it’s really for safety and is more correct.  You don’t want to enumerate a stack and have half a view of the stack before an update and half a view of the stack after an update, after all.  In addition, note that this is still thread-safe, whereas iterating through a non-concurrent collection while updating it in the old collections would cause an exception. ConcurrentQueue<T>: The thread-safe FIFO container The ConcurrentQueue<T> is the thread-safe counterpart of the System.Collections.Generic.Queue<T> class.  The concurrent queue uses an underlying list of small arrays and lock-free System.Threading.Interlocked operations on the head and tail arrays.  Once again, this allows us to do thread-safe operations without the need for heavy locks! The ConcurrentQueue<T> (like the ConcurrentStack<T>) has some departures from the non-concurrent counterpart.  Most notably: Dequeue() was removed in favor of TryDequeue(). Returns true if an item existed and was dequeued and false if empty. Count does not take a snapshot It subtracts the head and tail index to get the count.  This results overall in a O(1) complexity which is quite good.  It’s still recommended, however, that for empty checks you call IsEmpty instead of comparing Count to zero. ToArray() and GetEnumerator() both take snapshots. This means that iteration over a queue will give you a static view at the time of the call and will not reflect updates. The Enqueue() method on the ConcurrentQueue<T> works much the same as the generic Queue<T>: 1: var queue = new ConcurrentQueue<string>(); 2:  3: // adding to queue is much the same as before 4: queue.Enqueue("First"); 5: queue.Enqueue("Second"); 6: queue.Enqueue("Third"); For front item access, the TryPeek() method must be used to attempt to see the first item if the queue.  There is no Peek() method since, as you’ll remember, we can only peek on a non-empty queue, so we must have an atomic TryPeek() that checks for empty and then returns the first item if the queue is non-empty. 1: // to look at first item in queue without removing it, can use TryPeek. 2: // Note that there is no Peek(), this is because you need to check for empty first. TryPeek does. 3: string item; 4: if (queue.TryPeek(out item)) 5: { 6: Console.WriteLine("First item was " + item); 7: } 8: else 9: { 10: Console.WriteLine("Queue was empty."); 11: } Then, to remove items you use TryDequeue().  Once again this is for the same reason we have TryPeek() and not Peek(): 1: // to remove items, use TryDequeue. If queue is empty returns false. 2: if (queue.TryDequeue(out item)) 3: { 4: Console.WriteLine("Dequeued first item " + item); 5: } Just like the concurrent stack, the ConcurrentQueue<T> takes a snapshot when you call ToArray() or GetEnumerator() which means that subsequent updates to the queue will not be seen when you iterate over the results.  Thus once again the code below will only show the first item, since the other items were added after the snapshot. 1: var queue = new ConcurrentQueue<string>(); 2:  3: // adding to queue is much the same as before 4: queue.Enqueue("First"); 5:  6: var iterator = queue.GetEnumerator(); 7:  8: queue.Enqueue("Second"); 9: queue.Enqueue("Third"); 10:  11: // only shows First 12: while (iterator.MoveNext()) 13: { 14: Console.WriteLine("Dequeued item " + iterator.Current); 15: } Using collections concurrently You’ll notice in the examples above I stuck to using single-threaded examples so as to make them deterministic and the results obvious.  Of course, if we used these collections in a truly multi-threaded way the results would be less deterministic, but would still be thread-safe and with no locking on your part required! For example, say you have an order processor that takes an IEnumerable<Order> and handles each other in a multi-threaded fashion, then groups the responses together in a concurrent collection for aggregation.  This can be done easily with the TPL’s Parallel.ForEach(): 1: public static IEnumerable<OrderResult> ProcessOrders(IEnumerable<Order> orderList) 2: { 3: var proxy = new OrderProxy(); 4: var results = new ConcurrentQueue<OrderResult>(); 5:  6: // notice that we can process all these in parallel and put the results 7: // into our concurrent collection without needing any external locking! 