Don't use this for mass requests, because this is resource intensive. JOSM provides a useful interface for selecting the area you wish to download, and instant visualization of all the data you have downloaded. You can edit the data to re-upload it later.
You can also save the data to. But because it employs the main API, it is not intended for downloading large quantities of data. Heavy use or large numbers of requests from many users should use one of the above mentioned services instead. The region is specified by a bounding box , which consists of a minimum and maximum latitude and longitude. Choose as small a region as will be useful to you, since larger regions will result in larger data files, longer download times, and heavier load on the server.
When you're first starting out, choose a very small region so that you can figure things out quickly with small data sets. There are several ways of finding latitude and longitude values. Since we are interested in a bounding box, perhaps the clearest way is to use the bounding box selection features of the 'export data' link. On the homepage map pan and zoom to roughly the right area, and then click the 'export data' link on the left. This sidebar display includes the four values you need for a bounding box matching the extents of the viewport.
Click 'Manually select a different area' and then drag a box to select exactly the region you want. Contents Exit focus mode. Is this page helpful? Please rate your experience Yes No. Any additional feedback? Tip The examples in this article enclose path arguments with single quotes ''.
Upload a file Upload a directory Upload the contents of a directory Upload a specific file. Tip You can tweak your upload operation by using optional flags. Here's a few examples. Note AzCopy doesn't automatically calculate and store the file's md5 hash code. Note Append the --recursive flag to upload files in all sub-directories. Download a file Download a directory Download the contents of a directory Download specific files.
Tip You can tweak your download operation by using optional flags. Note If the Content-md5 property value of a file contains a hash, AzCopy calculates an MD5 hash for downloaded data and verifies that the MD5 hash stored in the file's Content-md5 property matches the calculated hash. Note Append the --recursive flag to download files in all sub-directories. Copy a file to another storage account Copy a directory to another storage account Copy a file share to another storage account Copy all file shares, directories, and files to another storage account.
Tip You can tweak your copy operation by using optional flags. Note Currently, this scenario is supported for accounts that have enabled hierarchical namespace via the blob endpoint. Tip You can tweak your sync operation by using optional flags.
Tip This example encloses path arguments with single quotes ''. Submit and view feedback for This product This page. View all page feedback. The salt needs to be unique per-user per-password. Every time a user creates an account or changes their password, the password should be hashed using a new random salt. Never reuse a salt. The salt also needs to be long, so that there are many possible salts. As a rule of thumb, make your salt is at least as long as the hash function's output.
The salt should be stored in the user account table alongside the hash. If you are writing a web application, you might wonder where to hash. Should the password be hashed in the user's browser with JavaScript, or should it be sent to the server "in the clear" and hashed there? Even if you are hashing the user's passwords in JavaScript, you still have to hash the hashes on the server. Consider a website that hashes users' passwords in the user's browser without hashing the hashes on the server.
To authenticate a user, this website will accept a hash from the browser and check if that hash exactly matches the one in the database.
This seems more secure than just hashing on the server, since the users' passwords are never sent to the server, but it's not. The problem is that the client-side hash logically becomes the user's password. All the user needs to do to authenticate is tell the server the hash of their password. If a bad guy got a user's hash they could use it to authenticate to the server, without knowing the user's password! So, if the bad guy somehow steals the database of hashes from this hypothetical website, they'll have immediate access to everyone's accounts without having to guess any passwords.
This isn't to say that you shouldn't hash in the browser, but if you do, you absolutely have to hash on the server too. Hashing in the browser is certainly a good idea, but consider the following points for your implementation:. If the connection between the browser and the server is insecure, a man-in-the-middle can modify the JavaScript code as it is downloaded to remove the hashing functionality and get the user's password.
Some web browsers don't support JavaScript, and some users disable JavaScript in their browser. So for maximum compatibility, your app should detect whether or not the browser supports JavaScript and emulate the client-side hash on the server if it doesn't. You need to salt the client-side hashes too. The obvious solution is to make the client-side script ask the server for the user's salt. Don't do that, because it lets the bad guys check if a username is valid without knowing the password.
Since you're hashing and salting with a good salt on the server too, it's OK to use the username or email concatenated with a site-specific string e. Salt ensures that attackers can't use specialized attacks like lookup tables and rainbow tables to crack large collections of hashes quickly, but it doesn't prevent them from running dictionary or brute-force attacks on each hash individually. High-end graphics cards GPUs and custom hardware can compute billions of hashes per second, so these attacks are still very effective.
