Changeset 1275 for pjproject/trunk/pjnath/src/pjnath/stun_msg.c

Timestamp:

May 15, 2007 10:42:56 AM (17 years ago)

Author:

bennylp

Message:

Fixed several STUN bugs: USERNAME, REALM etc are not allowed in the response, retransmission timer calculation bug, etc.

File:

• pjproject/trunk/pjnath/src/pjnath/stun_msg.c (modified) (10 diffs)

pjproject/trunk/pjnath/src/pjnath/stun_msg.c

@@ -18 +18 @@
  */
 #include <pjnath/stun_msg.h>
-#include <pjnath/stun_auth.h>
 #include <pjnath/errno.h>
 #include <pjlib-util/crc32.h>
@@ -1949 +1948 @@
  * MD5 digest of username, realm, and password. 
  */
-void pj_stun_calc_md5_key(pj_uint8_t digest[16],
-                          const pj_str_t *realm,
-                          const pj_str_t *username,
-                          const pj_str_t *passwd)
+static void calc_md5_key(pj_uint8_t digest[16],
+                         const pj_str_t *realm,
+                         const pj_str_t *username,
+                         const pj_str_t *passwd)
 {
     /* The 16-byte key for MESSAGE-INTEGRITY HMAC is formed by taking
@@ -1967 +1966 @@
 
 #define REMOVE_QUOTE(s) if (s.slen && *s.ptr=='"') \
-                    s.ptr++, s.slen--; \
-                if (s.slen && s.ptr[s.slen-1]=='"') \
-                    s.slen--;
+                            s.ptr++, s.slen--; \
+                        if (s.slen && s.ptr[s.slen-1]=='"') \
+                            s.slen--;
 
     /* Add username */
@@ -1998 +1997 @@
 
 /*
+ * Create authentication key to be used for encoding the message with
+ * MESSAGE-INTEGRITY. 
+ */
+PJ_DEF(void) pj_stun_create_key(pj_pool_t *pool,
+                                pj_str_t *key,
+                                const pj_str_t *realm,
+                                const pj_str_t *username,
+                                const pj_str_t *passwd)
+{
+    PJ_ASSERT_ON_FAIL(pool && key && username && passwd, return);
+
+    if (realm && realm->slen) {
+        key->ptr = (char*) pj_pool_alloc(pool, 16);
+        calc_md5_key((pj_uint8_t*)key->ptr, realm, username, passwd);
+        key->slen = 16;
+    } else {
+        pj_strdup(pool, key, passwd);
+    }
+}
+
+
+/*
 static char *print_binary(const pj_uint8_t *data, unsigned data_len)
 {
@@ -2029 +2050 @@
                                        pj_uint8_t *buf, unsigned buf_size,
                                        unsigned options,
-                                       const pj_str_t *password,
+                                       const pj_str_t *key,
                                        unsigned *p_msg_len)
 {
-    pj_stun_msg_hdr *hdr;
     pj_uint8_t *start = buf;
-    pj_stun_realm_attr *arealm = NULL;
-    pj_stun_username_attr *auname = NULL;
     pj_stun_msgint_attr *amsgint = NULL;
     pj_stun_fingerprint_attr *afingerprint = NULL;
-    unsigned printed = 0;
+    unsigned printed = 0, body_len;
     pj_status_t status;
     unsigned i;
@@ -2053 +2071 @@
     if (buf_size < sizeof(pj_stun_msg_hdr))
         return PJ_ETOOSMALL;
-    pj_memcpy(buf, &msg->hdr, sizeof(pj_stun_msg_hdr));
-    hdr = (pj_stun_msg_hdr*) buf;
-    hdr->magic = pj_htonl(hdr->magic);
-    hdr->type = pj_htons(hdr->type);
-    /* We'll fill in the length later */
+    
+    PUTVAL16H(buf, 0, msg->hdr.type);
+    PUTVAL16H(buf, 2, 0);   /* length will be calculated later */
+    PUTVAL32H(buf, 4, msg->hdr.magic);
+    pj_memcpy(buf+8, msg->hdr.tsx_id, sizeof(msg->hdr.tsx_id));
 
     buf += sizeof(pj_stun_msg_hdr);
     buf_size -= sizeof(pj_stun_msg_hdr);
 
