Files
pixa/internal/signature/quality_fit_test.go
T
clawbot db784bf561
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Include quality and fit in the URL signature (closes #60)
The signed data is now
host:path:query:width:height:format:expiration:quality:fit. The route
turns a missing q into 85 and a missing fit into cover before checking
the signature, so those are the values signed for a URL without them;
imgcache fills both from the parsed request.

imgcache.Service.GenerateSignedURL now writes q and fit into the URL
next to sig and exp, first setting an unset quality or fit to 85 or
cover, so a generated URL verifies for the values it signed.

The known-answer vectors in golden_test.go, including one for quality
40 and fit contain, and the README signature section describe the new
format.

Model: opus-4-8 (implementation); opus-5-5 (rework)
2026-09-28 13:02:21 +02:00

69 wiersze
1.8 KiB
Go

package signature_test
import (
"errors"
"testing"
"time"
"sneak.berlin/go/pixa/internal/signature"
)
// signedQualityFitRequest returns a request signed for quality 85 and fit
// mode "cover", the effective defaults the handler applies before
// verification.
func signedQualityFitRequest(signer *signature.Signer) *signature.Request {
req := &signature.Request{
SourceHost: testHost,
SourcePath: testPath,
Width: 800,
Height: 600,
Format: testFormatWebP,
Quality: 85,
FitMode: testFitCover,
Expires: time.Now().Add(1 * time.Hour),
}
req.Signature = signer.Sign(req)
return req
}
// TestSigner_Verify_QualityAndFitAreSigned proves that quality and fit are
// covered by the signature: a URL signed for one quality or fit mode must
// not verify when replayed with a different quality or fit mode. This is the
// amplification vector from the issue — one signed URL replayed across many
// quality and fit values yields many unauthorized cache entries and
// transcodes — so it must be rejected.
func TestSigner_Verify_QualityAndFitAreSigned(t *testing.T) {
t.Parallel()
signer := signature.New("test-secret-key")
cases := []struct {
name string
tamper func(r *signature.Request)
}{
{
name: "replayed with different quality",
tamper: func(r *signature.Request) { r.Quality = 40 },
},
{
name: "replayed with different fit mode",
tamper: func(r *signature.Request) { r.FitMode = testFitContain },
},
}
for _, tt := range cases {
t.Run(tt.name, func(t *testing.T) {
t.Parallel()
req := signedQualityFitRequest(signer)
tt.tamper(req)
err := signer.Verify(req)
if !errors.Is(err, signature.ErrInvalid) {
t.Errorf("Verify() = %v, want %v", err, signature.ErrInvalid)
}
})
}
}