Adobe flash encryption library

However, you might find it valuable to understand the techniques that the class uses. For example, you might want to adapt the class or incorporate some of its techniques for situations where a different level of data privacy is desired.

You can also view the source code on the project site or download it to follow along with the explanations. When code creates an EncryptionKeyGenerator instance and calls its getEncryptionKey method, several steps are taken to ensure that only the rightful user can access the data. The process is the same to generate an encryption key from a user-entered password before the database is created as well as to re-create the encryption key to open the database.

When code calls the getEncryptionKey method, it passes in a password as a parameter. The password is used as the basis for the encryption key. By using a piece of information that only the user knows, this design ensures that only the user who knows the password can access the data in the database. For maximum security, the application never stores the password. The first step the EncryptionKeyGenerator class takes when the getEncryptionKey method is called is to check the user-entered password to ensure that it meets the password strength requirements.

The EncryptionKeyGenerator class requires a password to be 8 - 32 characters long. The password must contain a mix of uppercase and lowercase letters and at least one number or symbol character. The validateStrongPassword method is a public method so that application code can check a password without calling the getEncryptionKey method to avoid causing an error.

Later in the process, the password is required to be bits long. The following is the code for the concatenatePassword method:. If the password is less than bits, the code concatenates the password with itself to make it bits. The next step is to get a bit salt value that in a later step is combined with the password.

A salt is a random value that is added to or combined with a user-entered value to form a password. Using a salt with a password ensures that even if a user chooses a real word or common term as a password, the password-plus-salt combination that the system uses is a random value.

This randomness helps guard against a dictionary attack, where an attacker uses a list of words to attempt to guess a password. If the application is calling the getEncryptionKey method for the first time, the code creates a random bit salt value.

Otherwise, the code loads the salt value from the encrypted local store. The code now has a bit password and a bit salt value. It next uses a bitwise XOR operation to combine the salt and the concatenated password into a single value. In effect, this technique creates a bit password consisting of characters from the entire range of possible characters.

This principle is true even though most likely the actual password input consists of primarily alphanumeric characters. This increased randomness provides the benefit of making the set of possible passwords large without requiring the user to enter a long complex password. Once the concatenated password and the salt have been combined, the next step is to further secure this value by hashing it using the SHA hashing algorithm.

Hashing the value makes it more difficult for an attacker to reverse-engineer it. The encryption key must be a ByteArray that is exactly 16 bytes bits long.

The result of the SHA hashing algorithm is always bits long. Consequently, the final step is to select bits from the hashed result to use as the actual encryption key. You could select a range of bits starting at some arbitrary point, you could select every other bit, or use some other way of selecting bits. The important thing is that the code selects distinct bits, and that the same bits are used each time. Adobe Flash Platform. View Help PDF 5. Uses for an encrypted database Creating an encrypted database Connecting to an encrypted database Changing the encryption key of a database Considerations for using encryption with a database Example: Generating and using an encryption key Using the EncryptionKeyGenerator class to obtain a secure encryption key Complete example code for generating and using an encryption key Understanding the EncryptionKeyGenerator class Obtain and validate a strong password Expand the password to bits Generate or retrieve a bit salt value Combine the bit password and salt using the XOR operator Hash the key Extract the encryption key from the hash.

Uses for an encrypted database Encryption is useful any time you want to restrict access to the information stored in a database. The following are some examples of cases where you would want to use an encrypted database: A read-only cache of private application data downloaded from a server A local application store for private data that is synchronized with a server data is sent to and loaded from the server Encrypted files used as the file format for documents created and edited by the application.

Creating an encrypted database To use an encrypted database, the database file must be encrypted when it is created. ByteArray ; encryptionKey. Connecting to an encrypted database Like creating an encrypted database, the procedure for opening a connection to an encrypted database is like connecting to an unencrypted database. SQLConnection ; conn.

OPEN, openHandler ; conn. Changing the encryption key of a database When a database is encrypted, you can change the encryption key for the database at a later time. Considerations for using encryption with a database The section Uses for an encrypted database presents several cases in which you would want to use an encrypted database.

The following are additional security considerations that are important to keep in mind when designing an application to use an encrypted database: A system is only as secure as its weakest link. Because the source code is accessible, two points to remember are: Never hard-code an encryption key in your source code Always assume that the technique used to generate an encryption key such as random character generator or a particular hashing algorithm can be easily worked out by an attacker AIR database encryption uses the Advanced Encryption Standard AES with Counter with CBC-MAC CCM mode.

Example: Generating and using an encryption key This example application demonstrates one technique for generating an encryption key. For the EncryptionKeyGenerator, the full name is: window. EncryptionKeyGenerator You can create an alias for the class to avoid having to type the full name.

