Is there a good tutorial code for an httpS client using the mongoose library? #3022

DiegoMartinezRdg · 2025-01-24T13:28:58Z

DiegoMartinezRdg
Jan 24, 2025

Im looking for a HTTPS client tutorial to verify connection to a HTTPS server, I was using TCP
But they told me it was not a good one to follow for tls.
Wich one would be good to follow so I can test the https client in windows 10?

Answered by scaprile

Jan 24, 2025

#3020 (comment)

mongoose/tutorials/http/http-client/main.c

Lines 18 to 57 in bf592a2

     static void fn(struct mg_connection *c, int ev, void *ev_data) {  
   if (ev == MG_EV_OPEN) {  
   // Connection created. Store connect expiration time in c->data  
   *(uint64_t *) c->data = mg_millis() + s_timeout_ms;  
   } else if (ev == MG_EV_POLL) {  
   if (mg_millis() > *(uint64_t *) c->data &&  
   (c->is_connecting || c->is_resolving)) {  
   mg_error(c, "Connect timeout");  
   }  
   } else if (ev == MG_EV_CONNECT) {  
   // Connected to server. Extract host name from URL  
   struct mg_str host = mg_url_host(s_url);  
    
   if (mg_url_is_ssl(s_url)) {  
   struct mg_tls_opts opts

View full answer

scaprile · 2025-01-24T13:34:41Z

scaprile
Jan 24, 2025
Collaborator

#3020
#3020 (comment)

0 replies

scaprile · 2025-01-24T13:42:12Z

scaprile
Jan 24, 2025
Collaborator

#3020 (comment)

mongoose/tutorials/http/http-client/main.c

Lines 18 to 57 in bf592a2

    
           static void fn(struct mg_connection *c, int ev, void *ev_data) { 
        
             if (ev == MG_EV_OPEN) { 
        
               // Connection created. Store connect expiration time in c->data 
        
               *(uint64_t *) c->data = mg_millis() + s_timeout_ms; 
        
             } else if (ev == MG_EV_POLL) { 
        
               if (mg_millis() > *(uint64_t *) c->data && 
        
                   (c->is_connecting || c->is_resolving)) { 
        
                 mg_error(c, "Connect timeout"); 
        
               } 
        
             } else if (ev == MG_EV_CONNECT) { 
        
               // Connected to server. Extract host name from URL 
        
               struct mg_str host = mg_url_host(s_url); 
        
               if (mg_url_is_ssl(s_url)) { 
        
                 struct mg_tls_opts opts = {.ca = mg_unpacked("/certs/ca.pem"), 
        
                                            .name = mg_url_host(s_url)}; 
        
                 mg_tls_init(c, &opts); 
        
               } 
        
               // Send request 
        
               int content_length = s_post_data ? strlen(s_post_data) : 0; 
        
               mg_printf(c, 
        
                         "%s %s HTTP/1.0\r\n" 
        
                         "Host: %.*s\r\n" 
        
                         "Content-Type: octet-stream\r\n" 
        
                         "Content-Length: %d\r\n" 
        
                         "\r\n", 
        
                         s_post_data ? "POST" : "GET", mg_url_uri(s_url), (int) host.len, 
        
                         host.buf, content_length); 
        
               mg_send(c, s_post_data, content_length); 
        
             } else if (ev == MG_EV_HTTP_MSG) { 
        
               // Response is received. Print it 
        
               struct mg_http_message *hm = (struct mg_http_message *) ev_data; 
        
               printf("%.*s", (int) hm->message.len, hm->message.buf); 
        
               c->is_draining = 1;        // Tell mongoose to close this connection 
        
               *(bool *) c->fn_data = true;  // Tell event loop to stop 
        
             } else if (ev == MG_EV_ERROR) { 
        
               *(bool *) c->fn_data = true;  // Error, tell event loop to stop 
        
             } 
        
           }

$ cd tutorials/http/http-client/
$ make clean example
rm -rf                    example                    *.o *.obj *.exe *.dSYM mbedtls ./pack                    
cc main.c mongoose.c  packed_fs.c       -W -Wall -Wextra -g -I.   -DMG_ENABLE_LINES=1 -DMG_ENABLE_PACKED_FS=1 -DMG_TLS=MG_TLS_BUILTIN -o example                                    
$ LOG_LEVEL=2 ./example https://www.cesanta.com/
5d9722 1 http.c:1076:http_cb            Content length missing from response
5d9723 1 http.c:1076:http_cb            Content length missing from response
5d9723 1 http.c:1076:http_cb            Content length missing from response
HTTP/1.1 200 OK
Server: nginx/1.18.0
Date: Fri, 24 Jan 2025 13:45:32 GMT
Content-Type: text/html
Connection: close

<!DOCTYPE html>
[...]
</html>
$

1 reply

DiegoMartinezRdg Jan 27, 2025
Author

I found that the example provided (http_client) only connects to https://cesanta.com.