-    /* Print each attribute */
+    /* Encode each attribute to the message */
     for (i=0; i<msg->attr_count; ++i) {
         const struct attr_desc *adesc;
@@ -2073 +2091 @@
             /* Stop when encountering MESSAGE-INTEGRITY */
             break;
-
-        } else if (attr_hdr->type == PJ_STUN_ATTR_USERNAME) {
-            pj_assert(auname == NULL);
-            auname = (pj_stun_username_attr*) attr_hdr;
-
-        } else if (attr_hdr->type == PJ_STUN_ATTR_REALM) {
-            pj_assert(arealm == NULL);
-            arealm = (pj_stun_realm_attr*) attr_hdr;
 
         } else if (attr_hdr->type == PJ_STUN_ATTR_FINGERPRINT) {
@@ -2124 +2134 @@
      */
     if (amsgint && afingerprint) {
-        msg->hdr.length = (pj_uint16_t)((buf - start) - 20 + 24 + 8);
+        body_len = (pj_uint16_t)((buf - start) - 20 + 24 + 8);
     } else if (amsgint) {
-        msg->hdr.length = (pj_uint16_t)((buf - start) - 20 + 24);
+        body_len = (pj_uint16_t)((buf - start) - 20 + 24);
     } else if (afingerprint) {
-        msg->hdr.length = (pj_uint16_t)((buf - start) - 20 + 8);
+        body_len = (pj_uint16_t)((buf - start) - 20 + 8);
     } else {
-        msg->hdr.length = (pj_uint16_t)((buf - start) - 20);
+        body_len = (pj_uint16_t)((buf - start) - 20);
     }
 
     /* hdr->length = pj_htons(length); */
-    start[2] = (pj_uint8_t)((msg->hdr.length >> 8) & 0x00FF);
-    start[3] = (pj_uint8_t)(msg->hdr.length & 0x00FF);
+    PUTVAL16H(start, 2, (pj_uint16_t)body_len);
 
     /* Calculate message integrity, if present */
     if (amsgint != NULL) {
-
-        pj_uint8_t md5_key_buf[16];
         pj_hmac_sha1_context ctx;
-        pj_str_t key;
+
+        /* Key MUST be specified */
+        PJ_ASSERT_RETURN(key, PJ_EINVALIDOP);
 
         /* MESSAGE-INTEGRITY must be the last attribute in the message, or
@@ -2162 +2171 @@
         }
 
-        /* Must have USERNAME attribute */
-        if (auname == NULL) {
-            /* Should not happen for message generated by us */
-            pj_assert(PJ_FALSE);
-            return PJ_STATUS_FROM_STUN_CODE(PJ_STUN_SC_MISSING_USERNAME);
-        }
-
-        /* Password must be specified */
-        PJ_ASSERT_RETURN(password, PJ_EINVAL);
-
-        /* Get the key to sign the message */
-        if (arealm == NULL ) {
-            /* For short term credential, the key is the password */
-            key = *password;
-
-        } else {
-            pj_stun_calc_md5_key(md5_key_buf, &arealm->value, 
-                                 &auname->value, password);
-            key.ptr = (char*) md5_key_buf;
-            key.slen = 16;
-        }
-
         /* Calculate HMAC-SHA1 digest, add zero padding to input
          * if necessary to make the input 64 bytes aligned.
          */
-        pj_hmac_sha1_init(&ctx, (pj_uint8_t*)key.ptr, key.slen);
+        pj_hmac_sha1_init(&ctx, (pj_uint8_t*)key->ptr, key->slen);
         pj_hmac_sha1_update(&ctx, (pj_uint8_t*)start, buf-start);
         if ((buf-start) & 0x3F) {
@@ -2221 +2208 @@
     }
 
-    /* Done */
+    /* Update message length. */
+    msg->hdr.length = (pj_uint16_t) ((buf - start) - 20);
+
+    /* Return the length */
     if (p_msg_len)
         *p_msg_len = (buf - start);