#include <netdb.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <sys/socket.h>

#include <openssl/crypto.h>
#include <openssl/x509.h>
#include <openssl/pem.h>
#include <openssl/ssl.h>

#include "common.h"


int main(void)
{
    const SSL_METHOD *meth;
    SSL_CTX *ctx;
    int ret;
    int sd;
    struct sockaddr_in sa;
    SSL *ssl;
    X509 *server_cert;
    char *str;
    char buf[64];

    /* Crypto */

    SSL_load_error_strings();
    OpenSSL_add_ssl_algorithms();

    meth = TLSv1_2_client_method();
    ctx = SSL_CTX_new(meth);
    CHK_NULL(ctx);

    ret = SSL_CTX_use_certificate_chain_file(ctx, "clientcert.pem");
    CHK_SSL(ret);

    ret = SSL_CTX_use_PrivateKey_file(ctx, "clientkey.pem", SSL_FILETYPE_PEM);
    CHK_SSL(ret);

    ret = SSL_CTX_check_private_key(ctx);
    CHK_SSL(ret);

    /* Networking */

    sd = socket(AF_INET, SOCK_STREAM, 0);
    CHK_ERR(sd, "socket");

    memset(&sa, 0, sizeof(sa));

    sa.sin_family      = AF_INET;
    sa.sin_addr.s_addr = inet_addr("127.0.0.1");
    sa.sin_port        = htons(1111);

    ret = connect(sd, (struct sockaddr *)&sa, sizeof(sa));
    CHK_ERR(ret, "connect");

    /* SSL negotiation. */

    ssl = SSL_new(ctx);
    CHK_NULL(ssl);    

    SSL_set_fd(ssl, sd);

    ret = SSL_connect(ssl);
    CHK_SSL_WRAPPER(ret);

    /* Info */

    printf("SSL connection using %s\n", SSL_get_cipher(ssl));

    server_cert = SSL_get_peer_certificate(ssl);
    CHK_NULL(server_cert);

    printf("Server certificate:\n");
  
    str = X509_NAME_oneline(X509_get_subject_name(server_cert), 0, 0);
    CHK_NULL(str);
    printf("\tsubject: %s\n", str);
    OPENSSL_free(str);

    str = X509_NAME_oneline(X509_get_issuer_name(server_cert), 0, 0);
    CHK_NULL(str);
    printf("\tissuer: %s\n", str);
    OPENSSL_free(str);

    X509_free(server_cert);

    /* Exchange */

    ret = SSL_write(ssl, "Hello Server!", strlen("Hello Server!"));
    CHK_SSL_WRAPPER(ret);

    ret = SSL_read(ssl, buf, sizeof(buf) - 1);
    CHK_SSL_WRAPPER(ret);

    buf[ret] = '\0';

    printf("Got %d chars: '%s'\n", ret, buf);

    /* End */

    SSL_shutdown(ssl);
    close(sd);
    SSL_free(ssl);
    SSL_CTX_free(ctx);

    return EXIT_SUCCESS;

}