Files
claw/src/security/hmac.rs
2026-03-25 03:25:47 +00:00

90 lines
2.5 KiB
Rust

use hmac::{Hmac, Mac};
use serde_json::Value;
use sha2::{Digest, Sha256};
use std::fmt::Write as _;
use crate::pipe::Action;
use crate::security::SecurityError;
type HmacSha256 = Hmac<Sha256>;
pub fn derive_session_key(hmac_seed: &str) -> Result<Vec<u8>, SecurityError> {
let seed = hex::decode(hmac_seed)?;
if seed.is_empty() {
return Err(SecurityError::InvalidSeed(
"hmac_seed must not be empty".to_string(),
));
}
let mut hasher = Sha256::new();
hasher.update(seed);
hasher.update(b"sgclaw-session-v1");
Ok(hasher.finalize().to_vec())
}
pub fn sign_command(
session_key: &[u8],
seq: u64,
action: &Action,
params: &Value,
expected_domain: &str,
) -> Result<String, SecurityError> {
if session_key.is_empty() {
return Err(SecurityError::InvalidSeed(
"session key must not be empty".to_string(),
));
}
let mut mac = HmacSha256::new_from_slice(session_key)
.map_err(|err| SecurityError::Hmac(err.to_string()))?;
let canonical = format!(
"{}\n{}\n{}\n{}",
seq,
action.as_str(),
stable_json_string(params)?,
expected_domain
);
mac.update(canonical.as_bytes());
Ok(hex::encode(mac.finalize().into_bytes()))
}
fn stable_json_string(value: &Value) -> Result<String, SecurityError> {
match value {
Value::Null | Value::Bool(_) | Value::Number(_) | Value::String(_) => {
serde_json::to_string(value).map_err(SecurityError::from)
}
Value::Array(items) => {
let mut out = String::from("[");
for (index, item) in items.iter().enumerate() {
if index > 0 {
out.push(',');
}
out.push_str(&stable_json_string(item)?);
}
out.push(']');
Ok(out)
}
Value::Object(map) => {
let mut keys: Vec<&str> = map.keys().map(String::as_str).collect();
keys.sort_unstable();
let mut out = String::from("{");
for (index, key) in keys.iter().enumerate() {
if index > 0 {
out.push(',');
}
write!(
out,
"{}:{}",
serde_json::to_string(key)?,
stable_json_string(&map[*key])?
)
.map_err(|err| SecurityError::Hmac(err.to_string()))?;
}
out.push('}');
Ok(out)
}
}
}