Implement data_length for many types (#552)

Author: alex

src/types.rs

@@ -261,6 +261,10 @@ impl SimpleAsn1Writable for Null {
     fn write_data(&self, _dest: &mut WriteBuf) -> WriteResult {
         Ok(())
     }
+
+    fn data_length(&self) -> Option<usize> {
+        Some(0)
+    }
 }
 
 impl SimpleAsn1Readable<'_> for bool {
@@ -357,6 +361,10 @@ impl<T: Asn1Writable> SimpleAsn1Writable for OctetStringEncoded<T> {
     fn write_data(&self, dest: &mut WriteBuf) -> WriteResult {
         self.0.write(&mut Writer::new(dest))
     }
+
+    fn data_length(&self) -> Option<usize> {
+        self.0.encoded_length()
+    }
 }
 
 /// Type for use with `Parser.read_element` and `Writer.write_element` for
@@ -428,6 +436,10 @@ impl SimpleAsn1Writable for PrintableString<'_> {
     fn write_data(&self, dest: &mut WriteBuf) -> WriteResult {
         dest.push_slice(self.0.as_bytes())
     }
+
+    fn data_length(&self) -> Option<usize> {
+        Some(self.0.len())
+    }
 }
 
 /// Type for use with `Parser.read_element` and `Writer.write_element` for
@@ -477,6 +489,10 @@ impl SimpleAsn1Writable for IA5String<'_> {
     fn write_data(&self, dest: &mut WriteBuf) -> WriteResult {
         dest.push_slice(self.0.as_bytes())
     }
+
+    fn data_length(&self) -> Option<usize> {
+        Some(self.0.len())
+    }
 }
 
 /// Type for use with `Parser.read_element` and `Writer.write_element` for
@@ -510,6 +526,10 @@ impl SimpleAsn1Writable for Utf8String<'_> {
     fn write_data(&self, dest: &mut WriteBuf) -> WriteResult {
         dest.push_slice(self.0.as_bytes())
     }
+
+    fn data_length(&self) -> Option<usize> {
+        Some(self.0.len())
+    }
 }
 
 /// Type for use with `Parser.read_element` and `Writer.write_element` for
@@ -565,6 +585,10 @@ impl SimpleAsn1Writable for VisibleString<'_> {
     fn write_data(&self, dest: &mut WriteBuf) -> WriteResult {
         dest.push_slice(self.0.as_bytes())
     }
+
+    fn data_length(&self) -> Option<usize> {
+        Some(self.0.len())
+    }
 }
 
 /// Type for use with `Parser.read_element` and `Writer.write_element` for
@@ -615,6 +639,10 @@ impl SimpleAsn1Writable for BMPString<'_> {
     fn write_data(&self, dest: &mut WriteBuf) -> WriteResult {
         dest.push_slice(self.as_utf16_be_bytes())
     }
+
+    fn data_length(&self) -> Option<usize> {
+        Some(self.as_utf16_be_bytes().len())
+    }
 }
 
 /// Type for use with `Parser.read_element` and `Writer.write_element` for
@@ -665,6 +693,10 @@ impl SimpleAsn1Writable for UniversalString<'_> {
     fn write_data(&self, dest: &mut WriteBuf) -> WriteResult {
         dest.push_slice(self.as_utf32_be_bytes())
     }
+
+    fn data_length(&self) -> Option<usize> {
+        Some(self.as_utf32_be_bytes().len())
+    }
 }
 
 const fn validate_integer(data: &[u8], signed: bool) -> ParseResult<()> {
@@ -1182,6 +1214,10 @@ impl SimpleAsn1Writable for UtcTime {
 
         dest.push_byte(b'Z')
     }
+
+    fn data_length(&self) -> Option<usize> {
+        Some(13)
+    }
 }
 
 /// Used for parsing and writing ASN.1 `GENERALIZED TIME` values used in X.509.

src/writer.rs

@@ -633,6 +633,14 @@ mod tests {
             .unwrap(),
             b"\x30\x03\x01\x01\xff"
         );
+        assert_eq!(
+            write(|w| {
+                w.write_element(&SequenceWriter::new(&|w: &mut Writer<'_>| {
+                    w.write_element(&b"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa")
+                }))
+            }).unwrap(),
+            b"\x30\x81\x84\x04\x81\x81aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
+        );
 
         assert_writes(&[(
             parse_single::<Sequence<'_>>(b"\x30\x06\x01\x01\xff\x02\x01\x06").unwrap(),