name: skill-digital-signing-crypto description: Implement electronic signatures and cryptographic validation for Spanish government documents. Includes X.509 certificate handling, sign/verify operations, audit trails, and compliance with eIDAS regulations. Use when documents require legal digital signatures for corporate transactions.

Digital Signing & Cryptography (eIDAS)

Quick Start

python

from app.crypto.signer import DocumentSigner

signer = DocumentSigner(keycloak_manager=keycloak)

# Sign
signature = signer.sign_document(
    document_id=123,
    user_cert=user_certificate,
    timestamp=datetime.utcnow()
)

# Verify
is_valid = signer.verify_signature(
    document_id=123,
    signature=signature,
    user_cert=user_certificate
)

Key Concepts

See references/x509-certs.md:

•Load X.509 certificates from Keycloak
•Validate certificate chain
•Check expiration/revocation

See references/signature-workflows.md:

•Single signature (one user)
•Countersignature (multiple approvals)
•Audit trail persistence

See references/audit-trail.md:

•Log all sign operations
•Store signature metadata
•Compliance with Spanish legal requirements

Scripts

bash

python scripts/crypto_utils.py --sign doc.pdf --key private.pem
python scripts/validate_certs.py --cert cert.pem