holger-intel 3.1.1

//! The online side's last step: an [`AdvisorySet`] becomes a signed
//! `holger.update-bundle/v1` with `product = holger.intel/v1`.
//!
//! Nothing here is a new format. The set is the bundle's one payload, the feed
//! record is its `Advisory` evidence, and `update-bundle`'s own `Preparation`,
//! `add_approval` and `finalize` do the hashing, the approvals and the release
//! signature — so `holger-verify` verifies an intel bundle exactly like a
//! firmware one, and `finalize` refuses to emit one that does not verify.

use std::path::{Path, PathBuf};

use anyhow::{Context, Result};
use chrono::{DateTime, Utc};
use holger_update_bundle::core::{EvidenceKind, PolicyResult, SourceProvenance};
use holger_update_bundle::digest::sha256_hex;
use holger_update_bundle::finalize::{add_approval, finalize};
use holger_update_bundle::prepare::{EvidenceInput, PayloadInput, Preparation};
use holger_update_bundle::{pack_bundle, TrustPolicy, VerifyReport};

use crate::set::AdvisorySet;
use crate::{ADVISORIES_MEDIA_TYPE, ADVISORIES_REL, INTEL_PRODUCT, SOURCES_REL};

/// One signer's certificate (DER) and ed25519 key (PKCS#8 DER). The key never
/// enters the bundle and is never printed.
pub struct SignerFiles {
    pub cert_der: Vec<u8>,
    pub key_pkcs8: Vec<u8>,
}

impl SignerFiles {
    pub fn read(cert: &Path, key: &Path) -> Result<Self> {
        Ok(Self {
            cert_der: std::fs::read(cert)
                .with_context(|| format!("read cert {}", cert.display()))?,
            key_pkcs8: std::fs::read(key).with_context(|| format!("read key {}", key.display()))?,
        })
    }
}

/// What the bundle says about itself, and who signs it.
pub struct BuildOptions {
    /// Monotonic per `(supplier, holger.intel/v1)`. The secure side refuses a
    /// bundle whose sequence is below the one it already holds.
    pub sequence: u64,
    pub created_at: DateTime<Utc>,
    pub expires_at: Option<DateTime<Utc>>,
    pub supplier: String,
    pub producer: String,
    /// The trust policy the downstream verifies against; `finalize` checks the
    /// bundle under it before it is written.
    pub policy: TrustPolicy,
    /// Approvals, `(role, signer)`, as many as the policy's two-person rule asks.
    pub approvals: Vec<(String, SignerFiles)>,
    pub release: SignerFiles,
    pub out: PathBuf,
}

/// The written bundle.
pub struct BuiltBundle {
    pub path: PathBuf,
    pub bundle_id: String,
    pub sequence: u64,
    pub advisories: usize,
    pub advisories_sha256: String,
    pub report: VerifyReport,
}

/// The default sequence for a bundle built at `t`: `YYYYMMDDHHMMSS`, which only
/// grows as long as the builder's clock does.
pub fn sequence_for(t: DateTime<Utc>) -> u64 {
    t.format("%Y%m%d%H%M%S").to_string().parse().unwrap_or(0)
}

/// Sign `set` into a bundle at `opts.out`.
pub fn build_bundle(set: &AdvisorySet, opts: BuildOptions) -> Result<BuiltBundle> {
    let payload = set.to_json_bytes()?;
    let sources = serde_json::to_vec_pretty(&set.sources)?;
    let digest = sha256_hex(&payload);
    let date = opts.created_at.format("%Y-%m-%d");
    let bundle_id = format!("holger-intel-{}-{date}", opts.sequence);
    let fetched_at = set.sources.iter().map(|s| s.fetched_at).max();
    let policy_digest = sha256_hex(opts.policy.to_ron()?.as_bytes());

    let prep = Preparation {
        bundle_id: bundle_id.clone(),
        sequence: opts.sequence,
        created_at: opts.created_at,
        expires_at: opts.expires_at,
        producer: opts.producer.clone(),
        supplier: opts.supplier.clone(),
        product: INTEL_PRODUCT.to_string(),
        release_version: format!("{date}.{}", opts.sequence),
        supported_hardware_models: vec![],
        supported_hardware_revisions: vec![],
        source_provenance: SourceProvenance {
            source_kind: "intel-feeds".into(),
            source_uri: None,
            source_repository: None,
            source_asset_path: None,
            fetched_at,
            reported_size: Some(payload.len() as u64),
            vendor_checksum: None,
            vendor_signature_status: None,
            tls_origin: None,
            transfer_receipt_digest: None,
        },
        policy_result: PolicyResult {
            policy_digest,
            advisory_snapshot_digest: Some(digest.clone()),
            verdict: "pass".into(),
            non_production: false,
        },
        supersedes: vec![],
        withdraws: vec![],
        payloads: vec![PayloadInput {
            relative_path: ADVISORIES_REL.into(),
            bytes: payload,
            media_type: ADVISORIES_MEDIA_TYPE.into(),
        }],
        evidence: vec![EvidenceInput {
            relative_path: SOURCES_REL.into(),
            bytes: sources,
            media_type: "application/json".into(),
            kind: EvidenceKind::Advisory,
        }],
    };
    let candidate = prep
        .build()
        .map_err(|e| anyhow::anyhow!("prepare intel bundle: {e}"))?;
    let mut members = candidate.members;
    let now = Utc::now();
    for (role, s) in &opts.approvals {
        add_approval(&mut members, role, &s.cert_der, &s.key_pkcs8, None, now)
            .map_err(|e| anyhow::anyhow!("approve intel bundle as {role}: {e}"))?;
    }
    let report = finalize(
        &mut members,
        &opts.policy,
        &opts.release.cert_der,
        &opts.release.key_pkcs8,
        now,
    )
    .map_err(|e| anyhow::anyhow!("sign intel bundle: {e}"))?;
    if let Some(p) = opts.out.parent().filter(|p| !p.as_os_str().is_empty()) {
        std::fs::create_dir_all(p).ok();
    }
    pack_bundle(&members, &opts.out).map_err(|e| anyhow::anyhow!("pack intel bundle: {e}"))?;
    Ok(BuiltBundle {
        path: opts.out,
        bundle_id,
        sequence: opts.sequence,
        advisories: set.advisories.len(),
        advisories_sha256: digest,
        report,
    })
}