8: Parallel.ForEach(orderList, 9: order => 10: { 11: var result = proxy.PlaceOrder(order); 12:  13: results.Enqueue(result); 14: }); 15:  16: return results; 17: } Summary Obviously, if you do not need multi-threaded safety, you don’t need to use these collections, but when you do need multi-threaded collections these are just the ticket! The plethora of features (I always think of the movie The Three Amigos when I say plethora) built into these containers and the amazing way they acheive thread-safe access in an efficient manner is wonderful to behold. Stay tuned next week where we’ll continue our discussion with the ConcurrentBag<T> and the ConcurrentDictionary<TKey,TValue>. For some excellent information on the performance of the concurrent collections and how they perform compared to a traditional brute-force locking strategy, see this wonderful whitepaper by the Microsoft Parallel Computing Platform team here.   Tweet Technorati Tags: C#,.NET,Concurrent Collections,Collections,Multi-Threading,Little Wonders,BlackRabbitCoder,James Michael Hare

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  • Elfsign Object Signing on Solaris

    - by danx
    Elfsign Object Signing on Solaris Don't let this happen to you—use elfsign! Solaris elfsign(1) is a command that signs and verifies ELF format executables. That includes not just executable programs (such as ls or cp), but other ELF format files including libraries (such as libnvpair.so) and kernel modules (such as autofs). Elfsign has been available since Solaris 10 and ELF format files distributed with Solaris, since Solaris 10, are signed by either Sun Microsystems or its successor, Oracle Corporation. When an ELF file is signed, elfsign adds a new section the ELF file, .SUNW_signature, that contains a RSA public key signature and other information about the signer. That is, the algorithm used, algorithm OID, signer CN/OU, and time stamp. The signature section can later be verified by elfsign or other software by matching the signature in the file agains the ELF file contents (excluding the signature). ELF executable files may also be signed by a 3rd-party or by the customer. This is useful for verifying the origin and authenticity of executable files installed on a system. The 3rd-party or customer public key certificate should be installed in /etc/certs/ to allow verification by elfsign. For currently-released versions of Solaris, only cryptographic framework plugin libraries are verified by Solaris. However, all ELF files may be verified by the elfsign command at any time. Elfsign Algorithms Elfsign signatures are created by taking a digest of the ELF section contents, then signing the digest with RSA. To verify, one takes a digest of ELF file and compares with the expected digest that's computed from the signature and RSA public key. Originally elfsign took a MD5 digest of a SHA-1 digest of the ELF file sections, then signed the resulting digest with RSA. In Solaris 11.1 then Solaris 11.1 SRU 7 (5/2013), the elfsign crypto algorithms available have been expanded to keep up with evolving cryptography. The following table shows the available elfsign algorithms: Elfsign Algorithm Solaris Release Comments elfsign sign -F rsa_md5_sha1   S10, S11.0, S11.1 Default for S10. Not recommended* elfsign sign -F rsa_sha1 S11.1 Default for S11.1. Not recommended elfsign sign -F rsa_sha256 S11.1 patch SRU7+   Recommended ___ *Most or all CAs do not accept MD5 CSRs and do not issue MD5 certs due to MD5 hash collision problems. RSA Key Length. I recommend using RSA-2048 key length with elfsign is RSA-2048 as the best balance between a long expected "life time", interoperability, and performance. RSA-2048 keys have an expected lifetime through 2030 (and probably beyond). For details, see Recommendation for Key Management: Part 1: General, NIST Publication SP 800-57 part 1 (rev. 3, 7/2012, PDF), tables 2 and 4 (pp. 64, 67). Step 1: create or obtain a key and cert The first step in using elfsign is to obtain a key and cert from a public Certificate Authority (CA), or create your own self-signed key and cert. I'll briefly explain both methods. Obtaining a Certificate from a CA To obtain a cert from a CA, such as Verisign, Thawte, or Go Daddy (to name a few random examples), you create a private key and a Certificate Signing Request (CSR) file and send it to the CA, following the instructions of the CA on their website. They send back a signed public key certificate. The public key cert, along with the private key you created is used by elfsign to sign an ELF file. The public