Problem B
M1: CCM
This is the $2$nd of $4$ steps in the Rover problem. The complete problem specification is on the NSA Cyber Challenge website.
Encoding
Every input and output line contains binary data encoded as a string using the “hexlify” method (named for the way Python implements it in the binascii module). The binary $32$-bit unsigned integer represented in hexadecimal as 0xDEADBEEF would simply be converted into an ASCII string “deadbeef” (always use lower-case letters). The most significant bytes come first.
Input
The first lines of the input will be the parameters to use for the rest of the input. The first line will contain the device ID (a single byte). The second line will contain the key. The keys are $32$ bytes so they will be represented by $64$ characters. The third line is the Initialization Vector ($16$ bytes). The fourth line is the B1 Nonce ($13$ bytes). The fifth line is the B2 Nonce ($15$ bytes). The sixth line is the A0 Nonce ($14$ bytes). The seventh line is the initial value for the counter ($2$ bytes).
After reading those initial parameters, the subsequent lines will be one byte commands that you will encrypt using CCM and calculate the CBC-MAC for.
Output
For each one byte command input, output the encrypted command byte followed by the $4$ bytes of the tag.
| Sample Input 1 | Sample Output 1 |
|---|---|
65 1042e7e22dc64b089be48c2b9f31e8ac68b153d5a13843b3b490613efb8e81dc 095f272c79d7f9ac3b02b4ba9a70ab00 00040100000000000000000000 000000000000000000000000000000 01008d493b30ae8b3c9696766cfa 2c43 bc 23 9a 23 bc 56 23 |
c9c76fd885 ef61ff2eb4 20cae56e04 4f0ef4b9f0 babaab02f3 a85aa99be6 7b8dcd3688 |
