qv_core/
claims.rs

1use std::collections::HashMap;
2use crate::error::{QVError, QVResult};
3
4/// A simple string → string claims map (MessagePack-compatible via manual encoding).
5///
6/// We avoid pulling in a full MessagePack dependency by encoding as a flat
7/// key-value map using a minimal subset:
8///   - fixmap (up to 15 entries):  0x8N
9///   - fixstr  (up to 31 bytes):   0xAL + utf8 bytes
10///   - str8   (up to 255 bytes):   0xd9 LL + utf8 bytes
11#[derive(Debug, Clone, Default)]
12pub struct Claims(pub HashMap<String, String>);
13
14impl Claims {
15    pub fn new() -> Self { Claims(HashMap::new()) }
16
17    pub fn insert(&mut self, key: impl Into<String>, value: impl Into<String>) {
18        self.0.insert(key.into(), value.into());
19    }
20
21    pub fn get(&self, key: &str) -> Option<&str> {
22        self.0.get(key).map(String::as_str)
23    }
24
25    pub fn require(&self, key: &str) -> QVResult<&str> {
26        self.get(key).ok_or_else(|| QVError::MissingClaim(key.to_string()))
27    }
28
29    /// Encode to bytes (subset MessagePack).
30    pub fn encode(&self) -> QVResult<Vec<u8>> {
31        if self.0.len() > 15 {
32            return Err(QVError::SerializationError("too many claims (max 15)".into()));
33        }
34        let mut out = Vec::new();
35        out.push(0x80 | self.0.len() as u8); // fixmap
36        for (k, v) in &self.0 {
37            encode_str(&mut out, k)?;
38            encode_str(&mut out, v)?;
39        }
40        Ok(out)
41    }
42
43    /// Decode from bytes.
44    pub fn decode(data: &[u8]) -> QVResult<Self> {
45        if data.is_empty() {
46            return Err(QVError::BufferTooShort { need: 1, have: 0 });
47        }
48        let first = data[0];
49        if first & 0xF0 != 0x80 {
50            return Err(QVError::SerializationError("expected fixmap".into()));
51        }
52        let n = (first & 0x0F) as usize;
53        let mut pos = 1;
54        let mut map = HashMap::new();
55        for _ in 0..n {
56            let (k, adv) = decode_str(&data[pos..])?;
57            pos += adv;
58            let (v, adv) = decode_str(&data[pos..])?;
59            pos += adv;
60            map.insert(k, v);
61        }
62        Ok(Claims(map))
63    }
64}
65
66fn encode_str(out: &mut Vec<u8>, s: &str) -> QVResult<()> {
67    let b = s.as_bytes();
68    if b.len() <= 31 {
69        out.push(0xA0 | b.len() as u8);
70    } else if b.len() <= 255 {
71        out.push(0xd9);
72        out.push(b.len() as u8);
73    } else {
74        return Err(QVError::SerializationError("claim string too long (max 255)".into()));
75    }
76    out.extend_from_slice(b);
77    Ok(())
78}
79
80fn decode_str(data: &[u8]) -> QVResult<(String, usize)> {
81    if data.is_empty() {
82        return Err(QVError::BufferTooShort { need: 1, have: 0 });
83    }
84    let (len, header) = if data[0] & 0xE0 == 0xA0 {
85        ((data[0] & 0x1F) as usize, 1)
86    } else if data[0] == 0xd9 {
87        if data.len() < 2 {
88            return Err(QVError::BufferTooShort { need: 2, have: data.len() });
89        }
90        (data[1] as usize, 2)
91    } else {
92        return Err(QVError::SerializationError(format!("unexpected msgpack byte {:#04x}", data[0])));
93    };
94    if data.len() < header + len {
95        return Err(QVError::BufferTooShort { need: header + len, have: data.len() });
96    }
97    let s = std::str::from_utf8(&data[header..header + len])
98        .map_err(|e| QVError::SerializationError(e.to_string()))?
99        .to_string();
100    Ok((s, header + len))
101}
qv_core/claims.rs

qv_core/
claims.rs
