72 lines
2.1 KiB
Go
72 lines
2.1 KiB
Go
// Package abogus computes the a_bogus signature required by 抖店/抖音 risk-controlled endpoints.
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//
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// Implementation: embeds a JavaScript file with the a_bogus algorithm and runs it via goja
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// (pure-Go JS engine, no CGO). The JS itself does not depend on any browser globals — it
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// takes the URL query string and User-Agent as inputs and returns the signature string.
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package abogus
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import (
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_ "embed"
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"fmt"
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"sync"
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"github.com/dop251/goja"
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)
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//go:embed a_bogus.js
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var aBogusJS string
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// Generator is reusable. NewGenerator compiles the JS once; Sign() is goroutine-safe.
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type Generator struct {
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program *goja.Program
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mu sync.Mutex
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pool []*goja.Runtime
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}
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// NewGenerator compiles the embedded a_bogus.js and returns a ready-to-use generator.
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func NewGenerator() (*Generator, error) {
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// strict=false: a_bogus.js 原文有 `n = ...`（未声明）等浏览器宽松模式特性，goja 严格模式会拒绝
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prog, err := goja.Compile("a_bogus.js", aBogusJS, false)
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if err != nil {
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return nil, fmt.Errorf("compile a_bogus.js: %w", err)
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}
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return &Generator{program: prog}, nil
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}
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// Sign computes the a_bogus signature for a given URL query string and User-Agent.
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// urlSearchParams is the raw query string WITHOUT a_bogus itself (everything else included).
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func (g *Generator) Sign(urlSearchParams, userAgent string) (string, error) {
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rt := g.acquire()
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defer g.release(rt)
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if _, err := rt.RunProgram(g.program); err != nil {
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return "", fmt.Errorf("run a_bogus.js: %w", err)
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}
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fn, ok := goja.AssertFunction(rt.Get("generate_a_bogus"))
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if !ok {
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return "", fmt.Errorf("generate_a_bogus is not a function")
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}
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v, err := fn(goja.Undefined(), rt.ToValue(urlSearchParams), rt.ToValue(userAgent))
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if err != nil {
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return "", fmt.Errorf("call generate_a_bogus: %w", err)
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}
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return v.String(), nil
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}
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func (g *Generator) acquire() *goja.Runtime {
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g.mu.Lock()
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defer g.mu.Unlock()
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if n := len(g.pool); n > 0 {
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rt := g.pool[n-1]
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g.pool = g.pool[:n-1]
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return rt
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}
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return goja.New()
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}
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func (g *Generator) release(rt *goja.Runtime) {
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g.mu.Lock()
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defer g.mu.Unlock()
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g.pool = append(g.pool, rt)
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}
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