Merge pull request #2950 from terinjokes/patches/swift-segment-hash

swift: correct segment path generation

registry/storage/driver/swift/swift.go

@@ -667,13 +667,16 @@ func (d *driver) swiftPath(path string) string {
 	return strings.TrimLeft(strings.TrimRight(d.Prefix+"/files"+path, "/"), "/")
 }
 
+// swiftSegmentPath returns a randomly generated path in the segments directory.
 func (d *driver) swiftSegmentPath(path string) (string, error) {
 	checksum := sha1.New()
-	random := make([]byte, 32)
+	checksum.Write([]byte(path))
-	if _, err := rand.Read(random); err != nil {
+
+	if _, err := io.CopyN(checksum, rand.Reader, 32); err != nil {
 		return "", err
 	}
-	path = hex.EncodeToString(checksum.Sum(append([]byte(path), random...)))
+
+	path = hex.EncodeToString(checksum.Sum(nil))
 	return strings.TrimLeft(strings.TrimRight(d.Prefix+"/segments/"+path[0:3]+"/"+path[3:], "/"), "/"), nil
 }
 

registry/storage/driver/swift/swift_test.go

@@ -243,3 +243,39 @@ func TestFilenameChunking(t *testing.T) {
 		t.Fatal("expected error for size = -1")
 	}
 }
+
+func TestSwiftSegmentPath(t *testing.T) {
+	d := &driver{
+		Prefix: "/test/segment/path",
+	}
+
+	s1, err := d.swiftSegmentPath("foo-baz")
+	if err != nil {
+		t.Fatalf("unexpected error generating segment path: %v", err)
+	}
+
+	s2, err := d.swiftSegmentPath("foo-baz")
+	if err != nil {
+		t.Fatalf("unexpected error generating segment path: %v", err)
+	}
+
+	if !strings.HasPrefix(s1, "test/segment/path/segments/") {
+		t.Fatalf("expected to be prefixed: %s", s1)
+	}
+
+	if !strings.HasPrefix(s1, "test/segment/path/segments/") {
+		t.Fatalf("expected to be prefixed: %s", s2)
+	}
+
+	if len(s1) != 68 {
+		t.Fatalf("unexpected segment path length, %d != %d", len(s1), 68)
+	}
+
+	if len(s2) != 68 {
+		t.Fatalf("unexpected segment path length, %d != %d", len(s2), 68)
+	}
+
+	if s1 == s2 {
+		t.Fatalf("expected segment paths to differ, %s == %s", s1, s2)
+	}
+}