Body and Attachment Test Vector Execution Guide

Normative test vectors · Common execution rules

Coverage

File: message-content-v1.json. Sections: body, attachment_encryption, and hash_references.

Fixed Inputs and References

body.media supplies attachment plaintext and references. Encryption cases in attachment_encryption and hash_references each retain their own plaintext, keys, AAD, and expected results. hash_references.resolution_cases resolves references only within the attachment array supplied by that case.

Execution Steps and Assertions

Body Format and Rendering

All body.body_cases items are valid body cases. When interpretation is provided, verify that interpretation too. invalid_body_cases MUST be rejected; rendering_safety_cases specifies handling requirements for raw HTML and unsafe links.

Valid content_type values in body vectors may omit charset or use utf-8; parameter names and values are case-insensitive. body_cases covers these valid forms, while charset parameters in invalid_body_cases verify rejection of other charsets and empty values.

Attachment Encryption

attachment_encryption provides an encrypted ContentReference, original plaintext, exact AAD, and ciphertext with its tag. Independently compare encryption inputs and verify external content decryption.

Hash References and Resolution

hash_references.uri_generation computes SHA-256 text and a ni: URI from fixed plaintext. hash_cases checks attachment hash fields; resolution_cases matches only against the attachments provided by each case. The index in resolved is the expected position in that case's attachment array; unresolved means no target matched, invalid_reference means a malformed reference, and invalid_attachments means invalid attachment fields or duplicate hashes.

expected_targets in markdown_cases contains only actually parsed ni: images and links. It excludes code, escaped syntax, plain text, and literal text in unknown formats.

Message Authentication of Attachment References

encrypted_attachment and re_encrypted_attachment in hash_references provide two sets of attachment encryption inputs and outputs for checking the plaintext digest, AAD, ciphertext, and decryption result.

private_message and group_message give exact body bytes, AAD, ciphertext, and signatures. Account messages use a fixed content key; group messages derive a 32-byte message_key from the supplied group application secret and use the fixed test input message_nonce. Neither involves construction of key boxes for sender or recipient devices.

Changing a body hash URI or attachment reference without regenerating the message authentication data MUST fail. Decryption of the attachment itself and verification of its plaintext digest remain independent checks.