text: /*
    Asynchronous TCP library for Espressif MCUs
  
    Copyright (c) 2016 Hristo Gochkov. All rights reserved.
    This file is part of the esp8266 core for Arduino environment.
  
    This library 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.
  
    This library 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 this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  */
  /*
   * Compatibility for AxTLS with LWIP raw tcp mode (http://lwip.wikia.com/wiki/Raw/TCP)
   * Original Code and Inspiration: Slavey Karadzhov
   */
  #include <async_config.h>
  #if ASYNC_TCP_SSL_ENABLED
  
  #include "lwip/opt.h"
  #include "lwip/tcp.h"
  #include "lwip/inet.h"
  #include <stdlib.h>
  #include <stdint.h>
  #include <stdarg.h>
  #include <stdbool.h>
  #include <tcp_axtls.h>
  
  uint8_t * default_private_key = NULL;
  uint16_t default_private_key_len = 0;
  
  uint8_t * default_certificate = NULL;
  uint16_t default_certificate_len = 0;
  
  static uint8_t _tcp_ssl_has_client = 0;
  
  SSL_CTX * tcp_ssl_new_server_ctx(const char *cert, const char *private_key_file, const char *password){
    uint32_t options = SSL_CONNECT_IN_PARTS;
    SSL_CTX *ssl_ctx;
  
    if(private_key_file){
      options |= SSL_NO_DEFAULT_KEY;
    }
  
    if ((ssl_ctx = ssl_ctx_new(options, SSL_DEFAULT_SVR_SESS)) == NULL){
      TCP_SSL_DEBUG("tcp_ssl_new_server_ctx: failed to allocate context\n");
      return NULL;
    }
  
    if (private_key_file){
      int obj_type = SSL_OBJ_RSA_KEY;
      if (strstr(private_key_file, ".p8"))
        obj_type = SSL_OBJ_PKCS8;
      else if (strstr(private_key_file, ".p12"))
        obj_type = SSL_OBJ_PKCS12;
  
      if (ssl_obj_load(ssl_ctx, obj_type, private_key_file, password)){
        TCP_SSL_DEBUG("tcp_ssl_new_server_ctx: load private key '%s' failed\n", private_key_file);
        return NULL;
      }
    }
  
    if (cert){
      if (ssl_obj_load(ssl_ctx, SSL_OBJ_X509_CERT, cert, NULL)){
        TCP_SSL_DEBUG("tcp_ssl_new_server_ctx: load certificate '%s' failed\n", cert);
        return NULL;
      }
    }
    return ssl_ctx;
  }
  
  struct tcp_ssl_pcb {
    struct tcp_pcb *tcp;
    int fd;
    SSL_CTX* ssl_ctx;
    SSL *ssl;
    uint8_t type;
    int handshake;
    void * arg;
    tcp_ssl_data_cb_t on_data;
    tcp_ssl_handshake_cb_t on_handshake;
    tcp_ssl_error_cb_t on_error;
    int last_wr;
    struct pbuf *tcp_pbuf;
    int pbuf_offset;
    struct tcp_ssl_pcb * next;
  };
  
  typedef struct tcp_ssl_pcb tcp_ssl_t;
  
  static tcp_ssl_t * tcp_ssl_array = NULL;
  static int tcp_ssl_next_fd = 0;
  
  uint8_t tcp_ssl_has_client(){
    return _tcp_ssl_has_client;
  }
  
  tcp_ssl_t * tcp_ssl_new(struct tcp_pcb *tcp) {
  
    if(tcp_ssl_next_fd < 0){
      tcp_ssl_next_fd = 0;//overflow
    }
  
    tcp_ssl_t * new_item = (tcp_ssl_t*)malloc(sizeof(tcp_ssl_t));
    if(!new_item){
      TCP_SSL_DEBUG("tcp_ssl_new: failed to allocate tcp_ssl\n");
      return NULL;
    }
  
    new_item->tcp = tcp;
    new_item->handshake = SSL_NOT_OK;
    new_item->arg = NULL;
    new_item->on_data = NULL;
    new_item->on_handshake = NULL;
    new_item->on_error = NULL;
    new_item->tcp_pbuf = NULL;
    new_item->pbuf_offset = 0;
    new_item->next = NULL;
    new_item->ssl_ctx = NULL;
    new_item->ssl = NULL;
    new_item->type = TCP_SSL_TYPE_CLIENT;
    new_item->fd = tcp_ssl_next_fd++;
  
    if(tcp_ssl_array == NULL){
      tcp_ssl_array = new_item;
    } else {
      tcp_ssl_t * item = tcp_ssl_array;
      while(item->next != NULL)
        item = item->next;
      item->next = new_item;
    }
  
