Hashes and Message Authentication Codes

Index

• Hash generation

  • Generate hash of a file

  • Generate a Message Authentication Code

Hash generation

OpenSSL also has features for generating hashes of various types.

Generate hash of a file

Using SHA1

openssl sha1 <FILE> 

SHA1(<FILE>)= 95e91837dc1a4a8eeb42208420d8620cb8d7785f

Using SHA256

openssl sha256 <FILE> 

SHA256(<FILE>)= b110ed205353743923c7d66811a2916e2cc3bb3a06e7411e79a4b124ca1322d0

Using RIPEMD160

openssl ripemd160 <FILE> 

RIPEMD160(<FILE>)= f9bb6ff349a5f03531af89774f9a6578a785aec8

It is also possible to use the openssl dgst command to create hashes from data.

Listing the available hash functions

To list the available hash functions, simply do:

openssl dgst -list

This will present all the hash functions that are supported by openssl:

Supported digests:
-blake2b512                -blake2s256                -md4
-md5                       -md5-sha1                  -mdc2
-ripemd                    -ripemd160                 -rmd160
-sha1                      -sha224                    -sha256
-sha3-224                  -sha3-256                  -sha3-384
-sha3-512                  -sha384                    -sha512
-sha512-224                -sha512-256                -shake128
-shake256                  -sm3                       -ssl3-md5
-ssl3-sha1                 -whirlpool

Create a hash from a file

To create a hash from a specific file, we need to do:

openssl dgst -sha256 <FILE>

That produces the appropriate value:

SHA2-256(<FILE>)= 76e3bccb0c1e24061c17f286e5eec8425e9fc22800a446dfbfe6fad3d3ecd950

Create a hash with a "salt"

The following command will create a hash value from a password (mypassword) with a "salt" value (mysaltvalue) - using the SHA256:

openssl passwd -5 -salt mysaltvalue mypassword 

Generate a Message Authentication Code

In order to generate a hash-based message authentication code, we need to provide the hash algorithm to be used and the secret key to encrypt the hash.

openssl sha1 -hmac 24899ec1e452d219121f0d07cd6975b7 <FILE>

HMAC-SHA1(<FILE>)= 384773867cb7bce6ffd97a95c26e65666c045ea7