c - 如何用c语言实现gmail的Oauth2.0

Question

在google的文档“Using OAuth 2.0 for Devices”中，提到我们应该在控制台中注册应用程序后将以下信息发送到accounts.google.com。

POST /o/oauth2/device/code HTTP/1.1
Host: accounts.google.com
Content-Type: application/x-www-form-urlencoded

client_id=812741506391-h38jh0j4fv0ce1krdkiq0hfvt6n5amrf.apps.googleusercontent.com& scope=email%20profile  
i implement that in c with the follwing steps:

1:声明一个全局数组:

static char gmail_request_token_url[] = "POST /o/oauth2/device/code HTTP/1.1\r\n"
                                      "Host: accounts.google.com\r\n"
                                       "Content-Type: application/x-www-form-urlencoded\r\n"
                                        "Content-Length: 289\r\n"
                                        "Accept: text/html,*/*\r\n"
                                        "User-Agent: Mozilla/5.0\r\n"
                                        "client_id=my.apps.googleusercontent.com&scope=email%20profile\r\n";

2:创建连接到“accounts.google.com”端口(80 或 443)的套接字并使用发送:

if(send(socket_fd, gmail_get_tokens, sizeof(gmail_get_tokens),0) > 0)
{
    printf("successfully  send content to google");
}

3:使用 while 循环来接收服务器的响应

while(1)
{
    ret = recv(......);


}

不幸的是，recv 的返回值始终为 0。这意味着它没有收到任何内容。我不知道出了什么问题。请帮助我。

Answer 1

the code i wrote is as follow.please so kind to help me find the problem in it.

/* File Name: server.c */
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<errno.h>
#include<sys/types.h>
#include<sys/socket.h>
#include<netinet/in.h>
#include <netdb.h>
#include <arpa/inet.h>
#include <unistd.h>
#define DEFAULT_PORT 8002
#define MAXLINE 4096
#define GMAIL_ACCOUNTS_SERVER "accounts.google.com"


static char gmail_request_token_url[] = "POST /o/oauth2/device/code HTTP/1.1\r\n"
                                      "Host: accounts.google.com\r\n"
                                       "Content-Type: application/x-www-form-urlencoded\r\n"
                                        "Content-Length: 289\r\n"
                                        "Accept: text/html,*/*\r\n"
                                        "User-Agent: Mozilla/5.0\r\n"
                                        "client_id=my.apps.googleusercontent.com&scope=email%20profile\r\n";

static char gmail_get_tokens[] ="POST /oauth2/v3/token HTTP/1.1\r\n"
                                "Host: accounts.google.com\r\n"
                                "Content-Type: application/x-www-form-urlencoded\r\n"
                                "Content-Length: 389\r\n"
                                "Accept: text/html,*/*\r\n"
                                "User-Agent: Mozilla/5.0\r\n"
"client_id=my.apps.googleusercontent.com&client_secret={my_client_secret}&code=authentication_code&grant_type=http://oauth.net/grant_type/device/1.0\r\n";







void main(void)
{
    int    socket_fd = -1;
    struct sockaddr_in   servaddr;
    struct sockaddr_in   clientaddr;
    char    buff[4096];
    int     n;
    struct hostent  *host = NULL;
    int reuse = 1;

    struct timeval tv;
    fd_set rset;
    int ret = 0;
    char requestbuffer[1024]={0};


  //  printf("the sizeof the request array is %d\n",sizeof(gmail_request_token_url));


    if( (socket_fd = socket(AF_INET, SOCK_STREAM, 0)) == -1 ){
        printf("create socket error: %s(errno: %d)\n",strerror(errno),errno);
        exit(0);
    }

    memset(buff,0,sizeof(buff));
    memset(&servaddr, 0, sizeof(servaddr));
    memset(&clientaddr,0,sizeof(clientaddr));

    servaddr.sin_family = AF_INET;
    servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
    servaddr.sin_port = htons(DEFAULT_PORT);


    clientaddr.sin_family = AF_INET;
    clientaddr.sin_port = htons(443);


    if (setsockopt(socket_fd,SOL_SOCKET,SO_REUSEADDR,&reuse,sizeof(int)) < 0)
    {
        printf("fail to set socket reuse\n");
    }
    else
    {
        printf("successfully set sock reuse\n");
    }



    if( bind(socket_fd, (struct sockaddr*)&servaddr, sizeof(servaddr)) == -1){
        printf("bind socket error: %s(errno: %d)\n",strerror(errno),errno);
        exit(0);
    }


    host = gethostbyname(GMAIL_ACCOUNTS_SERVER);//"get ip  address of accounts.google.com"
    if(host != NULL)
    {

        printf("successfully get google account name\n");
        clientaddr.sin_addr.s_addr = *(unsigned long *)host->h_addr_list[0];
        printf("the address is %s\n",inet_ntoa(clientaddr.sin_addr));

    }
    else
    {
        printf("fail to get google account name\n");
        clientaddr.sin_addr.s_addr = inet_addr("216.58.217.205");

    }



    if( connect(socket_fd, (struct sockaddr*)&clientaddr, sizeof(clientaddr)) < 0)
    {
        printf("connect error: %s(errno: %d)\n",strerror(errno),errno);
        return;

    }
    else
    {
        printf("successfull connect to the server\n");

    }



  //  if(send(socket_fd, gmail_request_token_url, sizeof(gmail_request_token_url),0) == -1)
     if(send(socket_fd, gmail_get_tokens, sizeof(gmail_get_tokens),0) == -1)
    {
        printf("fail to send content to google");
       // continue;
    }
    else
    {
        printf("successfulyy send request url %s\n",gmail_get_tokens);
    }
    FD_ZERO(&rset);
    FD_SET(socket_fd,&rset);


    while(1)
    {
        tv.tv_sec = 5;
        tv.tv_usec = 0;

        ret = select(socket_fd+1,&rset,NULL,NULL,&tv);

        printf("the ret is %d\n",ret);
        if (ret > 0)
        {
            printf("waiting for response from server\n");
            if (FD_ISSET(socket_fd,&rset))
            {
                printf("it is the fd,response");
                n = recv(socket_fd, buff, 1024, 0);
                if (n > 0)
                {
                    printf("successfully recv content from the server\n");
                    buff[n] = '\0';
                    printf("recv msg from client: %s %s\n", buff,strerror(errno));
                }

                else
                {
                    printf("fail to recv any message from the server %s\n",strerror(errno));
                    //close(fd);
                    //break;

                }
            }

        }
        else if(0 == ret)
        {
            printf("time out\n");
            continue;
        }
        else
        {
            printf("the ret is less than 0\n");
            continue;
        }


        sleep(1);
    }  
    close(socket_fd);
   // return 0;
}