Package 'attestix'

Attestix JCS-style canonical JSON

Description

Reproduces attestix/auth/crypto.py::canonicalize_json byte-for-byte.

Usage

atx_canonicalize(obj)

Arguments

obj	A JSON string, raw UTF-8 bytes, or a value tree produced by atx_json_parse.

Details

This is JCS-style, NOT strict RFC 8785. The two load-bearing divergences from RFC 8785 are:

1. NFC Unicode normalization is applied to every string value and every object key (RFC 8785 does not normalize).

2. Whole-number floats collapse to integers (1.0 -> 1); non-whole floats use Python's repr (the vectors only use integers and 1.5, on which every port agrees).

Keys are sorted by Unicode code point, separators are "," and ":" with no whitespace, output is raw UTF-8 (no \uXXXX escapes), and large integers (> 2^53) are preserved exactly.

Value

A raw vector of the canonical UTF-8 bytes.

Examples

bytes <- atx_canonicalize('{"b":2,"a":1}')
rawToChar(bytes) # {"a":1,"b":2}

---

Decode an Ed25519 did:key to its raw 32-byte public key

Description

Reproduces attestix/auth/crypto.py::did_key_to_public_key: strip the did:key:z prefix, base58btc-decode the multibase payload, assert the first two bytes are the 0xed 0x01 multicodec prefix, and return the remaining 32 raw bytes.

Usage

atx_decode_did_key(did)

Arguments

did	A did:key:z... string.

Value

A raw vector of length 32 (the Ed25519 public key).

Examples

did <- "did:key:z6Mko5TBPGKHkCxSgmf3aC6p6SGj2auwCfRmBydXJFEwL4ev"
length(atx_decode_did_key(did)) # 32

---

Return the multibase fragment portion of a did:key

Description

The verification method is <did>#<multibase> where <multibase> is the z... portion of the did:key. This returns that fragment with a leading #.

Usage

atx_did_key_fragment(did)

Arguments

did	A did:key:z... string.

Value

The #z... fragment.

---

Verify an Ed25519 (RFC 8032) signature

Description

Thin wrapper over sodium::sig_verify (libsodium). Returns a logical rather than signalling, so callers can fold it into a structured result.

Usage

atx_ed25519_verify(message, signature, public_key)

Arguments

message	Raw vector of the signed message bytes.
signature	Raw vector, 64 bytes.
public_key	Raw vector, 32 bytes.

Value

TRUE if the signature is valid, else FALSE.

Examples

## Not run: 
atx_ed25519_verify(msg, sig, pubkey)

## End(Not run)

---

Parse JSON into the canonicalisation value tree

Description

Convenience alias for atx_json_parse.

Usage

atx_parse_json(txt)

Arguments

txt	JSON text or raw UTF-8 bytes.

Value

The parsed value tree.

---

Encode a raw 32-byte Ed25519 public key to a did:key

Description

Inverse of atx_decode_did_key.

Usage

atx_public_key_to_did_key(pubkey)

Arguments

pubkey

A raw vector of length 32.

Value

A did:key:z... string.

---

Full verification method for a did:key (<did>#<multibase>).

Description

Full verification method for a did:key (<did>#<multibase>).

Usage

atx_verification_method(did)

Arguments

did	A did:key:z... string.

Value

The verification-method string.

---

Verify an Attestix W3C Verifiable Credential offline

Description

Mirrors attestix/services/credential_service.py::verify_credential. The signing payload is the credential with the proof and credentialStatus top-level keys removed; that payload is JCS-style canonicalized (see atx_canonicalize) and the Ed25519 signature in proof.proofValue is verified against the issuer public key.

Usage

atx_verify_credential(vc, public_key = NULL, now = Sys.time())

Arguments

vc	The credential as a JSON string, raw UTF-8 bytes, or a value tree from atx_json_parse.
public_key	The issuer Ed25519 public key. Accepts a raw 32-byte vector, a 64-char hex string, or NULL to derive it from the credential's issuer.id (or string issuer) did:key. In automatic resolution, a present verification method must refer to that issuer.
now	The reference time for the expiry check, as a POSIXct or ISO-8601 string. Defaults to Sys.time().

Details

Three independent checks are ANDed:

• signature_valid - Ed25519 verification of the canonical bytes.

• not_expired - now < expirationDate (tz-aware ISO-8601).

• not_revoked - credentialStatus$revoked is falsy.

Value

A list with logical fields signature_valid, not_expired, not_revoked, structure_valid, and the overall verify.

Examples

## Not run: 
res <- atx_verify_credential(vc_json)
isTRUE(res$verify)

## End(Not run)

---

Verify a UCAN delegation chain (Ed25519 per link + attenuation)

Description

Mirrors the recursive prf-chain verification in attestix/services/delegation_service.py. Each token in the chain is a PyJWT EdDSA JWT; the signed message is the compact header.payload form (base64url unpadded), NOT the JCS canonical form.

Usage

atx_verify_delegation_chain(
  chain,
  public_key,
  now = Sys.time(),
  revoked_jti = character(0)
)

Arguments

chain	A list describing the chain. Accepts the conformance-vector shape: parent_token, token (child), and optionally parent_att / child_att. Alternatively a list of compact JWT strings ordered root-first.
public_key	The Ed25519 server public key (raw 32 bytes or hex).
now	Reference time. Defaults to Sys.time().
revoked_jti	Optional revoked jti character vector.

Details

The chain verifies iff every token's signature is valid AND every token is unexpired and unrevoked AND each child's att is a subset of its parent's att (capability attenuation; escalation is rejected). Cycles (a repeated jti) are rejected.

Value

A list with parent_signature_valid, child_signature_valid, attenuation_is_subset, and the overall verify.

Examples

## Not run: 
atx_verify_delegation_chain(list(parent_token = pt, token = ct), pk)

## End(Not run)

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