multipart: parse and validate Content-Disposition

src/header/mod.rs

@@ -8,6 +8,7 @@ use bytes::{Bytes, BytesMut};
 use mime::Mime;
 use modhttp::header::GetAll;
 use modhttp::Error as HttpError;
+use percent_encoding;
 
 pub use modhttp::header::*;
 
@@ -259,3 +260,122 @@ where
     }
     Ok(())
 }
+
+// From hyper v0.11.27 src/header/parsing.rs
+
+/// An extended header parameter value (i.e., tagged with a character set and optionally,
+/// a language), as defined in [RFC 5987](https://tools.ietf.org/html/rfc5987#section-3.2).
+#[derive(Clone, Debug, PartialEq)]
+pub struct ExtendedValue {
+    /// The character set that is used to encode the `value` to a string.
+    pub charset: Charset,
+    /// The human language details of the `value`, if available.
+    pub language_tag: Option<LanguageTag>,
+    /// The parameter value, as expressed in octets.
+    pub value: Vec<u8>,
+}
+
+/// Parses extended header parameter values (`ext-value`), as defined in
+/// [RFC 5987](https://tools.ietf.org/html/rfc5987#section-3.2).
+///
+/// Extended values are denoted by parameter names that end with `*`.
+///
+/// ## ABNF
+///
+/// ```text
+/// ext-value     = charset  "'" [ language ] "'" value-chars
+///               ; like RFC 2231's <extended-initial-value>
+///               ; (see [RFC2231], Section 7)
+///
+/// charset       = "UTF-8" / "ISO-8859-1" / mime-charset
+///
+/// mime-charset  = 1*mime-charsetc
+/// mime-charsetc = ALPHA / DIGIT
+///               / "!" / "#" / "$" / "%" / "&"
+///               / "+" / "-" / "^" / "_" / "`"
+///               / "{" / "}" / "~"
+///               ; as <mime-charset> in Section 2.3 of [RFC2978]
+///               ; except that the single quote is not included
+///               ; SHOULD be registered in the IANA charset registry
+///
+/// language      = <Language-Tag, defined in [RFC5646], Section 2.1>
+///
+/// value-chars   = *( pct-encoded / attr-char )
+///
+/// pct-encoded   = "%" HEXDIG HEXDIG
+///               ; see [RFC3986], Section 2.1
+///
+/// attr-char     = ALPHA / DIGIT
+///               / "!" / "#" / "$" / "&" / "+" / "-" / "."
+///               / "^" / "_" / "`" / "|" / "~"
+///               ; token except ( "*" / "'" / "%" )
+/// ```
+pub fn parse_extended_value(val: &str) -> Result<ExtendedValue, ::error::ParseError> {
+
+    // Break into three pieces separated by the single-quote character
+    let mut parts = val.splitn(3,'\'');
+
+    // Interpret the first piece as a Charset
+    let charset: Charset = match parts.next() {
+        None => return Err(::error::ParseError::Header),
+        Some(n) => FromStr::from_str(n).map_err(|_| ::error::ParseError::Header)?,
+    };
+
+    // Interpret the second piece as a language tag
+    let lang: Option<LanguageTag> = match parts.next() {
+        None => return Err(::error::ParseError::Header),
+        Some("") => None,
+        Some(s) => match s.parse() {
+            Ok(lt) => Some(lt),
+            Err(_) => return Err(::error::ParseError::Header),
+        }
+    };
+
+    // Interpret the third piece as a sequence of value characters
+    let value: Vec<u8> = match parts.next() {
+        None => return Err(::error::ParseError::Header),
+        Some(v) => percent_encoding::percent_decode(v.as_bytes()).collect(),
+    };
+
+    Ok(ExtendedValue {
+        charset: charset,
+        language_tag: lang,
+        value: value,
+    })
+}
+
+
+impl fmt::Display for ExtendedValue {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let encoded_value =
+            percent_encoding::percent_encode(&self.value[..], self::percent_encoding_http::HTTP_VALUE);
+        if let Some(ref lang) = self.language_tag {
+            write!(f, "{}'{}'{}", self.charset, lang, encoded_value)
+        } else {
+            write!(f, "{}''{}", self.charset, encoded_value)
+        }
+    }
+}
+
+/// Percent encode a sequence of bytes with a character set defined in
+/// [https://tools.ietf.org/html/rfc5987#section-3.2][url]
+///
+/// [url]: https://tools.ietf.org/html/rfc5987#section-3.2
+pub fn http_percent_encode(f: &mut fmt::Formatter, bytes: &[u8]) -> fmt::Result {
+    let encoded = percent_encoding::percent_encode(bytes, self::percent_encoding_http::HTTP_VALUE);
+    fmt::Display::fmt(&encoded, f)
+}
+mod percent_encoding_http {
+    use percent_encoding;
+
+    // internal module because macro is hard-coded to make a public item
+    // but we don't want to public export this item
+    define_encode_set! {
+        // This encode set is used for HTTP header values and is defined at
+        // https://tools.ietf.org/html/rfc5987#section-3.2
+        pub HTTP_VALUE = [percent_encoding::SIMPLE_ENCODE_SET] | {
+            ' ', '"', '%', '\'', '(', ')', '*', ',', '/', ':', ';', '<', '-', '>', '?',
+            '[', '\\', ']', '{', '}'
+        }
+    }
+}