Files
OpenFlare/backend/plugins/domain/auth/pow/prng.go
T

55 lines
1.2 KiB
Go

// Copyright 2026 Arctel.net
// SPDX-License-Identifier: Apache-2.0
package pow
import (
"fmt"
"strings"
)
// fnv1a returns the 32-bit FNV-1a hash of a string
//
// FNV-1a 算法位移常量
func fnv1a(str string) uint32 {
var hash uint32 = 2166136261
for i := 0; i < len(str); i++ {
hash ^= uint32(str[i])
hash += (hash << 1) + (hash << 4) + (hash << 7) + (hash << 8) + (hash << 24)
}
return hash
}
// fnv1aResume resumes FNV-1a hashing from a given state
//
// FNV-1a 算法位移常量
func fnv1aResume(state uint32, str string) uint32 {
h := state
for i := 0; i < len(str); i++ {
h ^= uint32(str[i])
h += (hashShift(h))
}
return h
}
// hashShift computes FNV-1a mix additions
func hashShift(h uint32) uint32 {
return (h << 1) + (h << 4) + (h << 7) + (h << 8) + (h << 24)
}
// prngFromHash generates a hex string of specified length using an initial hash state
//
// xorshift 算法位移常量
func prngFromHash(initialHash uint32, length int) string {
state := initialHash
var result strings.Builder
for result.Len() < length {
state ^= state << 13
state ^= state >> 17
state ^= state << 5
hexStr := fmt.Sprintf("%08x", state)
result.WriteString(hexStr)
}
return result.String()[:length]
}