WIP test cancelable reader crio 1.31

copy/single.go

@@ -11,6 +11,7 @@ import (
 	"slices"
 	"strings"
 	"sync"
+	"time"
 
 	"github.com/containers/image/v5/docker/reference"
 	"github.com/containers/image/v5/internal/image"
@@ -74,7 +75,13 @@ func (c *copier) copySingleImage(ctx context.Context, unparsedImage *image.Unpar
 	// Please keep this policy check BEFORE reading any other information about the image.
 	// (The multiImage check above only matches the MIME type, which we have received anyway.
 	// Actual parsing of anything should be deferred.)
-	if allowed, err := c.policyContext.IsRunningImageAllowed(ctx, unparsedImage); !allowed || err != nil { // Be paranoid and fail if either return value indicates so.
+	// Create a timeout context for GPG key import operations to prevent indefinite hanging.
+	// This timeout is passed down to the cancellable reader which will interrupt operations
+	// if they take too long, preventing file descriptor leaks.
+	const importTimeout = 60 * time.Second
+	policyCtx, cancel := context.WithTimeout(ctx, importTimeout)
+	defer cancel()
+	if allowed, err := c.policyContext.IsRunningImageAllowed(policyCtx, unparsedImage); !allowed || err != nil { // Be paranoid and fail if either return value indicates so.
 		return copySingleImageResult{}, fmt.Errorf("Source image rejected: %w", err)
 	}
 	src, err := image.FromUnparsedImage(ctx, c.options.SourceCtx, unparsedImage)

signature/mechanism.go

@@ -4,6 +4,7 @@ package signature
 
 import (
 	"bytes"
+	"context"
 	"errors"
 	"fmt"
 	"io"
@@ -65,7 +66,7 @@ func NewGPGSigningMechanism() (SigningMechanism, error) {
 // of these keys.
 // The caller must call .Close() on the returned SigningMechanism.
 func NewEphemeralGPGSigningMechanism(blob []byte) (SigningMechanism, []string, error) {
-	return newEphemeralGPGSigningMechanism([][]byte{blob})
+	return newEphemeralGPGSigningMechanism([][]byte{blob}, context.Background())
 }
 
 // gpgUntrustedSignatureContents returns UNTRUSTED contents of the signature WITHOUT ANY VERIFICATION,

signature/mechanism_gpgme.go

@@ -5,8 +5,10 @@ package signature
 
 import (
 	"bytes"
+	"context"
 	"errors"
 	"fmt"
+	"io"
 	"os"
 
 	"github.com/containers/image/v5/signature/internal"
@@ -36,7 +38,9 @@ func newGPGSigningMechanismInDirectory(optionalDir string) (signingMechanismWith
 // recognizes _only_ public keys from the supplied blobs, and returns the identities
 // of these keys.
 // The caller must call .Close() on the returned SigningMechanism.
-func newEphemeralGPGSigningMechanism(blobs [][]byte) (signingMechanismWithPassphrase, []string, error) {
+// The context is used for cancellation - when it times out or is cancelled, the
+// cancellable reader will interrupt key import operations.
+func newEphemeralGPGSigningMechanism(blobs [][]byte, ctx context.Context) (signingMechanismWithPassphrase, []string, error) {
 	dir, err := os.MkdirTemp("", "containers-ephemeral-gpg-")
 	if err != nil {
 		return nil, nil, err
@@ -47,17 +51,18 @@ func newEphemeralGPGSigningMechanism(blobs [][]byte) (signingMechanismWithPassph
 			os.RemoveAll(dir)
 		}
 	}()
-	ctx, err := newGPGMEContext(dir)
+	gpgmeCtx, err := newGPGMEContext(dir)
 	if err != nil {
 		return nil, nil, err
 	}
 	mech := &gpgmeSigningMechanism{
-		ctx:          ctx,
+		ctx:          gpgmeCtx,
 		ephemeralDir: dir,
 	}
+
 	keyIdentities := []string{}
 	for _, blob := range blobs {
-		ki, err := mech.importKeysFromBytes(blob)
+		ki, err := mech.importKeysFromBytes(blob, ctx)
 		if err != nil {
 			return nil, nil, err
 		}
@@ -95,12 +100,41 @@ func (m *gpgmeSigningMechanism) Close() error {
 	return nil
 }
 
