# Finding hash algorithm given password and hash

Is it possible to find the hash algorithm used for a password given that you have the clear-text password and its hash?

The algorithm in question hashes the string 'password' to 'da0feea11db421a7be1173895497e71f', and there is no salt used.

• Google gives you the result... $\texttt{md5(19f7c908f1a949ca0003b5c30ccc5282)} = \texttt{da0feea11db421a7be1173895497e71f}$ – Biv Jul 7 '17 at 14:04
• @Biv: as you probably realized it, the above fact gives assurance that whatever generated da0feea11db421a7be1173895497e71f is MD5-based (the other alternative is a preimage attack on MD5). For the rest, we can't be sure. That's a hell of a strange password hash algorithm if its last step is MD5-hashing the lowercase hexadecimal for a 128-bit value, but if the input really is the string 'password' I see no other credible alternative. – fgrieu Jul 7 '17 at 16:02
• Somewhat related: Determine hashing algorithm – e-sushi Jul 7 '17 at 20:27