40 lines
852 B
Go
40 lines
852 B
Go
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// Copyright (c) 2016 The btcsuite developers
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// Use of this source code is governed by an ISC
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// license that can be found in the LICENSE file.
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package txauthor
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import (
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"crypto/rand"
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"encoding/binary"
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mrand "math/rand"
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"sync"
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)
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// cprng is a cryptographically random-seeded math/rand prng. It is seeded
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// during package init. Any initialization errors result in panics. It is safe
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// for concurrent access.
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var cprng = cprngType{}
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type cprngType struct {
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r *mrand.Rand
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mu sync.Mutex
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}
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func init() {
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buf := make([]byte, 8)
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_, err := rand.Read(buf)
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if err != nil {
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panic("Failed to seed prng: " + err.Error())
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}
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seed := int64(binary.LittleEndian.Uint64(buf))
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cprng.r = mrand.New(mrand.NewSource(seed))
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}
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func (c *cprngType) Int31n(n int32) int32 {
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defer c.mu.Unlock() // Int31n may panic
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c.mu.Lock()
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return c.r.Int31n(n)
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}
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