Repeated sha256 on brain wallet

The writer of this article https://pastebin.com/raw/jCDFcESz explains that

Sha256('sender') x 2 yields the address 18aMGf2AxQ3YXyNv9sKxiHYCXcBJeJv9d1

I am however getting the address 1DcTtaa37w971TmoafPpE9Pk16xc42YA87

What am I doing wrong?

artfullyContrived

Posted 2019-03-06T09:51:39.567

Reputation: 103

1Please post your code; it's hard to guess what the problem might be just by looking at the output. – Nate Eldredge – 2019-03-06T14:43:15.963

Answers

A few things to check:

Make sure you are computing the HASH256 on the decoded byte values of the string. In other words, HASH256(0x73656e646572)
Make sure you are doing 2 rounds of SHA256
Using secp256k1 to generate a compressed public key
This is a P2PKH address (prefix is 1) so the steps to generate the address from the public key are:
1. pubkeyhash = HASH160(compressed pubkey) i.e.RIPEMD160(SHA256(compressed pubkey)
2. prepend 00 byte prefix for P2PKH
3. BASE58CHECK(pubkeyhash)

$ echo -n sender | openssl sha256
(stdin)= 0a367b92cf0b037dfd89960ee832d56f7fc151681bb41e53690e776f5786998a

$ echo 0a367b92cf0b037dfd89960ee832d56f7fc151681bb41e53690e776f5786998a | xxd -r -p | openssl sha256
(stdin)= 098f6d68ce86adb2d8ba672a06227f7d177baca3568092e4cda159acca5eb0c7

$ openssl ec -inform DER -text -noout -in <(cat <(echo -n "302e0201010420") <(echo -n "098f6d68ce86adb2d8ba672a06227f7d177baca3568092e4cda159acca5eb0c7") <(echo -n "a00706052b8104000a") | xxd -r -p) 2>/dev/null | tail -6 | head -5 | sed 's/[ :]//g' | tr -d '\n' && echo
04f4e5977bcb050452289ebc750b56be65086bfdf3411bb9c346430716545d66b8dede7516256f34fa362b10b3ec85ccdf58c25733e00e5d33120fb66a79e596f6

# result is even (ends in 0xf6) so prefix first 32 bytes with 02 (for odd use 03)
$ echo 02f4e5977bcb050452289ebc750b56be65086bfdf3411bb9c346430716545d66b8 | xxd -r -p | openssl sha256
(stdin)= cb59a26ae2e385719a66f568476bace40a8789c5fe91d74be6381e29feb20ecb

$ echo cb59a26ae2e385719a66f568476bace40a8789c5fe91d74be6381e29feb20ecb | xxd -r -p | openssl ripemd160
(stdin)= 53178717ab3d70c50fe8ec8598a9c2a8a703abc5

$ echo 0053178717ab3d70c50fe8ec8598a9c2a8a703abc5 | xxd -r -p | base58 -c && echo
18aMGf2AxQ3YXyNv9sKxiHYCXcBJeJv9d1

using base58

JBaczuk

Posted 2019-03-06T09:51:39.567

Reputation: 6 172

Your second command is missing | openssl sha256 and output; you can combine the first two and save xxd with echo -n sender | openssl sha256 -binary | openssl sha256 and similarly for the two from pubkey to address. Instead of cat with three <(echo) you can do one echo -- or one herestring: -in <(xxd -r -p <<<"hexprefix""hexprivkey""hexsuffix") – dave_thompson_085 – 2019-03-08T22:34:46.577

@dave_thompson_085 thanks, edited – JBaczuk – 2019-03-08T23:04:33.943

static void test ( )
{
  const MyByteArray x ( QByteArray ( "sender" ) );
  _trace ( x.sha256  ( ).getAddressHashCompressed ( ).toString ( ) );
  _trace ( x.sha256d ( ).getAddressHashCompressed ( ).toString ( ) );
}

the output is:

1DcTtaa37w971TmoafPpE9Pk16xc42YA87
18aMGf2AxQ3YXyNv9sKxiHYCXcBJeJv9d1

So, your code runs sha256 only once, but not twice

amaclin

Posted 2019-03-06T09:51:39.567

Reputation: 5 763

18aMGf2AxQ3YXyNv9sKxiHYCXcBJeJv9d1

% echo -n "sender" | bx base16-encode | bx sha256 | bx ec-to-public | bx ec-to-address -v 0

1DcTtaa37w971TmoafPpE9Pk16xc42YA87

skaht

Posted 2019-03-06T09:51:39.567

Reputation: 2 588