Re: Save passwords in scripts
Serge Orlov wrote: Florian Lindner wrote: Paul Rubin wrote: - sort of similar: have a separate process running that knows the password (administrator enters it at startup time). That process listens on a unix socket and checks the ID of the client. It reveals the password to authorized clients, i.e. your readable script running under sudo. This keeps the password from ever being stored on disk. - Modify the script itself to run as a long-running service instead of as something that gets started and restarted all the time. Have an admin start it and type the password into it at startup time. Users then connect to it (maybe with a web browser) and send it commands. - Move the user operations from the script to server side database procedures that do their own validity checking. Then you don't need a password. I'll evaluate the 3 ideas above further. I'm surprised there are no building blocks for a sudo replacement in the UNIX world, at least I googled and couldn't find them. Basically you need to split you script into two parts: priveledged server and user client. They can talk xml-rpc over unix socket. Can I find out the identity of the client (PID/UID) when using unix socket? If you need performance you can also open another socket for sending huge binary objects. With regards to clear text password and admin, you can only obfuscate or make it hard to obtain the password. It's just to keep honest admins honest. Same story on windows, btw. Serge. Florian -- http://mail.python.org/mailman/listinfo/python-list
Re: Save passwords in scripts
Florian Lindner [EMAIL PROTECTED] writes: Can I find out the identity of the client (PID/UID) when using unix socket? Unix sockets have a feature called ancillary messages that lets you do that, but the Python socket module currently doesn't support the feature. There's an open sourceforge bug about it and I'd like to get around to submitting a patch for it one of these days, but of course it would be great if you did it first. -- http://mail.python.org/mailman/listinfo/python-list
Re: Save passwords in scripts
I had a similar problem a few years ago and decided that if I really had to store passwords, I could at least make them a bit harder to get at. I was using a the ConfigParser module to store other info in a config file, so I added entries for the UserID and password to the config file, as well as an indicator entry (yes/no). Then I took all other values in the config file, put their info in a delimited string (padded on both ends with a random number of characters) and cleared the entries in the config file. I used the old Rotor module to encrypt the string, UUencoded the result and stored the Rotor encrypted, UUencoded result in a special config entry. UUencoding makes the encrypted entry usable converts unpritable characters, rendering the entry usable in a config file. The uptake was that if the indicator entry was no, the program read the config file normally. If the indicator entry was yes, the program UUDecoded the special config entry, decrypted using the Rotor module, parsed the string and used the results for config entries. I also wrote a separate program to encrypt/decrypt the config file entries so it could be modified in the clear and then reencrypted afterward. The system worked for me. While the security is arguable, it was certainly better than storing them in the clear. I'm sure an astute individual could figure out what I did and break it by analyzing the source code, but it was quite effective for hiding info from the casual observer. While the Rotor module is been deprecated, I'm sure the same thing could be done with any encryption module that can use file-like objects. I used Rotor because it was in the basic Python distribution, and I didn't want to relay on external modules. Hope it helps! Tim Sharpe Florian Lindner wrote: Peter Hansen wrote: Florian Lindner wrote: I've a scripts that allows limited manipulation of a database to users. This script of course needs to save a password for the database connection. The users, on the other hand need read permission on the script in order to execute it but should not be able to read out the password. What is the common way to solve this problem? The common way is to do something ill-conceived and insecure. The correct approach is to use a secure technique that does not involve storing the passwords themselves, but instead storing a hash version of them (e.g. MD5 or SHA), or by requiring the users to enter their passwords at the time the information is required. Hashes could not work, since I need to give the password to a DB server. My script is the client, not the server. It does not check passwords supplied by the users, just use the hard-coded password to connect to the DB server. My current way is to allow the users to execute the script with sudo while not having read permission when acting as a ordinary user. But I don't like this solutions and consider it very ugly. Storing passwords in the clear is always ugly and insecure. Think about the situation where a user (unwisely) picks a password that he also uses for, say, his online banking. If the password is stored in the clear, then anyone with root access can see it and even if you trust all your administrators, or are the only admin yourself, it's still not a good idea to let an admin see a user's password. It's not a users password. It's a password of a db user which owns several system tables and the users should be able to manipulate them in a constrained manner. I fully agree with you. That's why I'm looking for a better, more secure solution. Florian -- http://mail.python.org/mailman/listinfo/python-list
Re: Save passwords in scripts
