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use crate::util::hash::hash;
use std::error::Error;
use std::result::Result;
use crate::traits::{Exception, ValidAddress};
use rust_base58::{FromBase58, ToBase58};
use secp256k1::PublicKey;
fn check_sum(arr: &[u8; 20]) -> String {
let arr_hash = hash(arr, 32);
let string = arr_hash.to_base58();
string[0..4].to_string()
}
pub type AddressResult<T> = Result<T, Box<Error>>;
pub type Address = [u8; 20];
impl ValidAddress<PublicKey, Address> for Address {
fn to_string(&self) -> String {
let base58_address = self.to_base58();
"H".to_string() + &base58_address + &check_sum(&self)
}
fn from_string(string: &String) -> AddressResult<Address> {
if string.len() < 5 {
return Err(Box::new(Exception::new("Address is too short")));
}
if !string.starts_with("H") {
return Err(Box::new(Exception::new("Address must begin with an H")));
}
let (address, checksum) = string.split_at(string.len() - 4);
let decoded_bytes;
if let Ok(b) = address[1..address.len()].from_base58() {
decoded_bytes = b;
} else {
return Err(Box::new(Exception::new("Failed to decode address string")));
}
if decoded_bytes.len() != 20 {
return Err(Box::new(Exception::new(&format!(
"{} is {} bytes long",
address,
decoded_bytes.len()
))));
}
let mut address_bytes: [u8; 20] = [0; 20];
address_bytes.copy_from_slice(&decoded_bytes[0..20]);
let checksum_bytes = check_sum(&address_bytes);
if &checksum_bytes != checksum {
return Err(Box::new(Exception::new(&format!(
"{} did not match {}",
checksum,
checksum_bytes.to_string()
))));
}
Ok(address_bytes)
}
fn from_pubkey(pubkey: PublicKey) -> Address {
let pub_key_hash = hash(&pubkey.serialize(), 32);
let mut addr = [0; 20];
for i in 12..32 {
addr[i - 12] = pub_key_hash[i];
}
addr
}
fn from_bytes(bytes: &[u8; 20]) -> Address {
let mut addr = [0; 20];
for i in 0..20 {
addr[i] = bytes[i]
}
addr
}
}
#[cfg(test)]
mod tests {
use super::*;
use secp256k1::Secp256k1;
#[test]
fn it_makes_an_address_string() {
let address: Address = [
11, 216, 55, 107, 140, 247, 121, 126, 90, 115, 233, 197, 108, 128, 64, 46, 135, 184,
87, 180,
];
let expected_address_string = "HAa7S1QqVRMw13VdUnrSkn5w6oNK891W";
assert_eq!(expected_address_string, address.to_string());
}
#[test]
fn it_makes_an_address_from_string() {
let address_string = "HAa7S1QqVRMw13VdUnrSkn5w6oNK891W".to_string();
let address: Address = Address::from_string(&address_string).unwrap();
assert_eq!(address.to_string(), address_string);
}
#[test]
fn it_makes_an_address_from_pubkey() {
let pubkey_bytes = [
2, 170, 74, 64, 253, 208, 212, 90, 203, 135, 144, 142, 65, 16, 248, 16, 212, 186, 252,
206, 57, 137, 163, 162, 40, 81, 138, 12, 183, 237, 70, 48, 136,
];
let secp = Secp256k1::without_caps();
let pubkey = PublicKey::from_slice(&secp, &pubkey_bytes).unwrap();
let address_string = "HM8NwBmP6FKyhiBaxQMWcZiAoZqQFk8a".to_string();
let address_from_string = Address::from_string(&address_string).unwrap();
let address_from_pubkey = Address::from_pubkey(pubkey);
assert_eq!(address_from_string, address_from_pubkey);
}
#[test]
fn it_checks_checksum() {
let address_string = "HAa7S1QqVRMw13VdUnrSkn5w6oNK36MM".to_string();
let address = Address::from_string(&address_string);
match address {
Ok(_addr) => panic!("{} is not a valid address string!", address_string),
Err(_) => {}
}
}
#[test]
fn it_checks_equality() {
let address_string = "HAa7S1QqVRMw13VdUnrSkn5w6oNK891W".to_string();
let address: Address = Address::from_string(&address_string).unwrap();
let other_address: [u8; 20] = [
11, 216, 55, 107, 140, 247, 121, 126, 90, 115, 233, 197, 108, 128, 64, 46, 135, 184,
87, 180,
];
assert_eq!(address, other_address);
}
#[test]
fn it_fails_on_malformed_addresses() {
let empty_string = "".to_string();
let empty_address = Address::from_string(&empty_string);
assert!(empty_address.is_err());
let h_string = "H".to_string();
let h_address = Address::from_string(&h_string);
assert!(h_address.is_err());
let h_plus_checksum = "H1234".to_string();
let h_plus_checksum_address = Address::from_string(&h_plus_checksum);
assert!(h_plus_checksum_address.is_err());
let short_address = "H1223425fjsf".to_string();
let short_address_address = Address::from_string(&short_address);
assert!(short_address_address.is_err());
let address_string = "Not a valid address string".to_string();
let address = Address::from_string(&address_string);
assert!(address.is_err());
}
}