    TCP_SSL_DEBUG("tcp_ssl_new: %d\n", new_item->fd);
    return new_item;
  }
  
  tcp_ssl_t* tcp_ssl_get(struct tcp_pcb *tcp) {
    if(tcp == NULL) {
      return NULL;
    }
    tcp_ssl_t * item = tcp_ssl_array;
    while(item && item->tcp != tcp){
      item = item->next;
    }
    return item;
  }
  
  int tcp_ssl_new_client(struct tcp_pcb *tcp){
    SSL_CTX* ssl_ctx;
    tcp_ssl_t * tcp_ssl;
  
    if(tcp == NULL) {
      return -1;
    }
  
    if(tcp_ssl_get(tcp) != NULL){
      TCP_SSL_DEBUG("tcp_ssl_new_client: tcp_ssl already exists\n");
      return -1;
    }
  
    ssl_ctx = ssl_ctx_new(SSL_CONNECT_IN_PARTS | SSL_SERVER_VERIFY_LATER, 1);
    if(ssl_ctx == NULL){
      TCP_SSL_DEBUG("tcp_ssl_new_client: failed to allocate ssl context\n");
      return -1;
    }
  
    tcp_ssl = tcp_ssl_new(tcp);
    if(tcp_ssl == NULL){
      ssl_ctx_free(ssl_ctx);
      return -1;
    }
  
    tcp_ssl->ssl_ctx = ssl_ctx;
  
    tcp_ssl->ssl = ssl_client_new(ssl_ctx, tcp_ssl->fd, NULL, 0, NULL);
    if(tcp_ssl->ssl == NULL){
      TCP_SSL_DEBUG("tcp_ssl_new_client: failed to allocate ssl\n");
      tcp_ssl_free(tcp);
      return -1;
    }
  
    return tcp_ssl->fd;
  }
  
  int tcp_ssl_new_server(struct tcp_pcb *tcp, SSL_CTX* ssl_ctx){
    tcp_ssl_t * tcp_ssl;
  
    if(tcp == NULL) {
      return -1;
    }
  
    if(ssl_ctx == NULL){
      return -1;
    }
  
    if(tcp_ssl_get(tcp) != NULL){
      TCP_SSL_DEBUG("tcp_ssl_new_server: tcp_ssl already exists\n");
      return -1;
    }
  
    tcp_ssl = tcp_ssl_new(tcp);
    if(tcp_ssl == NULL){
      return -1;
    }
  
    tcp_ssl->type = TCP_SSL_TYPE_SERVER;
    tcp_ssl->ssl_ctx = ssl_ctx;
  
    _tcp_ssl_has_client = 1;
    tcp_ssl->ssl = ssl_server_new(ssl_ctx, tcp_ssl->fd);
    if(tcp_ssl->ssl == NULL){
      TCP_SSL_DEBUG("tcp_ssl_new_server: failed to allocate ssl\n");
      tcp_ssl_free(tcp);
      return -1;
    }
  
    return tcp_ssl->fd;
  }
  
  int tcp_ssl_free(struct tcp_pcb *tcp) {
  
    if(tcp == NULL) {
      return -1;
    }
  
    tcp_ssl_t * item = tcp_ssl_array;
  
    if(item->tcp == tcp){
      tcp_ssl_array = tcp_ssl_array->next;
      if(item->tcp_pbuf != NULL){
        pbuf_free(item->tcp_pbuf);
      }
      TCP_SSL_DEBUG("tcp_ssl_free: %d\n", item->fd);
      if(item->ssl)
        ssl_free(item->ssl);
      if(item->type == TCP_SSL_TYPE_CLIENT && item->ssl_ctx)
        ssl_ctx_free(item->ssl_ctx);
      if(item->type == TCP_SSL_TYPE_SERVER)
        _tcp_ssl_has_client = 0;
      free(item);
      return 0;
    }
  
