42 lines
1.1 KiB
Go
42 lines
1.1 KiB
Go
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package web_fetch
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import (
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"context"
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"fmt"
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"net/http"
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"net/http/httptest"
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"strings"
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"testing"
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)
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func TestFetchURLContentBlocksRedirectToLoopback(t *testing.T) {
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internalHit := make(chan struct{}, 1)
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internal := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
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internalHit <- struct{}{}
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fmt.Fprint(w, "<html><body>WEKNORA_INTERNAL_CANARY_178193</body></html>")
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}))
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defer internal.Close()
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if _, err := FetchURLContent(context.Background(), internal.URL); err == nil {
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t.Fatal("direct loopback URL was not rejected")
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}
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attacker := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
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http.Redirect(w, r, internal.URL, http.StatusFound)
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}))
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defer attacker.Close()
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got, err := FetchURLContent(context.Background(), attacker.URL+"/entry")
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if err == nil {
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if strings.Contains(got, "WEKNORA_INTERNAL_CANARY_178193") {
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t.Fatalf("redirect followed to loopback, got %q", got)
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}
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t.Fatal("expected redirect to loopback to be blocked")
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}
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select {
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case <-internalHit:
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t.Fatal("internal loopback server was reached via redirect")
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default:
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}
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}
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