On Wed, May 06, 2020 at 08:44:57PM +0200, Andreas Tengicki wrote: > SSL_CTX_load_verify_locations(srvCtx->ctx,NULL,"../certs"); //???? Have you run "c_rehash" on "../certs" (not keen on relative file names here myself). > Client Side > ========= > > SSL_CTX_set_ecdh_auto(ctx, 1); > SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER, NULL); > SSL_CTX_use_certificate_chain_file(ctx, "../certs/client/ca.crt"); > SSL_CTX_use_certificate_file(ctx, "../certs/client/client.crt", SSL_FILETYPE_PEM); > SSL_CTX_use_PrivateKey_file(ctx, "../certs/client/client.key", SSL_FILETYPE_PEM); What is the client doing for "verify_locations"? -- Viktor.