    while(item->next && item->next->tcp != tcp)
      item = item->next;
  
    if(item->next == NULL){
      return ERR_TCP_SSL_INVALID_CLIENTFD_DATA;//item not found
    }
  
    tcp_ssl_t * i = item->next;
    item->next = i->next;
    if(i->tcp_pbuf != NULL){
      pbuf_free(i->tcp_pbuf);
    }
    TCP_SSL_DEBUG("tcp_ssl_free: %d\n", i->fd);
    if(i->ssl)
      ssl_free(i->ssl);
    if(i->type == TCP_SSL_TYPE_CLIENT && i->ssl_ctx)
      ssl_ctx_free(i->ssl_ctx);
    if(i->type == TCP_SSL_TYPE_SERVER)
      _tcp_ssl_has_client = 0;
    free(i);
    return 0;
  }
  
  #ifdef AXTLS_2_0_0_SNDBUF
  int tcp_ssl_sndbuf(struct tcp_pcb *tcp){
    int expected;
    int available;
    int result = -1;
  
    if(tcp == NULL) {
      return result;
    }
    tcp_ssl_t * tcp_ssl = tcp_ssl_get(tcp);
    if(!tcp_ssl){
      TCP_SSL_DEBUG("tcp_ssl_sndbuf: tcp_ssl is NULL\n");
      return result;
    }
    available = tcp_sndbuf(tcp);
    if(!available){
      TCP_SSL_DEBUG("tcp_ssl_sndbuf: tcp_sndbuf is zero\n");
      return 0;
    }
    result = available;
    while((expected = ssl_calculate_write_length(tcp_ssl->ssl, result)) > available){
      result -= (expected - available) + 4;
    }
  
    if(expected > 0){
      //TCP_SSL_DEBUG("tcp_ssl_sndbuf: tcp_sndbuf is %d from %d\n", result, available);
      return result;
    }
  
    return 0;
  }
  #endif
  
  int tcp_ssl_write(struct tcp_pcb *tcp, uint8_t *data, size_t len) {
    if(tcp == NULL) {
      return -1;
    }
    tcp_ssl_t * tcp_ssl = tcp_ssl_get(tcp);
    if(!tcp_ssl){
      TCP_SSL_DEBUG("tcp_ssl_write: tcp_ssl is NULL\n");
      return 0;
    }
    tcp_ssl->last_wr = 0;
  
  #ifdef AXTLS_2_0_0_SNDBUF
    int expected_len = ssl_calculate_write_length(tcp_ssl->ssl, len);
    int available_len = tcp_sndbuf(tcp);
    if(expected_len < 0 || expected_len > available_len){
      TCP_SSL_DEBUG("tcp_ssl_write: data will not fit! %u < %d(%u)\r\n", available_len, expected_len, len);
      return -1;
    }
  #endif
  
    int rc = ssl_write(tcp_ssl->ssl, data, len);
  
    //TCP_SSL_DEBUG("tcp_ssl_write: %u -> %d (%d)\r\n", len, tcp_ssl->last_wr, rc);
  
    if (rc < 0){
      if(rc != SSL_CLOSE_NOTIFY) {
        TCP_SSL_DEBUG("tcp_ssl_write error: %d\r\n", rc);
      }
      return rc;
    }
  
    return tcp_ssl->last_wr;
  }
  
  /**
   * Reads data from the SSL over TCP stream. Returns decrypted data.
   * @param tcp_pcb *tcp - pointer to the raw tcp object
   * @param pbuf *p - pointer to the buffer with the TCP packet data
   *
   * @return int
   *      0 - when everything is fine but there are no symbols to process yet
   *      < 0 - when there is an error
   *      > 0 - the length of the clear text characters that were read
   */
  int tcp_ssl_read(struct tcp_pcb *tcp, struct pbuf *p) {
    if(tcp == NULL) {
      return -1;
    }
    tcp_ssl_t* fd_data = NULL;
  
    int read_bytes = 0;
    int total_bytes = 0;
    uint8_t *read_buf;
  
    fd_data = tcp_ssl_get(tcp);
    if(fd_data == NULL) {
      TCP_SSL_DEBUG("tcp_ssl_read: tcp_ssl is NULL\n");
      return ERR_TCP_SSL_INVALID_CLIENTFD_DATA;
    }
  
    if(p == NULL) {
      TCP_SSL_DEBUG("tcp_ssl_read:p == NULL\n");
      return ERR_TCP_SSL_INVALID_DATA;
    }
  
