On Wed, Sep 15, 2021 at 12:01 PM Jeffrey Walton <noloa...@gmail.com> wrote: > > > But my problem afterward (which I didn't mention to this point, because I > > thought it will solve itself when I have a correct y-coordinate) is, that > > if I try to save this public key as PEM, I only get > > > > -----BEGIN PUBLIC KEY----- > > MFowMFow-----END PUBLIC KEY----- > > > > as result. This was also my result with wrong y and failed validation.
Here's what I am seeing with your data. It looks OK to me. I think we need to see your program to determine what is going sideways. $ cat test.cxx #include <iostream> #include <string> #include "cryptlib.h" #include "filters.h" #include "eccrypto.h" #include "osrng.h" #include "files.h" #include "sha.h" #include "hex.h" #include "pem.h" int main(int argc, char* argv[]) { using namespace CryptoPP; std::string pt = "40BA49FCBA45C7EEB2261B1BE0EBC7C14D6484B9EF8A23B060EBE67F97252BBC" "987BA49DF364A0C9926F2B6DE1BAF46068A13A2C5C9812B2F3451F48B75719EE"; HexDecoder decoder; decoder.Put((byte*)&pt[0], pt.size()); decoder.MessageEnd(); ECP::Point q; size_t len = decoder.MaxRetrievable(); q.identity = false; q.x.Decode(decoder, len/2); q.y.Decode(decoder, len/2); ECDSA<ECP, SHA256>::PublicKey pkey; pkey.Initialize(ASN1::brainpoolP256r1(), q); FileSink fs("pubkey.pem"); PEM_Save(fs, pkey); return 0; } And: $ ./test.exe $ cat pubkey.pem -----BEGIN PUBLIC KEY----- MFowFAYHKoZIzj0CAQYJKyQDAwIIAQEHA0IABEC6Sfy6RcfusiYbG+Drx8FNZIS5 74ojsGDr5n+XJSu8mHuknfNkoMmSbytt4br0YGihOixcmBKy80UfSLdXGe4= -----END PUBLIC KEY----- And: $ openssl ec -in pubkey.pem -inform PEM -pubin -text Public-Key: (256 bit) pub: 04:40:ba:49:fc:ba:45:c7:ee:b2:26:1b:1b:e0:eb: c7:c1:4d:64:84:b9:ef:8a:23:b0:60:eb:e6:7f:97: 25:2b:bc:98:7b:a4:9d:f3:64:a0:c9:92:6f:2b:6d: e1:ba:f4:60:68:a1:3a:2c:5c:98:12:b2:f3:45:1f: 48:b7:57:19:ee ASN1 OID: brainpoolP256r1 Jeff -- You received this message because you are subscribed to the Google Groups "Crypto++ Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to cryptopp-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/cryptopp-users/CAH8yC8kX0OOrO2KwNGfehzjfY%2BR3tTJ0pAWH58QvFQqpg9TUhQ%40mail.gmail.com.