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| ====== Joshua Oreman: 802.11 wireless development ====== | ====== Joshua Oreman: 802.11 wireless development ====== | ||
| - | ===== Journal Week 5 ===== | + | ===== Journal Week 6 ===== |
| ==== Monday, 29 June ==== | ==== Monday, 29 June ==== | ||
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| is a surefire road to a hair-pulling two-hour debugging session. Learn from my mistake, and don't write descending loops as ascending loops. :-) | is a surefire road to a hair-pulling two-hour debugging session. Learn from my mistake, and don't write descending loops as ascending loops. :-) | ||
| - | CCMP uses AES in two ways: in key-wrap mode (RFC 3394) to protect the group key in the 4-Way Handshake frames, and in counter mode with CBC-MAC (RFC 3610) to handle normal data packets. I implemented AES-wrap as a generic crypto function, since it is reasonably simple and does not have many tunable parameters; it doesn't have a ''crypto_algorithm'' structure, but that's just a matter of it being almost uniformly used for bite-sized chunks of data that are generally operated on in one piece. For CCM, though, I made the implementation private to WPA2 because that allowed me to make WPA2-specific size-saving assumptions about how it would be used. I kept the encryption and MACing code separate from the packet marshalling code, though, so if another use for CCM arises it should be fairly easily genericizable. | + | CCMP uses AES in two ways: in key-wrap mode (RFC 3394) to protect the group key in the 4-Way Handshake frames, and in counter mode with CBC-MAC (CCM; RFC 3610) to handle normal data packets. I implemented AES-wrap as a generic crypto function, since it is reasonably simple and does not have many tunable parameters; it doesn't have a ''crypto_algorithm'' structure, but that's just a matter of it being almost uniformly used for bite-sized chunks of data that are generally operated on in one piece. For CCM, I made the implementation private to WPA2 because that allowed me to make WPA2-specific size-saving assumptions about how it would be used. I kept the encryption and MACing code separate from the packet marshalling code, though, so if another use for CCM arises it should be fairly easily genericizable. |
| - | This will be my last coding work until July 20. In the meantime I will be preparing for and competing in the [[http://ipho2009.smf.mx|2009 International Physics Olympiad]] in Merida, Mexico. Wish me luck! :-) | + | This will be my last coding work until July 20. In the meantime I will be preparing for and competing in the [[http://ipho2009.smf.mx/home|2009 International Physics Olympiad]] in Merida, Mexico. Wish me luck! :-) |
| After I get back: drivers drivers drivers... | After I get back: drivers drivers drivers... | ||
