feat(cleartext): Do not include line ending separator in plaintext (#242)

The cleartext plaintext should exclude the line ending separator defined by the Cleartext Signed Message Structure. The line ending separator change was made to enhance interoperability, as the original implementation was non-deterministic—potentially adding a newline when the input lacked one.

GopenPGP removes the additional line ending separator, but this could be directly handled by go-crypto.

Author: lubux

openpgp/clearsign/clearsign.go

@@ -173,6 +173,7 @@ func Decode(data []byte) (b *Block, rest []byte) {
 		b.Plaintext = append(b.Plaintext, line...)
 		b.Plaintext = append(b.Plaintext, lf)
 	}
+	b.Plaintext = b.Plaintext[:len(b.Plaintext)-1]
 
 	// We want to find the extent of the armored data (including any newlines at
 	// the end).

openpgp/clearsign/clearsign_test.go

@@ -58,8 +58,8 @@ func testParse(t *testing.T, input []byte, expected, expectedPlaintext string) {
 }
 
 func TestParse(t *testing.T) {
-	testParse(t, clearsignInput, "Hello world\r\nline 2", "Hello world\nline 2\n")
-	testParse(t, clearsignInput2, "\r\n\r\n(This message has a couple of blank lines at the start and end.)\r\n\r\n", "\n\n(This message has a couple of blank lines at the start and end.)\n\n\n")
+	testParse(t, clearsignInput, "Hello world\r\nline 2", "Hello world\nline 2")
+	testParse(t, clearsignInput2, "\r\n\r\n(This message has a couple of blank lines at the start and end.)\r\n\r\n", "\n\n(This message has a couple of blank lines at the start and end.)\n\n")
 }
 
 func TestParseWithNoNewlineAtEnd(t *testing.T) {
@@ -77,21 +77,21 @@ func TestParseWithNoNewlineAtEnd(t *testing.T) {
 var signingTests = []struct {
 	in, signed, plaintext string
 }{
-	{"", "", "\n"},
-	{"a", "a", "a\n"},
-	{"a\n", "a\r\n", "a\n\n"},
-	{"-a\n", "-a\r\n", "-a\n\n"},
-	{"--a\nb", "--a\r\nb", "--a\nb\n"},
+	{"", "", ""},
+	{"a", "a", "a"},
+	{"a\n", "a\r\n", "a\n"},
+	{"-a\n", "-a\r\n", "-a\n"},
+	{"--a\nb", "--a\r\nb", "--a\nb"},
 	// leading whitespace
-	{" a\n", " a\r\n", " a\n\n"},
-	{"  a\n", "  a\r\n", "  a\n\n"},
+	{" a\n", " a\r\n", " a\n"},
+	{"  a\n", "  a\r\n", "  a\n"},
 	// trailing whitespace (should be stripped)
-	{"a \n", "a\r\n", "a\n\n"},
-	{"a ", "a", "a\n"},
-	{"  \n", "\r\n", "\n\n"},
-	{"  ", "", "\n"},
-	{"a\n  \n  \nb\n", "a\r\n\r\n\r\nb\r\n", "a\n\n\nb\n\n"},
-	{"a\n  \n  \nb\n", "a\r\n\r\n\r\nb\r\n", "a\n\n\nb\n\n"},
+	{"a \n", "a\r\n", "a\n"},
+	{"a ", "a", "a"},
+	{"  \n", "\r\n", "\n"},
+	{"  ", "", ""},
+	{"a\n  \n  \nb\n", "a\r\n\r\n\r\nb\r\n", "a\n\n\nb\n"},
+	{"a\n  \n  \nb\n", "a\r\n\r\n\r\nb\r\n", "a\n\n\nb\n"},
 }
 
 func TestVerifyV6(t *testing.T) {