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;
8use crate::util::helpers::Base64;
9use base64;
10use minidom::IntoAttributeValue;
11use std::num::ParseIntError;
12use std::ops::{Deref, DerefMut};
13use std::str::FromStr;
14
15/// List of the algorithms we support, or Unknown.
16#[allow(non_camel_case_types)]
17#[derive(Debug, Clone, PartialEq, Eq, Hash)]
18pub enum Algo {
19 /// The Secure Hash Algorithm 1, with known vulnerabilities, do not use it.
20 ///
21 /// See https://tools.ietf.org/html/rfc3174
22 Sha_1,
23
24 /// The Secure Hash Algorithm 2, in its 256-bit version.
25 ///
26 /// See https://tools.ietf.org/html/rfc6234
27 Sha_256,
28
29 /// The Secure Hash Algorithm 2, in its 512-bit version.
30 ///
31 /// See https://tools.ietf.org/html/rfc6234
32 Sha_512,
33
34 /// The Secure Hash Algorithm 3, based on Keccak, in its 256-bit version.
35 ///
36 /// See https://keccak.team/files/Keccak-submission-3.pdf
37 Sha3_256,
38
39 /// The Secure Hash Algorithm 3, based on Keccak, in its 512-bit version.
40 ///
41 /// See https://keccak.team/files/Keccak-submission-3.pdf
42 Sha3_512,
43
44 /// The BLAKE2 hash algorithm, for a 256-bit output.
45 ///
46 /// See https://tools.ietf.org/html/rfc7693
47 Blake2b_256,
48
49 /// The BLAKE2 hash algorithm, for a 512-bit output.
50 ///
51 /// See https://tools.ietf.org/html/rfc7693
52 Blake2b_512,
53
54 /// An unknown hash not in this list, you can probably reject it.
55 Unknown(String),
56}
57
58impl FromStr for Algo {
59 type Err = Error;
60
61 fn from_str(s: &str) -> Result<Algo, Error> {
62 Ok(match s {
63 "" => return Err(Error::ParseError("'algo' argument can’t be empty.")),
64
65 "sha-1" => Algo::Sha_1,
66 "sha-256" => Algo::Sha_256,
67 "sha-512" => Algo::Sha_512,
68 "sha3-256" => Algo::Sha3_256,
69 "sha3-512" => Algo::Sha3_512,
70 "blake2b-256" => Algo::Blake2b_256,
71 "blake2b-512" => Algo::Blake2b_512,
72 value => Algo::Unknown(value.to_owned()),
73 })
74 }
75}
76
77impl From<Algo> for String {
78 fn from(algo: Algo) -> String {
79 String::from(match algo {
80 Algo::Sha_1 => "sha-1",
81 Algo::Sha_256 => "sha-256",
82 Algo::Sha_512 => "sha-512",
83 Algo::Sha3_256 => "sha3-256",
84 Algo::Sha3_512 => "sha3-512",
85 Algo::Blake2b_256 => "blake2b-256",
86 Algo::Blake2b_512 => "blake2b-512",
87 Algo::Unknown(text) => return text,
88 })
89 }
90}
91
92impl IntoAttributeValue for Algo {
93 fn into_attribute_value(self) -> Option<String> {
94 Some(String::from(self))
95 }
96}
97
98generate_element!(
99 /// This element represents a hash of some data, defined by the hash
100 /// algorithm used and the computed value.
101 #[derive(PartialEq)]
102 Hash, "hash", HASHES,
103 attributes: [
104 /// The algorithm used to create this hash.
105 algo: Required<Algo> = "algo"
106 ],
107 text: (
108 /// The hash value, as a vector of bytes.
109 hash: Base64<Vec<u8>>
110 )
111);
112
113impl Hash {
114 /// Creates a [Hash] element with the given algo and data.
115 pub fn new(algo: Algo, hash: Vec<u8>) -> Hash {
116 Hash { algo, hash }
117 }
118
119 /// Like [new](#method.new) but takes base64-encoded data before decoding
120 /// it.
121 pub fn from_base64(algo: Algo, hash: &str) -> Result<Hash, Error> {
122 Ok(Hash::new(algo, base64::decode(hash)?))
123 }
124}
125
126/// Helper for parsing and serialising a SHA-1 attribute.
127#[derive(Debug, Clone, PartialEq)]
128pub struct Sha1HexAttribute(Hash);
129
130impl FromStr for Sha1HexAttribute {
131 type Err = ParseIntError;
132
133 fn from_str(hex: &str) -> Result<Self, Self::Err> {
134 let mut bytes = vec![];
135 for i in 0..hex.len() / 2 {
136 let byte = u8::from_str_radix(&hex[2 * i..2 * i + 2], 16)?;
137 bytes.push(byte);
138 }
139 Ok(Sha1HexAttribute(Hash::new(Algo::Sha_1, bytes)))
140 }
141}
142
143impl IntoAttributeValue for Sha1HexAttribute {
144 fn into_attribute_value(self) -> Option<String> {
145 let mut bytes = vec![];
146 for byte in self.0.hash {
147 bytes.push(format!("{:02x}", byte));
148 }
149 Some(bytes.join(""))
150 }
151}
152
153impl DerefMut for Sha1HexAttribute {
154 fn deref_mut(&mut self) -> &mut Self::Target {
155 &mut self.0
156 }
157}
158
159impl Deref for Sha1HexAttribute {
160 type Target = Hash;
161
162 fn deref(&self) -> &Self::Target {
163 &self.0
164 }
165}
166
167#[cfg(test)]
168mod tests {
169 use super::*;
170 use minidom::Element;
171 use std::convert::TryFrom;
172
173 #[cfg(target_pointer_width = "32")]
174 #[test]
175 fn test_size() {
176 assert_size!(Algo, 16);
177 assert_size!(Hash, 28);
178 }
179
180 #[cfg(target_pointer_width = "64")]
181 #[test]
182 fn test_size() {
183 assert_size!(Algo, 32);
184 assert_size!(Hash, 56);
185 }
186
187 #[test]
188 fn test_simple() {
189 let elem: Element = "<hash xmlns='urn:xmpp:hashes:2' algo='sha-256'>2XarmwTlNxDAMkvymloX3S5+VbylNrJt/l5QyPa+YoU=</hash>".parse().unwrap();
190 let hash = Hash::try_from(elem).unwrap();
191 assert_eq!(hash.algo, Algo::Sha_256);
192 assert_eq!(
193 hash.hash,
194 base64::decode("2XarmwTlNxDAMkvymloX3S5+VbylNrJt/l5QyPa+YoU=").unwrap()
195 );
196 }
197
198 #[test]
199 fn test_unknown() {
200 let elem: Element = "<replace xmlns='urn:xmpp:message-correct:0'/>"
201 .parse()
202 .unwrap();
203 let error = Hash::try_from(elem).unwrap_err();
204 let message = match error {
205 Error::ParseError(string) => string,
206 _ => panic!(),
207 };
208 assert_eq!(message, "This is not a hash element.");
209 }
210
211 #[test]
212 fn test_invalid_child() {
213 let elem: Element = "<hash xmlns='urn:xmpp:hashes:2'><coucou/></hash>"
214 .parse()
215 .unwrap();
216 let error = Hash::try_from(elem).unwrap_err();
217 let message = match error {
218 Error::ParseError(string) => string,
219 _ => panic!(),
220 };
221 assert_eq!(message, "Unknown child in hash element.");
222 }
223}