Modifying Code for 24-Word Mnemonics

Hey, I’m not really into programming, so I can't help much with changing the code. But if you wanna brute-force those 24 BIP39 words, check out BTCRecover. It's getting updates and supports GPUs.

To handle longer mnemonics, you gotta bump up the block size in HMAC from 128 bits to 256 bits. A 24-word mnemonic is over 128 bytes, so the current setup won't cut it. You’ll need to change a lot in the code, especially in those int_to_address.cl and just_seed.cl files since they’re set for 12 words.

I saw what mcdouglasx said and took it as a challenge. So, check this out: I made the ipad_key and opad_key arrays 128 bytes for HMAC. When the mnemonic is longer than 128 bytes (like with 24 words), the extra key part isn’t handled right. We need a key normalization process for HMAC. If the key is bigger than 128 bytes for SHA-512, it should be hashed down, then padded to 128 bytes if it’s short.

+1 to the key normalization idea. Sounds smart. But this seems like a huge code overhaul. Is it even worth it? Just curious, are you sure about the hashing bit? Seems like a lot of work for just a mnemonic.