1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
use std::fmt;
use std::str::{self, FromStr};

use unicase::UniCase;

use header::{Header, HeaderFormat, parsing};

/// `StrictTransportSecurity` header, defined in [RFC6797](https://tools.ietf.org/html/rfc6797)
///
/// This specification defines a mechanism enabling web sites to declare
/// themselves accessible only via secure connections and/or for users to be
/// able to direct their user agent(s) to interact with given sites only over
/// secure connections.  This overall policy is referred to as HTTP Strict
/// Transport Security (HSTS).  The policy is declared by web sites via the
/// Strict-Transport-Security HTTP response header field and/or by other means,
/// such as user agent configuration, for example.
///
/// # ABNF
///
/// ```plain
///      [ directive ]  *( ";" [ directive ] )
///
///      directive                 = directive-name [ "=" directive-value ]
///      directive-name            = token
///      directive-value           = token | quoted-string
///
/// ```
///
/// # Example values
/// * `max-age=31536000`
/// * `max-age=15768000 ; includeSubDomains`
///
/// # Example
/// ```
/// # extern crate hyper;
/// # fn main() {
/// use hyper::header::{Headers, StrictTransportSecurity};
///
/// let mut headers = Headers::new();
///
/// headers.set(
///    StrictTransportSecurity::including_subdomains(31536000u64)
/// );
/// # }
/// ```
#[derive(Clone, PartialEq, Debug)]
pub struct StrictTransportSecurity {
    /// Signals the UA that the HSTS Policy applies to this HSTS Host as well as
    /// any subdomains of the host's domain name.
    pub include_subdomains: bool,

    /// Specifies the number of seconds, after the reception of the STS header
    /// field, during which the UA regards the host (from whom the message was
    /// received) as a Known HSTS Host.
    pub max_age: u64
}

impl StrictTransportSecurity {
    /// Create an STS header that includes subdomains
    pub fn including_subdomains(max_age: u64) -> StrictTransportSecurity {
        StrictTransportSecurity {
            max_age: max_age,
            include_subdomains: true
        }
    }

    /// Create an STS header that excludes subdomains
    pub fn excluding_subdomains(max_age: u64) -> StrictTransportSecurity {
        StrictTransportSecurity {
            max_age: max_age,
            include_subdomains: false
        }
    }
}

enum Directive {
    MaxAge(u64),
    IncludeSubdomains,
    Unknown
}

impl FromStr for StrictTransportSecurity {
    type Err = ::Error;

    fn from_str(s: &str) -> ::Result<StrictTransportSecurity> {
        s.split(';')
            .map(str::trim)
            .map(|sub| if UniCase(sub) == UniCase("includeSubdomains") {
                Ok(Directive::IncludeSubdomains)
            } else {
                let mut sub = sub.splitn(2, '=');
                match (sub.next(), sub.next()) {
                    (Some(left), Some(right))
                    if UniCase(left.trim()) == UniCase("max-age") => {
                        right
                            .trim()
                            .trim_matches('"')
                            .parse()
                            .map(Directive::MaxAge)
                    },
                    _ => Ok(Directive::Unknown)
                }
            })
            .fold(Ok((None, None)), |res, dir| match (res, dir) {
                (Ok((None, sub)), Ok(Directive::MaxAge(age))) => Ok((Some(age), sub)),
                (Ok((age, None)), Ok(Directive::IncludeSubdomains)) => Ok((age, Some(()))),
                (Ok((Some(_), _)), Ok(Directive::MaxAge(_))) => Err(::Error::Header),
                (Ok((_, Some(_))), Ok(Directive::IncludeSubdomains)) => Err(::Error::Header),
                (_, Err(_)) => Err(::Error::Header),
                (res, _) => res
            })
            .and_then(|res| match res {
                (Some(age), sub) => Ok(StrictTransportSecurity {
                    max_age: age,
                    include_subdomains: sub.is_some()
                }),
                _ => Err(::Error::Header)
            })
    }
}

impl Header for StrictTransportSecurity {
    fn header_name() -> &'static str {
        "Strict-Transport-Security"
    }

    fn parse_header(raw: &[Vec<u8>]) -> ::Result<StrictTransportSecurity> {
        parsing::from_one_raw_str(raw)
    }
}

impl HeaderFormat for StrictTransportSecurity {
    fn fmt_header(&self, f: &mut fmt::Formatter) -> fmt::Result {
        if self.include_subdomains {
            write!(f, "max-age={}; includeSubdomains", self.max_age)
        } else {
            write!(f, "max-age={}", self.max_age)
        }
    }
}

#[cfg(test)]
mod tests {
    use super::StrictTransportSecurity;
    use header::Header;

    #[test]
    fn test_parse_max_age() {
        let h = Header::parse_header(&[b"max-age=31536000".to_vec()][..]);
        assert_eq!(h.ok(), Some(StrictTransportSecurity { include_subdomains: false, max_age: 31536000u64 }));
    }

    #[test]
    fn test_parse_max_age_no_value() {
        let h: ::Result<StrictTransportSecurity> = Header::parse_header(&[b"max-age".to_vec()][..]);
        assert!(h.is_err());
    }

    #[test]
    fn test_parse_quoted_max_age() {
        let h = Header::parse_header(&[b"max-age=\"31536000\"".to_vec()][..]);
        assert_eq!(h.ok(), Some(StrictTransportSecurity { include_subdomains: false, max_age: 31536000u64 }));
    }

    #[test]
    fn test_parse_spaces_max_age() {
        let h = Header::parse_header(&[b"max-age = 31536000".to_vec()][..]);
        assert_eq!(h.ok(), Some(StrictTransportSecurity { include_subdomains: false, max_age: 31536000u64 }));
    }

    #[test]
    fn test_parse_include_subdomains() {
        let h = Header::parse_header(&[b"max-age=15768000 ; includeSubDomains".to_vec()][..]);
        assert_eq!(h.ok(), Some(StrictTransportSecurity { include_subdomains: true, max_age: 15768000u64 }));
    }

    #[test]
    fn test_parse_no_max_age() {
        let h: ::Result<StrictTransportSecurity> = Header::parse_header(&[b"includeSubDomains".to_vec()][..]);
        assert!(h.is_err());
    }

    #[test]
    fn test_parse_max_age_nan() {
        let h: ::Result<StrictTransportSecurity> = Header::parse_header(&[b"max-age = derp".to_vec()][..]);
        assert!(h.is_err());
    }

    #[test]
    fn test_parse_duplicate_directives() {
        assert!(StrictTransportSecurity::parse_header(&[b"max-age=100; max-age=5; max-age=0".to_vec()][..]).is_err());
    }
}

bench_header!(bench, StrictTransportSecurity, { vec![b"max-age=15768000 ; includeSubDomains".to_vec()] });