1 files changed, 64 insertions, 0 deletions
diff --git a/src/asn1_types/strings/string.rs b/src/asn1_types/strings/string.rs
new file mode 100644
index 0000000..81f6ba8
--- /dev/null
+++ b/src/asn1_types/strings/string.rs
@@ -0,0 +1,64 @@
+use crate::*;
+use alloc::string::String;
+use core::convert::TryFrom;
+
+impl<'a> TryFrom<Any<'a>> for String {
+    type Error = Error;
+
+    fn try_from(any: Any<'a>) -> Result<String> {
+        TryFrom::try_from(&any)
+    }
+}
+
+impl<'a, 'b> TryFrom<&'b Any<'a>> for String {
+    type Error = Error;
+
+    fn try_from(any: &'b Any<'a>) -> Result<String> {
+        any.tag().assert_eq(Self::TAG)?;
+        let s = Utf8String::try_from(any)?;
+        Ok(s.data.into_owned())
+    }
+}
+
+impl CheckDerConstraints for String {
+    fn check_constraints(any: &Any) -> Result<()> {
+        // X.690 section 10.2
+        any.header.assert_primitive()?;
+        Ok(())
+    }
+}
+
+impl DerAutoDerive for String {}
+
+impl Tagged for String {
+    const TAG: Tag = Tag::Utf8String;
+}
+
+#[cfg(feature = "std")]
+impl ToDer for String {
+    fn to_der_len(&self) -> Result<usize> {
+        let sz = self.as_bytes().len();
+        if sz < 127 {
+            // 1 (class+tag) + 1 (length) + len
+            Ok(2 + sz)
+        } else {
+            // 1 (class+tag) + n (length) + len
+            let n = Length::Definite(sz).to_der_len()?;
+            Ok(1 + n + sz)
+        }
+    }
+
+    fn write_der_header(&self, writer: &mut dyn std::io::Write) -> SerializeResult<usize> {
+        let header = Header::new(
+            Class::Universal,
+            false,
+            Self::TAG,
+            Length::Definite(self.len()),
+        );
+        header.write_der_header(writer).map_err(Into::into)
+    }
+
+    fn write_der_content(&self, writer: &mut dyn std::io::Write) -> SerializeResult<usize> {
+        writer.write(self.as_ref()).map_err(Into::into)
+    }
+}