ASN.1 schema and validation

Author: davxy

codec/data/block.json

@@ -155,7 +155,7 @@
         "guarantees": [
             {
                 "report": {
-                    "packge_spec": {
+                    "package_spec": {
                         "hash": "0x30466e0ae1b05dde5249872475f6beeac368fd014b5a3413ceb32d3872143284",
                         "len": 42,
                         "root": "0x7af11fdaa717c398e223211842b41392f18df4bbc4ea0f4cfb972f19c7a64949",

codec/data/extrinsic.json

@@ -130,7 +130,7 @@
     "guarantees": [
         {
             "report": {
-                "packge_spec": {
+                "package_spec": {
                     "hash": "0x30466e0ae1b05dde5249872475f6beeac368fd014b5a3413ceb32d3872143284",
                     "len": 42,
                     "root": "0x7af11fdaa717c398e223211842b41392f18df4bbc4ea0f4cfb972f19c7a64949",

codec/data/guarantees_extrinsic.json

@@ -1,7 +1,7 @@
 [
     {
         "report": {
-            "packge_spec": {
+            "package_spec": {
                 "hash": "0x30466e0ae1b05dde5249872475f6beeac368fd014b5a3413ceb32d3872143284",
                 "len": 42,
                 "root": "0x7af11fdaa717c398e223211842b41392f18df4bbc4ea0f4cfb972f19c7a64949",

codec/data/work_report.json

@@ -1,5 +1,5 @@
 {
-    "packge_spec": {
+    "package_spec": {
         "hash": "0x30466e0ae1b05dde5249872475f6beeac368fd014b5a3413ceb32d3872143284",
         "len": 42,
         "root": "0x7af11fdaa717c398e223211842b41392f18df4bbc4ea0f4cfb972f19c7a64949",

codec/schema.asn

@@ -0,0 +1,240 @@
+TypesModule DEFINITIONS ::= BEGIN
+
+-- Tiny Constants
+
+validators-count INTEGER ::= 6
+epoch-length INTEGER ::= 12
+core-count INTEGER ::= 2
+
+-- (validators-count * 2/3 + 1)
+validators-super-majority INTEGER ::= 5
+-- (core-count + 1) / 8
+avail-bitfield-bytes INTEGER ::= 1
+
+-- Generic Primitive Types
+
+U8 ::= INTEGER (0..255)
+U16 ::= INTEGER(0..65535)
+U32 ::= INTEGER (0..4294967295)
+I64 ::= INTEGER(-9223372036854775808..9223372036854775807)
+
+ByteSequence ::= OCTET STRING
+ByteArray32 ::= OCTET STRING (SIZE(32))
+
+-- Application Specific Primitive Types
+
+OpaqueHash ::= ByteArray32
+
+TimeSlot ::= U32
+ServiceId ::= U32
+Gas ::= I64
+ValidatorIndex ::= U16
+CoreIndex ::= U16
+
+BandersnatchKey ::= ByteArray32
+Ed25519Key ::= ByteArray32
+
+BandersnatchVrfSignature ::= OCTET STRING (SIZE(96))
+BandersnatchRingSignature ::= OCTET STRING (SIZE(784))
+Ed25519Signature ::= OCTET STRING (SIZE(64))
+
+-- Refine Context
+
+RefineContext ::= SEQUENCE {
+	anchor OpaqueHash,
+	state-root OpaqueHash,
+	beefy-root OpaqueHash,
+	lookup-anchor OpaqueHash,
+	lookup-anchor-slot TimeSlot,
+	prerequisite OpaqueHash OPTIONAL
+}
+
+-- Work Package
+
+ImportSpec ::= SEQUENCE {
+    tree-root OpaqueHash,
+    index U32
+}
+
+ExtrinsicSpec ::= SEQUENCE {
+    hash OpaqueHash,
+    len U32
+}
+
+Authorizer ::= SEQUENCE {
+    code-hash OpaqueHash,
+    params ByteSequence
+}
+
+WorkItem ::= SEQUENCE {
+    service ServiceId,
+    code-hash OpaqueHash,
+    payload ByteSequence,
+    gas-limit Gas,
+    import-segments SEQUENCE OF ImportSpec,
+    extrinsic SEQUENCE OF ExtrinsicSpec,
+    export-count U16
+}
+
+WorkPackage ::= SEQUENCE {
+    authorization ByteSequence,
+    auth-code-host ServiceId,
+    authorizer Authorizer,
+    context RefineContext,
+    items SEQUENCE OF WorkItem
+}
+
+-- Work Report
+
+WorkExecResult ::= CHOICE {
+    ok [0] ByteSequence,
+    out-of-gas [1] NULL,
+    panic [2] NULL,
+    bad-code [3] NULL,
+    code-oversize [4] NULL
+}
+
+WorkResult ::= SEQUENCE {
+    service ServiceId,
+    code-hash OpaqueHash,
+    payload-hash OpaqueHash,
+    gas-ratio Gas,
+    result WorkExecResult
+}
+
+WorkPackageSpec ::= SEQUENCE {
+    hash OpaqueHash,
+    len U32,
+    root OpaqueHash,
+    segments OpaqueHash
+}
+
+WorkReport ::= SEQUENCE {
+    package-spec WorkPackageSpec,
+    context RefineContext,
+    core-index CoreIndex,
+    authorizer-hash OpaqueHash,
+    auth-output ByteSequence,
+    results SEQUENCE OF WorkResult
+}
+
+-- Header
+
+EpochMark ::= SEQUENCE {
+    entropy OpaqueHash,
+    validators SEQUENCE SIZE(validators-count) OF BandersnatchKey
+}
+
+TicketBody ::= SEQUENCE {
+    id OpaqueHash,
+    attempt U8
+}
+
+TicketsMark ::= SEQUENCE SIZE(epoch-length) OF TicketBody
+
+Header ::= SEQUENCE {
+    parent OpaqueHash,
+    parent-state-root OpaqueHash,
+    extrinsic-hash OpaqueHash,
+    slot TimeSlot,
+    epoch-mark EpochMark OPTIONAL,
+    tickets-mark TicketsMark OPTIONAL,
+    offenders-mark SEQUENCE OF Ed25519Key,
+    author-index ValidatorIndex,
+    entropy-source BandersnatchVrfSignature,
+    seal BandersnatchVrfSignature
+}
+
+-- Tickets
+
+TicketEnvelope ::= SEQUENCE {
+    attempt U8,
+    signature BandersnatchRingSignature
+}
+
+TicketsExtrinsic ::= SEQUENCE OF TicketEnvelope
+
+-- Disputes
+
+Judgement ::= SEQUENCE {
+    vote BOOLEAN,
+    index ValidatorIndex,
+    signature Ed25519Signature
+}
+
+Verdict ::= SEQUENCE {
+    target OpaqueHash,
+    age U32,
+    votes SEQUENCE SIZE(validators-super-majority) OF Judgement
+}
+
+Culprit ::= SEQUENCE {
+    target OpaqueHash,
+    key Ed25519Key,
+    signature Ed25519Signature
+}
+
+Fault ::= SEQUENCE {
+    target OpaqueHash,
+    vote BOOLEAN,
+    key Ed25519Key,
+    signature Ed25519Signature
+}
+
+DisputesExtrinsic ::= SEQUENCE {
+    verdicts SEQUENCE OF Verdict,
+    culprits SEQUENCE OF Culprit,
+    faults SEQUENCE OF Fault
+}
+
+-- Preimages
+
+Preimage ::= SEQUENCE {
+    requester ServiceId,
+    blob ByteSequence
+}
+
+PreimagesExtrinsic ::= SEQUENCE OF Preimage
+
+-- Assurances
+
+AvailAssurance ::= SEQUENCE {
+    anchor OpaqueHash,
+    bitfield OCTET STRING (SIZE(avail-bitfield-bytes)),
+    validator-index ValidatorIndex,
+    signature Ed25519Signature
+}
+
+AssurancesExtrinsic ::= SEQUENCE OF AvailAssurance
+
+-- Guarantees
+
+ValidatorSignature ::= SEQUENCE {
+    validator-index ValidatorIndex,
+    signature Ed25519Signature
+}
+
+ReportGuarantee ::= SEQUENCE {
+    report WorkReport,
+    slot TimeSlot,
+    signatures SEQUENCE OF ValidatorSignature
+}
+
+GuaranteesExtrinsic ::= SEQUENCE OF ReportGuarantee
+
+-- Block
+
+Extrinsic ::= SEQUENCE {
+    tickets TicketsExtrinsic,
+    disputes DisputesExtrinsic,
+    preimages PreimagesExtrinsic,
+    assurances AssurancesExtrinsic,
+    guarantees GuaranteesExtrinsic
+}
+
+Block ::= SEQUENCE {
+    header Header,
+    extrinsic Extrinsic
+}
+
+END