Fails on https://httpbin.org and https://openssl.org and any other one I tested.

I suppose It could be a certificate related problem?

FYI I checked the preprocessor options (there are just like the example) and the code is exactly the one you ran (even when I receive diferent output).

3e235037 3 net.c:182:mg_connect 1 -1 https://openssl.org/
3e235037 3 net.c:182:mg_connect 2 -1 udp://8.8.8.8:53
3e235047 4 dns.c:260:mg_sendnsreq 1 resolving openssl.org @ udp://8.8.8.8:53, txnid 1
3e235047 4 sock.c:134:mg_io_send 2 29 0
3e235047 3 sock.c:145:mg_send 2 280 0:0:0 29 err 0
3e235056 4 sock.c:746:mg_mgr_poll 2 r- tchrc 0 0
3e235056 4 sock.c:265:recv_raw 2 45 0
3e235056 3 sock.c:326:read_conn 2 280 0:0:0 45 err 0
3e235056 3 dns.c:172:dns_cb 1 openssl.org is 34.49.79.89
3e235056 3 sock.c:421:mg_connect_resolv 1 284 -> 34.49.79.89:443 pend
3e235056 4 sock.c:746:mg_mgr_poll 1 -- tChrc 0 0
3e235066 4 sock.c:746:mg_mgr_poll 2 -- tchrc 0 0
3e235066 4 sock.c:746:mg_mgr_poll 1 -w tChrc 0 0
3e235066 4 tls_builtin.c:1314:mg_tls_in no certificate provided
3e2350a4 4 sock.c:134:mg_io_send 1 179 0
3e2350b4 4 sock.c:746:mg_mgr_poll 2 -- tchrc 0 0
3e2350b4 4 sock.c:746:mg_mgr_poll 1 r- TcHrc 0 0
3e2350b4 4 sock.c:265:recv_raw 1 7 0
3e2350b4 1 event.c:31:mg_error 1 284 tls alert 40
3e2350b4 3 sock.c:326:read_conn 1 284 84:0:7 -2 err 0
3e2350b4 3 net.c:154:mg_close_conn 1 284 closed
3e2350b4 4 sock.c:746:mg_mgr_poll 2 -- tchrC 0 0
3e2350c4 3 net.c:154:mg_close_conn 2 280 closed
3e2350c4 3 net.c:256:mg_mgr_free All connections closed

