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- package internal
- import "encoding/binary"
- func ChaCha20Block(s *[16]uint32, out []byte, rounds int) {
- var x0,x1,x2,x3,x4,x5,x6,x7,x8,x9,x10,x11,x12,x13,x14,x15 = s[0],s[1],s[2],s[3],s[4],s[5],s[6],s[7],s[8],s[9],s[10],s[11],s[12],s[13],s[14],s[15]
- for i := 0; i < rounds; i+=2 {
- var x uint32
-
- x0+=x4
- x=x12^x0
- x12=(x << 16) | (x >> (32 - 16))
- x8+=x12
- x=x4^x8
- x4=(x << 12) | (x >> (32 - 12))
- x0+=x4
- x=x12^x0
- x12=(x << 8) | (x >> (32 - 8))
- x8+=x12
- x=x4^x8
- x4=(x << 7) | (x >> (32 - 7))
- x1+=x5
- x=x13^x1
- x13=(x << 16) | (x >> (32 - 16))
- x9+=x13
- x=x5^x9
- x5=(x << 12) | (x >> (32 - 12))
- x1+=x5
- x=x13^x1
- x13=(x << 8) | (x >> (32 - 8))
- x9+=x13
- x=x5^x9
- x5=(x << 7) | (x >> (32 - 7))
- x2+=x6
- x=x14^x2
- x14=(x << 16) | (x >> (32 - 16))
- x10+=x14
- x=x6^x10
- x6=(x << 12) | (x >> (32 - 12))
- x2+=x6
- x=x14^x2
- x14=(x << 8) | (x >> (32 - 8))
- x10+=x14
- x=x6^x10
- x6=(x << 7) | (x >> (32 - 7))
- x3+=x7
- x=x15^x3
- x15=(x << 16) | (x >> (32 - 16))
- x11+=x15
- x=x7^x11
- x7=(x << 12) | (x >> (32 - 12))
- x3+=x7
- x=x15^x3
- x15=(x << 8) | (x >> (32 - 8))
- x11+=x15
- x=x7^x11
- x7=(x << 7) | (x >> (32 - 7))
- x0+=x5
- x=x15^x0
- x15=(x << 16) | (x >> (32 - 16))
- x10+=x15
- x=x5^x10
- x5=(x << 12) | (x >> (32 - 12))
- x0+=x5
- x=x15^x0
- x15=(x << 8) | (x >> (32 - 8))
- x10+=x15
- x=x5^x10
- x5=(x << 7) | (x >> (32 - 7))
- x1+=x6
- x=x12^x1
- x12=(x << 16) | (x >> (32 - 16))
- x11+=x12
- x=x6^x11
- x6=(x << 12) | (x >> (32 - 12))
- x1+=x6
- x=x12^x1
- x12=(x << 8) | (x >> (32 - 8))
- x11+=x12
- x=x6^x11
- x6=(x << 7) | (x >> (32 - 7))
- x2+=x7
- x=x13^x2
- x13=(x << 16) | (x >> (32 - 16))
- x8+=x13
- x=x7^x8
- x7=(x << 12) | (x >> (32 - 12))
- x2+=x7
- x=x13^x2
- x13=(x << 8) | (x >> (32 - 8))
- x8+=x13
- x=x7^x8
- x7=(x << 7) | (x >> (32 - 7))
- x3+=x4
- x=x14^x3
- x14=(x << 16) | (x >> (32 - 16))
- x9+=x14
- x=x4^x9
- x4=(x << 12) | (x >> (32 - 12))
- x3+=x4
- x=x14^x3
- x14=(x << 8) | (x >> (32 - 8))
- x9+=x14
- x=x4^x9
- x4=(x << 7) | (x >> (32 - 7))
- }
- binary.LittleEndian.PutUint32(out[0:4], s[0]+x0)
- binary.LittleEndian.PutUint32(out[4:8], s[1]+x1)
- binary.LittleEndian.PutUint32(out[8:12], s[2]+x2)
- binary.LittleEndian.PutUint32(out[12:16], s[3]+x3)
- binary.LittleEndian.PutUint32(out[16:20], s[4]+x4)
- binary.LittleEndian.PutUint32(out[20:24], s[5]+x5)
- binary.LittleEndian.PutUint32(out[24:28], s[6]+x6)
- binary.LittleEndian.PutUint32(out[28:32], s[7]+x7)
- binary.LittleEndian.PutUint32(out[32:36], s[8]+x8)
- binary.LittleEndian.PutUint32(out[36:40], s[9]+x9)
- binary.LittleEndian.PutUint32(out[40:44], s[10]+x10)
- binary.LittleEndian.PutUint32(out[44:48], s[11]+x11)
- binary.LittleEndian.PutUint32(out[48:52], s[12]+x12)
- binary.LittleEndian.PutUint32(out[52:56], s[13]+x13)
- binary.LittleEndian.PutUint32(out[56:60], s[14]+x14)
- binary.LittleEndian.PutUint32(out[60:64], s[15]+x15)
- }
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