ic_auth/
session_request.rs

1//! Canonical session request identity, independent of proof verification or storage.
2//!
3//! Hashing a request does not authenticate a token, select host TTL policy or
4//! grant scopes. Session admission and replay remain separate engine obligations.
5
6use crate::canonical::{CanonicalAuthError, validate_scope_label};
7use ic_auth_protocol_types::{AuthRole, DelegatedRoleGrant};
8use sha2::{Digest, Sha256};
9use thiserror::Error;
10
11/// Request shape, narrowing and lifetime rejection; no cryptographic verification.
12#[derive(Debug, Error, Eq, PartialEq)]
13pub enum SessionRequestError {
14    #[error("session request has invalid scope bounds, duplicate scopes or zero TTL")]
15    InvalidRequest,
16    #[error("invalid session TTL policy, requested lifetime or expiry overflow")]
17    InvalidLifetime,
18    #[error("requested scopes are not granted for the protected receiver role")]
19    ScopeRejected,
20    #[error(transparent)]
21    Canonical(#[from] CanonicalAuthError),
22}
23
24/// Checked current maximum session lifetime, in seconds (1..=1800).
25/// Authorization needs this bound, without an admission default.
26/// Construction cannot bypass range admission:
27/// ```compile_fail
28/// use ic_auth::session_request::SessionTtlLimit;
29/// let invalid = SessionTtlLimit(0);
30/// ```
31#[derive(Clone, Copy, Debug, Eq, PartialEq)]
32pub struct SessionTtlLimit(u64);
33impl SessionTtlLimit {
34    pub fn new(seconds: u64) -> Result<Self, SessionRequestError> {
35        if seconds == 0 || seconds > crate::limits::MAX_SESSION_SECS {
36            return Err(SessionRequestError::InvalidLifetime);
37        }
38        Ok(Self(seconds))
39    }
40    pub const fn seconds(self) -> u64 {
41        self.0
42    }
43}
44
45/// Checked default and maximum TTL for fresh admission. Neither value is taken
46/// from a submitted request. Live authorization uses only `maximum()`.
47#[derive(Clone, Copy, Debug, Eq, PartialEq)]
48pub struct SessionTtlPolicy {
49    default_secs: u64,
50    maximum: SessionTtlLimit,
51}
52impl SessionTtlPolicy {
53    pub fn new(default_secs: u64, maximum_secs: u64) -> Result<Self, SessionRequestError> {
54        let maximum = SessionTtlLimit::new(maximum_secs)?;
55        if default_secs == 0 || default_secs > maximum_secs {
56            return Err(SessionRequestError::InvalidLifetime);
57        }
58        Ok(Self {
59            default_secs,
60            maximum,
61        })
62    }
63    pub const fn default_secs(self) -> u64 {
64        self.default_secs
65    }
66    pub const fn maximum(self) -> SessionTtlLimit {
67        self.maximum
68    }
69}
70
71/// Canonical narrowing request: 1..=16 unique scopes, at most 1024 scope bytes.
72/// Input order is normalized before hashing; duplicates are rejected.
73#[derive(Clone, Debug, Eq, PartialEq)]
74pub struct SessionRequest {
75    scopes: Vec<String>,
76    ttl_secs: Option<u64>,
77}
78impl SessionRequest {
79    pub fn new(
80        mut scopes: Vec<String>,
81        ttl_secs: Option<u64>,
82    ) -> Result<Self, SessionRequestError> {
83        check_scopes(&scopes)?;
84        scopes.sort_unstable();
85        if scopes.windows(2).any(|pair| pair[0] == pair[1]) || ttl_secs == Some(0) {
86            return Err(SessionRequestError::InvalidRequest);
87        }
88        Ok(Self { scopes, ttl_secs })
89    }
90    /// Exact requested TTL in seconds; None leaves selection to protected host policy.
91    pub const fn ttl_secs(&self) -> Option<u64> {
92        self.ttl_secs
93    }
94    pub fn scopes(&self) -> &[String] {
95        &self.scopes
96    }
97    /// Calculate a requested lease against protected TTL policy (maximum 1800s).
98    /// This authenticates nothing and does not cap login or authority deadlines.
99    /// The host supplies its clock and default/maximum policy, never the request.
100    pub fn expires_at_ns(
101        &self,
102        now_ns: u64,
103        policy: SessionTtlPolicy,
104    ) -> Result<u64, SessionRequestError> {
105        let ttl = self.ttl_secs.unwrap_or(policy.default_secs());
106        if ttl > policy.maximum().seconds() {
107            return Err(SessionRequestError::InvalidLifetime);
108        }
109        now_ns
110            .checked_add(ttl * crate::limits::NS_PER_SECOND)
111            .ok_or(SessionRequestError::InvalidLifetime)
112    }
113    fn check_granted_scopes(&self, granted: &[String]) -> Result<(), SessionRequestError> {
114        if !crate::certificate_issuance::scopes_are_subset(&self.scopes, granted) {
115            return Err(SessionRequestError::ScopeRejected);
116        }
117        Ok(())
118    }
119    /// Evaluate narrowing and requested TTL at this caller's protected snapshot.
120    /// Admission and verified claims both use this policy; each retains its own
121    /// authority checks and the verified lease additionally caps signed deadlines.
122    pub(crate) fn evaluate(
123        &self,
124        grants: &[DelegatedRoleGrant],
125        role: &AuthRole,
126        now_ns: u64,
127        policy: SessionTtlPolicy,
128    ) -> Result<u64, SessionRequestError> {
129        let grant = grants
130            .iter()
131            .find(|grant| &grant.target == role)
132            .ok_or(SessionRequestError::ScopeRejected)?;
133        self.check_granted_scopes(&grant.scopes)?;
134        self.expires_at_ns(now_ns, policy)
135    }
136    /// Exact Canic V1 request hash; None and an explicit default TTL differ.
137    pub fn hash(&self) -> [u8; 32] {
138        let mut hash = Sha256::new();
139        hash.update(b"canic-application-session-request-v1");
140        hash.update((self.scopes.len() as u64).to_be_bytes());
141        for scope in &self.scopes {
142            hash.update((scope.len() as u64).to_be_bytes());
143            hash.update(scope.as_bytes());
144        }
145        match self.ttl_secs {
146            None => hash.update([0]),
147            Some(ttl) => {
148                hash.update([1]);
149                hash.update(ttl.to_be_bytes());
150            }
151        }
152        hash.finalize().into()
153    }
154}
155
156pub(crate) fn check_scopes(scopes: &[String]) -> Result<(), SessionRequestError> {
157    if scopes.is_empty() || scopes.len() > crate::limits::MAX_SESSION_SCOPES {
158        return Err(SessionRequestError::InvalidRequest);
159    }
160    // The count bound and canonical 64-byte label bound imply <=1024 bytes.
161    for scope in scopes {
162        validate_scope_label(scope)?;
163    }
164    Ok(())
165}
ic_auth/session_request.rs

ic_auth/
session_request.rs