3e2bca81 3 net.c:182:mg_connect 1 -1 https://httpbin.org/
3e2bca90 3 net.c:182:mg_connect 2 -1 udp://8.8.8.8:53
3e2bcabf 4 dns.c:260:mg_sendnsreq 1 resolving httpbin.org @ udp://8.8.8.8:53, txnid 1
3e2bcabf 4 sock.c:134:mg_io_send 2 29 0
3e2bcacf 3 sock.c:145:mg_send 2 280 0:0:0 29 err 0
3e2bcacf 4 sock.c:746:mg_mgr_poll 2 r- tchrc 0 0
3e2bcacf 4 sock.c:265:recv_raw 2 61 0
3e2bcadf 3 sock.c:326:read_conn 2 280 0:0:0 61 err 0
3e2bcadf 3 dns.c:172:dns_cb 1 httpbin.org is 3.82.76.149
3e2bcadf 3 sock.c:421:mg_connect_resolv 1 284 -> 3.82.76.149:443 pend
3e2bcadf 4 sock.c:746:mg_mgr_poll 1 -- tChrc 0 0
3e2bcb1d 4 sock.c:746:mg_mgr_poll 2 -- tchrc 0 0
3e2bcb1d 4 sock.c:746:mg_mgr_poll 1 -- tChrc 0 0
3e2bcb4c 4 sock.c:746:mg_mgr_poll 2 -- tchrc 0 0
3e2bcb4c 4 sock.c:746:mg_mgr_poll 1 -w tChrc 0 0
3e2bcb4c 4 tls_builtin.c:1314:mg_tls_in no certificate provided
3e2bcb9a 4 sock.c:134:mg_io_send 1 179 0
3e2bcbd9 4 sock.c:746:mg_mgr_poll 2 -- tchrc 0 0
3e2bcbe8 4 sock.c:746:mg_mgr_poll 1 -- TcHrc 0 0
3e2bcc07 4 sock.c:746:mg_mgr_poll 2 -- tchrc 0 0
3e2bcc17 4 sock.c:746:mg_mgr_poll 1 r- TcHrc 0 0
3e2bcc17 4 sock.c:265:recv_raw 1 -1 10054
3e2bcc17 3 sock.c:326:read_conn 1 284 84:0:0 -2 err 10054
3e2bcc17 4 sock.c:746:mg_mgr_poll 2 -- tchrc 0 0
3e2bcc17 4 sock.c:746:mg_mgr_poll 1 r- TcHrc 0 0
3e2bcc17 4 sock.c:265:recv_raw 1 -1 10054
3e2bcc17 3 sock.c:326:read_conn 1 284 84:0:0 -2 err 10054
3e2bcc27 4 sock.c:746:mg_mgr_poll 2 -- tchrc 0 0
3e2bcc27 4 sock.c:746:mg_mgr_poll 1 r- TcHrc 0 0
3e2bcc27 4 sock.c:265:recv_raw 1 -1 10054
3e2bcc27 3 sock.c:326:read_conn 1 284 84:0:0 -2 err 10054
3e2bcc27 4 sock.c:746:mg_mgr_poll 2 -- tchrc 0 0
3e2bcc36 4 sock.c:746:mg_mgr_poll 1 r- TcHrc 0 0
3e2bcc36 4 sock.c:265:recv_raw 1 -1 10054
3e2bcc36 3 sock.c:326:read_conn 1 284 84:0:0 -2 err 10054
[Loops infinitely doing this]

scaprile · 2025-01-27T12:55:03Z

scaprile
Jan 27, 2025
Collaborator

The fact that the example does not work for you, the way you try it, in those sites you want it to work, does not mean it only works for cesanta.com.
Connecting using TLS requires having proper CA certificates and agreeing on TLS version and cyphers, particularly on embedded-oriented libraries (Mongoose) that can be 1.3 only (Mongoose) and/or favor the use of elliptic curve (EC) cyphers in place of more demanding ones (RSA) (Mongoose).

LMGTFY

SSL fatal error, handshake failure 40 indicates the secure connection failed to establish because the client and the server couldn't agree on connection ...

Error 10054 means that the server closed the connection. Why? Because the server detected something not OK according to their rules. This could be an SSL version as you tried

Built-in TLS1.3 stack
Mongoose implements a built-in TLS 1.3 stack. It can be enabled by one of the following ways:

Let's see

How to build
Use the MG_TLS macro in your compile options:
MG_TLS=MG_TLS_BUILTIN to use Mongoose built-in TLS functions
MG_TLS=MG_TLS_MBED to build using MbedTLS
MG_TLS=MG_TLS_OPENSSL to build using OpenSSL
MG_TLS=MG_TLS_WOLFSSL to build using WolfSSL. This library also requires that you define the macro EXTERNAL_OPTS_OPENVPN

