Re: Possible to store invalid SCRAM-SHA-256 Passwords - Mailing list pgsql-bugs

"Jonathan S. Katz" <jkatz@postgresql.org> writes:
> OK, so I have something that sort of works, i.e:

> if (strncmp(shadow_pass, "md5", 3) == 0 &&
>     strlen(shadow_pass) == MD5_PASSWD_LEN &&
>     strspn(shadow_pass, MD5_PASSWD_CHARSET) == MD5_PASSWD_LEN
> )

> where MD5_PASSWD_CHARSET = "mabcdef0123456789"

> ...but you may notice something: the CHARSET contains an "m" as we store
> that "md5" prefix on the md5 hashed passwords.

Yeah, that's silly; why not

     strspn(shadow_pass + 3, MD5_PASSWD_CHARSET) == MD5_PASSWD_LEN - 3

It's not like this code isn't very well aware of the first 3 characters
being not like the others.

            regards, tom lane