To make these attacks less effective, we can use a technique known as key stretching. The idea is to make the hash function very slow, so that even with a fast GPU or custom hardware, dictionary and brute-force attacks are too slow to be worthwhile. The goal is to make the hash function slow enough to impede attacks, but still fast enough to not cause a noticeable delay for the user. Key stretching is implemented using a special type of CPU-intensive hash function. Don't try to invent your own—simply iteratively hashing the hash of the password isn't enough as it can be parallelized in hardware and executed as fast as a normal hash.
These algorithms take a security factor or iteration count as an argument. This value determines how slow the hash function will be. For desktop software or smartphone apps, the best way to choose this parameter is to run a short benchmark on the device to find the value that makes the hash take about half a second.
This way, your program can be as secure as possible without affecting the user experience. If you use a key stretching hash in a web application, be aware that you will need extra computational resources to process large volumes of authentication requests, and that key stretching may make it easier to run a Denial of Service DoS attack on your website.
I still recommend using key stretching, but with a lower iteration count. You should calculate the iteration count based on your computational resources and the expected maximum authentication request rate.
Always design your system so that the iteration count can be increased or decreased in the future. If you are worried about the computational burden, but still want to use key stretching in a web application, consider running the key stretching algorithm in the user's browser with JavaScript.
The iteration count should be set low enough that the system is usable with slower clients like mobile devices, and the system should fall back to server-side computation if the user's browser doesn't support JavaScript. Client-side key stretching does not remove the need for server-side hashing.
You must hash the hash generated by the client the same way you would hash a normal password. As long as an attacker can use a hash to check whether a password guess is right or wrong, they can run a dictionary or brute-force attack on the hash. The next step is to add a secret key to the hash so that only someone who knows the key can use the hash to validate a password.
This can be accomplished two ways. Either the hash can be encrypted using a cipher like AES, or the secret key can be included in the hash using a keyed hash algorithm like HMAC. This is not as easy as it sounds. The key has to be kept secret from an attacker even in the event of a breach. If an attacker gains full access to the system, they'll be able to steal the key no matter where it is stored.
The key must be stored in an external system, such as a physically separate server dedicated to password validation, or a special hardware device attached to the server such as the YubiHSM. I highly recommend this approach for any large scale more than , users service. I consider it necessary for any service hosting more than 1,, user accounts. If you can't afford multiple dedicated servers or special hardware devices, you can still get some of the benefits of keyed hashes on a standard web server.
Most databases are breached using SQL Injection Attacks , which, in most cases, don't give attackers access to the local filesystem disable local filesystem access in your SQL server if it has this feature.
If you generate a random key and store it in a file that isn't accessible from the web, and include it into the salted hashes, then the hashes won't be vulnerable if your database is breached using a simple SQL injection attack.
Don't hard-code a key into the source code, generate it randomly when the application is installed. This isn't as secure as using a separate system to do the password hashing, because if there are SQL injection vulnerabilities in a web application, there are probably other types, such as Local File Inclusion, that an attacker could use to read the secret key file.
But, it's better than nothing. Please note that keyed hashes do not remove the need for salt. Clever attackers will eventually find ways to compromise the keys, so it is important that hashes are still protected by salt and key stretching. Password hashing protects passwords in the event of a security breach.
It does not make the application as a whole more secure. Much more must be done to prevent the password hashes and other user data from being stolen in the first place.
Even experienced developers must be educated in security in order to write secure applications. Unless you understand all the vulnerabilities on the list, do not attempt to write a web application that deals with sensitive data. It is the employer's responsibility to ensure all developers are adequately trained in secure application development.
Having a third party "penetration test" your application is a good idea. Even the best programmers make mistakes, so it always makes sense to have a security expert review the code for potential vulnerabilities. Find a trustworthy organization or hire staff to review your code on a regular basis. If available, the official package from your Unix-like distribution is the recommended method of installing GIMP!
The flatpak build is new and has known limitations, though it will likely provide faster updates, following GIMP releases closely. Therefore choose your installation medium according to your needs. The flatpak link above should open your software installer and prompt you to install GIMP.
Yet it may not work out-of-the-box on some platforms since the flatpak technology is new. If that is the case, ensure flatpak is installed and if clicking the link still does not prompt to install GIMP, then manually install by command line:.
Once installed, it will be made available exactly the same way as other applications menus, desktop overview, or any specific application launch process used by your desktop. If this is not the case, we suggest to report a bug to your desktop or distribution asking for proper support of flatpak. In the meantime, you can still run it by command line not as the recommended method, only a workaround :. This installation will also provide regular update.
You don't have to come back on this page and install again it will not work! Once again, if your distribution does not have proper support, you can always fall back to using the following command line:. Please refer to the documentation for your Unix-like system on the installation of software. Updated on GIMP 2.
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