OpenSSL "rsautl" - Decrypt Large File with RSA Key
How to decrypt a large file with an RSA private key using OpenSSL "rsautl" command? I received a large encrypted file from my friend who used the RSA-AES hybrid encryption process with my public key.
If your friend encrypted a large file with the RSA-AES hybrid encryption process with your public key, you should receive the large encrypted file and an encrypted AES password from him/her.
Decrypting the large encrypted file can be done use the process described blow:
1. Decrypt the encrypted AES password file to get the AES password with your RSA private key. This can be done using the OpenSSL "rsa -decrypt" command.
2. Decrypt the large encrypted with the AES password. This can be done using the OpenSSL "enc -d -aes*" command.
For example, if you are the owner of the RSA public key and received two encrypted files from your friend described in the last tutorial, you can decrypt them as shown below:
C:\Users\fyicenter>dir *cipher.txt 128 aes_pass_cipher.txt 160 cipher.txt C:\Users\fyicenter>\local\openssl\openssl.exe OpenSSL> rsautl -decrypt -inkey my_rsa.key -in aes256_pass_cipher.txt -out aes256_pass_decipher.txt OpenSSL> enc -d -aes256 -pass file:./aes256_pass_decipher.txt -in cipher.txt -out decipher.txt C:\Users\fyicenter>type decipher.txt The quick brown fox jumped over the lazy dog. The quick brown fox jumped over the lazy dog. The quick brown fox jumped over the lazy dog.
Commands used in this test:
2017-05-20, 4675👍, 0💬
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