init: seed framework reference content from agent-runtimes main repo

harnesses/capabilities/agent-communication/v1/finalize.sh

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+#!/usr/bin/env python3
+"""ACL finalize script: validate staging path, copy to secure tmpfs, sign, commit.
+
+AC-10: Reject draft paths outside /workspace/.acl-staging/
+AC-40: Copy draft to root-owned /run/acl-finalize/<task_id>/ before all processing
+AC-41: Stamp + sign + commit in one process; no partial state outside finalize tmpfs
+AC-42: Commit signed bytes via git hash-object --stdin + git commit-tree (no git add)
+"""
+
+import os
+import pathlib
+import secrets
+import subprocess
+import sys
+
+
+def validate_draft_path(draft_arg: str) -> pathlib.Path:
+    """AC-10: Validate draft resolves under /workspace/.acl-staging/."""
+    staging_dir = pathlib.Path("/workspace/.acl-staging").resolve()
+    draft = pathlib.Path(draft_arg).resolve()
+    if staging_dir not in draft.parents:
+        print("error: draft path must be under /workspace/.acl-staging/", file=sys.stderr)
+        sys.exit(1)
+    if not draft.exists():
+        print(f"error: draft file not found: {draft_arg}", file=sys.stderr)
+        sys.exit(1)
+    return draft
+
+
+def copy_to_finalize_dir(draft: pathlib.Path, task_id: str) -> pathlib.Path:
+    """AC-40: Atomically copy draft to a root-owned finalize tmpfs path.
+
+    After this call, only `tmp` is referenced — the original `draft` path
+    is never read again (closes the TOCTOU window AC-40 describes).
+    """
+    finalize_dir = pathlib.Path("/run/acl-finalize") / task_id
+    finalize_dir.mkdir(parents=True, exist_ok=True, mode=0o700)
+    tmp = finalize_dir / (secrets.token_hex(8) + ".draft")
+    tmp.write_bytes(draft.read_bytes())
+    tmp.chmod(0o600)
+    # From here, only use `tmp` — never reference `draft` again
+    return tmp
+
+
+def sign_and_commit(tmp: pathlib.Path, task_id: str) -> None:
+    """AC-42: Canonicalize, sign, and commit via git hash-object --stdin.
+
+    Never calls git add. Signed bytes go directly into git object store.
+    Retry loop (AC-31/AC-36): up to 3 attempts with pull --rebase on failure.
+    """
+    # Import shared canonical library (AC-43)
+    _project = str(pathlib.Path(__file__).resolve().parent.parent.parent.parent.parent)
+    if _project not in sys.path:
+        sys.path.insert(0, _project)
+    from lib.acl_canonical import canonical_serialize, validate_frontmatter
+
+    raw = tmp.read_bytes()
+
+    # AC-13/AC-14: Validate and parse frontmatter
+    frontmatter = validate_frontmatter(raw)
+
+    # AC-15: Canonical serialization
+    # Extract body (text after the second ---)
+    body = ""
+    text = raw.decode("utf-8")
+    parts = text.split("---\n", 2)
+    if len(parts) >= 3:
+        body = parts[2]
+
+    canonical: bytes = canonical_serialize(frontmatter, body)
+
+    # AC-16: Sign with Ed25519 over signed_sha256 || nonce || commit_hash
+    import hashlib
+    from cryptography.hazmat.primitives.serialization import load_pem_private_key
+
+    key_bytes = pathlib.Path("/run/agent/acl/ed25519.key").read_bytes()
+    private_key = load_pem_private_key(key_bytes, password=None)
+
+    signed_sha256 = hashlib.sha256(canonical).digest()
+    nonce_bytes = secrets.token_bytes(32)
+    # commit_hash placeholder — real value computed after git commit-tree
+    placeholder_commit_hash = bytes(32)
+    sig_input = signed_sha256 + nonce_bytes + placeholder_commit_hash
+    sig = private_key.sign(sig_input)
+
+    signed = canonical + b"\n# sig: " + sig.hex().encode() + b"\n"
+
+    # AC-42: git hash-object --stdin (no git add, no disk re-read after sign)
+    blob_result = subprocess.run(
+        ["git", "hash-object", "-w", "--stdin"],
+        input=signed,
+        capture_output=True,
+        check=True,
+    )
+    blob_oid = blob_result.stdout.strip().decode()
+
+    # AC-42: Assemble commit via git mktree + git commit-tree (NOT git commit)
+    import time as _time
+
+    outbox_path = f"outbox/{task_id}/{int(_time.time() * 1000)}.md"
+
+    # Build tree entry for the outbox blob
+    tree_input = f"100644 blob {blob_oid}\t{outbox_path}\n".encode()
+    tree_result = subprocess.run(
+        ["git", "mktree"],
+        input=tree_input,
+        capture_output=True,
+        check=True,
+    )
+    tree_oid = tree_result.stdout.strip().decode()
+
+    # Get current HEAD for parent commit
+    parent_result = subprocess.run(
+        ["git", "rev-parse", "HEAD"],
+        capture_output=True,
+    )
+    parent_args = []
+    if parent_result.returncode == 0 and parent_result.stdout.strip():
+        parent_args = ["-p", parent_result.stdout.strip().decode()]
+
+    # Create commit via git commit-tree (NOT git commit — AC-42)
+    commit_result = subprocess.run(
+        ["git", "commit-tree", tree_oid] + parent_args + ["-m", "ACL message"],
+        capture_output=True,
+        check=True,
+    )
+    commit_oid = commit_result.stdout.strip().decode()
+
+    # Update the local ref to point at the new commit
+    subprocess.run(
+        ["git", "update-ref", "refs/heads/main", commit_oid],
+        check=True,
+    )
+
+    # AC-31/AC-36: Retry push loop — up to 3 attempts with pull --rebase on failure
+    for _attempt in range(3):
+        push_result = subprocess.run(["git", "push"], capture_output=True)
+        if push_result.returncode == 0:
+            break
+        subprocess.run(["git", "pull", "--rebase"], check=False)
+    else:
+        print("error: push_race_lost", file=sys.stderr)
+        sys.exit(1)
+
+
+def main(argv: list | None = None) -> int:
+    """Entry point."""
+    if argv is None:
+        argv = sys.argv
+
+    if len(argv) < 2:
+        print("usage: acl-finalize <draft>", file=sys.stderr)
+        return 1
+
+    task_id = os.environ.get("ACL_TASK_ID", "unknown")
+
+    # AC-10: Validate path is under staging dir
+    draft = validate_draft_path(argv[1])
+
+    # AC-40: Copy to root-owned finalize tmpfs before any processing
+    tmp = copy_to_finalize_dir(draft, task_id)
+
+    try:
+        # AC-41: stamp + sign + commit in one process invocation
+        sign_and_commit(tmp, task_id)
+    finally:
+        # Clean up finalize copy on any exit
+        try:
+            tmp.unlink(missing_ok=True)
+        except Exception:
+            pass
+
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())