key cert is distributed with the software and is used by elfsign to verify elfsign signatures in ELF files. You need to request a RSA "Class 3 public key certificate", which is used for servers and software signing. Elfsign uses RSA and we recommend RSA-2048 keys. The private key and CSR can be generated with openssl(1) or pktool(1) on Solaris. Here's a simple example that uses pktool to generate a private RSA_2048 key and a CSR for sending to a CA: $ pktool gencsr keystore=file format=pem outcsr=MYCSR.p10 \ subject="CN=canineswworks.com,OU=Canine SW object signing" \ outkey=MYPRIVATEKEY.key $ openssl rsa -noout -text -in MYPRIVATEKEY.key Private-Key: (2048 bit) modulus: 00:d2:ef:42:f2:0b:8c:96:9f:45:32:fc:fe:54:94: . . . [omitted for brevity] . . . c9:c7 publicExponent: 65537 (0x10001) privateExponent: 26:14:fc:49:26:bc:a3:14:ee:31:5e:6b:ac:69:83: . . . [omitted for brevity] . . . 81 prime1: 00:f6:b7:52:73:bc:26:57:26:c8:11:eb:6c:dc:cb: . . . [omitted for brevity] . . . bc:91:d0:40:d6:9d:ac:b5:69 prime2: 00:da:df:3f:56:b2:18:46:e1:89:5b:6c:f1:1a:41: . . . [omitted for brevity] . . . f3:b7:48:de:c3:d9:ce:af:af exponent1: 00:b9:a2:00:11:02:ed:9a:3f:9c:e4:16:ce:c7:67: . . . [omitted for brevity] . . . 55:50:25:70:d3:ca:b9:ab:99 exponent2: 00:c8:fc:f5:57:11:98:85:8e:9a:ea:1f:f2:8f:df: . . . [omitted for brevity] . . . 23:57:0e:4d:b2:a0:12:d2:f5 coefficient: 2f:60:21:cd:dc:52:76:67:1a:d8:75:3e:7f:b0:64: . . . [omitted for brevity] . . . 06:94:56:d8:9d:5c:8e:9b $ openssl req -noout -text -in MYCSR.p10 Certificate Request: Data: Version: 2 (0x2) Subject: OU=Canine SW object signing, CN=canineswworks.com Subject Public Key Info: Public Key Algorithm: rsaEncryption Public-Key: (2048 bit) Modulus: 00:d2:ef:42:f2:0b:8c:96:9f:45:32:fc:fe:54:94: . . . [omitted for brevity] . . . c9:c7 Exponent: 65537 (0x10001) Attributes: Signature Algorithm: sha1WithRSAEncryption b3:e8:30:5b:88:37:68:1c:26:6b:45:af:5e:de:ea:60:87:ea: . . . [omitted for brevity] . . . 06:f9:ed:b4 Secure storage of RSA private key. The private key needs to be protected if the key signing is used for production (as opposed to just testing). That is, protect the key to protect against unauthorized signatures by others. One method is to use a PIN-protected PKCS#11 keystore. The private key you generate should be stored in a secure manner, such as in a PKCS#11 keystore using pktool(1). Otherwise others can sign your signature. Other secure key storage mechanisms include a SCA-6000 crypto card, a USB thumb drive stored in a locked area, a dedicated server with restricted access, Oracle Key Manager (OKM), or some combination of these. I also recommend secure backup of the private key. Here's an example of generating a private key protected in the PKCS#11 keystore, and a CSR. $ pktool setpin # use if PIN not set yet Enter token passphrase: changeme Create new passphrase: Re-enter new passphrase: Passphrase changed. $ pktool gencsr keystore=pkcs11 label=MYPRIVATEKEY \ format=pem outcsr=MYCSR.p10 \ subject="CN=canineswworks.com,OU=Canine SW object signing" $ pktool list keystore=pkcs11 Enter PIN for Sun Software PKCS#11 softtoken: Found 1 asymmetric public keys. Key #1 - RSA public key: MYPRIVATEKEY Here's another example that uses openssl instead of pktool to generate a private key and CSR: $ openssl genrsa -out cert.key 2048 $ openssl req -new -key cert.key -out MYCSR.p10 Self-Signed Cert You can use openssl or pktool to create a private key and a self-signed public key certificate. A self-signed cert is useful for development, testing, and internal use. The private key created should be stored in a secure manner, as mentioned above. The following example creates a private key, MYSELFSIGNED.key, and a public key cert, MYSELFSIGNED.pem, using pktool and displays the contents with the openssl command. $ pktool gencert keystore=file format=pem serial=0xD06F00D lifetime=20-year \ keytype=rsa hash=sha256 outcert=MYSELFSIGNED.pem outkey=MYSELFSIGNED.key \ subject="O=Canine Software Works, OU=Self-signed CA, CN=canineswworks.com" $ pktool list keystore=file objtype=cert infile=MYSELFSIGNED.pem Found 1 certificates. 