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33 lines
907 B
Go
33 lines
907 B
Go
// Copyright 2022 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package subtle
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import "github.com/emmansun/gmsm/internal/alias"
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// XORBytes sets dst[i] = x[i] ^ y[i] for all i < n = min(len(x), len(y)),
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// returning n, the number of bytes written to dst.
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// If dst does not have length at least n,
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// XORBytes panics without writing anything to dst.
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//
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// dst and x or y may overlap exactly or not at all,
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// otherwise XORBytes may panic.
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func XORBytes(dst, x, y []byte) int {
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n := len(x)
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if len(y) < n {
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n = len(y)
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}
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if n == 0 {
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return 0
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}
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if n > len(dst) {
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panic("subtle.XORBytes: dst too short")
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}
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if alias.InexactOverlap(dst[:n], x[:n]) || alias.InexactOverlap(dst[:n], y[:n]) {
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panic("subtle.XORBytes: invalid overlap")
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}
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xorBytes(&dst[0], &x[0], &y[0], n) // arch-specific
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return n
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}
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