Hi guys i want to write two programd to learn the details of ecdsa signature. program A read the private key from private.pem, sign a string, like "abcde1234", save the signature as sig.pem. program B read the public key from pub.pem, read the sig.pem, and verify the signature. can anybody provide me a example code? my implementation is as follow: 1, generate the ecc keys by "openssl ecparam -genkey -name secp256r1 -out private.pem" and extract the public key by "openssl ec -in private.pem -out public.pem -pubout" 2, read the private key by "PEM_read_PrivateKey()", and sign with "ECDSA_do_sign", there is no problem. program A works well. 3, the problem is how to read the public key from public.pem ? i find PEM_read_bio_PUBKEY from app/apps.c, but i can't find the source code. how can i verify the signature without knowing the private key? -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mta.openssl.org/pipermail/openssl-users/attachments/20150925/e8981f2e/attachment.html>