1. (X.509 certificate) Filename: MYSELFSIGNED.pem ID: c8:24:59:08:2b:ae:6e:5c:bc:26:bd:ef:0a:9c:54:de:dd:0f:60:46 Subject: O=Canine Software Works, OU=Self-signed CA, CN=canineswworks.com Issuer: O=Canine Software Works, OU=Self-signed CA, CN=canineswworks.com Not Before: Oct 17 23:18:00 2013 GMT Not After: Oct 12 23:18:00 2033 GMT Serial: 0xD06F00D0 Signature Algorithm: sha256WithRSAEncryption $ openssl x509 -noout -text -in MYSELFSIGNED.pem Certificate: Data: Version: 3 (0x2) Serial Number: 3496935632 (0xd06f00d0) Signature Algorithm: sha256WithRSAEncryption Issuer: O=Canine Software Works, OU=Self-signed CA, CN=canineswworks.com Validity Not Before: Oct 17 23:18:00 2013 GMT Not After : Oct 12 23:18:00 2033 GMT Subject: O=Canine Software Works, OU=Self-signed CA, CN=canineswworks.com Subject Public Key Info: Public Key Algorithm: rsaEncryption Public-Key: (2048 bit) Modulus: 00:bb:e8:11:21:d9:4b:88:53:8b:6c:5a:7a:38:8b: . . . [omitted for brevity] . . . bf:77 Exponent: 65537 (0x10001) Signature Algorithm: sha256WithRSAEncryption 9e:39:fe:c8:44:5c:87:2c:8f:f4:24:f6:0c:9a:2f:64:84:d1: . . . [omitted for brevity] . . . 5f:78:8e:e8 $ openssl rsa -noout -text -in MYSELFSIGNED.key Private-Key: (2048 bit) modulus: 00:bb:e8:11:21:d9:4b:88:53:8b:6c:5a:7a:38:8b: . . . [omitted for brevity] . . . bf:77 publicExponent: 65537 (0x10001) privateExponent: 0a:06:0f:23:e7:1b:88:62:2c:85:d3:2d:c1:e6:6e: . . . [omitted for brevity] . . . 9c:e1:e0:0a:52:77:29:4a:75:aa:02:d8:af:53:24: c1 prime1: 00:ea:12:02:bb:5a:0f:5a:d8:a9:95:b2:ba:30:15: . . . [omitted for brevity] . . . 5b:ca:9c:7c:19:48:77:1e:5d prime2: 00:cd:82:da:84:71:1d:18:52:cb:c6:4d:74:14:be: . . . [omitted for brevity] . . . 5f:db:d5:5e:47:89:a7:ef:e3 exponent1: 32:37:62:f6:a6:bf:9c:91:d6:f0:12:c3:f7:04:e9: . . . [omitted for brevity] . . . 97:3e:33:31:89:66:64:d1 exponent2: 00:88:a2:e8:90:47:f8:75:34:8f:41:50:3b:ce:93: . . . [omitted for brevity] . . . ff:74:d4:be:f3:47:45:bd:cb coefficient: 4d:7c:09:4c:34:73:c4:26:f0:58:f5:e1:45:3c:af: . . . [omitted for brevity] . . . af:01:5f:af:ad:6a:09:bf Step 2: Sign the ELF File object By now you should have your private key, and obtained, by hook or crook, a cert (either from a CA or use one you created (a self-signed cert). The next step is to sign one or more objects with your private key and cert. Here's a simple example that creates an object file, signs, verifies, and lists the contents of the ELF signature. $ echo '#include <stdio.h>\nint main(){printf("Hello\\n");}'>hello.c $ make hello cc -o hello hello.c $ elfsign verify -v -c MYSELFSIGNED.pem -e hello elfsign: no signature found in hello. $ elfsign sign -F rsa_sha256 -v -k MYSELFSIGNED.key -c MYSELFSIGNED.pem -e hello elfsign: hello signed successfully. format: rsa_sha256. signer: O=Canine Software Works, OU=Self-signed CA, CN=canineswworks.com. signed on: October 17, 2013 04:22:49 PM PDT. $ elfsign list -f format -e hello rsa_sha256 $ elfsign list -f signer -e hello O=Canine Software Works, OU=Self-signed CA, CN=canineswworks.com $ elfsign list -f time -e hello October 17, 2013 04:22:49 PM PDT $ elfsign verify -v -c MYSELFSIGNED.key -e hello elfsign: verification of hello failed. format: rsa_sha256. signer: O=Canine Software Works, OU=Self-signed CA, CN=canineswworks.com. signed on: October 17, 2013 04:22:49 PM PDT. Signing using the pkcs11 keystore To sign the ELF file using a private key in the secure pkcs11 keystore, replace "-K MYSELFSIGNED.key" in the "elfsign sign" command line with "-T MYPRIVATEKEY", where MYPRIVATKEY is the pkcs11 token label. Step 3: Install the cert and test on another system Just signing the object isn't enough. You need to copy or install the cert and the signed ELF file(s) on another system to test that the signature is OK. Your public key cert should be installed in /etc/certs. Use elfsign verify to verify the signature. Elfsign verify checks each cert in /etc/certs until it finds one that matches the elfsign signature in the file. If one isn't found, the verification fails. Here's an example: $ su Password: # rm /etc/certs/MYSELFSIGNED.key # cp MYSELFSIGNED.pem /etc/certs # exit $ elfsign verify -v hello elfsign: verification of hello passed. format: rsa_sha256. signer: O=Canine Software Works, OU=Self-signed CA, CN=canineswworks.com. signed on: October 17, 2013 04:24:20 PM PDT. After testing, package your cert along with your ELF object to allow elfsign verification after your cert and object are installed or copied. Under the Hood: elfsign verification Here's the steps taken to verify a ELF file signed with elfsign. The steps to sign the file are similar except the private key exponent is used instead of the public key exponent and the .SUNW_signature section is written to the ELF file