Implementation of the hex Ethereum-address parser, with EIP-55 checksum verification (HARDENING.md §7.1). More...

#include "eth_addr.h"
#include <string.h>
#include <stdbool.h>
#include "keccak256.h"
#include "CW_Utils.h"

Include dependency graph for eth_addr.cpp:

Functions
static int	hex_nibble_val (char c)
	Decode a single ASCII hex digit.
bool	eth_addr_parse (const char *hex, uint8_t out[ETH_ADDR_LEN])
	Parse a 20-byte Ethereum address from a hex string.
bool	eth_addr_format (const uint8_t addr[ETH_ADDR_LEN], char *out, size_t n)
	Render a 20-byte address as an EIP-55 mixed-case "0x..." string.

Detailed Description

Implementation of the hex Ethereum-address parser, with EIP-55 checksum verification (HARDENING.md §7.1).

Definition in file eth_addr.cpp.

Function Documentation

◆ eth_addr_format()

bool eth_addr_format	(	const uint8_t	addr[ETH_ADDR_LEN],
		char *	out,
		size_t	n )

Render a 20-byte address as an EIP-55 mixed-case "0x..." string.

The inverse of eth_addr_parse, and it produces the checksummed form on purpose: an address derived on the device (from a card's public key, say) is then displayed exactly as the operator's own wallet displays it, which is the whole point of showing it to them. It also means the value that goes into storage carries a checksum, so the boot-time parse is a real check on it rather than the no-op it is for an all-lowercase string.

Parameters

[in]	addr	20-byte address.
[out]	out	Buffer for "0x" + 40 hex + NUL.
[in]	n	Capacity of `out`; needs at least 43 bytes.

Returns: true on success, false if out is too small (and then left empty).

Definition at line 109 of file eth_addr.cpp.

References ETH_ADDR_HEX_LEN, ETH_ADDR_LEN, and keccak256().

Referenced by card_read_payouts(), and sign_and_broadcast().

◆ eth_addr_parse()

bool eth_addr_parse	(	const char *	hex,
		uint8_t	out[ETH_ADDR_LEN] )

Parse a 20-byte Ethereum address from a hex string.

Accepts an optional 0x / 0X prefix, then requires exactly 40 hex characters and rejects any non-hex input instead of silently decoding garbage. A mixed-case input is treated as EIP-55 checksummed and its checksum is verified (keccak256 recomputed, rejected on case mismatch); an all-lower/all-upper input is accepted as un-checksummed.

Parameters

[in]	hex	Address string (with or without `0x` prefix).
[out]	out	20-byte decoded address; zeroed then left partially written on failure — must not be used unless true is returned.