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Updated SM4 with AESENCLAST (markdown)

Sun Yimin 2021-10-26 11:10:06 +08:00
parent d94b871e1d
commit 5e1a1898cd
1 changed files with 22 additions and 0 deletions
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22
SM4-with-AESENCLAST.md

@ -89,6 +89,28 @@ sm4_box_aesbox_4
x.bytes[i] = v x.bytes[i] = v
} }
``` ```
**How to calculate lookup table from M, C?**
```
{Mi+C | i>=0 && i<256}
// Generate lookup table based on M matrix and C
func gen_lookup_table(m [8]byte, c byte) {
for i := 0; i < 16; i++ {
for j := 0; j < 16; j++ {
x := ((byte(bits.OnesCount8(byte(i*16+j)&m[0])) & 1) << 7) ^
((byte(bits.OnesCount8(byte(i*16+j)&m[1])) & 1) << 6) ^
((byte(bits.OnesCount8(byte(i*16+j)&m[2])) & 1) << 5) ^
((byte(bits.OnesCount8(byte(i*16+j)&m[3])) & 1) << 4) ^
((byte(bits.OnesCount8(byte(i*16+j)&m[4])) & 1) << 3) ^
((byte(bits.OnesCount8(byte(i*16+j)&m[5])) & 1) << 2) ^
((byte(bits.OnesCount8(byte(i*16+j)&m[6])) & 1) << 1) ^
((byte(bits.OnesCount8(byte(i*16+j)&m[7])) & 1) << 0) ^ c
fmt.Printf("0x%02X, ", x)
}
fmt.Println()
}
}
```
**How to calculate M, C from lookup table?** **How to calculate M, C from lookup table?**