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tristandostaler/hymn-attack-example.txt Secret

Created June 16, 2021 02:28
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hymn-attack-example.txt
Original cookie: 1111111111|0000000000000000000001303|1303
Original of what we want: 1111111111|1000000000000000000001303|1303
Encoded Cookie: 00110001 00110001 00110001 00110001 00110001 00110001 00110001 00110001 00110001 00110001 01111100 00110000 00110000 00110000 00110000 00110000 00110000 00110000 00110000 00110000 00110000 00110000 00110000 00110000 00110000 00110000 00110000 00110000 00110000 00110000 00110000 00110000 00110001 00110011 00110000 00110011 01111100 00110001 00110011 00110000 00110011
Encoded What we want: 00110001 00110001 00110001 00110001 00110001 00110001 00110001 00110001 00110001 00110001 01111100 00110001 00110000 00110000 00110000 00110000 00110000 00110000 00110000 00110000 00110000 00110000 00110000 00110000 00110000 00110000 00110000 00110000 00110000 00110000 00110000 00110000 00110001 00110011 00110000 00110011 01111100 00110001 00110011 00110000 00110011
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So we need to XOR the last bit of the 12'th byte with 00000001:
00110000 XOR 00000001 = 00110001
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