Add ASCII plist reader

The reader currently parses OpenStep format ASCII plists but it may be
extended to the GnuStep format in the future so is called AsciiReader.

Co-authored-by: Francois Stephany <[email protected]>
Co-authored-by: Ed Barnard <[email protected]>

fuzz/Cargo.toml

@@ -19,6 +19,10 @@ git = "https://github.com/rust-fuzz/libfuzzer-sys.git"
 [workspace]
 members = ["."]
 
+[[bin]]
+name = "ascii_reader"
+path = "fuzz_targets/ascii_reader.rs"
+
 [[bin]]
 name = "binary_reader"
 path = "fuzz_targets/binary_reader.rs"

fuzz/fuzz_targets/ascii_reader.rs

@@ -0,0 +1,14 @@
+#![no_main]
+#[macro_use]
+extern crate libfuzzer_sys;
+extern crate plist;
+
+use plist::stream::AsciiReader;
+use plist::Value;
+use std::io::Cursor;
+
+fuzz_target!(|data: &[u8]| {
+    let cursor = Cursor::new(data);
+    let reader = AsciiReader::new(cursor);
+    let _ = Value::from_events(reader);
+});

src/de.rs

@@ -428,6 +428,13 @@ pub fn from_reader<R: Read + Seek, T: de::DeserializeOwned>(reader: R) -> Result
     de::Deserialize::deserialize(&mut de)
 }
 
+/// Deserializes an instance of type `T` from a byte stream containing an ASCII encoded plist.
+pub fn from_reader_ascii<R: Read, T: de::DeserializeOwned>(reader: R) -> Result<T, Error> {
+    let reader = stream::AsciiReader::new(reader);
+    let mut de = Deserializer::new(reader);
+    de::Deserialize::deserialize(&mut de)
+}
+
 /// Deserializes an instance of type `T` from a byte stream containing an XML encoded plist.
 pub fn from_reader_xml<R: Read, T: de::DeserializeOwned>(reader: R) -> Result<T, Error> {
     let reader = stream::XmlReader::new(reader);

src/error.rs

@@ -33,6 +33,12 @@ pub(crate) enum ErrorKind {
         found: EventKind,
     },
 
+    // Ascii format-specific errors
+    UnclosedString,
+    IncompleteComment,
+    InvalidUtf8AsciiStream,
+    InvalidOctalString,
+
     // Xml format-specific errors
     UnclosedXmlElement,
     UnexpectedXmlCharactersExpectedElement,

src/lib.rs

@@ -118,7 +118,7 @@ mod ser;
 pub use self::{de::Deserializer, ser::Serializer};
 #[cfg(feature = "serde")]
 pub use self::{
-    de::{from_bytes, from_file, from_reader, from_reader_xml, from_value},
+    de::{from_bytes, from_file, from_reader, from_reader_ascii, from_reader_xml, from_value},
     ser::{
         to_file_binary, to_file_xml, to_value, to_writer_binary, to_writer_xml,
         to_writer_xml_with_options,

src/serde_tests.rs

@@ -799,6 +799,69 @@ fn deserialize_dictionary_binary_nskeyedarchiver() {
     assert_eq!(version, 100000);
 }
 
+fn try_parse_xml(bom: bool, whitespace: bool, decl: bool, comment: bool, doctype: bool) -> bool {
+    #[derive(Deserialize)]
+    struct LayerinfoData {
+        color: Option<String>,
+    }
+
+    let mut data = Vec::new();
+    if bom {
+        // The UTF-8 byte order mark
+        data.extend(b"\xef\xbb\xbf");
+    }
+
+    if whitespace {
+        data.extend(b"\r\n\t ");
+    }
+
+    if decl {
+        data.extend(br#"<?xml version="1.0" encoding="UTF-8"?>"#);
+    }
+
+    if comment {
+        data.extend(br#"<!-- hello -->"#);
+    }
+
+    if doctype {
+        data.extend(br#"<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">"#);
+    }
+
+    data.extend(
+        br#"<plist version="1.0">
+        <dict>
+            <key>color</key>
+            <string>1,0.75,0,0.7</string>
+        </dict>
+        </plist>
+        "#,
+    );
+
+    if let Ok(lib_dict) = crate::from_bytes::<LayerinfoData>(&data) {
+        lib_dict.color.unwrap() == "1,0.75,0,0.7"
+    } else {
+        false
+    }
+}
+
+#[test]
+fn xml_detection() {
+    for bom in [true, false] {
+        for whitespace in [true, false] {
+            for decl in [true, false] {
+                for comment in [true, false] {
+                    for doctype in [true, false] {
+                        assert!(
+                        try_parse_xml(bom, whitespace, decl, comment, doctype),
+                        "bom={bom}, whitespace={whitespace}, decl={decl}, comment={comment}, doctype={doctype}"
+                    );
+                    }
+                }
+            }
+        }
+    }
+}
+
 #[test]
 fn dictionary_deserialize_dictionary_in_struct() {
     // Example from <https://github.com/ebarnard/rust-plist/issues/54>