added JWT demo programs

.gitignore

@@ -0,0 +1,8 @@
+*.o
+deps
+jansson
+libjwt
+src/server
+src/jwt_demo_hs256
+src/jwt_demo_rs256
+.gitignore

src/Makefile

@@ -11,7 +11,10 @@ LDLIBS=-L$(DEP_LIB_DIR) -ljwt -ljansson -lcrypto -ldl
 HEADERS=socket.h http.h hexdump.h buffer.h bufio.h
 OBJ=main.o socket.o hexdump.o http.o bufio.o
 
-all:    server
+
+OTHERS=jwt_demo_rs256 jwt_demo_hs256
+
+all:    server $(OTHERS)
 
 $(OBJ) : $(HEADERS)
 
@@ -19,4 +22,4 @@ server: $(OBJ)
 	$(CC) $(LDFLAGS) -o $@ $(OBJ) $(LDLIBS) 
 
 clean:
-	/bin/rm $(OBJ)
+	/bin/rm $(OBJ) $(OTHERS)

src/http.c

@@ -34,19 +34,19 @@ char * server_root;     // root from which static files are served
 
 
 /* Parse HTTP request line, setting req_method, req_path, and req_version. */
-static int
+static bool
 http_parse_request(struct http_transaction *ta)
 {
     size_t req_offset;
     ssize_t len = bufio_readline(ta->client->bufio, &req_offset);
     if (len <= 0)
-        return len;
+        return false;
 
     char *request = bufio_offset2ptr(ta->client->bufio, req_offset);
     char *endptr;
     char *method = strtok_r(request, " ", &endptr);
     if (method == NULL)
-        return -1;
+        return false;
 
     if (!strcmp(method, "GET"))
         ta->req_method = HTTP_GET;
@@ -57,37 +57,37 @@ http_parse_request(struct http_transaction *ta)
 
     char *req_path = strtok_r(NULL, " ", &endptr);
     if (req_path == NULL)
-        return -1;
+        return false;
 
     ta->req_path = bufio_ptr2offset(ta->client->bufio, req_path);
 
     char *http_version = strtok_r(NULL, CRLF, &endptr);
     if (http_version == NULL)  // would be HTTP 0.9
-        return -1;
+        return false;
 
     if (!strcmp(http_version, "HTTP/1.1"))
         ta->req_version = HTTP_1_1;
     else if (!strcmp(http_version, "HTTP/1.0"))
         ta->req_version = HTTP_1_0;
     else
-        return -1;
+        return false;
 
-    return 0;
+    return true;
 }
 
 /* Process HTTP headers. */
-static int
+static bool
 http_process_headers(struct http_transaction *ta)
 {
     for (;;) {
         size_t header_offset;
         ssize_t len = bufio_readline(ta->client->bufio, &header_offset);
-        char *header = bufio_offset2ptr(ta->client->bufio, header_offset);
         if (len <= 0)
-            return len;
+            return false;
 
+        char *header = bufio_offset2ptr(ta->client->bufio, header_offset);
         if (len == 2 && STARTS_WITH(header, CRLF))       // empty CRLF
-            return 0;
+            return true;
 
         header[len-2] = '\0';
         /* Each header field consists of a name followed by a 
@@ -100,7 +100,7 @@ http_process_headers(struct http_transaction *ta)
         char *field_value = strtok_r(NULL, " \t", &endptr);    // skip leading & trailing OWS
 
         if (field_name == NULL)
-            return -1;
+            return false;
 
         // printf("Header: %s: %s\n", field_name, field_value);
         if (!strcasecmp(field_name, "Content-Length")) {
@@ -109,8 +109,6 @@ http_process_headers(struct http_transaction *ta)
 
         /* Handle other headers here. */
     }
-
-    return 0;
 }
 
 const int MAX_HEADER_LEN = 2048;
@@ -331,16 +329,16 @@ http_handle_transaction(struct http_client *self)
     memset(&ta, 0, sizeof ta);
     ta.client = self;
 
-    if (http_parse_request(&ta) == -1)
+    if (!http_parse_request(&ta))
-        return -1;
+        return false;
 
-    if (http_process_headers(&ta) == -1)
+    if (!http_process_headers(&ta))
-        return -1;
+        return false;
 
     if (ta.req_content_len > 0) {
         int rc = bufio_read(self->bufio, ta.req_content_len, &ta.req_body);
         if (rc != ta.req_content_len)
-            return -1; 
+            return false;
 
         // To see the body, use this:
         // char *body = bufio_offset2ptr(ta.client->bufio, ta.req_body);

