1// Copyright (c) 2017 Emmanuel Gil Peyrot <linkmauve@linkmauve.fr>
 2//
 3// This Source Code Form is subject to the terms of the Mozilla Public
 4// License, v. 2.0. If a copy of the MPL was not distributed with this
 5// file, You can obtain one at http://mozilla.org/MPL/2.0/.
 6
 7use crate::util::error::Error;
 8
 9/// Codec for plain text content.
10pub struct PlainText;
11
12impl PlainText {
13    pub fn decode(s: &str) -> Result<Option<String>, Error> {
14        Ok(match s {
15            "" => None,
16            text => Some(text.to_owned()),
17        })
18    }
19
20    pub fn encode(string: &Option<String>) -> Option<String> {
21        string.as_ref().map(ToOwned::to_owned)
22    }
23}
24
25/// Codec for trimmed plain text content.
26pub struct TrimmedPlainText;
27
28impl TrimmedPlainText {
29    pub fn decode(s: &str) -> Result<String, Error> {
30        Ok(match s.trim() {
31            "" => return Err(Error::ParseError("URI missing in uri.")),
32            text => text.to_owned(),
33        })
34    }
35
36    pub fn encode(string: &str) -> Option<String> {
37        Some(string.to_owned())
38    }
39}
40
41/// Codec wrapping base64 encode/decode.
42pub struct Base64;
43
44impl Base64 {
45    pub fn decode(s: &str) -> Result<Vec<u8>, Error> {
46        Ok(base64::decode(s)?)
47    }
48
49    pub fn encode(b: &[u8]) -> Option<String> {
50        Some(base64::encode(b))
51    }
52}
53
54/// Codec wrapping base64 encode/decode, while ignoring whitespace characters.
55pub struct WhitespaceAwareBase64;
56
57impl WhitespaceAwareBase64 {
58    pub fn decode(s: &str) -> Result<Vec<u8>, Error> {
59        let s: String = s.chars().filter(|ch| *ch != ' ' && *ch != '\n' && *ch != '\t').collect();
60        Ok(base64::decode(&s)?)
61    }
62
63    pub fn encode(b: &[u8]) -> Option<String> {
64        Some(base64::encode(b))
65    }
66}
67
68/// Codec for colon-separated bytes of uppercase hexadecimal.
69pub struct ColonSeparatedHex;
70
71impl ColonSeparatedHex {
72    pub fn decode(s: &str) -> Result<Vec<u8>, Error> {
73        let mut bytes = vec![];
74        for i in 0..(1 + s.len()) / 3 {
75            let byte = u8::from_str_radix(&s[3 * i..3 * i + 2], 16)?;
76            if 3 * i + 2 < s.len() {
77                assert_eq!(&s[3 * i + 2..3 * i + 3], ":");
78            }
79            bytes.push(byte);
80        }
81        Ok(bytes)
82    }
83
84    pub fn encode(b: &[u8]) -> Option<String> {
85        let mut bytes = vec![];
86        for byte in b {
87            bytes.push(format!("{:02X}", byte));
88        }
89        Some(bytes.join(":"))
90    }
91}