/*
  * TLS/SSL Protocol
  * Copyright (c) 2011 Martin Storsjo
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg 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
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 #include "avformat.h"
 #include "internal.h"
 #include "network.h"
 #include "os_support.h"
 #include "url.h"
 #include "tls.h"

 #include "libavcodec/internal.h"

 #include "libavutil/avstring.h"

 #include "libavutil/avutil.h"

 #include "libavutil/opt.h"
 #include "libavutil/parseutils.h"

 #include "libavutil/thread.h"

 
 #include <openssl/bio.h>
 #include <openssl/ssl.h>
 #include <openssl/err.h>
 

 static int openssl_init;
 

 typedef struct TLSContext {
     const AVClass *class;
     TLSShared tls_shared;
     SSL_CTX *ctx;
     SSL *ssl;
 } TLSContext;
 

 #if HAVE_THREADS
 #include <openssl/crypto.h>
 pthread_mutex_t *openssl_mutexes;
 static void openssl_lock(int mode, int type, const char *file, int line)
 {
     if (mode & CRYPTO_LOCK)
         pthread_mutex_lock(&openssl_mutexes[type]);
     else
         pthread_mutex_unlock(&openssl_mutexes[type]);
 }
 #if !defined(WIN32) && OPENSSL_VERSION_NUMBER < 0x10000000
 static unsigned long openssl_thread_id(void)
 {
     return (intptr_t) pthread_self();
 }
 #endif
 #endif
 
 int ff_openssl_init(void)
 {
     avpriv_lock_avformat();
     if (!openssl_init) {
         SSL_library_init();
         SSL_load_error_strings();
 #if HAVE_THREADS
         if (!CRYPTO_get_locking_callback()) {
             int i;
             openssl_mutexes = av_malloc_array(sizeof(pthread_mutex_t), CRYPTO_num_locks());
             if (!openssl_mutexes) {
                 avpriv_unlock_avformat();
                 return AVERROR(ENOMEM);
             }
 
             for (i = 0; i < CRYPTO_num_locks(); i++)
                 pthread_mutex_init(&openssl_mutexes[i], NULL);
             CRYPTO_set_locking_callback(openssl_lock);
 #if !defined(WIN32) && OPENSSL_VERSION_NUMBER < 0x10000000
             CRYPTO_set_id_callback(openssl_thread_id);
 #endif
         }
 #endif
     }
     openssl_init++;
     avpriv_unlock_avformat();
 
     return 0;
 }
 
 void ff_openssl_deinit(void)
 {
     avpriv_lock_avformat();
     openssl_init--;
     if (!openssl_init) {
 #if HAVE_THREADS
         if (CRYPTO_get_locking_callback() == openssl_lock) {
             int i;
             CRYPTO_set_locking_callback(NULL);
             for (i = 0; i < CRYPTO_num_locks(); i++)
                 pthread_mutex_destroy(&openssl_mutexes[i]);
             av_free(openssl_mutexes);
         }
 #endif
     }
     avpriv_unlock_avformat();
 }
 

 static int print_tls_error(URLContext *h, int ret)
 {
     av_log(h, AV_LOG_ERROR, "%s\n", ERR_error_string(ERR_get_error(), NULL));
     return AVERROR(EIO);
 }
 
 static int tls_close(URLContext *h)
 {
     TLSContext *c = h->priv_data;
     if (c->ssl) {
         SSL_shutdown(c->ssl);
         SSL_free(c->ssl);
     }
     if (c->ctx)
         SSL_CTX_free(c->ctx);
     if (c->tls_shared.tcp)
         ffurl_close(c->tls_shared.tcp);

     ff_openssl_deinit();

     return 0;
 }
 
 static int url_bio_create(BIO *b)
 {
     b->init = 1;
     b->ptr = NULL;
     b->flags = 0;
     return 1;
 }
 
 static int url_bio_destroy(BIO *b)
 {
     return 1;
 }
 
 static int url_bio_bread(BIO *b, char *buf, int len)
 {
     URLContext *h = b->ptr;
     int ret = ffurl_read(h, buf, len);
     if (ret >= 0)
         return ret;
     BIO_clear_retry_flags(b);
     if (ret == AVERROR_EXIT)
         return 0;
     return -1;
 }
 
 static int url_bio_bwrite(BIO *b, const char *buf, int len)
 {
     URLContext *h = b->ptr;
     int ret = ffurl_write(h, buf, len);
     if (ret >= 0)
         return ret;
     BIO_clear_retry_flags(b);
     if (ret == AVERROR_EXIT)
         return 0;
     return -1;
 }
 
 static long url_bio_ctrl(BIO *b, int cmd, long num, void *ptr)
 {
     if (cmd == BIO_CTRL_FLUSH) {
         BIO_clear_retry_flags(b);
         return 1;
     }
     return 0;
 }
 
