yaole
42 lines
1.0 KiB
Go
42 lines
1.0 KiB
Go
package entropy
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import (
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"sync"
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"xdx.jelly/xgcl/grand/drng/entropy/rdtsc"
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)
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// SysTimeEntropySource 系统时间熵源
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type SysTimeEntropySource struct {
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mu sync.Mutex
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}
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// GetEntropy
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func (e *SysTimeEntropySource) GetEntropy(minEntropy int64, minEntropyInputLength int64, maxEntropyInputLength int64) ([]byte, error) {
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//使用互斥锁保证熵源的独占性
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e.mu.Lock()
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defer e.mu.Unlock()
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// SysTimeEntropySource熵源的Markov测试min entropy ~ 0.58
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// 因此向熵源最少要取minEntropy / 0.58 ~ 2*minEntropy
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n := minEntropy << 1
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if n < minEntropyInputLength {
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n = minEntropyInputLength
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}
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entropy := make([]byte, n)
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for i := int64(0); i < n; i++ {
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// var b byte
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// for j := 0; j < 8; j++ {
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// t := rdtsc.GetCPUTimeStamp()
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// // xor of the the last two bits are used.
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// // for a rdtsc usually used 20~50 cycles.
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// // b |= byte((t^(t>>1)^(t>>2)^(t>>3))&1) << j
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// b |= byte(t&1) << j
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// }
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// entropy[i] = b
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entropy[i] = byte(rdtsc.GetCPUTimeStamp())
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}
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return entropy, nil
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}
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