Make parser more strict

- It will now error if you have characters after the end of a quoted string, i.e. `"key"bad=val` or `key="val"bad`
- It will now error if there is an empty key
- Fixed a minor bug with the calculation of the location of the error, it was not counting quotes properly before

Signed-off-by: Daniel Mikusa <[email protected]>

labels/build.go

@@ -109,8 +109,10 @@ func ReadKey(buf string) (string, string, error) {
 
 		// end quote
 		if (ch == '"' || ch == '\'') && needClosingQuote {
-			// throw out anything between closing quote and equals sign
-			_, rest, _ = ReadToNext(rest, `=`)
+			invalid, rest, _ := ReadToNext(rest, `=`)
+			if len(strings.TrimSpace(invalid)) > 0 {
+				return "", rest, fmt.Errorf("unable to have characters after a trailing quote")
+			}
 			return item, rest, nil
 		}
 
@@ -121,7 +123,7 @@ func ReadKey(buf string) (string, string, error) {
 
 		// end of key or no more data
 		if (ch == '=' || rest == "") && needClosingQuote {
-			return item, rest, fmt.Errorf("unable to find a closing quote")
+			return "", rest, fmt.Errorf("unable to find a closing quote")
 		} else if ch == '=' || rest == "" {
 			return item, rest, nil
 		}
@@ -155,8 +157,10 @@ func ReadValue(buf string) (string, string, error) {
 
 		// end quote
 		if (ch == '"' || ch == '\'') && needClosingQuote {
-			// throw out anything between closing quote and equals sign
-			_, rest, _ = ReadToNext(rest, ` `)
+			invalid, rest, _ := ReadToNext(rest, ` `)
+			if len(strings.TrimSpace(invalid)) > 0 {
+				return "", rest, fmt.Errorf("unable to have characters after a trailing quote")
+			}
 			return item, rest, nil
 		}
 
@@ -177,7 +181,7 @@ func ReadValue(buf string) (string, string, error) {
 
 		// end of data buffer
 		if rest == "" && needClosingQuote {
-			return item, rest, fmt.Errorf("unable to find a closing quote")
+			return "", rest, fmt.Errorf("unable to find a closing quote")
 		} else if rest == "" {
 			return item, rest, nil
 		}
@@ -196,17 +200,26 @@ func ParseLabels(rest string) (map[string]string, error) {
 	)
 
 	for {
+		before := len(rest)
 		key, rest, err = ReadKey(rest)
-		pos += len(key) + 1
+		pos += before - len(rest)
 
 		if err != nil {
-			return nil, fmt.Errorf("unable to read key ending at char %d\n%w", pos, err)
+			return nil, fmt.Errorf("unable to read key ending at char %d\n%w", pos-1, err)
 		}
 
+		if len(key) == 0 {
+			return nil, fmt.Errorf("unable to have empty key ending at char %d", pos-1)
+		}
+
+		before = len(rest)
 		val, rest, err = ReadValue(rest)
-		pos += len(val) + 1
+		pos += before - len(rest)
 
 		if err != nil {
+			if len(rest) > 0 {
+				pos -= 1
+			}
 			return nil, fmt.Errorf("unable to read value ending at char %d\n%w", pos, err)
 		}
 

labels/build_test.go

@@ -268,7 +268,7 @@ func testBuild(t *testing.T, context spec.G, it spec.S) {
 
 		it("parses a complex label", func() {
 			assertMap(`some-label=(example)value some-label-2=""hi there" test='hi'`,
-				nil, "unable to read key ending at char 51")
+				nil, "unable to read value ending at char 43\nunable to have characters after a trailing quote")
 		})
 
 		it("parses with embedded equal signs", func() {
@@ -277,6 +277,28 @@ func testBuild(t *testing.T, context spec.G, it spec.S) {
 			assertMap(`foo="bar=baz"`,
 				map[string]string{"foo": "bar=baz"}, "")
 		})
+
+		it("fails on an empty key", func() {
+			assertMap(`""=bar`,
+				nil, "unable to have empty key ending at char 2")
+		})
+
+		it("fails if characters after a quote", func() {
+			assertMap(`"foo"junk=bar`,
+				nil, "unable to read key ending at char 9\nunable to have characters after a trailing quote")
+			assertMap(`foo="bar"junk`,
+				nil, "unable to read value ending at char 13\nunable to have characters after a trailing quote")
+		})
+
+		it("parses complicated statement", func() {
+			assertMap(`some-label=(example)value some-label-2=""hi t""here="" test=\'hi\'`,
+				nil, "unable to read value ending at char 43\nunable to have characters after a trailing quote")
+		})
+
+		it("parses complicated statement", func() {
+			assertMap(`some-label=(example)value some-label-2="hi t"here="" test=\'hi\'`,
+				nil, "unable to read value ending at char 52\nunable to have characters after a trailing quote")
+		})
 	})
 
 }