/* server-tls-cryptocb.c
 *
 * Copyright (C) 2006-2020 wolfSSL Inc.
 *
 * This file is part of wolfSSL. (formerly known as CyaSSL)
 *
 * wolfSSL is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * wolfSSL is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
 */

/* the usual suspects */
#include <stdlib.h>
#include <stdio.h>
#include <string.h>

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

/* wolfSSL */
#ifndef WOLFSSL_USER_SETTINGS
    #include <wolfssl/options.h>
#endif
#include <wolfssl/ssl.h>
#include <wolfssl/wolfcrypt/sha256.h>
#include <wolfssl/wolfcrypt/cryptocb.h>
#include <wolfssl/wolfcrypt/error-crypt.h>

#include "cryptocb-common.h"

#define DEFAULT_PORT 11111

/* Uncomment to force TLS v1.3
#define USE_ECDHE_ECDSA
#define USE_TLSV13
*/

#ifdef USE_ECDHE_ECDSA
#define CERT_FILE   "../certs/server-ecc.pem"
#define KEY_FILE    "../certs/ecc-key.pem"
#define CA_FILE     "../certs/client-ecc-cert.pem"
#else
#define CERT_FILE   "../certs/server-cert.pem"
#define KEY_FILE    "../certs/server-key.pem"
#define CA_FILE     "../certs/client-cert.pem"
#endif


int main(int argc, char** argv)
{
    int                ret = 0;
#ifdef WOLF_CRYPTO_CB
    int                sockfd = SOCKET_INVALID;
    int                connd = SOCKET_INVALID;
    struct sockaddr_in servAddr;
    struct sockaddr_in clientAddr;
    socklen_t          size = sizeof(clientAddr);
    char               buff[256];
    size_t             len;
    int                shutdown = 0;
    const char*        reply = "I hear ya fa shizzle!\n";
    int                on;

    /* declare wolfSSL objects */
    WOLFSSL_CTX* ctx = NULL;
    WOLFSSL*     ssl = NULL;
    WOLFSSL_CIPHER* cipher;

    int devId = 1; /* anything besides -2 (INVALID_DEVID) */
    myCryptoCbCtx myCtx;

#if 0
    wolfSSL_Debugging_ON();
#endif

    /* Initialize wolfSSL */
    wolfSSL_Init();

    /* example data for callback */
    memset(&myCtx, 0, sizeof(myCtx));
    myCtx.exampleVar = 1;

    /* register a devID for crypto callbacks */
    ret = wc_CryptoCb_RegisterDevice(devId, myCryptoCb, &myCtx);
    if (ret != 0) {
        fprintf(stderr, "ERROR: wc_CryptoCb_RegisterDevice failed %d\n", ret);
        goto exit;
    }

    /* Create and initialize WOLFSSL_CTX */
#ifdef USE_TLSV13
    ctx = wolfSSL_CTX_new(wolfTLSv1_3_server_method());
#else
    ctx = wolfSSL_CTX_new(wolfTLSv1_2_server_method());
#endif
    if (ctx == NULL) {
        fprintf(stderr, "ERROR: failed to create WOLFSSL_CTX\n");
        ret = -1;
        goto exit;
    }

    /* register a devID for crypto callbacks */
    wolfSSL_CTX_SetDevId(ctx, devId);

    /* Load server certificates into WOLFSSL_CTX */
    if ((ret = wolfSSL_CTX_use_certificate_file(ctx, CERT_FILE, WOLFSSL_FILETYPE_PEM))
        != WOLFSSL_SUCCESS) {
        fprintf(stderr, "ERROR: failed to load %s, please check the file.\n",
                CERT_FILE);
        goto exit;
    }

    /* Load server key into WOLFSSL_CTX */
    if ((ret = wolfSSL_CTX_use_PrivateKey_file(ctx, KEY_FILE, WOLFSSL_FILETYPE_PEM))
        != WOLFSSL_SUCCESS) {
        fprintf(stderr, "ERROR: failed to load %s, please check the file.\n",
                KEY_FILE);
        goto exit;
    }

    /* Load CA certificate into WOLFSSL_CTX for validating peer */
    if ((ret = wolfSSL_CTX_load_verify_locations(ctx, CA_FILE, NULL))
         != WOLFSSL_SUCCESS) {
        fprintf(stderr, "ERROR: failed to load %s, please check the file.\n",
                CA_FILE);
        goto exit;
    }

    /* enable mutual authentication */
    wolfSSL_CTX_set_verify(ctx,
        WOLFSSL_VERIFY_PEER | WOLFSSL_VERIFY_FAIL_IF_NO_PEER_CERT, NULL);

