How can I Decrypt the code which is Encrypted by md5 method in PostgreSQL

Question

How can I Decrypt the code which is Encrypted by md5 method in PostgreSQL.

eg: md5("logesh") returns '82e05c4839aba7c637881489bec50dd1'

How can I decrypted this code.

Answer 1

You can't. MD5 isn't encryption. It's a one-way cryptographic hash function. With enough compute power and/or storage you can brute force md5 to figure out what the plaintext might have been but it's only one possible plaintext for that hash. It's designed to be both slow and difficult to reverse, and impossible to reverse 1:1. There are known MD5 collisions.

PostgreSQL's use of "encrypt" in WITH ENCRYPTED PASSWORD is somewhat incorrect, it should really be WITH HASHED PASSWORD. But too late to change it now.

If you want encryption look into pgcrypto which offers AES-128 routines, etc. Or do your encryption and decryption client-side where key exposure in logs, pg_stat_statements etc isn't such a concern.