Note: To maintain the highest level of security and privacy for data, an application must require the user to enter a password each time the application connects to the database. You can download the as3corelib package including source code and documentation. You can also download the SWC or source code files from the project page.

Place the source code for the EncryptionKeyGenerator class or the as3corelib SWC in a location where your application source code can find it. In your application source code, add an import statement for the EncryptionKeyGenerator class. Before the point where the code creates the database or opens a connection to it, add code to create an EncryptionKeyGenerator instance by calling the EncryptionKeyGenerator constructor. The EncryptionKeyGenerator instance uses this password as the basis for the encryption key shown in the next step.

The EncryptionKeyGenerator instance tests the password against certain strong password validation requirements. If the validation fails, an error occurs. That way you can determine whether the password meets the minimum requirements for a strong password and avoid an error. The getEncryptionKey method generates and returns the encryption key a byte ByteArray.

You can then use the encryption key to create your new encrypted database or open your existing one. The getEncryptionKey method has one required parameter, which is the password obtained in step 5. The EncryptionKeyGenerator creates a random value known as a salt that is used as part of the encryption key. Instead of using the default key, you might want to specify your own ELS key. In that case, specify a custom key by passing it as the second getEncryptionKey parameter, as shown here:.

With an encryption key returned by the getEncryptionKey method, your code can create a new encrypted database or attempt to open the existing encrypted database. In this example, the application is designed to open the database in asynchronous execution mode. The code sets up the appropriate event listeners and calls the openAsync method, passing the encryption key as the final argument:.

In the listener methods, the code removes the event listener registrations. It then displays a status message indicating whether the database was created, opened, or whether an error occurred.

The most noteworthy part of these event handlers is in the openError method. In that method an if statement checks if the database exists meaning that the code is attempting to connect to an existing database and if the error ID matches the constant EncryptionKeyGenerator.

If both of these conditions are true, it probably means that the password the user entered is incorrect. The following is the code that checks the error ID:. For the complete code for the example event listeners, see Complete example code for generating and using an encryption key. The example uses the EncryptionKeyGenerator class to create an encryption key from a password.

The application MXML file contains the source code for a simple application that creates or opens a connection to an encrypted database:. The application FLA file contains the source code for a simple application that creates or opens a connection to an encrypted database. The FLA file has four components placed on the stage:. The code for the application is defined on a keyframe on frame 1 of the main timeline. The following is the code for the application:. The process for using the class is explained in Using the EncryptionKeyGenerator class to obtain a secure encryption key.

However, you might find it valuable to understand the techniques that the class uses. For example, you might want to adapt the class or incorporate some of its techniques for situations where a different level of data privacy is desired. You can also view the source code on the project site or download it to follow along with the explanations.

When code creates an EncryptionKeyGenerator instance and calls its getEncryptionKey method, several steps are taken to ensure that only the rightful user can access the data. The process is the same to generate an encryption key from a user-entered password before the database is created as well as to re-create the encryption key to open the database.

When code calls the getEncryptionKey method, it passes in a password as a parameter. The password is used as the basis for the encryption key. By using a piece of information that only the user knows, this design ensures that only the user who knows the password can access the data in the database. For maximum security, the application never stores the password. The first step the EncryptionKeyGenerator class takes when the getEncryptionKey method is called is to check the user-entered password to ensure that it meets the password strength requirements.

The EncryptionKeyGenerator class requires a password to be 8 - 32 characters long. The password must contain a mix of uppercase and lowercase letters and at least one number or symbol character. The code is as follows:. The validateStrongPassword method is a public method so that application code can check a password without calling the getEncryptionKey method to avoid causing an error.

Later in the process, the password is required to be bits long. The getEncryptionKey method calls the concatenatePassword method to perform the task of creating the long password. The following is the code for the concatenatePassword method:. If the password is less than bits, the code concatenates the password with itself to make it bits. The next step is to get a bit salt value that in a later step is combined with the password. A salt is a random value that is added to or combined with a user-entered value to form a password.

Using a salt with a password ensures that even if a user chooses a real word or common term as a password, the password-plus-salt combination that the system uses is a random value. This randomness helps guard against a dictionary attack, where an attacker uses a list of words to attempt to guess a password.

If the application is calling the getEncryptionKey method for the first time, the code creates a random bit salt value.

Otherwise, the code loads the salt value from the encrypted local store. The salt is stored in a variable named salt.

The code determines if it has already created a salt by attempting to load the salt from the encrypted local store:. If the code is creating a new salt value, the makeSalt method generates a bit random value.

Because the value is eventually stored in the encrypted local store, it is generated as a ByteArray object. The makeSalt method uses the Math. This is because of the maximum path length in Windows. If the distributor is using AIR, rather than Flash, the issue might be caused by a path length limitation.