+type cancelableReader struct {
+	ctx    context.Context
+	reader io.Reader
+}
+
+func (r *cancelableReader) Read(p []byte) (int, error) {
+	// Check if context is cancelled before each read
+	if err := r.ctx.Err(); err != nil {
+		return 0, err
+	}
+	n, err := r.reader.Read(p)
+	// Check again after read in case cancellation happened during the read
+	if err == nil && r.ctx.Err() != nil {
+		return n, r.ctx.Err()
+	}
+	return n, err
+}
+
 // importKeysFromBytes imports public keys from the supplied blob and returns their identities.
 // The blob is assumed to have an appropriate format (the caller is expected to know which one).
 // NOTE: This may modify long-term state (e.g. key storage in a directory underlying the mechanism);
 // but we do not make this public, it can only be used through newEphemeralGPGSigningMechanism.
-func (m *gpgmeSigningMechanism) importKeysFromBytes(blob []byte) ([]string, error) {
-	inputData, err := gpgme.NewDataBytes(blob)
+// Uses a cancellable reader to prevent indefinite hanging and file descriptor leaks.
+// The cancellable reader will return an error when cancellation is detected, causing Import to fail.
+// The context is used for cancellation - when it times out or is cancelled, the reader will
+// interrupt the operation.
+func (m *gpgmeSigningMechanism) importKeysFromBytes(blob []byte, ctx context.Context) ([]string, error) {
+	// Create a cancellable reader that wraps the blob data
+
+	reader := &cancelableReader{
+		ctx:    ctx,
+		reader: bytes.NewReader(blob),
+	}
+
+	inputData, err := gpgme.NewDataReader(reader)
 	if err != nil {
 		return nil, err
 	}

signature/mechanism_openpgp.go

@@ -5,6 +5,7 @@ package signature
 
 import (
 	"bytes"
+	"context"
 	"errors"
 	"fmt"
 	"io"
@@ -64,7 +65,8 @@ func newGPGSigningMechanismInDirectory(optionalDir string) (signingMechanismWith
 // recognizes _only_ public keys from the supplied blob, and returns the identities
 // of these keys.
 // The caller must call .Close() on the returned SigningMechanism.
-func newEphemeralGPGSigningMechanism(blobs [][]byte) (signingMechanismWithPassphrase, []string, error) {
+// The context parameter is accepted for API compatibility but not used in this implementation.
+func newEphemeralGPGSigningMechanism(blobs [][]byte, ctx context.Context) (signingMechanismWithPassphrase, []string, error) {
 	m := &openpgpSigningMechanism{
 		keyring: openpgp.EntityList{},
 	}

signature/mechanism_test.go

@@ -4,6 +4,7 @@ package signature
 
 import (
 	"bytes"
+	"context"
 	"os"
 	"path/filepath"
 	"testing"
@@ -150,7 +151,7 @@ func TestNewEphemeralGPGSigningMechanism(t *testing.T) {
 	require.NoError(t, err)
 	keyBlob2, err := os.ReadFile("./fixtures/public-key-2.gpg")
 	require.NoError(t, err)
-	mech, keyIdentities, err = newEphemeralGPGSigningMechanism([][]byte{keyBlob1, keyBlob2})
+	mech, keyIdentities, err = newEphemeralGPGSigningMechanism([][]byte{keyBlob1, keyBlob2}, context.Background())
 	require.NoError(t, err)
 	defer mech.Close()
 	assert.Equal(t, []string{TestKeyFingerprint, TestKeyFingerprintWithPassphrase}, keyIdentities)

signature/policy_eval_signedby.go

@@ -41,7 +41,7 @@ func (pr *prSignedBy) isSignatureAuthorAccepted(ctx context.Context, image priva
 	}
 
 	// FIXME: move this to per-context initialization
-	mech, trustedIdentities, err := newEphemeralGPGSigningMechanism(data)
+	mech, trustedIdentities, err := newEphemeralGPGSigningMechanism(data, ctx)
 	if err != nil {
 		return sarRejected, nil, err
 	}