Let's try MbedTLS

$ make clean example CFLAGS_EXTRA="-DMG_TLS=MG_TLS_MBED -lmbedtls -lmbedcrypto -lmbedx509"
rm -rf                    example                    *.o *.obj *.exe *.dSYM mbedtls ./pack
cc main.c mongoose.c  packed_fs.c       -W -Wall -Wextra -g -I.   -DMG_ENABLE_LINES=1 -DMG_ENABLE_PACKED_FS=1 -DMG_TLS=MG_TLS_MBED -lmbedtls -lmbedcrypto -lmbedx509 -o example
$ LOG_LEVEL=3 ./example https://openssl.org/  2a90ec5 3 net.c:174:mg_connect          1 -1 https://openssl.org/
2a90ec5 3 net.c:174:mg_connect          2 -1 udp://8.8.8.8:53
2a90ec5 3 sock.c:141:mg_send            2 4 0:0:0 29 err 0
2a90ee7 3 sock.c:308:read_conn          2 4 0:0:0 45 err 0
2a90ee7 3 dns.c:169:dns_cb              1 openssl.org is 34.49.79.89
2a90ee7 3 sock.c:399:mg_connect_resolve 1 5 -> 34.49.79.89:443 pend
2a90eee 3 tls_mbed.c:107:mg_tls_init    1 Setting TLS
2a90ef1 3 tls_mbed.c:141:mg_tls_init    1 hostname verification: openssl.org
2a90efa 3 sock.c:308:read_conn          1 5 84:0:0 -2 err 115
2a90efa 3 sock.c:308:read_conn          1 5 84:0:0 -2 err 115
2a90f04 3 sock.c:308:read_conn          1 5 84:0:0 -2 err 115
2a90f0b 3 tls_mbed.c:80:mg_tls_handshak 1 success
2a90f0b 3 sock.c:308:read_conn          1 5 84:0:0 -2 err 115
2a90f0b 3 sock.c:319:write_conn         1 5 snd 84/16384 rcv 0/16384 n=84 err=0
2a90fd2 3 sock.c:308:read_conn          1 5 0:0:1400 1379 err 0
2a90fd2 3 sock.c:308:read_conn          1 5 0:1379:2358 1379 err 0
2a90fd2 3 sock.c:308:read_conn          1 5 0:2758:958 1379 err 0
2a90fd2 3 sock.c:308:read_conn          1 5 0:4137:0 -1 err 115
HTTP/1.0 200 OK

$ LOG_LEVEL=3 ./example https://httpbin.org/
2aa7c35 3 net.c:174:mg_connect          1 -1 https://httpbin.org/
2aa7c35 3 net.c:174:mg_connect          2 -1 udp://8.8.8.8:53
2aa7c35 3 sock.c:141:mg_send            2 4 0:0:0 29 err 0
2aa7c3b 3 sock.c:308:read_conn          2 4 0:0:0 61 err 0
2aa7c3b 3 dns.c:169:dns_cb              1 httpbin.org is 3.82.76.149
2aa7c3b 3 sock.c:399:mg_connect_resolve 1 5 -> 3.82.76.149:443 pend
2aa7ce6 3 tls_mbed.c:107:mg_tls_init    1 Setting TLS
2aa7ce8 3 tls_mbed.c:141:mg_tls_init    1 hostname verification: httpbin.org
2aa7d94 3 sock.c:308:read_conn          1 5 84:0:0 -2 err 115
2aa7d94 3 sock.c:308:read_conn          1 5 84:0:0 -2 err 115
2aa7d9e 3 sock.c:308:read_conn          1 5 84:0:0 -2 err 115
2aa7e48 3 tls_mbed.c:80:mg_tls_handshak 1 success
2aa7e48 3 sock.c:308:read_conn          1 5 84:0:0 -2 err 115
2aa7e48 3 sock.c:319:write_conn         1 5 snd 84/16384 rcv 0/16384 n=84 err=0
2aa7ef6 3 sock.c:308:read_conn          1 5 0:0:0 -2 err 115
2aa7ef6 3 sock.c:308:read_conn          1 5 0:0:0 -2 err 115
2aa7ef7 3 sock.c:308:read_conn          1 5 0:0:0 -2 err 115
2aa7ef7 3 sock.c:308:read_conn          1 5 0:0:0 -2 err 115
2aa7ef7 3 sock.c:308:read_conn          1 5 0:0:0 -2 err 115
2aa7ef7 3 sock.c:308:read_conn          1 5 0:0:31 9827 err 0
HTTP/1.1 200 OK
Date: Mon, 27 Jan 2025 12:24:11 GMT

No, it is not a certificate problem, it is TLS version or cypher availability issue

Build with TLS support
Check the "How to build" section of the TLS tutorial for specific information on building options for your OS

Most examples can pull and build a known and tested version of MbedTLS. Then, depending on your operating system, you may have additional options