    //TCP_SSL_DEBUG("READY TO READ SOME DATA\n");
  
    fd_data->tcp_pbuf = p;
    fd_data->pbuf_offset = 0;
  
    do {
      read_bytes = ssl_read(fd_data->ssl, &read_buf);
      //TCP_SSL_DEBUG("tcp_ssl_ssl_read: %d\n", read_bytes);
      if(read_bytes < SSL_OK) {
        if(read_bytes != SSL_CLOSE_NOTIFY) {
          TCP_SSL_DEBUG("tcp_ssl_read: read error: %d\n", read_bytes);
        }
        total_bytes = read_bytes;
        break;
      } else if(read_bytes > 0){
        if(fd_data->on_data){
          fd_data->on_data(fd_data->arg, tcp, read_buf, read_bytes);
        }
        total_bytes+= read_bytes;
      } else {
        if(fd_data->handshake != SSL_OK) {
          fd_data->handshake = ssl_handshake_status(fd_data->ssl);
          if(fd_data->handshake == SSL_OK){
            //TCP_SSL_DEBUG("tcp_ssl_read: handshake OK\n");
            if(fd_data->on_handshake)
              fd_data->on_handshake(fd_data->arg, fd_data->tcp, fd_data->ssl);
          } else if(fd_data->handshake != SSL_NOT_OK){
            TCP_SSL_DEBUG("tcp_ssl_read: handshake error: %d\n", fd_data->handshake);
            if(fd_data->on_error)
              fd_data->on_error(fd_data->arg, fd_data->tcp, fd_data->handshake);
            return fd_data->handshake;
          }
        }
      }
    } while (p->tot_len - fd_data->pbuf_offset > 0);
  
    tcp_recved(tcp, p->tot_len);
    fd_data->tcp_pbuf = NULL;
    pbuf_free(p);
  
    return total_bytes;
  }
  
  SSL * tcp_ssl_get_ssl(struct tcp_pcb *tcp){
    tcp_ssl_t * tcp_ssl = tcp_ssl_get(tcp);
    if(tcp_ssl){
      return tcp_ssl->ssl;
    }
    return NULL;
  }
  
  bool tcp_ssl_has(struct tcp_pcb *tcp){
    return tcp_ssl_get(tcp) != NULL;
  }
  
  int tcp_ssl_is_server(struct tcp_pcb *tcp){
    tcp_ssl_t * tcp_ssl = tcp_ssl_get(tcp);
    if(tcp_ssl){
      return tcp_ssl->type;
    }
    return -1;
  }
  
  void tcp_ssl_arg(struct tcp_pcb *tcp, void * arg){
    tcp_ssl_t * item = tcp_ssl_get(tcp);
    if(item) {
      item->arg = arg;
    }
  }
  
  void tcp_ssl_data(struct tcp_pcb *tcp, tcp_ssl_data_cb_t arg){
    tcp_ssl_t * item = tcp_ssl_get(tcp);
    if(item) {
      item->on_data = arg;
    }
  }
  
  void tcp_ssl_handshake(struct tcp_pcb *tcp, tcp_ssl_handshake_cb_t arg){
    tcp_ssl_t * item = tcp_ssl_get(tcp);
    if(item) {
      item->on_handshake = arg;
    }
  }
  
  void tcp_ssl_err(struct tcp_pcb *tcp, tcp_ssl_error_cb_t arg){
    tcp_ssl_t * item = tcp_ssl_get(tcp);
    if(item) {
      item->on_error = arg;
    }
  }
  
  static tcp_ssl_file_cb_t _tcp_ssl_file_cb = NULL;
  static void * _tcp_ssl_file_arg = NULL;
  
  void tcp_ssl_file(tcp_ssl_file_cb_t cb, void * arg){
    _tcp_ssl_file_cb = cb;
    _tcp_ssl_file_arg = arg;
  }
  
