Get adress from WIF private Key

[Sanka555]

Java. bitcoinj

i have private key

String str="5HpHagT65TZzG1PH3CSu63k8DbpvD8s5ip4nEB3kEsreAnchuDf";

i try get compress and decompress. 2 adress. in this format :
1EHNa6Q4Jz2uvNExL497mE43ikXhwF6kZm  1BgGZ9tcN4rm9KBzDn7KprQz87SZ26SAMH

i do

NetworkParameters params = MainNetParams.get();
      ECKey key;

      if (str.length() == 51 || str.length() == 52) {
          DumpedPrivateKey dumpedPrivateKey = DumpedPrivateKey.fromBase58(params, str);
          key = dumpedPrivateKey.getKey();            //ERROR
      } else {
          BigInteger privKey = Base58.decodeToBigInteger(str);
          key = ECKey.fromPrivate(privKey);
      }
.
.
.

and

Exception in thread "main" java.lang.IllegalArgumentException
   at com.google.common.base.Preconditions.checkArgument(Preconditions.java:128)
   at org.bitcoinj.core.ECKey.<init>(ECKey.java:195)
   at org.bitcoinj.core.ECKey.fromPrivate(ECKey.java:243)
   at org.bitcoinj.core.ECKey.fromPrivate(ECKey.java:259)
   at org.bitcoinj.core.DumpedPrivateKey.getKey(DumpedPrivateKey.java:101)
   at com.example.demo2.controllers.AdressFromKey.main(AdressFromKey.java:35)

what am i doing wrong?

[larry_vw_1955]

Java. bitcoinj


what am i doing wrong?

no idea about that but that addresses corresponds to hex private key of 0x1. cool. don't use that address because people knows about it alot.

[n0nce]

According to the error message, I looked at the code and found this:

Code: (https://github.com/bitcoinj/bitcoinj/blob/31c7e5fbceb9884cb02d2dabc755009caa2d613e/core/src/main/java/org/bitcoinj/core/DumpedPrivateKey.java#L100)

public ECKey getKey() {
    return ECKey.fromPrivate(Arrays.copyOf(bytes, 32), isPubKeyCompressed());
}

So, you're calling getKey() just fine, but something breaks when this method calls ECKey.fromPrivate(...).
It seems to me that there's something wrong with bytes, so probably your initialization of dumpedPrivateKey is wrong. Might want to look into that a bit more.

Thanks to @larry_vw_1955, I think I got it.

that addresses corresponds to hex private key of 0x1.

We can see in the Java code that it doesn't permit private keys zero or one exactly because they're not allowed to be used:

Code: (https://github.com/bitcoinj/bitcoinj/blob/31c7e5fbceb9884cb02d2dabc755009caa2d613e/core/src/main/java/org/bitcoinj/core/ECKey.java#L193)

checkArgument(!priv.equals(BigInteger.ZERO));
checkArgument(!priv.equals(BigInteger.ONE));

[pooya87]

We can see in the Java code that it doesn't permit private keys zero or one exactly because they're not allowed to be used:

It is worth mentioning that zero is an invalid bitcoin private key because it is outside the allowed private key range ([0,N)). But one is a perfectly valid private key and it is a bug in the library to reject it as invalid with an exception.

[Sanka555]

Thanks a lot.  My task turned out to be very successful

I am trying to generate these keys
https://keys.lol/bitcoin/1

and get the corresponding addresses. They all knock out a bug.

Maybe there is some way to hardcode and get these addresses without libraries?

[n0nce]

Thanks a lot.  My task turned out to be very successful

I am trying to generate these keys
https://keys.lol/bitcoin/1

and get the corresponding addresses. They all knock out a bug.

Maybe there is some way to hardcode and get these addresses without libraries?

Either remove that assertion which doesn't allow private key 1, which as @pooya87 said, is a bug anyway, or skip private key 1 and start with key 2 simply.