 static int url_bio_bputs(BIO *b, const char *str)
 {
     return url_bio_bwrite(b, str, strlen(str));
 }
 
 static BIO_METHOD url_bio_method = {
     .type = BIO_TYPE_SOURCE_SINK,
     .name = "urlprotocol bio",
     .bwrite = url_bio_bwrite,
     .bread = url_bio_bread,
     .bputs = url_bio_bputs,
     .bgets = NULL,
     .ctrl = url_bio_ctrl,
     .create = url_bio_create,
     .destroy = url_bio_destroy,
 };
 
 static int tls_open(URLContext *h, const char *uri, int flags, AVDictionary **options)
 {
     TLSContext *p = h->priv_data;
     TLSShared *c = &p->tls_shared;
     BIO *bio;
     int ret;
 

     if ((ret = ff_openssl_init()) < 0)

         return ret;
 
     if ((ret = ff_tls_open_underlying(c, h, uri, options)) < 0)
         goto fail;
 
     p->ctx = SSL_CTX_new(c->listen ? TLSv1_server_method() : TLSv1_client_method());
     if (!p->ctx) {
         av_log(h, AV_LOG_ERROR, "%s\n", ERR_error_string(ERR_get_error(), NULL));
         ret = AVERROR(EIO);
         goto fail;
     }
     if (c->ca_file) {
         if (!SSL_CTX_load_verify_locations(p->ctx, c->ca_file, NULL))
             av_log(h, AV_LOG_ERROR, "SSL_CTX_load_verify_locations %s\n", ERR_error_string(ERR_get_error(), NULL));
     }
     if (c->cert_file && !SSL_CTX_use_certificate_chain_file(p->ctx, c->cert_file)) {
         av_log(h, AV_LOG_ERROR, "Unable to load cert file %s: %s\n",
                c->cert_file, ERR_error_string(ERR_get_error(), NULL));
         ret = AVERROR(EIO);
         goto fail;
     }
     if (c->key_file && !SSL_CTX_use_PrivateKey_file(p->ctx, c->key_file, SSL_FILETYPE_PEM)) {
         av_log(h, AV_LOG_ERROR, "Unable to load key file %s: %s\n",
                c->key_file, ERR_error_string(ERR_get_error(), NULL));
         ret = AVERROR(EIO);
         goto fail;
     }
     // Note, this doesn't check that the peer certificate actually matches
     // the requested hostname.
     if (c->verify)
         SSL_CTX_set_verify(p->ctx, SSL_VERIFY_PEER|SSL_VERIFY_FAIL_IF_NO_PEER_CERT, NULL);
     p->ssl = SSL_new(p->ctx);
     if (!p->ssl) {
         av_log(h, AV_LOG_ERROR, "%s\n", ERR_error_string(ERR_get_error(), NULL));
         ret = AVERROR(EIO);
         goto fail;
     }
     bio = BIO_new(&url_bio_method);
     bio->ptr = c->tcp;
     SSL_set_bio(p->ssl, bio, bio);
     if (!c->listen && !c->numerichost)
         SSL_set_tlsext_host_name(p->ssl, c->host);
     ret = c->listen ? SSL_accept(p->ssl) : SSL_connect(p->ssl);
     if (ret == 0) {
         av_log(h, AV_LOG_ERROR, "Unable to negotiate TLS/SSL session\n");
         ret = AVERROR(EIO);
         goto fail;
     } else if (ret < 0) {
         ret = print_tls_error(h, ret);
         goto fail;
     }
 
     return 0;
 fail:
     tls_close(h);
     return ret;
 }
 
 static int tls_read(URLContext *h, uint8_t *buf, int size)
 {
     TLSContext *c = h->priv_data;
     int ret = SSL_read(c->ssl, buf, size);
     if (ret > 0)
         return ret;
     if (ret == 0)
         return AVERROR_EOF;
     return print_tls_error(h, ret);
 }
 
 static int tls_write(URLContext *h, const uint8_t *buf, int size)
 {
     TLSContext *c = h->priv_data;
     int ret = SSL_write(c->ssl, buf, size);
     if (ret > 0)
         return ret;
     if (ret == 0)
         return AVERROR_EOF;
     return print_tls_error(h, ret);
 }
 
 static const AVOption options[] = {
     TLS_COMMON_OPTIONS(TLSContext, tls_shared),
     { NULL }
 };
 
 static const AVClass tls_class = {
     .class_name = "tls",
     .item_name  = av_default_item_name,
     .option     = options,
     .version    = LIBAVUTIL_VERSION_INT,
 };
 
 URLProtocol ff_tls_openssl_protocol = {
     .name           = "tls",
     .url_open2      = tls_open,
     .url_read       = tls_read,
     .url_write      = tls_write,
     .url_close      = tls_close,
     .priv_data_size = sizeof(TLSContext),
     .flags          = URL_PROTOCOL_FLAG_NETWORK,
     .priv_data_class = &tls_class,
 };