  int ax_get_file(const char *filename, uint8_t **buf) {
      //TCP_SSL_DEBUG("ax_get_file: %s\n", filename);
      if(_tcp_ssl_file_cb){
        return _tcp_ssl_file_cb(_tcp_ssl_file_arg, filename, buf);
      }
      *buf = 0;
      return 0;
  }
  
  tcp_ssl_t* tcp_ssl_get_by_fd(int fd) {
    tcp_ssl_t * item = tcp_ssl_array;
    while(item && item->fd != fd){
      item = item->next;
    }
    return item;
  }
  /*
   * The LWIP tcp raw version of the SOCKET_WRITE(A, B, C)
   */
  int ax_port_write(int fd, uint8_t *data, uint16_t len) {
    tcp_ssl_t *fd_data = NULL;
    int tcp_len = 0;
    err_t err = ERR_OK;
  
    //TCP_SSL_DEBUG("ax_port_write: %d, %d\n", fd, len);
  
    fd_data = tcp_ssl_get_by_fd(fd);
    if(fd_data == NULL) {
      //TCP_SSL_DEBUG("ax_port_write: tcp_ssl[%d] is NULL\n", fd);
      return ERR_MEM;
    }
  
    if (data == NULL || len == 0) {
      return 0;
    }
  
    if (tcp_sndbuf(fd_data->tcp) < len) {
      tcp_len = tcp_sndbuf(fd_data->tcp);
      if(tcp_len == 0) {
        TCP_SSL_DEBUG("ax_port_write: tcp_sndbuf is zero: %d\n", len);
        return ERR_MEM;
      }
    } else {
      tcp_len = len;
    }
  
    if (tcp_len > 2 * fd_data->tcp->mss) {
      tcp_len = 2 * fd_data->tcp->mss;
    }
  
    err = tcp_write(fd_data->tcp, data, tcp_len, TCP_WRITE_FLAG_COPY);
    if(err < ERR_OK) {
      if (err == ERR_MEM) {
        TCP_SSL_DEBUG("ax_port_write: No memory %d (%d)\n", tcp_len, len);
        return err;
      }
      TCP_SSL_DEBUG("ax_port_write: tcp_write error: %d\n", err);
      return err;
    } else if (err == ERR_OK) {
      //TCP_SSL_DEBUG("ax_port_write: tcp_output: %d / %d\n", tcp_len, len);
      err = tcp_output(fd_data->tcp);
      if(err != ERR_OK) {
        TCP_SSL_DEBUG("ax_port_write: tcp_output err: %d\n", err);
        return err;
      }
    }
  
    fd_data->last_wr += tcp_len;
  
    return tcp_len;
  }
  
  /*
   * The LWIP tcp raw version of the SOCKET_READ(A, B, C)
   */
  int ax_port_read(int fd, uint8_t *data, int len) {
    tcp_ssl_t *fd_data = NULL;
    uint8_t *read_buf = NULL;
    uint8_t *pread_buf = NULL;
    u16_t recv_len = 0;
  
    //TCP_SSL_DEBUG("ax_port_read: %d, %d\n", fd, len);
  
    fd_data = tcp_ssl_get_by_fd(fd);
    if (fd_data == NULL) {
      TCP_SSL_DEBUG("ax_port_read: tcp_ssl[%d] is NULL\n", fd);
      return ERR_TCP_SSL_INVALID_CLIENTFD_DATA;
    }
  
    if(fd_data->tcp_pbuf == NULL || fd_data->tcp_pbuf->tot_len == 0) {
      return 0;
    }
  
    read_buf =(uint8_t*)calloc(fd_data->tcp_pbuf->len + 1, sizeof(uint8_t));
    pread_buf = read_buf;
    if (pread_buf != NULL){
      recv_len = pbuf_copy_partial(fd_data->tcp_pbuf, read_buf, len, fd_data->pbuf_offset);
      fd_data->pbuf_offset += recv_len;
    }
  
    if (recv_len != 0) {
      memcpy(data, read_buf, recv_len);
    }
  
    if(len < recv_len) {
      TCP_SSL_DEBUG("ax_port_read: got %d bytes more than expected\n", recv_len - len);
    }
  
    free(pread_buf);
    pread_buf = NULL;
  
    return recv_len;
  }
  
  void ax_wdt_feed() {}
  
  #endif
  