#if 0
    /* Examples: "TLS13-AES256-GCM-SHA384",
     *           "TLS13-AES128-GCM-SHA256" or
     *           "TLS13-CHACHA20-POLY1305-SHA256" */
    wolfSSL_CTX_set_cipher_list(ctx, "TLS13-AES256-GCM-SHA384");
#endif

    /* Create a socket that uses an internet IPv4 address,
     * Sets the socket to be stream based (TCP),
     * 0 means choose the default protocol. */
    if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
        fprintf(stderr, "ERROR: failed to create the socket\n");
        ret = -1;
        goto exit;
    }

    on = 1;
    setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR,
        (char*)&on, (socklen_t)sizeof(on));


    /* Initialize the server address struct with zeros */
    memset(&servAddr, 0, sizeof(servAddr));

    /* Fill in the server address */
    servAddr.sin_family      = AF_INET;             /* using IPv4      */
    servAddr.sin_port        = htons(DEFAULT_PORT); /* on DEFAULT_PORT */
    servAddr.sin_addr.s_addr = INADDR_ANY;          /* from anywhere   */


    /* Bind the server socket to our port */
    if (bind(sockfd, (struct sockaddr*)&servAddr, sizeof(servAddr)) == -1) {
        fprintf(stderr, "ERROR: failed to bind\n");
        ret = -1;
        goto exit;
    }

    /* Listen for a new connection, allow 5 pending connections */
    if (listen(sockfd, 5) == -1) {
        fprintf(stderr, "ERROR: failed to listen\n");
        ret = -1;
        goto exit;
    }


    /* Continue to accept clients until shutdown is issued */
    while (!shutdown) {
        printf("Waiting for a connection...\n");

        /* Accept client connections */
        if ((connd = accept(sockfd, (struct sockaddr*)&clientAddr, &size))
            == -1) {
            fprintf(stderr, "ERROR: failed to accept the connection\n\n");
            ret = -1;
            goto exit;
        }

        /* Create a WOLFSSL object */
        if ((ssl = wolfSSL_new(ctx)) == NULL) {
            fprintf(stderr, "ERROR: failed to create WOLFSSL object\n");
            ret = -1;
            goto exit;
        }

        /* Attach wolfSSL to the socket */
        wolfSSL_set_fd(ssl, connd);

        /* Establish TLS connection */
        ret = wolfSSL_accept(ssl);
        if (ret != WOLFSSL_SUCCESS) {
            fprintf(stderr, "wolfSSL_accept error = %d\n",
                wolfSSL_get_error(ssl, ret));
            goto exit;
        }


        printf("Client connected successfully\n");

        cipher = wolfSSL_get_current_cipher(ssl);
        printf("SSL cipher suite is %s\n", wolfSSL_CIPHER_get_name(cipher));


        /* Read the client data into our buff array */
        memset(buff, 0, sizeof(buff));
        if ((ret = wolfSSL_read(ssl, buff, sizeof(buff)-1)) == -1) {
            fprintf(stderr, "ERROR: failed to read\n");
            goto exit;
        }

        /* Print to stdout any data the client sends */
        printf("Client: %s\n", buff);

        /* Check for server shutdown command */
        if (strncmp(buff, "shutdown", 8) == 0) {
            printf("Shutdown command issued!\n");
            shutdown = 1;
        }


        /* Write our reply into buff */
        memset(buff, 0, sizeof(buff));
        memcpy(buff, reply, strlen(reply));
        len = strnlen(buff, sizeof(buff));

        /* Reply back to the client */
        if ((ret = wolfSSL_write(ssl, buff, len)) != len) {
            fprintf(stderr, "ERROR: failed to write\n");
            goto exit;
        }

        /* Notify the client that the connection is ending */
        wolfSSL_shutdown(ssl);
        printf("Shutdown complete\n");

        /* Cleanup after this connection */
        wolfSSL_free(ssl);      /* Free the wolfSSL object              */
        ssl = NULL;
        close(connd);           /* Close the connection to the client   */
    }

    ret = 0;

exit:
    /* Cleanup and return */
    wolfSSL_free(ssl);          /* Free the wolfSSL object                  */
    if (connd != SOCKET_INVALID)
        close(connd);           /* Close the connection to the client       */
    if (sockfd != SOCKET_INVALID)
        close(sockfd);          /* Close the socket listening for clients   */
    wolfSSL_CTX_free(ctx);      /* Free the wolfSSL context object          */
    wolfSSL_Cleanup();          /* Cleanup the wolfSSL environment          */
#else
    printf("Please configure wolfSSL with --enable-cryptocb and try again\n");
#endif /* WOLF_CRYPTO_CB */

    (void)argc;
    (void)argv;

    return ret;               /* Return reporting a success               */
}
