# SharpAESCrypt The SharpAESCrypt commandline tool uses the provided AES encryption library but exposes it as a commandline tool. The SharpAESCryp tool is called `Duplicati.CommandLine.SharpAESCrypt.exe` on Windows and `duplicati-aescrypt` on Linux and MacOS. The library and commandline tool implements the [AESCrypt file format](https://www.aescrypt.com/aes_stream_format.html), so the commandline tool is compatible with any other tool using the [AESCrypt file format](https://www.aescrypt.com/download/). To encrypt a file, use the syntax: ``` duplicati-aescrypt e ``` And similarly to decrypt a file: ``` duplicati-aescrypt d ``` For decryption, it is possible to use the "optimistic mode", which will leave the decrypted file on disk, even if it does not pass the validation. This is insecure, because the file contents can be modified if the integrity checks fail, but in some cases it can help to recover lost data: ``` duplicati-aescrypt do ``` If you are encrypting files with a different tool, note that SharpAESCrypt adds an additional check, similar to [PCKS#7 padding](https://en.wikipedia.org/wiki/Padding_\(cryptography\)#PKCS#5_and_PKCS#7), which is not part of the AESCrypt specification. This does not change the file format, but makes it harder to inject trailing bytes. However, since other tools do not follow this standard, the decryption will reject such (otherwise valid) files. To decrypt such files, enable the compatibility mode: ``` duplicati-aescrypt dc ``` To enable the compatibility check for regular Duplicati operations, add the environment variable: ``` AES_IGNORE_PADDING_BYTES=1 ``` --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.duplicati.com/duplicati-programs/command-line-interface-cli-1/sharpaescrypt.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.