Is there any possibility to connect to an SSH server using /ssh:user#server with read-only access, even if the account has write access? I need this to prevent accidental write.
Here is the function I use to connect:
(defun connect-b2b ()
(interactive)
(find-file-other-window "/ssh:user#server:/")
buffer-read-only)
(global-set-key (kbd "C-c C-d") 'connect-b2b)
Note that buffer-read-only does not help, neither does vc-toggle-read-only.
Update: Just to be clear what I want to achieve, I have an account with read+write access, however since this is a business critical server I wanted to prevent accidental changes. Unfortunately I cant change permissions on the user account itself, therefore I wanted to enforce this locally.
Third suggestion: Use sshfs to provide the remote filesystem locally, and mount it read-only, and then point Emacs at that.
That way you're not subject to all of the pitfalls of being able to run commands directly on the remote server as a user who has write-permissions.
If I've interpreted the question rightly, directory-local variables are a potential workaround. This would be overridden if there were dir-local configs nearer to the path in question, however, so YMMV.
(dir-locals-set-class-variables
'read-only
'((nil . ((buffer-read-only . t)))))
(dir-locals-set-directory-class "/ssh:user#server:/" 'read-only)
I'm still able to for example touch a file in the specified directory.
That's got nothing to do with Emacs. You're asking for Emacs to employ OS-level access controls, which it can't do, because it's not the OS. In your case it's not even running on the same machine.
You need to create a new user with more limited access, and connect as that user instead.
Related
I need to develope an ABAP program which does some actions for SAP Basis. This program will be run in test/development systems only and it's not safe to run the program in productive system.
I need any safe way how to prevent the program running in productive. I can read a category field in T000 table and check if the system is a productive or not, but this way is not 100% safe. Any user with debug/variable modification authorizations will be able to avoid this.
A possible solution is not import the ABAP program to productive system at all. At the same time we have a system copy from productive to QA (the Oracle DB is copied from PROD to QA completely and renamed). This means the new program will be erased in QA after each PROD->QA copy and we will need to import it from DEV to QA again. So, this way is not convinient.
Is there any way which is more safe?
There are very few safeguards against someone who maliciously uses the debugger to change values in a running program (and has the permissions to do so). If someone with that permission wants to actively harm your system, he/she/it will be able to do so one way or another.
Manage that risk through strict permissions management.
If that is not sufficient, do not transport the program, however inconvenient that may seem.
Still, you should guard against accidental execution, and for that, the role of the client (can be "productive", "customizing", "test"; via transaction code SCC4; it's stored in table column T000-CCCATEGORY and can be read via function module TR_SYS_PARAMS) should be sufficient.
Anyone with a developer/debug authorization basically can do everything in your system. I mean even you do not ship your program, I myself can create a z-program to make the same thing as your program do if I have a dev role.
so let's focus your statement here: Productive System. How many users can have the dev authorization? I think it should be strictly controlled by your Admin.
In addition to T000 "Productive" check, you can also add authority check, for example, S_ADMI_FCD and logging in your code to restrict and safe the program.
Hope it helps. Thank you!
The solution would be to call an operating system command which could be found only in the test/quality system and not on the productive system.
Essentially I need somewhere to store an expiration date for my software and do not want this to be accidentally deleted (the likelihood of anyone tampering with my software is relatively minimal). I thought about writing this to the registry, however this appears to require administrative permissions. Is there any way to get around this issue?
Thanks
The better alternative would be to use Isolated Storage.
If you really need to modify the registry, and you don't have sufficient privileges to do so, you would need to either ask for an administrator's credentials, so you could temporary elevate your privileges, or you would need to make a request to another process, such as a service, which is already running under another account with sufficient privileges.
If Isolated Storage is a bigger tool than you need for the job, another simpler option would be to use an App.config setting. You can create a setting in your project properties designer screen, and then you can read/write the setting via My.Settings.
I have a particular file I want to monitor for file read attempts by all applications on OSX. I'd like to be able to interrupt the requests so I could decide which applications have permission to read the file and which don't (by querying the user, or checking a cache of user responses). Is this possible with the OSX API? If not, is it even possible to get a list of which applications or processes do read a file?