harnesses/capabilities/agent-communication/v1/harness.yaml

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+kind: capability
+name: agent-communication
+version: 1
+description: "ACL: agent-to-agent messaging via git-backed conversation repo"
+requires: []
+
+secrets_required:
+  - name: AGENT_ED25519_KEY
+  - name: AGENT_ED25519_PUB
+  - name: AGENT_MTLS_CERT
+  - name: AGENT_MTLS_KEY
+
+env:
+  ACL_TASK_ID: ""
+  ACL_ORIGIN_TASK_ID: ""
+  ACL_CONVERSATION_REPO_URL: ""
+
+scripts:
+  init: "./init.sh"

harnesses/capabilities/agent-communication/v1/init.sh

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+#!/bin/bash
+# Agent communication capability layer initialization script
+# Sets up the ACL tmpfs key directory. The dispatcher mounts
+# /opt/harness/bin/acl-finalize directly (AC-2).
+
+set -euo pipefail
+
+echo "Initializing agent-communication capability layer..."
+
+# Create tmpfs for ACL key material (AC-7: noexec,nosuid,mode=0700)
+ACL_KEY_DIR="/run/agent/acl"
+mkdir -p "${ACL_KEY_DIR}"
+mount -t tmpfs -o noexec,nosuid,mode=0700 tmpfs "${ACL_KEY_DIR}"
+
+# Write Ed25519 private key from env to tmpfs (AC-7: mode 0600)
+if [[ -n "${AGENT_ED25519_KEY:-}" ]]; then
+    printf '%s' "${AGENT_ED25519_KEY}" > "${ACL_KEY_DIR}/ed25519.key"
+    chmod 0600 "${ACL_KEY_DIR}/ed25519.key"
+    unset AGENT_ED25519_KEY
+fi
+
+# Write Ed25519 public key from env to tmpfs (mode 0644)
+if [[ -n "${AGENT_ED25519_PUB:-}" ]]; then
+    printf '%s' "${AGENT_ED25519_PUB}" > "${ACL_KEY_DIR}/ed25519.pub"
+    chmod 0644 "${ACL_KEY_DIR}/ed25519.pub"
+    unset AGENT_ED25519_PUB
+fi
+
+# Write mTLS cert and key from env to tmpfs (AC-8)
+if [[ -n "${AGENT_MTLS_CERT:-}" ]]; then
+    printf '%s' "${AGENT_MTLS_CERT}" > "${ACL_KEY_DIR}/mtls.crt"
+    chmod 0600 "${ACL_KEY_DIR}/mtls.crt"
+    unset AGENT_MTLS_CERT
+fi
+
+if [[ -n "${AGENT_MTLS_KEY:-}" ]]; then
+    printf '%s' "${AGENT_MTLS_KEY}" > "${ACL_KEY_DIR}/mtls.key"
+    chmod 0600 "${ACL_KEY_DIR}/mtls.key"
+    unset AGENT_MTLS_KEY
+fi
+
+# Ensure /opt/harness/bin/ exists (dispatcher mounts acl-finalize here)
+mkdir -p /opt/harness/bin
+
+echo "Agent communication environment ready"