MD4, MD5
MD4 and MD5 (message-digest) is a widely used hash function producing a 128-bit hash value.
Decrypt
MD4
Put the md4 hash into the file.
echo -n '<md4-hash>' > hash.txt
Then crack it.
john --format=raw-md4 --wordlist=wordlist.txt hash.txt
# or
hashcat -m 900 -a 0 hash.txt wordlist.txt
MD5
Put the md5 hash into the file.
echo -n '<md5-hash>' > hash.txt
Then crack it.
john --format=raw-md5 --wordlist=wordlist.txt hash.txt
# or
hashcat -m 0 -a 0 hash.txt wordlist.txt
Encrypt
MD4
No contents yet
MD5
echo -n 'hello' | md5sum
md5sum sample.txt