src/jwt_demo_hs256.c

@@ -0,0 +1,56 @@
+/*
+ * Quick demo of how to use libjwt using a HS256.
+ *
+ * @author gback, CS 3214, Spring 2018
+ */
+#include <jwt.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <time.h>
+
+static const char * NEVER_EMBED_A_SECRET_IN_CODE = "supa secret";
+
+int
+main()
+{
+    jwt_t *mytoken;
+
+    if (jwt_new(&mytoken))
+        perror("jwt_new"), exit(-1);
+
+    if (jwt_add_grant(mytoken, "sub", "user0"))
+        perror("jwt_add_grant sub"), exit(-1);
+
+    time_t now = time(NULL);
+    if (jwt_add_grant_int(mytoken, "iat", now))
+        perror("jwt_add_grant iat"), exit(-1);
+
+    if (jwt_add_grant_int(mytoken, "exp", now + 3600 * 24))
+        perror("jwt_add_grant exp"), exit(-1);
+
+    if (jwt_set_alg(mytoken, JWT_ALG_HS256, 
+            (unsigned char *)NEVER_EMBED_A_SECRET_IN_CODE, strlen(NEVER_EMBED_A_SECRET_IN_CODE)))
+        perror("jwt_set_alg"), exit(-1);
+
+    printf("dump:\n");
+    if (jwt_dump_fp(mytoken, stdout, 1))
+        perror("jwt_dump_fp"), exit(-1);
+
+    char *encoded = jwt_encode_str(mytoken);
+    if (encoded == NULL)
+        perror("jwt_encode_str"), exit(-1);
+
+    printf("encoded as %s\nTry entering this at jwt.io\n", encoded);
+
+    jwt_t *ymtoken;
+    if (jwt_decode(&ymtoken, encoded, 
+            (unsigned char *)NEVER_EMBED_A_SECRET_IN_CODE, strlen(NEVER_EMBED_A_SECRET_IN_CODE)))
+        perror("jwt_decode"), exit(-1);
+
+    char *grants = jwt_get_grants_json(ymtoken, NULL); // NULL means all
+    if (grants == NULL)
+        perror("jwt_get_grants_json"), exit(-1);
+
+    printf("redecoded: %s\n", grants);
+}

src/jwt_demo_rs256.c

@@ -0,0 +1,74 @@
+/*
+ * Quick demo of how to use libjwt using a RS256.
+ * You must have created a private/public key pair like so:
+ *
+ *  openssl genpkey -algorithm RSA -out myprivatekey.pem -pkeyopt rsa_keygen_bits:2048
+ *  openssl rsa -in myprivatekey.pem -pubout > mykey.pub
+ *
+ * @author gback, CS 3214, Spring 2018
+ */
+#include <jwt.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <time.h>
+
+unsigned char private_key[16384];
+unsigned char public_key[16384];
+
+static void 
+read_key(unsigned char *key, const char *name)
+{
+    FILE *f = fopen(name, "r");
+    if (f == NULL)
+        perror("fopen"), exit(-1);
+    size_t len = fread(key, 1, 8192, f);
+    key[len] = '\0';
+    fclose(f);
+}
+
+int
+main()
+{
+    read_key(private_key, "myprivatekey.pem");
+    read_key(public_key, "mykey.pub");
+
+    jwt_t *mytoken;
+
+    if (jwt_new(&mytoken))
+        perror("jwt_new"), exit(-1);
+
+    if (jwt_add_grant(mytoken, "sub", "user0"))
+        perror("jwt_add_grant sub"), exit(-1);
+
+    time_t now = time(NULL);
+    if (jwt_add_grant_int(mytoken, "iat", now))
+        perror("jwt_add_grant iat"), exit(-1);
+
+    if (jwt_add_grant_int(mytoken, "exp", now + 3600 * 24))
+        perror("jwt_add_grant exp"), exit(-1);
+
+    if (jwt_set_alg(mytoken, JWT_ALG_RS256, 
+            private_key, strlen((char *)private_key)))
+        perror("jwt_set_alg"), exit(-1);
+
+    printf("dump:\n");
+    if (jwt_dump_fp(mytoken, stdout, 1))
+        perror("jwt_dump_fp"), exit(-1);
+
+    char *encoded = jwt_encode_str(mytoken);
+    if (encoded == NULL)
+        perror("jwt_encode_str"), exit(-1);
+
+    printf("encoded as %s\nTry entering this at jwt.io\n", encoded);
+
+    jwt_t *ymtoken;
+    if (jwt_decode(&ymtoken, encoded, public_key, strlen((char *)public_key)))
+        perror("jwt_decode"), exit(-1);
+
+    char *grants = jwt_get_grants_json(ymtoken, NULL); // NULL means all
+    if (grants == NULL)
+        perror("jwt_get_grants_json"), exit(-1);
+
+    printf("redecoded: %s\n", grants);
+}

src/login.html

@@ -0,0 +1,41 @@
+<!doctype html>
+<html>
+<!-- minimal demo of expected login functionality -->
+<body>
+    <form onsubmit="return login(this)">
+        Username: <input name="username" >
+        Password: <input name="password" >
+        <input type="submit"/>
+    </form>
+    <div id="result">The result of the request will appear here.</div>
+    <script>
+    const result = document.getElementById('result');
+
+    function login(form) {
+        fetch("/api/login",
+        {
+            headers: {
+              'Accept': 'application/json',
+              'Content-Type': 'application/json'
+            },
+            method: "POST",
+            body: JSON.stringify({
+                username: form.username.value,
+                password: form.password.value
+            })
+        }).then((res) => { 
+            if (res.status == 200) {
+                res.json().then((data) => {
+                    result.innerText = `Success: token ${JSON.stringify(data)}`;
+                });
+            } else {
+                result.innerText = `Received: ${res.status} ${res.statusText}`;
+            }
+        }).catch((error) => { 
+            result.innerText = `Error: ${error.message}`;
+        });
+
+        return false;   // prevent default action
+    }
+    </script>
+</body>

src/main.c

@@ -23,6 +23,7 @@ server_loop(char *port_string)
 {
     int accepting_socket = socket_open_bind_listen(port_string, 1024);
     for (;;) {
+        fprintf(stderr, "Waiting for client...\n");
         int client_socket = socket_accept_client(accepting_socket);
         if (client_socket == -1)
             return;