Merge pull request #274 from stevvooe/tarsum-verification-deadlock

digest: correctly close pipe after error in tarsum verification
This commit is contained in:
Olivier Gambier 2015-03-18 18:38:31 -07:00
commit d957768537
3 changed files with 89 additions and 3 deletions

View file

@ -58,7 +58,7 @@ var (
// ErrDigestInvalidFormat returned when digest format invalid. // ErrDigestInvalidFormat returned when digest format invalid.
ErrDigestInvalidFormat = fmt.Errorf("invalid checksum digest format") ErrDigestInvalidFormat = fmt.Errorf("invalid checksum digest format")
// ErrDigestUnsupported returned when the digest algorithm is unsupported by registry. // ErrDigestUnsupported returned when the digest algorithm is unsupported.
ErrDigestUnsupported = fmt.Errorf("unsupported digest algorithm") ErrDigestUnsupported = fmt.Errorf("unsupported digest algorithm")
) )

View file

@ -56,8 +56,11 @@ func NewDigestVerifier(d Digest) (Verifier, error) {
// TODO(sday): Ick! A goroutine per digest verification? We'll have to // TODO(sday): Ick! A goroutine per digest verification? We'll have to
// get the tarsum library to export an io.Writer variant. // get the tarsum library to export an io.Writer variant.
go func() { go func() {
io.Copy(ioutil.Discard, ts) if _, err := io.Copy(ioutil.Discard, ts); err != nil {
pw.Close() pr.CloseWithError(err)
} else {
pr.Close()
}
}() }()
return &tarsumVerifier{ return &tarsumVerifier{

View file

@ -3,8 +3,10 @@ package digest
import ( import (
"bytes" "bytes"
"crypto/rand" "crypto/rand"
"encoding/base64"
"io" "io"
"os" "os"
"strings"
"testing" "testing"
"github.com/docker/distribution/testutil" "github.com/docker/distribution/testutil"
@ -67,6 +69,87 @@ func TestDigestVerifier(t *testing.T) {
} }
} }
// TestVerifierUnsupportedDigest ensures that unsupported digest validation is
// flowing through verifier creation.
func TestVerifierUnsupportedDigest(t *testing.T) {
unsupported := Digest("bean:0123456789abcdef")
_, err := NewDigestVerifier(unsupported)
if err == nil {
t.Fatalf("expected error when creating verifier")
}
if err != ErrDigestUnsupported {
t.Fatalf("incorrect error for unsupported digest: %v %p %p", err, ErrDigestUnsupported, err)
}
}
// TestJunkNoDeadlock ensures that junk input into a digest verifier properly
// returns errors from the tarsum library. Specifically, we pass in a file
// with a "bad header" and should see the error from the io.Copy to verifier.
// This has been seen with gzipped tarfiles, mishandled by the tarsum package,
// but also on junk input, such as html.
func TestJunkNoDeadlock(t *testing.T) {
expected := Digest("tarsum.dev+sha256:62e15750aae345f6303469a94892e66365cc5e3abdf8d7cb8b329f8fb912e473")
junk := bytes.Repeat([]byte{'a'}, 1024)
verifier, err := NewDigestVerifier(expected)
if err != nil {
t.Fatalf("unexpected error creating verifier: %v", err)
}
rd := bytes.NewReader(junk)
if _, err := io.Copy(verifier, rd); err == nil {
t.Fatalf("unexpected error verifying input data: %v", err)
}
}
// TestBadTarNoDeadlock runs a tar with a "bad" tar header through digest
// verifier, ensuring that the verifier returns an error properly.
func TestBadTarNoDeadlock(t *testing.T) {
// TODO(stevvooe): This test is exposing a bug in tarsum where if we pass
// a gzipped tar file into tarsum, the library returns an error. This
// should actually work. When the tarsum package is fixed, this test will
// fail and we can remove this test or invert it.
// This tarfile was causing deadlocks in verifiers due mishandled copy error.
// This is a gzipped tar, which we typically don't see but should handle.
//
// From https://registry-1.docker.io/v2/library/ubuntu/blobs/tarsum.dev+sha256:62e15750aae345f6303469a94892e66365cc5e3abdf8d7cb8b329f8fb912e473
const badTar = `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`
expected := Digest("tarsum.dev+sha256:62e15750aae345f6303469a94892e66365cc5e3abdf8d7cb8b329f8fb912e473")
verifier, err := NewDigestVerifier(expected)
if err != nil {
t.Fatalf("unexpected error creating verifier: %v", err)
}
rd := base64.NewDecoder(base64.StdEncoding, strings.NewReader(badTar))
if _, err := io.Copy(verifier, rd); err == nil {
t.Fatalf("unexpected error verifying input data: %v", err)
}
if verifier.Verified() {
// For now, we expect an error, since tarsum library cannot handle
// compressed tars (!!!).
t.Fatalf("no error received after invalid tar")
}
}
// TODO(stevvooe): Add benchmarks to measure bytes/second throughput for // TODO(stevvooe): Add benchmarks to measure bytes/second throughput for
// DigestVerifier. We should be tarsum/gzip limited for common cases but we // DigestVerifier. We should be tarsum/gzip limited for common cases but we
// want to verify this. // want to verify this.