Openssl encrypt file

Unless you believe that closed source, proprietary cryptography is superior to open source cryptography. That argument, security by obscurity has been made many times and lost. This is unsafe. Quiark, Please enlighten us and share your wisdom — why is this unsafe in your opinion?

An actual proof will be most appreciated. Unless things have changed in the past 2 years, Openssl uses custom and insecure constructs and practices to encrypt data. NOTE : I just posted these to give anyone who reads this something to think about. Have a question or suggestion? Please leave a comment to start the discussion. Please keep in mind that all comments are moderated and your email address will NOT be published.

Save my name, email, and website in this browser for the next time I comment. Notify me of followup comments via e-mail. You can also subscribe without commenting. Remember, even if the file is intercepted, its contents are encrypted, so the contents can't be revealed:. If Bob uses the usual methods to try to open and view the encrypted message, he won't be able to read it:. Bob needs to do his part by decrypting the message using OpenSSL, but this time using the -decrypt command-line argument.

He needs to provide the following information to the utility:. To send his message, Bob follows the same process Alice used, but since the message is intended for Alice, he uses Alice's public key to encrypt the file:. So she decrypts the message with OpenSSL, only this time she provides her secret key and saves the output to a file:.

It can do many tasks besides encrypting files. You can find out all the ways you can use it by accessing the OpenSSL docs page , which includes links to the manual, the OpenSSL Cookbook , frequently asked questions, and more. To learn more, play around with its various included encryption algorithms to see how it works.

Thanks for the detailed guide on security measures! As described, they seem to be very ensuring. Well, hackers do not sleep so it is very useful to include such practices in the app development process. Just to be sure ;. OpenSSL is a practical tool for ensuring your sensitive and secret messages can't be opened by outsiders.

Image by :. Get the highlights in your inbox every week. There are two general types: Secret-key or symmetric encryption Public-key or asymmetric encryption Secret-key encryption uses the same key for encryption and decryption, while public-key encryption uses different keys for encryption and decryption.

Public-key encryption More on security. The defensive coding guide Webinar: Automating system security and compliance with a standard operating system 10 layers of Linux container security SELinux coloring book More security articles. Vh 48 4c eb 40 5e 50 fe 19 ea 28 a8 b8 7a 13 69 d7 HL. Y 82 56 81 80 7b 89 07 7c 21 24 63 5e 61 0c ae 2a. Z 12 e4 9a 31 57 b3 03 6e dd e1 16 7f 6b c0 b3 8b How to encrypt files with gocryptfs on Linux. Gocryptfs encrypts at the file level, so synchronization operations can work efficiently on each file.

Brian "bex" Exelbierd Red Hat. Need a primer on cryptography basics, especially regarding OpenSSL? Read on. Remember, the encrypted file is only as safe as the secret is truly secret. While not used in the provided examples, -salt is recommended and will protect against dictionary attacks.

Where enc means encrypt, -aes is the cipher defaults to -aescbc , -base64 encoded, -in dt. Where enc -d means decrypt, -aes is the cipher make sure to use the same cipher as used when encrypting , -base64 if encoded, -in dt. As you noticed in the previous example without pbkdf2, the key derivation was deprecated and it recommends to use -pbkdf2 for key derivation. Note that the only difference when using pbkdf2 is the corresponding flag.

Other flags stay the same. The default number of PBKDF2 iterations is 10,, but this can be changed to a higher number using the -iter flag. For example, the 1Password service derives keys with , iterations. To decrypt the pbkdf2 encrypted data if using iterations other than the default make sure to include that with -iter :.

Hopefully, that provides useful examples for how to encrypt and decrypt data using openssl. Please leave comments with any questions or suggestions and improvements. See the official openssl docs for asymmetric encryption and symmetric encryption.

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