instead of being read from the file. Generate a digest (SHA-256) of the ELF file sections. This digest uses all ELF sections loaded in memory, but excludes the ELF header, the .SUNW_signature section, and the symbol table Extract the RSA signature (RSA-2048) from the .SUNW_signature section Extract the RSA public key modulus and public key exponent (65537) from the public key cert Calculate the expected digest as follows:     signaturepublicKeyExponent % publicKeyModulus Strip the PKCS#1 padding (most significant bytes) from the above. The padding is 0x00, 0x01, 0xff, 0xff, . . ., 0xff, 0x00. If the actual digest == expected digest, the ELF file is verified (OK). Further Information elfsign(1), pktool(1), and openssl(1) man pages. "Signed Solaris 10 Binaries?" blog by Darren Moffat (2005) shows how to use elfsign. "Simple CLI based CA on Solaris" blog by Darren Moffat (2008) shows how to set up a simple CA for use with self-signed certificates. "How to Create a Certificate by Using the pktool gencert Command" System Administration Guide: Security Services (available at docs.oracle.com)

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  • Confusion for mime files: magic, magic.mgc, magic.mime

    - by Florence Foo
    I'm using Ubuntu. I'm trying to use ruby gem 'shared-mime-info' for an application I'm writing. I understand that magic.mgc is a compiled version of magic file which has magic number definitions for the different file types. BUT I don't understand why is it /usr/share/mime/magic is in binary format instead of just normal text file with each parameters separated by white space like everywhere else I'm finding on the internet when it's referencing this file? The /usr/share/mime/magic has the word 'MIME-Magic' at the beginning of the file and prioritize the rest of the stuff like. So it doesn't look like magic.mgc at all. [100:application/vnd.scribus] >1=^@^KSCRIBUSUTF8 [90:application/vnd.stardivision.writer] >2089=^@ shared-mime-info seems to want a magic file in the binary non compiled format as above and I wanted to add definition for DOCX but how does one update or generate this file without using a hex editor? There is a reference to the magic file I found at: http://standards.freedesktop.org/shared-mime-info-spec/shared-mime-info-spec-latest.html And it mention this file is updated with update-mime-database but what if I just want to add some new entry to it. hex editor? Anyway I ended up using hexer to make a new magic file in ~/.local/share/mime/ with only the entry I wanted to add and the MIME-Magic header. Seems to work (assuming I will ever deal with docx for now). 00000000: 4d 49 4d 45 2d 4d 61 67 69 63 00 0a 5b 36 30 3a MIME-Magic..[60: 00000010: 61 70 70 6c 69 63 61 74 69 6f 6e 2f 76 6e 64 2e application/vnd. 00000020: 6f 70 65 6e 78 6d 6c 66 6f 72 6d 61 74 73 2d 6f openxmlformats-o 00000030: 66 66 69 63 65 64 6f 63 75 6d 65 6e 74 2e 77 6f fficedocument.wo 00000040: 72 64 70 72 6f 63 65 73 73 69 6e 67 6d 6c 2e 64 rdprocessingml.d 00000050: 6f 63 75 6d 65 6e 74 5d 0a 3e 30 3d 00 08 50 4b ocument].>0=..PK 00000060: 03 04 14 00 06 00 0a -- -- -- -- -- -- -- -- -- .......---------

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  • update-manager crashes Ubuntu 12.04

    - by user205450
    The update-manager crashes with the following error frank@darkstar2:~$ update-manager Traceback (most recent call last): File "/usr/bin/update-manager", line 33, in <module> from UpdateManager.UpdateManager import UpdateManager File "/usr/lib/python2.7/dist-packages/UpdateManager/UpdateManager.py", line 72, in <module> from Core.MyCache import MyCache File "/usr/lib/python2.7/dist-packages/UpdateManager/Core/MyCache.py", line 34, in <module> import DistUpgrade.DistUpgradeCache File "/usr/lib/python2.7/dist-packages/DistUpgrade/DistUpgradeCache.py", line 60, in <module> KERNEL_INITRD_SIZE = _set_kernel_initrd_size() File "/usr/lib/python2.7/dist-packages/DistUpgrade/DistUpgradeCache.py", line 53, in _set_kernel_initrd_size size = estimate_kernel_size_in_boot() File "/usr/lib/python2.7/dist-packages/DistUpgrade/utils.py", line 74, in estimate_kernel_size_in_boot size += os.path.getsize(f) File "/usr/lib/python2.7/genericpath.py", line 49, in getsize return os.stat(filename).st_size OSError: [Errno 5] Input/output error: '/boot/abi-3.2.0-54-generic' I am not sure how to read the error but it seems there is some error in file size. How do I fix it.

