aes_encrypt() key_str: What are good values to use?

[Paul Medynski]

Hi all,

I'm looking at using aes_encrypt() to store user passwords in a tinyblob column. However, the mysql docs don't explain exactly how aes_encrypt() uses the key_str argument, so I don't know what a "good value" to use would be.

For example, if I pass in a 21-character key string, will aes_encrypt() use the entire string, or will it use the leftmost 16 characters (128 bits in an 8-bit chacacter set), or will it use the rightmost 16 characters, or will it do something entirely different?

I don't want to end up using a key_str that produces weaker encryption. Of course, I'm pretty much an encryption n00b, so maybe none if this matters and I can just use whatever key_str I want and everything will be fine :)

Any suggestions?

-Paul