serde_encoded_bytes/encoding/
base64.rs

1use alloc::{string::String, vec::Vec};
2
3use base64::{engine::general_purpose, Engine as _};
4use serde::de;
5
6use super::Encoding;
7
8/// Encodes the byte sequence into a base64 representation.
9///
10/// Uses the standard base64 alphabet (with `+` and `/`) and does not include padding.
11pub struct Base64;
12
13impl Encoding for Base64 {
14    fn encode(bytes: &[u8]) -> String {
15        general_purpose::STANDARD_NO_PAD.encode(bytes)
16    }
17
18    fn decode<E: de::Error>(string: &str) -> Result<Vec<u8>, E> {
19        general_purpose::STANDARD_NO_PAD
20            .decode(string)
21            .map_err(de::Error::custom)
22    }
23}
24
25/// Encodes the byte sequence into a base64-url representation.
26///
27/// Uses the URL-safe base64 alphabet (with `-` and `_` instead of `+` and `/`)
28/// and does not include padding.
29pub struct Base64Url;
30
31impl Encoding for Base64Url {
32    fn encode(bytes: &[u8]) -> String {
33        general_purpose::URL_SAFE_NO_PAD.encode(bytes)
34    }
35
36    fn decode<E: de::Error>(string: &str) -> Result<Vec<u8>, E> {
37        general_purpose::URL_SAFE_NO_PAD
38            .decode(string)
39            .map_err(de::Error::custom)
40    }
41}
42
43#[cfg(test)]
44mod tests {
45    use alloc::string::{String, ToString};
46
47    use serde::{Deserialize, Serialize};
48
49    use super::{Base64, Base64Url};
50    use crate::ArrayLike;
51
52    #[derive(Debug, PartialEq, Eq, Serialize, Deserialize)]
53    struct ArrayStruct(#[serde(with = "ArrayLike::<Base64>")] [u8; 4]);
54
55    #[derive(Debug, PartialEq, Eq, Serialize, Deserialize)]
56    struct ArrayStructUrlSafe(#[serde(with = "ArrayLike::<Base64Url>")] [u8; 4]);
57
58    fn hr_serialize<T: Serialize>(value: T) -> Result<String, String> {
59        serde_json::to_string(&value).map_err(|err| err.to_string())
60    }
61
62    fn hr_deserialize<'de, T: Deserialize<'de>>(string: &'de str) -> Result<T, String> {
63        serde_json::from_str::<T>(string).map_err(|err| err.to_string())
64    }
65
66    #[test]
67    fn roundtrip() {
68        let val = ArrayStruct([1, 0xf2, 63, 0xf4]);
69
70        let val_str = hr_serialize(&val).unwrap();
71        assert_eq!(val_str, "\"AfI/9A\"");
72        let val_back = hr_deserialize::<ArrayStruct>(&val_str).unwrap();
73        assert_eq!(val, val_back);
74    }
75
76    #[test]
77    fn roundtrip_url_safe() {
78        let val = ArrayStructUrlSafe([1, 0xf2, 63, 0xf4]);
79
80        let val_str = hr_serialize(&val).unwrap();
81        assert_eq!(val_str, "\"AfI_9A\"");
82        let val_back = hr_deserialize::<ArrayStructUrlSafe>(&val_str).unwrap();
83        assert_eq!(val, val_back);
84    }
85}