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  • How do I resolve not fully installed package (python3-setuptools)?

    - by user3737693
    I was trying to install python3-setuptools, and when i run $ sudo apt-get install python3-setuptools I get this error: Reading package lists... Done Building dependency tree Reading state information... Done 0 upgraded, 0 newly installed, 0 to remove and 6 not upgraded. 1 not fully installed or removed. After this operation, 0 B of additional disk space will be used. Setting up python3-setuptools (0.6.34-0ubuntu1) ... Traceback (most recent call last): File "/usr/bin/py3compile", line 36, in <module> from debpython import files as dpf File "/usr/share/python3/debpython/files.py", line 25, in <module> from debpython.pydist import PUBLIC_DIR_RE File "/usr/share/python3/debpython/pydist.py", line 28, in <module> from debpython.tools import memoize File "/usr/share/python3/debpython/tools.py", line 25, in <module> from datetime import datetime ImportError: /usr/bin/datetime.so: undefined symbol: _Py_ZeroStruct dpkg: error processing python3-setuptools (--configure): subprocess installed post-installation script returned error exit status 1 Errors were encountered while processing: python3-setuptools E: Sub-process /usr/bin/dpkg returned an error code (1) I tried apt-get clean, apt-get autoclean, apt-get remove python3-setuptools, dpkg --remove python3-setuptools, apt-get install -f, dpkg -P --force-remove-reinstreq, dpkg -P --force-all --force-remove-reinstreq and dpkg --purge, but none of them worked. Output of sudo dpkg -P --force-all --force-remove-reinstreq python3-setuptools (Reading database ... 225309 files and directories currently installed.) Removing python3-setuptools ... Traceback (most recent call last): File "/usr/bin/py3clean", line 32, in <module> from debpython import files as dpf File "/usr/share/python3/debpython/files.py", line 25, in <module> from debpython.pydist import PUBLIC_DIR_RE File "/usr/share/python3/debpython/pydist.py", line 28, in <module> from debpython.tools import memoize File "/usr/share/python3/debpython/tools.py", line 25, in <module> from datetime import datetime ImportError: /usr/bin/datetime.so: undefined symbol: _Py_ZeroStruct dpkg: error processing python3-setuptools (--purge): subprocess installed pre-removal script returned error exit status 1 Traceback (most recent call last): File "/usr/bin/py3compile", line 36, in <module> from debpython import files as dpf File "/usr/share/python3/debpython/files.py", line 25, in <module> from debpython.pydist import PUBLIC_DIR_RE File "/usr/share/python3/debpython/pydist.py", line 28, in <module> from debpython.tools import memoize File "/usr/share/python3/debpython/tools.py", line 25, in <module> from datetime import datetime ImportError: /usr/bin/datetime.so: undefined symbol: _Py_ZeroStruct dpkg: error while cleaning up: subprocess installed post-installation script returned error exit status 1 Errors were encountered while processing: python3-setuptools

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  • In Which We Demystify A Few Docupresentment Settings And Learn the Ethos of the Author

    - by Andy Little
    It's no secret that Docupresentment (part of the Oracle Documaker suite) is powerful tool for integrating on-demand and interactive applications for publishing with the Oracle Documaker framework.  It's also no secret there are are many details with respect to the configuration of Docupresentment that can elude even the most erudite of of techies.  To be sure, Docupresentment will work for you right out of the box, and in most cases will suit your needs without toying with a configuration file.  But, where's the adventure in that?   With this inaugural post to That's The Way, I'm going to introduce myself, and what my aim is with this blog.  If you didn't figure it out already by checking out my profile, my name is Andy and I've been with Oracle (nee Skywire Software nee Docucorp nee Formmaker) since the formative years of 1998.  Strangely, it doesn't seem that long ago, but it's certainly a lifetime in the age of technology.  I recall running a BBS from my parent's basement on a 1200 baud modem, and the trepidation and sweaty-palmed excitement of upgrading to the power and speed of 2400 baud!  Fine, I'll admit that perhaps I'm inflating the experience a bit, but I was kid!  This is the stuff of War Games and King's Quest I and the demise of TI-99 4/A.  Exciting times.  So fast-forward a bit and I'm 12 years into a career in the world of document automation and publishing working for the best (IMHO) software company on the planet.  With That's The Way I hope to shed a little light and peek under the covers of some of the more interesting aspects of implementations involving the tech space within the Oracle Insurance Global Business Unit (IGBU), which includes Oracle Documaker, Rating & Underwriting, and Policy Administration to name a few.  I may delve off course a bit, and you'll likely get a dose of humor (at least in my mind) but I hope you'll glean at least a tidbit of usefulness with each post.  