Linux-使用文件中的密钥进行openssl sha256

Question

I have a 32 byte key stored in a file called test_key.key

I wish to use openssl to create hash of a different file called mytext.txt. I need to create the hash using HMAC-SHA-256 & the key in test_key.key

I thought I had it working with the following command:

openssl dgst -sha256 -hmac $test_key.key mytext.txt

However, on closer examination I noticed it was using the string "test_key.key", not the actual file contents. I have tried a few different variations of this for the key file such as:

"$test_key.key"
'$test_key.key'
/test_key.key

Sadly, they all seem to have the same problem.

Can anyone advise me on this? I wish to keep this as a one line command if possible.

Answer 1

openssl dgst -sha256 -hmac $(<test_key.key) mytext.txt 

（提供给用户David C. Rankin）