Distributors should shorten the name of their AIR application to something reasonable. The subErrorId contains a client-specific error or line error. The distributor should confirm that the error is reproducible with specific pieces of content. You might have to repackage broken content.

For more information, see Error code This error code can also be thrown if a security error occurs during network access. Examples include the destination server does not the client to connect by usingcrossdomain.

For more information, see DRM error possible root cause and resolution. The subErrorId contains a client-specific, server-specific or line error. If you are using Google Chrome on Windows, provide an explanation about how to allow plugin access that is not in a sandbox.

The distributor should complete one of the following tasks: If the error is consistent across platforms, you shouldescalate the issue with Adobe. If the error is confined to Chrome on Windows, guide the user to allow unsandboxed plugin access.

Distributors should update their SWF to version 19 or later. For the Chrome-specific error, a error is thrown. This change was introduced in Chrome Stable channel version Note: Error might happen with Flash Playerversions We recommend that you upgrade to the latest Flash Player version. If the issue occurs on iOS in a development phase, ask the developer to confirm whether the issue is observed when switching between builds that were downloaded from third-party, pre-release distribution systems for example, HockeyApp and a local build from Xcode.

Attributes of a previous installation are not entirely overwritten when switching between a build distributed from HockeyApp and a build from Xcode.

This situation might trigger the error. To resolve this issue, the developer should remove the older build from the device before installing the new build.

This error is not expected to occur frequently. In corporate environments that uses roaming profiles, if a user was viewing content that is protected by DRM, the chances error occurring increases as the user logs in from different machines. If possible, distributor should try to get this information from user. If the error occurs frequently, escalate to Adobe. You must notify Adobe whether resetting license store did or did not solve the problem and tell Adobe on which browsers the error is occurring.

The subErrorIdcontains a client-specific or line error. If the GlobalStore is failing at a rate greater than the expected failure rate of the hard drives of your user base, escalate the issue to Adobe. In the server logs, an Error code isMachineTokenInvalid. However, at the client level, Error code is translated to Error code CRL files. If the files are in this directory, double-click the files in Windows Explorer and in the CRL viewer application, determine whether any of the files have expired.

For more information, see Firewall rules. If the CRL files are not available or have expired, you must confirm whether the license server can be reached. Open a network sniffer e. You can observe the network traffic to see whether calls to the following URL endpoints are successful: Note: You can also enter the following CRL URLs in a browser to see whether you can manually download each file.

Note: An error might occur when a large number or a burst of clients report a error to a temporary network issue when renewing a CRL file. When the network issue was resolved, the issues were also resolved. To resolve this issue, you might want to review the logs and purge the existing CRL files. If there are no server issues, prompt the user to reset as described in Error code If retry fails, log the issue. If retries are failing at a rate greater than the expected failure rate of the hard drives of your user base, escalate the issue to Adobe.

On the client, there is no way to determine what went wrong. There is always a very descriptive stack trace in the log to indicate the problem. The subErrorId contains a server-specific or line error. The distributor should look at server logs to identify which server is sending this error. For errors that have a sub-error code , the server cannot decrypt the request.

In addition, if customers are using the Reference Implementation, they must ensure that there are no typos in theflashaccessrefimpl.

The subErrorId contains a server-specific error from the publishers customized license server. The server returned an error in the application-specific namespace. If your service does not intend to use authentication, log the identify of the content that is causing this error. This error should not require an escalation, unless the content is not supposed to be configured to require authentication.

In this case, repackage the offending content with proper policy. To resolve this issue, check whether the client clock is not set correctly. To set the client clock, repackage the content or modify the license server configuration. To open a restricted PDF in these applications, the user must enter the permissions password.

If you forget a password, you cannot recover it from the PDF. All Adobe products enforce the restrictions set by the permissions password. However, if third-party products do not support these settings, document recipients are able to bypass some or all of the restrictions you set.

Type the password in the corresponding field. Select what the user can print from the Printing Allowed menu:. Low Resolution dpi. Printing may be slower because each page is printed as a bitmap image. High Resolution. Lets users print at any resolution, directing high-quality vector output to PostScript and other printers that support advanced high-quality printing features. Select what the user can change from the Changes Allowed menu:. Prevents users from making any changes to the document that are listed in the Changes Allowed menu, such as filling in form fields and adding comments.

Inserting, Deleting, And Rotating Pages. Lets users insert, delete, and rotate pages, and create bookmarks and thumbnails. Lets users fill in forms and add digital signatures. Lets users add comments and digital signatures, and fill in forms. Any Except Extracting Pages. Lets users edit the document, create and fill in form fields, and add comments and digital signatures. Select an Acrobat version from the Compatibility menu. You can remove security from an open PDF if you have the permissions to do so.

If the PDF is secured with a server-based security policy, only the policy author or a server administrator can change it.