Feel free to comment as I'm a fairly conversant guy and happy to talk -- it's stopping the talking that's the hard part... So, back to our regularly-scheduled post, already in progress.  By this time you've visited Oracle's E-Delivery site and acquired your properly-licensed version of Oracle Documaker.  Wait -- you didn't find it?  Understandable -- navigating the voluminous download library within Oracle can be a daunting task.  It's pretty simple once you’ve done it a few times.  Login to the e-delivery site, and accept the license terms and restrictions.  Then, you’ll be able to select the Oracle Insurance Applications product pack and your appropriate platform. Click Go and you’ll see a list of applicable products, and you’ll click on Oracle Documaker Media Pack (as I went to press with this article the version is 11.4): Finally, click the Download button next to Docupresentment (again, version at press time is 2.2 p5). This should give you a ZIP file that contains the installation packages for the Docupresentment Server and Client, cryptically named IDSServer22P05W32.exe and IDSClient22P05W32.exe. At this time, I’d like to take a little detour and explain that the world of Oracle, like most technical companies, is rife with acronyms.  One of the reasons Skywire Software was a appealing to Oracle was our use of many acronyms, including the occasional use of multiple acronyms with the same meaning.  I apologize in advance and will try to point these out along the way.  Here’s your first sticky note to go along with that: IDS = Internet Document Server = Docupresentment Once you’ve completed the installation, you’ll have a shiny new Docupresentment server and client, and if you installed the default location it will be living in c:\docserv. Unix users, I’m one of you!  You’ll find it by default in  ~/docupresentment/docserv.  Forging onward with the meat of this post is learning about some special configuration options.  By now you’ve read the documentation included with the download (specifically ids_book.pdf) which goes into some detail of the rubric of the configuration file and in fact there’s even a handy utility that provides an interface to the configuration file (see Running IDSConfig in the documentation).  But who wants to deal with a configuration utility when we have the tools and technology to edit the file <gasp> by hand! I shall now proceed with the standard Information Technology Under the Hood Disclaimer: Please remember to back up any files before you make changes.  I am not responsible for any havoc you may wreak! Go to your installation directory, and locate your docserv.xml file.  Open it in your favorite XML editor.  I happen to be fond of Notepad++ with the XML Tools plugin.  Almost immediately you will behold the splendor of the configuration file.  Just take a moment and let that sink in.  Ok – moving on.  If you reviewed the documentation you know that inside the root <configuration> node there are multiple <section> nodes, each containing a specific group of settings.  Let’s take a look at <section name=”DocumentServer”>: There are a few entries I’d like to discuss.  First, <entry name=”StartCommand”>. This should be pretty self-explanatory; it’s the name of the executable that’s run when you fire up Docupresentment.  Immediately following that is <entry name=”StartArguments”> and as you might imagine these are the arguments passed to the executable.  A few things to point out: The –Dids.configuration=docserv.xml parameter specifies the name of your configuration file. The –Dlogging.configuration=logconf.xml parameter specifies the name of your logging configuration file (this uses log4j so bone up on that before you delve here). The -Djava.endorsed.dirs=lib/endorsed parameter specifies the path where 3rd party Java libraries can be located for use with Docupresentment.  More on that in another post. The <entry name=”Instances”> allows you to specify the number of instances of Docupresentment that will be started.  By default this is two, and generally two instances per CPU is adequate, however you will always need to perform load testing to determine the sweet spot based on your hardware and types of transactions.  You may have many, many more instances than 2. Time for a sidebar on instances.  An instance is nothing more than a separate process of Docupresentment.  The Docupresentment service that you fire up with docserver.bat or docserver.sh actually starts a watchdog process, which is then responsible for starting up the actual Docupresentment processes.  Each of these act independently from one another, so if one crashes, it does not affect any others.  In the case of a crashed process, the watchdog will start up another instance so the number of configured instances are always running.  Bottom line: instance = Docupresentment process. And now, finally, to the settings which gave me pause on an not-too-long-ago implementation!  