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discv5::EnrParser

Parses and validates Ethereum Node Records (EIP-778). More...

#include <discv5_enr.hpp>

Public Functions

Name
Result< EnrRecord > parse(const std::string & enr_uri)
Parse and validate an ENR URI of the form "enr:".
Result< std::vector< uint8_t > > decode_uri(const std::string & enr_uri)
Decode the base64url body of an ENR URI into raw bytes.
Result< std::vector< uint8_t > > base64url_decode(const std::string & body)
Base64url-decode a raw body string (without the "enr:" prefix).
Result< EnrRecord > decode_rlp(const std::vector< uint8_t > & raw)
RLP-decode raw bytes into an EnrRecord (no signature verification).
VoidResult verify_signature(EnrRecord & record)
Verify the secp256k1-v4 signature embedded in record.
Result< ValidatedPeer > to_validated_peer(const EnrRecord & record)
Convert a fully-parsed EnrRecord into a ValidatedPeer.

Detailed Description

class discv5::EnrParser;

Parses and validates Ethereum Node Records (EIP-778).

Responsibilities:

  • Decode the base64url body of an "enr:…" URI.
  • RLP-decode the record into signature + key–value content.
  • Verify the secp256k1-v4 ECDSA signature.
  • Extract all standard fields into an EnrRecord.
  • Reject incomplete records that cannot yield a dialable ValidatedPeer.

The class is stateless and all public methods are const/noexcept-safe.

Public Functions Documentation

function parse

static Result< EnrRecord > parse(
    const std::string & enr_uri
)

Parse and validate an ENR URI of the form "enr:".

Parameters:

  • enr_uri Null-terminated ENR URI string.

Return: Populated EnrRecord on success, discv5Error on failure.

On success returns a fully populated EnrRecord whose node_id and at least one dialable endpoint (ip/udp_port or ip6/udp6_port) are set.

function decode_uri

static Result< std::vector< uint8_t > > decode_uri(
    const std::string & enr_uri
)

Decode the base64url body of an ENR URI into raw bytes.

Parameters:

  • enr_uri Full URI string including the "enr:" prefix.

Return: Raw RLP bytes on success, error on failure.

Strips the leading "enr:" prefix (case-sensitive) and decodes the remainder as unpadded RFC-4648 §5 base64url.

function base64url_decode

static Result< std::vector< uint8_t > > base64url_decode(
    const std::string & body
)

Base64url-decode a raw body string (without the "enr:" prefix).

Parameters:

  • body Base64url-encoded string.

Return: Decoded bytes on success, error on failure.

Accepts both padded and unpadded base64url input.

function decode_rlp

static Result< EnrRecord > decode_rlp(
    const std::vector< uint8_t > & raw
)

RLP-decode raw bytes into an EnrRecord (no signature verification).

Parameters:

  • raw Raw RLP bytes of the full ENR record.

Return: Partially-populated EnrRecord, or error on decode failure.

Populates all key–value fields but leaves node_id and the signature validity flag untouched — the caller should call verify_signature separately.

function verify_signature

static VoidResult verify_signature(
    EnrRecord & record
)

Verify the secp256k1-v4 signature embedded in record.

Parameters:

  • record EnrRecord whose raw_rlp and compressed_pubkey are already populated (as returned by decode_rlp).

Return: outcome::success() on valid signature, error otherwise.

Uses the compressed public key from the "secp256k1" field to verify the signature over keccak256(RLP([seq, k1, v1, …])). On success sets record.node_id to the recovered 64-byte uncompressed key.

function to_validated_peer

static Result< ValidatedPeer > to_validated_peer(
    const EnrRecord & record
)

Convert a fully-parsed EnrRecord into a ValidatedPeer.

Parameters:

  • record Populated EnrRecord (signature already verified).

Return: ValidatedPeer on success, kEnrMissingAddress on failure.

Fails if neither an IPv4 nor an IPv6 dialable endpoint is present.

Updated on 2026-04-13 at 23:22:46 -0700