I'm not saying there's no way to do this, but what #Jonathan is talking about isn't it.
That API is for tracking the creation, change, and destruction of files. Notably this tool is used by things like Spotlight to watch activity on the filesystem for new, interesting files.
But, wisely, reading isn't one of the events it tracks.
And even if reading WAS tracked, it is still the wrong mechanism, as it's a notification system after the fact, not in line with the call itself.
I seriously doubt what you want is possible the way you describe it.
With Access Control Lists, you can limit access at the user level (Fred can read the file, but Bob can not). This is a setting on the file itself. But there's no mechanism to allow Bobs App1 to read a file, while Bobs App2 can not, since there's really no formal mechanism of "application identity" beyond the command to executed, or whatever the program "says" its name is (both of which can be spoofed if motivated enough).
However, feel free to crawl the Darwin sources -- no doubt the answer is buried in there somewhere near the open(2) call.
EDIT, regarding comment.
What are you trying to do? What's the overall context?
Another thing that you may want to try is to use FUSE.
FUSE is a utility that let's you have "user space filesystems". People use FUSE for many purposes, like reading NTFS volumes, or mounting remote system via SSH.
They have a simple example, that gives you a skeleton that you can fill in for your purposes.
For most of the use cases, you'll simple defer to the system. However, for OPEN you will add your logic. Then you could point your FUSE utility at a directory, and "mount it". Then all of the files below that directory can use your new behavior.
I'm still not sure how you will identify Apps by name, but if it's not a real "security" issue, just for local control, I imaging you can come up with something. Activity Monitor has apps names, so they must be available, and FUSE will be running within the process space (I think), rather than through some external mechanism.
All that said, I think FUSE is your best bet, but it's probably not appropriate if you want to do this to "any file" with no preparation by the user (like not installing FUSE). If you wanted to do "any file", your FUSE system would need to be mounted at root, and then you'll simply have a full "clone" of the filesystem, with those files from the normal root "unprotected", while those from your new FUSE root will be protected. So, if someone wanted to NOT use your FUSE system, the real file is readily available to them through the actual file location.
If not, is it even possible to get a list of which applications or processes do read a file?
The command-line tool fs_util allows you to monitor filesystem activity, including reading.
The writings of Amit Singh should come in very handy. He explored the API that provides FileSystem events a few years ago, and provided a sample tool that allows you to intercept FS events. It's open source!
If i remember his conclusion properly, their isn't an official API, but you can use apple's tools to achieve what you want.
I am writing a program in Objective-C (Xcode 3.2, on Snow Leopard) that is capable of either selectively blocking certain sites for a duration or only allow certain sites (and thus block all others) for a duration. The reasoning behind this program is rather simple. I tend to get distracted when I have full internet access, but I do need internet access during my working hours to get to a number of work-related websites. Clearly, this is not a permanent block, but only helps me to focus whenever I find myself wandering a bit too much.
At the moment, I am using a Unix script that is called via AppleScript to obtain Administrator permissions. It then activates a number of ipfw rules and clears those after a specific duration to restore full internet access. Simple and effective, but since I am running as a standard user, it gets cumbersome to enter my administrator password each and every time I want to go "offline". Furthermore, this is a great opportunity to learn to work with XCode and Objective-C. At the moment, everything works as expected, minus the actual blocking. I can add a number of sites in a list, specify whether or not I want to block or allow these websites and I can "start" the blocking by specifying a time until which I want to stay "offline".
However, I find it hard to obtain clear information on how I can run a privileged Unix command from Objective-C. Ideally, I would like to be able to store information with respect to the Administrator account into the Keychain to use these later on, so that I can simply move into "offline" mode with the convenience of clicking a button. Even more ideally, there might be some class in Objective-C with which I can block access to some/all websites for this particular user without needing to rely on privileged Unix commands. A third possibility is in starting this program with root permissions and the reducing the permissions until I need them, but since this is a GUI application that is nested in the menu bar of OS X, the results are rather awkward and getting it to run each and every time with root permission is no easy task.
Anyone who can offer me some pointers or advice? Please, no security-warnings, I am fully aware that what I want to do is a potential security threat.
