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50 lines
1.1 KiB
Go
50 lines
1.1 KiB
Go
//go:build !noasm && gc && amd64
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// +build !noasm,gc,amd64
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package sha1cd
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import (
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"math"
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"unsafe"
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shared "github.com/pjbgf/sha1cd/internal"
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)
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type sliceHeader struct {
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base uintptr
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len int
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cap int
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}
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// blockAMD64 hashes the message p into the current state in dig.
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// Both m1 and cs are used to store intermediate results which are used by the collision detection logic.
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//
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//go:noescape
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func blockAMD64(dig *digest, p sliceHeader, m1 []uint32, cs [][5]uint32)
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func block(dig *digest, p []byte) {
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m1 := [shared.Rounds]uint32{}
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cs := [shared.PreStepState][shared.WordBuffers]uint32{}
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for len(p) >= shared.Chunk {
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// Only send a block to be processed, as the collission detection
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// works on a block by block basis.
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ips := sliceHeader{
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base: uintptr(unsafe.Pointer(&p[0])),
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len: int(math.Min(float64(len(p)), float64(shared.Chunk))),
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cap: shared.Chunk,
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}
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blockAMD64(dig, ips, m1[:], cs[:])
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col := checkCollision(m1, cs, dig.h)
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if col {
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dig.col = true
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blockAMD64(dig, ips, m1[:], cs[:])
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blockAMD64(dig, ips, m1[:], cs[:])
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}
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p = p[shared.Chunk:]
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}
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}
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