Linked Questions

7
votes
2answers
7k views

File security when encrypting files directly with the openssl command / and what about SHA1 hashing password first?

I've been using this command to encrypt files for a while now: openssl aes-256-cbc -a -salt -in secrets.txt -out secrets.txt.enc Then I type in a password. Can someone tell me, roughly speaking, ...
3
votes
2answers
4k views

Basic question regarding OpenSSL and AES-GCM

While researching how to encrypt private keys for SSH connections as securely as possible, I have run into the following very basic understanding problems (Note: I have used the newest stable release ...
3
votes
2answers
8k views

With openssl des3, what are the passphrase parameters?

I'm using OpenSSL's des3 tool to encrypt a file, e.g. openssl des3 -salt -k SUPER_SECURE_PASSPHRASE < inputFile > outputFile Everything's working, but now I have to choose a final, fixed ...
4
votes
1answer
2k views

Why brute-force the password instead of the key directly?

This answer on another question on security stackexchange by a very reputed user explains why he prefers GnuPG over OpenSSL for file encryption. From what I understand, it can be summarized as this: ...
4
votes
1answer
4k views

Which file encryption algorithm is used by Synology's Cloud Sync feature? [closed]

I'm trying to find out which encryption method is used by a piece of software I use, viz. the 'Cloud Sync' feature of Synology's DSM 6.0 running on a Synology NAS. (Background. This Cloud Sync ...
2
votes
1answer
1k views

openssl problem decrypting passhrase-encrypted file using the derived IV, Key and Salt

So I followed openssl: recover key and IV by passphrase and managed to retrieve my salt, key and IV using -P in openssl. openssl enc -aes-256-cbc -in encrypted -pass "pass:password" -out m.jpg this ...
4
votes
1answer
2k views

IV Reverse AES-256-CBC PKCS#7

I'm a freshmen in cryptography and want to know more about IV reversing. There's a lot of posts about finding the passphrase with a new IV. But what about the other situation? This is for educational ...
5
votes
1answer
337 views

Why is the Key Derivation Function important?

Let's consider this openssl command : openssl enc -aes-256-cbc -pass pass:PASSWORD Why is it important to have a good Key Derivation Function? This answer to another question suggest that GnuPG is ...
0
votes
0answers
605 views

Generate symmetric key programmatically using openssl EVP

Am learning OpenSSL EVP API and trying to understand the ways to generate a symmetric key using OpenSSL EVP in C++ program. I have two questions in this regard: 1) To understand what the command ...
0
votes
1answer
330 views

Secure file encryption with OpenSSL and a little trick?

I try to really securely encrypt a file with OpenSSL. I´m new to OpenSSL and just read here, that it´s not very secure due to it´s behavior in generating salt & IV, and storing it within the ...