If you want to do something with admin privileges, and you don't want to have to authenticate each time, it sounds like you need to look at setuid.
Make little command-line executable to do the rule changing, and then set that tool's owner to root. Then, set the setuid bit. Now, you can run it as a user and it will run as root.
Look here for more info:
http://en.wikipedia.org/wiki/Setuid
You have to create a separate process that runs with higher privileges. Have a look at the BetterAuthorizationSample on how to run such helper applications using launchd.
I've got an Access 2007 database that I developed which connects to SQL Server for the actual data storage. I used the Package Solution Wizard to create a distributable installer which included access runtime (with an ACCDE file) which I went around and installed on 15 or so PCs. Anyway, my question is, what is the best way to distribute updates to this database? Right now I'd need to go around and remove and reinstall. That's not a problem... I was just wondering if there was another way.
I've tried leaving the front end on a network share but it seems that most people suggest storing the front-end on the local machine, which makes sense. The problems I've run into when I leave it on a network share (at least with Access 2003 mdbs) is that I find myself needing to compact and repair often and I also have to kill the open sessions (user's who have the file open) when upgrading. I would imagine it could also hypothetically create an unnecessary bottleneck if the user was not on the local network.
Automating front-end distribution is trivial. It's a problem that has been solved repeatedly. Tony Toews's http://autofeupdater.com is one such solution that is extremely easy to implement and completely transparent to the end user.
We developed a vbscript 'launcher' for our access apps. That is what is linked to on the start menu of user's pcs and it does the following.
It checks a version.txt file located on a network share to see whether it contains different text to a locally stored copy
If the text is different it copies the access mdb and the new version.txt to the user's hard drive.
Finally it runs the mdb in access
In order to distribute an update to the user's pc all that is required is to change the text in version.txt on the network share.
Perhaps you can implement something similar to this
Make a batch file on the server (network drive).
Create a shortcut link to that batch file.
Copy the shortcut to User's Desktop.
When user double-clicks on shortcut, it will copy a fresh copy from network to local.
Replace old database.adp on the server drive when you update a new version.
Each user gets a copy of database.adp on their machine.
Remove Security warning when opening file from network share is here.
Batch File
#ECHO OFF
REM copy from network drive to local
xcopy "Your_Network_Drive\database.adp" "C:\User\database.adp" /Y /R /F
REM call your database file - Access 2007
"C:\Program Files\Microsoft Office\Office12\MSAccess.EXE" "C:\User\database.adp"
This is a very old post and I used the autofeupdater until it stopped working so I wrote one of my own and it has evolved over the last few years into something that I have used with many clients. It's so simple to use and there is no interface. Just an EXE and a very simple config file.
Please check it out here. I can also help with custom solutions if none of the configurations work for your needs. http://www.dafran.ca/MS-Access-Front-End-Loader.aspx
After trying all of the solutions above (not exactly these solutions but these are the common suggestions in the Access community), I developed a system entirely within Access using VBA that allows an admin DB to create and publish objects to client DBs without the need for user intervention or management of multiple DB files.
This approach has several benefits:
1. It simplifies the development process by having a dedicated environment (admin DB) for development and testing totally separate from the client DBs.
2. It simplifies the update/distribution process by allowing a developer to push out updates in real time that client DBs can implement in the background, without involving users. Can also allow devs to roll back to previous versions if desired.
3. It could be used as a kind of change management system within Access for developers who want to commit multiple changes to objects and modules and retain past changes.
4. It allows for easier user access control by allowing an admin to easily assign certain objects to specific users/roles without needing to maintain multiple versions of the DB.
I will hopefully post the code to GitHub soon, I just have to get clearance from my workplace to release it. I will edit this post to include the link when I have.
We have usually kept the Access front ends on network drives, and just put up with the need to compact and repair on a regular basis. You will probably find you need to do that even when they are installed locally, anyway.
If you must have it installed locally, there are various tools which will enable you to "push out" software updates, and the guys over on ServerFault would have more information on those. Assuming such tools aren't available, the only other option I can think of is to write a small loader program that checks the local .MDB against a master copy on the server, and re-copies it across if they are different, before then launching the MDB.