How to identify and crack a MySQL 4.1+ / SHA1(SHA1()) hash

MySQL 4.1+ / SHA1(SHA1()) is a database hash type. It is fast and typically unsalted, which makes weak passwords recoverable quickly on consumer GPU hardware. This page shows how to recognise it and the exact commands to attack it.

All identification runs locally in WebAssembly. The commands below write the hash to a local file on your machine — nothing is sent to this site.

Identifying the hash

The hash identifier on the home page detects MySQL 4.1+ / SHA1(SHA1()) entirely in your browser — your hash is never uploaded. A typical example looks like this:

*2470C0C06DEE42FD1618BB99005ADCA2EC9D1E19

Cracking MySQL 4.1+ / SHA1(SHA1()) with hashcat

Save the hash to a file and run hashcat in mode -m 300. Start with a wordlist such as rockyou.txt:

echo '*2470C0C06DEE42FD1618BB99005ADCA2EC9D1E19' > hash.txt && hashcat -m 300 hash.txt /usr/share/wordlists/rockyou.txt

Add a rule set to mutate dictionary words (capitalisation, leetspeak, appended digits) and dramatically widen coverage:

echo '*2470C0C06DEE42FD1618BB99005ADCA2EC9D1E19' > hash.txt && hashcat -m 300 hash.txt /usr/share/wordlists/rockyou.txt -r /usr/share/hashcat/rules/best64.rule

Cracking MySQL 4.1+ / SHA1(SHA1()) with John the Ripper

John the Ripper can attack the same hash with the mysql-sha1 format:

echo '*2470C0C06DEE42FD1618BB99005ADCA2EC9D1E19' > hash.txt && john --format=mysql-sha1 --wordlist=/usr/share/wordlists/rockyou.txt hash.txt