Egypt ITIDA CMS Signatures with JSON Canonicalization

When sending signed documents to Egypt ITIDA, the expected format is a CAdES-BES signature (i.e. CMS/PKCS#7) embedded within your document payload—commonly encoded in Base64 and following specific structure rules:

Required Format

1. CAdES-BES Signature (PKCS#7, OID 1.2.840.113549.1.7.2)
   • Based on CMS, including mandatory signed attributes such as contentType, messageDigest, and signingCertificateV2.
2. No Data Inline in Signature
   • The content is detached and not embedded inside the CMS; only the signature bytes are included.
3. JSON Canonicalization (if signing JSON)
   • Apply the ITIDA-specified JSON canonical format before hashing/signing. Chilkat automatically applies the canonicalization when the CanonicalizeITIDA member is specified in CmsOptions. See the examples below.
4. Base64 Encoding
   • The final signature is base64-encoded and inserted into the document—typically in a JSON/XML element like:

     {
     "originalDocument": { ... },
     "cadesSignature": "<base64-signature-here>"
     }

Coding Examples

Egypt ITIDA requires signed documents in a CAdES-BES CMS format, using ITIDA’s JSON canonicalization (for JSON payloads), with only the Base64 encoded signature attached—not the original data itself.