Support optional serde feature.

Cargo.toml

@@ -14,9 +14,11 @@ rust-version = "1.34.2"
 
 [dependencies]
 base64 = "0.13.0"
+serde = { version = "1", optional = true, features = ["serde_derive"] }
 
 [dev-dependencies]
 criterion = "0.3.0"
+serde_json = "1"
 
 [[bench]]
 name = "pem_benchmark"

src/lib.rs

@@ -103,6 +103,9 @@
     unused_qualifications
 )]
 
+#[cfg(feature = "serde")]
+use serde::{Serialize, Deserialize};
+
 mod errors;
 mod parser;
 use parser::{parse_captures, parse_captures_iter, Captures};
@@ -131,6 +134,7 @@ pub struct EncodeConfig {
 
 /// A representation of Pem-encoded data
 #[derive(PartialEq, Debug, Clone)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub struct Pem {
     /// The tag extracted from the Pem-encoded data
     pub tag: String,
@@ -613,4 +617,16 @@ RzHX0lkJl9Stshd/7Gbt65/QYq+v+xvAeT0CoyIg
 
         assert_eq!(SAMPLE_LF, encoded);
     }
+
+    #[cfg(feature = "serde")]
+    #[test]
+    fn test_serde() {
+        let pem = Pem {
+            tag: String::from("Mock tag"),
+            contents: "Mock contents".as_bytes().to_vec(),
+        };
+        let value = serde_json::to_string_pretty(&pem).unwrap();
+        let result = serde_json::from_str(&value).unwrap();
+        assert_eq!(pem, result);
+    }
 }