feat(m7.3): MCP tenant-scoped bearer tokens (#92)

MCP server validates per-tenant bearer tokens on incoming calls and routes each tool to the caller's tenant DB. Closes the cross-tenant data leak in the MCP path identified in M7.3.
2026-06-30 15:27:21 +00:00
parent ac24ca766a
commit a3a96fe2cc
14 changed files with 622 additions and 35 deletions
@@ -0,0 +1,69 @@
+//! Per-tenant API tokens used by `compliance-mcp` to authenticate MCP
+//! HTTP requests on behalf of LLM clients (Claude Desktop, Cursor,
+//! ChatGPT, etc.) that can't run a Keycloak OIDC flow.
+//!
+//! Tokens are opaque strings of the form `mcpt_<44 url-safe random
+//! chars>`. The raw value is shown to the user exactly once at
+//! creation; the database only ever sees the SHA-256 hash. Lookups go
+//! through the cross-tenant `<prefix>__admin.mcp_tokens` collection
+//! and return the `tenant_id` the MCP server should route to.
+
+use chrono::{DateTime, Utc};
+use serde::{Deserialize, Serialize};
+
+/// Persisted token metadata. `token_hash` is the SHA-256 hex of the
+/// raw token; the raw token itself is never stored.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct McpToken {
+    #[serde(rename = "_id", skip_serializing_if = "Option::is_none")]
+    pub id: Option<bson::oid::ObjectId>,
+    /// SHA-256 hex of the raw token. Unique index in the collection.
+    pub token_hash: String,
+    /// First 8 chars of the raw token — purely for UI display so users
+    /// can identify which token is which without re-issuing.
+    pub token_prefix: String,
+    /// Routes to `<db_prefix>_<tenant_id>` on MCP requests.
+    pub tenant_id: String,
+    /// User-given label, e.g. "Claude Desktop" or "Sharang's laptop".
+    pub name: String,
+    /// Keycloak `sub` of the user who created this token, for audit.
+    pub created_by: String,
+    #[serde(with = "super::serde_helpers::bson_datetime")]
+    pub created_at: DateTime<Utc>,
+    #[serde(default, with = "super::serde_helpers::opt_bson_datetime")]
+    pub last_used_at: Option<DateTime<Utc>>,
+    /// Soft-delete flag. A revoked token doc stays around for audit
+    /// but never authenticates.
+    #[serde(default)]
+    pub revoked: bool,
+}
+
+/// Public projection of a token — never includes the hash.
+/// Returned by `GET /api/v1/mcp-tokens`.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct McpTokenView {
+    pub id: String,
+    pub name: String,
+    /// `mcpt_xxxx…` so the user can identify which row is which.
+    pub token_prefix: String,
+    pub created_by: String,
+    #[serde(with = "super::serde_helpers::bson_datetime")]
+    pub created_at: DateTime<Utc>,
+    #[serde(default, with = "super::serde_helpers::opt_bson_datetime")]
+    pub last_used_at: Option<DateTime<Utc>>,
+    pub revoked: bool,
+}
+
+impl From<&McpToken> for McpTokenView {
+    fn from(t: &McpToken) -> Self {
+        Self {
+            id: t.id.map(|o| o.to_hex()).unwrap_or_default(),
+            name: t.name.clone(),
+            token_prefix: t.token_prefix.clone(),
+            created_by: t.created_by.clone(),
+            created_at: t.created_at,
+            last_used_at: t.last_used_at,
+            revoked: t.revoked,
+        }
+    }
+}