Florian Lindner wrote: Paul Rubin wrote: - sort of similar: have a separate process running that knows the password (administrator enters it at startup time). That process listens on a unix socket and checks the ID of the client. It reveals the password to authorized clients, i.e. your readable script running under sudo. This keeps the password from ever being stored on disk. - Modify the script itself to run as a long-running service instead of as something that gets started and restarted all the time. Have an admin start it and type the password into it at startup time. Users then connect to it (maybe with a web browser) and send it commands. - Move the user operations from the script to server side database procedures that do their own validity checking. Then you don't need a password. I'll evaluate the 3 ideas above further. I'm surprised there are no building blocks for a sudo replacement in the UNIX world, at least I googled and couldn't find them. Basically you need to split you script into two parts: priveledged server and user client. They can talk xml-rpc over unix socket. If you need performance you can also open another socket for sending huge binary objects. With regards to clear text password and admin, you can only obfuscate or make it hard to obtain the password. It's just to keep honest admins honest. Same story on windows, btw. Serge. -- http://mail.python.org/mailman/listinfo/python-list
Save passwords in scripts
Hello, I've a scripts that allows limited manipulation of a database to users. This script of course needs to save a password for the database connection. The users, on the other hand need read permission on the script in order to execute it but should not be able to read out the password. What is the common way to solve this problem? My current way is to allow the users to execute the script with sudo while not having read permission when acting as a ordinary user. But I don't like this solutions and consider it very ugly. Thanks, Florian -- http://mail.python.org/mailman/listinfo/python-list
Re: Save passwords in scripts
Florian Lindner wrote: I've a scripts that allows limited manipulation of a database to users. This script of course needs to save a password for the database connection. The users, on the other hand need read permission on the script in order to execute it but should not be able to read out the password. What is the common way to solve this problem? The common way is to do something ill-conceived and insecure. The correct approach is to use a secure technique that does not involve storing the passwords themselves, but instead storing a hash version of them (e.g. MD5 or SHA), or by requiring the users to enter their passwords at the time the information is required. My current way is to allow the users to execute the script with sudo while not having read permission when acting as a ordinary user. But I don't like this solutions and consider it very ugly. Storing passwords in the clear is always ugly and insecure. Think about the situation where a user (unwisely) picks a password that he also uses for, say, his online banking. If the password is stored in the clear, then anyone with root access can see it and even if you trust all your administrators, or are the only admin yourself, it's still not a good idea to let an admin see a user's password. -Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: Save passwords in scripts
Peter Hansen wrote: Florian Lindner wrote: I've a scripts that allows limited manipulation of a database to users. This script of course needs to save a password for the database connection. The users, on the other hand need read permission on the script in order to execute it but should not be able to read out the password. What is the common way to solve this problem? The common way is to do something ill-conceived and insecure. The correct approach is to use a secure technique that does not involve storing the passwords themselves, but instead storing a hash version of them (e.g. MD5 or SHA), or by requiring the users to enter their passwords at the time the information is required. Hashes could not work, since I need to give the password to a DB server. My script is the client, not the server. It does not check passwords supplied by the users, just use the hard-coded password to connect to the DB server. My current way is to allow the users to execute the script with sudo while not having read permission when acting as a ordinary user. But I don't like this solutions and consider it very ugly. Storing passwords in the clear is always ugly and insecure. Think about the situation where a user (unwisely) picks a password that he also uses for, say, his online banking. If the password is stored in the clear, then anyone with root access can see it and even if you trust all your administrators, or are the only admin yourself, it's still not a good idea to let an admin see a user's password. It's not a users password. It's a password of a db user which owns several system tables and the users should be able to manipulate them in a constrained manner. I fully agree with you. That's why I'm looking for a better, more secure solution. Florian -- http://mail.python.org/mailman/listinfo/python-list
Re: Save passwords in scripts
Florian Lindner wrote: Hello, I've a scripts that allows limited manipulation of a database to users. This script of course needs to save a password for the database connection. The users, on the other hand need read permission on the script in order to execute it but should not be able to read out the password. What is the common way to solve this problem? My current way is to allow the users to execute the script with sudo while not having read permission when acting as a ordinary user. But I don't like this solutions and consider it very ugly. Thanks, Florian Which DB? afaik postgre has user-level authentication which means you don't even need a password. /Esben -- http://mail.python.org/mailman/listinfo/python-list