codec/validate.py

@@ -0,0 +1,59 @@
+#!/usr/bin/env python3
+
+from pathlib import Path
+import asn1tools
+import json
+import sys
+
+import os
+import re
+
+# - JSON uses snake case, ASN.1 requires kebab case
+# - JSON prefix octet strings with '0x', ASN doesn't like it
+def make_asn1_parsable(json_str):
+    return json_str.replace('_', '-').replace('0x', '')
+
+def path_to_struct_name(path):
+    # Strip the directory path and extension
+    name = os.path.splitext(os.path.basename(path))[0]   
+    # Remove "_X" if it ends with a number
+    name = re.sub(r'_\d+$', '', name)   
+    # Convert kebab-case or snake_case to PascalCase
+    name = re.sub(r'[-_](\w)', lambda m: m.group(1).upper(), name)   
+    # Capitalize the first character
+    name = name[0].upper() + name[1:]   
+    return name    
+
+def validate_case(schema, path):
+    print("* Validating: ", path)
+
+    type_name = path_to_struct_name(path)
+
+    # Decode from json using the schema
+    json_bytes = open(path, "rb").read()
+    json_str_org = json_bytes.decode('utf-8')
+    json_str_org = make_asn1_parsable(json_str_org)
+    
+    json_bytes = json_str_org.encode('utf-8')
+    decoded = schema.decode(type_name, json_bytes, check_constraints=True)
+
+    # Encode to json using the schema
+    encoded = schema.encode(type_name, decoded, check_constraints=True)
+    # Original json uses snake case, asn1 requires kebab case
+    json_str = encoded.decode('utf-8')
+    json_obj = json.loads(json_str)
+    # Strings are converted to arrays of characters,
+    # map back to single string.
+    json_str = json.dumps(json_obj, indent = 4)
+
+    assert (json_str.rstrip().lower() == json_str_org.rstrip().lower())
+
+
+def main():
+    # Validate tiny
+    schema = asn1tools.compile_files(["schema.asn"], codec="jer")
+    for path in Path("data").iterdir():
+        if path.is_file() and path.suffix == ".json":
+            validate_case(schema, path)
+
+main()