Windows
Only what the example provides in its Makefile is supported

mongoose/tutorials/http/http-client/Makefile

Lines 38 to 40 in 8de9699

    
           mbedtls:                  # Pull and build mbedTLS library 
        
           	git clone --depth 1 -b v2.28.2 https://github.com/mbed-tls/mbedtls $@ 
        
           	$(MAKE) -C mbedtls/library

$ make clean mbedtls example CFLAGS_EXTRA="-DMG_TLS=MG_TLS_MBED mbedtls/library/libmbedtls.a  mbedtls/library/libmbedcrypto.a  mbedtls/library/libmbedx509.a"
rm -rf                    example                    *.o *.obj *.exe *.dSYM mbedtls ./pack
git clone --depth 1 -b v2.28.2 https://github.com/mbed-tls/mbedtls mbedtls
Cloning into 'mbedtls'...
[...]
make -C mbedtls/library
make[1]: Entering directory '/home/scaprile/work/cesanta/mongoose/tutorials/http/http-client/mbedtls/library'
  CC    aes.c
  CC    aesni.c
[...]
  AR    libmbedtls.a
make[1]: Leaving directory '/home/scaprile/work/cesanta/mongoose/tutorials/http/http-client/mbedtls/library'
cc main.c mongoose.c  packed_fs.c       -W -Wall -Wextra -g -I.   -DMG_ENABLE_LINES=1 -DMG_ENABLE_PACKED_FS=1 -DMG_TLS=MG_TLS_MBED mbedtls/library/libmbedtls.a  mbedtls/library/libmbedcrypto.a  mbedtls/library/libmbedx509.a -o example

$ LOG_LEVEL=3 ./example https://httpbin.org/
2bc5c43 3 net.c:174:mg_connect          1 -1 https://httpbin.org/
2bc5c43 3 net.c:174:mg_connect          2 -1 udp://8.8.8.8:53
2bc5c43 3 sock.c:141:mg_send            2 4 0:0:0 29 err 0
2bc5c5d 3 sock.c:308:read_conn          2 4 0:0:0 61 err 0
2bc5c5d 3 dns.c:169:dns_cb              1 httpbin.org is 44.223.214.11
2bc5c5d 3 sock.c:399:mg_connect_resolve 1 5 -> 44.223.214.11:443 pend
2bc5d08 3 tls_mbed.c:107:mg_tls_init    1 Setting TLS
2bc5d0b 3 tls_mbed.c:141:mg_tls_init    1 hostname verification: httpbin.org
2bc5db8 3 sock.c:308:read_conn          1 5 84:0:0 -2 err 115
2bc5db8 3 sock.c:308:read_conn          1 5 84:0:0 -2 err 115
2bc5dc2 3 sock.c:308:read_conn          1 5 84:0:0 -2 err 115
2bc5e6d 3 tls_mbed.c:80:mg_tls_handshak 1 success
2bc5e6d 3 sock.c:308:read_conn          1 5 84:0:0 -2 err 115
2bc5e6d 3 sock.c:319:write_conn         1 5 snd 84/16384 rcv 0/16384 n=84 err=0
2bc5f20 3 sock.c:308:read_conn          1 5 0:0:0 234 err 0
2bc5f20 3 sock.c:308:read_conn          1 5 0:234:0 -2 err 115
2bc5f20 3 sock.c:308:read_conn          1 5 0:234:0 -2 err 115
2bc5f20 3 sock.c:308:read_conn          1 5 0:234:0 -2 err 115
2bc5f20 3 sock.c:308:read_conn          1 5 0:234:0 -2 err 115
2bc5f21 3 sock.c:308:read_conn          1 5 0:234:0 -2 err 115
2bc5f21 3 sock.c:308:read_conn          1 5 0:234:0 -2 err 115
2bc5f21 3 sock.c:308:read_conn          1 5 0:234:31 9593 err 0
HTTP/1.1 200 OK
Date: Mon, 27 Jan 2025 12:43:43 GMT
Content-Type: text/html; charset=utf-8

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	static void fn(struct mg_connection c, int ev, void ev_data) {
	if (ev == MG_EV_OPEN) {
	// Connection created. Store connect expiration time in c->data
	(uint64_t ) c->data = mg_millis() + s_timeout_ms;
	} else if (ev == MG_EV_POLL) {
	if (mg_millis() > (uint64_t ) c->data &&
	(c->is_connecting \|\| c->is_resolving)) {
	mg_error(c, "Connect timeout");
	}
	} else if (ev == MG_EV_CONNECT) {
	// Connected to server. Extract host name from URL
	struct mg_str host = mg_url_host(s_url);

	if (mg_url_is_ssl(s_url)) {
	struct mg_tls_opts opts

Is there a good tutorial code for an httpS client using the mongoose library? #3022

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DiegoMartinezRdg Jan 24, 2025

Replies: 3 comments · 1 reply

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scaprile Jan 24, 2025 Collaborator

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DiegoMartinezRdg Jan 27, 2025 Author

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Jan 24, 2025

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