Re: Save passwords in scripts
Florian Lindner [EMAIL PROTECTED] writes: I've a scripts that allows limited manipulation of a database to users. This script of course needs to save a password for the database connection. The users, on the other hand need read permission on the script in order to execute it but should not be able to read out the password. What is the common way to solve this problem? My current way is to allow the users to execute the script with sudo while not having read permission when acting as a ordinary user. But I don't like this solutions and consider it very ugly. There's not a one-size-fits-all answer. A bunch of possibilities: - Just have execute permission on the script, not read permission - If the database server and client are running on the same machine, use a unix-domain socket instead of a tcp socket, and modify the server to check that only a specific uid is running the client (you can do this check with an ancillary message on the socket). Then use sudo to get the client to run as that user. You can then leave read permission enabled on the script. - sort of similar: have a separate process running that knows the password (administrator enters it at startup time). That process listens on a unix socket and checks the ID of the client. It reveals the password to authorized clients, i.e. your readable script running under sudo. This keeps the password from ever being stored on disk. - Modify the script itself to run as a long-running service instead of as something that gets started and restarted all the time. Have an admin start it and type the password into it at startup time. Users then connect to it (maybe with a web browser) and send it commands. - Move the user operations from the script to server side database procedures that do their own validity checking. Then you don't need a password. - Run the script on a machine where users can't run arbitrary programs other than the script. Set up the db server to not accept any connections other than from that machine. Etc. etc., you get the idea. -- http://mail.python.org/mailman/listinfo/python-list
Re: Save passwords in scripts
Esben Pedersen wrote: Florian Lindner wrote: Hello, I've a scripts that allows limited manipulation of a database to users. This script of course needs to save a password for the database connection. The users, on the other hand need read permission on the script in order to execute it but should not be able to read out the password. What is the common way to solve this problem? My current way is to allow the users to execute the script with sudo while not having read permission when acting as a ordinary user. But I don't like this solutions and consider it very ugly. Thanks, Florian Which DB? afaik postgre has user-level authentication which means you don't even need a password. But all users are manipulating rows in one table and I need to check to make sanity checks on the input. Florian -- http://mail.python.org/mailman/listinfo/python-list
Re: Save passwords in scripts
Paul Rubin wrote: Florian Lindner [EMAIL PROTECTED] writes: I've a scripts that allows limited manipulation of a database to users. This script of course needs to save a password for the database connection. The users, on the other hand need read permission on the script in order to execute it but should not be able to read out the password. What is the common way to solve this problem? My current way is to allow the users to execute the script with sudo while not having read permission when acting as a ordinary user. But I don't like this solutions and consider it very ugly. There's not a one-size-fits-all answer. A bunch of possibilities: - Just have execute permission on the script, not read permission This does not work. In ordner to execute the interpreter have to read the script. [EMAIL PROTECTED] ~/python $ ./account.py /usr/bin/python: can't open file './account.py' Or you know a way it works? - If the database server and client are running on the same machine, use a unix-domain socket instead of a tcp socket, and modify the server to check that only a specific uid is running the client (you can do this check with an ancillary message on the socket). Then use sudo to get the client to run as that user. You can then leave read permission enabled on the script. This a bit overkill for my needs. - sort of similar: have a separate process running that knows the password (administrator enters it at startup time). That process listens on a unix socket and checks the ID of the client. It reveals the password to authorized clients, i.e. your readable script running under sudo. This keeps the password from ever being stored on disk. - Modify the script itself to run as a long-running service instead of as something that gets started and restarted all the time. Have an admin start it and type the password into it at startup time. Users then connect to it (maybe with a web browser) and send it commands. - Move the user operations from the script to server side database procedures that do their own validity checking. Then you don't need a password. I'll evaluate the 3 ideas above further. - Run the script on a machine where users can't run arbitrary programs other than the script. Set up the db server to not accept any connections other than from that machine. Not possible here. Thanks for your suggestions, Florian -- http://mail.python.org/mailman/listinfo/python-list