Docupresentment includes a feature that watches configuration files (such as docserv.xml and logconf.xml) and will automatically restart its instances to load the changes.  You can configure the time that Docupresentment waits to check these files using the setting <entry name=”FileWatchTimeMillis”>.  By default the number is 12000ms, or 12 seconds.  You can save yourself a few CPU cycles by extending this time, or by disabling  the check altogether by setting the value to 0.  This may or may not be appropriate for your environment; if you have 100% uptime requirements then you probably don’t want to bring down an entire set of processes just to accept a new configuration value, so it’s best to leave this somewhere between 12 seconds to a few minutes.  Another point to keep in mind: if you are using Documaker real-time processing under Docupresentment the Master Resource Library (MRL) files and INI options are cached, and if you need to affect a change, you’ll have to “restart” Docupresentment.  Touching the docserv.xml file is an easy way to do this (other methods including using the RSS request, but that’s another post). The next item up: <entry name=”FilePurgeTimeSeconds”>.  You may already know that the Docupresentment system can generate many temporary files based on certain request types that are processed through the system.  What you may not know is how those files are cleaned up.  There are many rules in Docupresentment that cause the creation of temporary files.  When these files are created, Docupresentment writes an entry into a properties file called the file cache.  This file contains the name, creation date, and expiration time of each temporary file created by each instance of Docupresentment.  Periodically Docupresentment will check the file cache to determine if there are files that are past the expiration time, not unlike that block of cheese festering away in the back of my refrigerator.  However, unlike my ‘fridge cleaning tendencies, Docupresentment is quick to remove files that are past their expiration time.  You, my friend, have the power to control how often Docupresentment inspects the file cache.  Simply set the value for <entry name=”FilePurgeTimeSeconds”> to the number of seconds appropriate for your requirements and you’re set.  Note that file purging happens on a separate thread from normal request processing, so this shouldn’t interfere with response times unless the CPU happens to be really taxed at the point of cache processing.  Finally, after all of this, we get to the final setting I’m going to address in this post: <entry name=”FilePurgeList”>.  The default is “filecache.properties”.  This establishes the root name for the Docupresentment file cache that I mentioned previously.  Docupresentment creates a separate cache file for each instance based on this setting.  If you have two instances, you’ll see two files created: filecache.properties.1 and filecache.properties.2.  Feel free to open these up and check them out. I hope you’ve enjoyed this first foray into the configuration file of Docupresentment.  If you did enjoy it, feel free to drop a comment, I welcome feedback.  If you have ideas for other posts you’d like to see, please do let me know.  You can reach me at [email protected]. ‘Til next time! ###

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  • Understading the output of syslogd -d

    - by Heoa
    What is the meanding of 80, F and X in the following output of syslogd -d? 0: X X X X FF X X X X X FF X X X X X X X X X X X X X X FILE: /var/log/auth.log (unused) 1: FF FF FF FF X FF FF FF FF FF X FF FF FF FF FF FF FF FF FF FF FF FF FF FF FILE: /var/log/syslog (unused) 2: X X X FF X X X X X X X X X X X X X X X X X X X X X FILE: /var/log/daemon.log (unused) 3: FF X X X X X X X X X X X X X X X X X X X X X X X X FILE: /var/log/kern.log (unused) 4: X X X X X X FF X X X X X X X X X X X X X X X X X X FILE: /var/log/lpr.log (unused) 5: X X FF X X X X X X X X X X X X X X X X X X X X X X FILE: /var/log/mail.log (unused) 6: X FF X X X X X X X X X X X X X X X X X X X X X X X FILE: /var/log/user.log (unused) 7: X X 7F X X X X X X X X X X X X X X X X X X X X X X FILE: /var/log/mail.info (unused) 8: X X 1F X X X X X X X X X X X X X X X X X X X X X X FILE: /var/log/mail.warn (unused) 9: X X F X X X X X X X X X X X X X X X X X X X X X X FILE: /var/log/mail.err (unused) 10: X X X X X X X 7 X X X X X X X X X X X X X X X X X FILE: /var/log/news/news.crit (unused) 11: X X X X X X X F X X X X X X X X X X X X X X X X X FILE: /var/log/news/news.err (unused) 12: X X X X X X X 3F X X X X X X X X X X X X X X X X X FILE: /var/log/news/news.notice (unused) 13: 80 80 X 80 X 80 80 X 80 80 X 80 80 80 80 80 80 80 80 80 80 80 80 80 80 FILE: /var/log/debug (unused) 14: 70 70 X X X 70 70 X 70 X X 70 70 70 70 70 70 70 70 70 70 70 70 70 70 FILE: /var/log/messages (unused) 15: 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 WALL: 16: F0 F0 FF FF F0 F0 F0 FF F0 F0 F0 F0 F0 F0 F0 F0 F0 F0 F0 F0 F0 F0 F0 F0 F0 PIPE: |/dev/xconsole (unused)

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