X-Git-Url: http://git.ozlabs.org/?p=ppp.git;a=blobdiff_plain;f=pppd%2Fchap_ms.c;h=016b42e0c10ee9a845a3e96ad8aa55dcb2b0464c;hp=aec12262ed46375d304b12f9b397acb88be21ba4;hb=d883b2dbafeed3ebd9d7a56ab1469373bd001a3b;hpb=dd39af173ba7e20360fff462cd5848aeb9471a4c

diff --git a/pppd/chap_ms.c b/pppd/chap_ms.c
index aec1226..016b42e 100644
--- a/pppd/chap_ms.c
+++ b/pppd/chap_ms.c
@@ -320,25 +320,90 @@ chapms_make_response(unsigned char *response, int id, char *our_name,
 	ChapMS(challenge, secret, secret_len, response);
 }
 
+struct chapms2_response_cache_entry {
+	int id;
+	unsigned char challenge[16];
+	unsigned char response[MS_CHAP2_RESPONSE_LEN];
+	unsigned char auth_response[MS_AUTH_RESPONSE_LENGTH];
+};
+
+#define CHAPMS2_MAX_RESPONSE_CACHE_SIZE 10
+static struct chapms2_response_cache_entry
+    chapms2_response_cache[CHAPMS2_MAX_RESPONSE_CACHE_SIZE];
+static int chapms2_response_cache_next_index = 0;
+static int chapms2_response_cache_size = 0;
+
+static void
+chapms2_add_to_response_cache(int id, unsigned char *challenge,
+			      unsigned char *response,
+			      unsigned char *auth_response)
+{
+	int i = chapms2_response_cache_next_index;
+
+	chapms2_response_cache[i].id = id;
+	memcpy(chapms2_response_cache[i].challenge, challenge, 16);
+	memcpy(chapms2_response_cache[i].response, response,
+	       MS_CHAP2_RESPONSE_LEN);
+	memcpy(chapms2_response_cache[i].auth_response,
+	       auth_response, MS_AUTH_RESPONSE_LENGTH);
+	chapms2_response_cache_next_index =
+		(i + 1) % CHAPMS2_MAX_RESPONSE_CACHE_SIZE;
+	if (chapms2_response_cache_next_index > chapms2_response_cache_size)
+		chapms2_response_cache_size = chapms2_response_cache_next_index;
+	dbglog("added response cache entry %d", i);
+}
+
+static struct chapms2_response_cache_entry*
+chapms2_find_in_response_cache(int id, unsigned char *challenge,
+		      unsigned char *auth_response)
+{
+	int i;
+
+	for (i = 0; i < chapms2_response_cache_size; i++) {
+		if (id == chapms2_response_cache[i].id
+		    && (!challenge
+			|| memcmp(challenge,
+				  chapms2_response_cache[i].challenge,
+				  16) == 0)
+		    && (!auth_response
+			|| memcmp(auth_response,
+				  chapms2_response_cache[i].auth_response,
+				  MS_AUTH_RESPONSE_LENGTH) == 0)) {
+			dbglog("response found in cache (entry %d)", i);
+			return &chapms2_response_cache[i];
+		}
+	}
+	return NULL;  /* not found */
+}
+
 static void
 chapms2_make_response(unsigned char *response, int id, char *our_name,
 		      unsigned char *challenge, char *secret, int secret_len,
 		      unsigned char *private)
 {
+	const struct chapms2_response_cache_entry *cache_entry;
+	unsigned char auth_response[MS_AUTH_RESPONSE_LENGTH];
+
 	challenge++;	/* skip length, should be 16 */
 	*response++ = MS_CHAP2_RESPONSE_LEN;
+	cache_entry = chapms2_find_in_response_cache(id, challenge, NULL);
+	if (cache_entry) {
+		memcpy(response, cache_entry->response, MS_CHAP2_RESPONSE_LEN);
+		return;
+	}
 	ChapMS2(challenge,
 #ifdef DEBUGMPPEKEY
 		mschap2_peer_challenge,
 #else
 		NULL,
 #endif
-		our_name, secret, secret_len, response, private,
+		our_name, secret, secret_len, response, auth_response,
 		MS_CHAP2_AUTHENTICATEE);
+	chapms2_add_to_response_cache(id, challenge, response, auth_response);
 }
 
 static int
-chapms2_check_success(unsigned char *msg, int len, unsigned char *private)
+chapms2_check_success(int id, unsigned char *msg, int len)
 {
 	if ((len < MS_AUTH_RESPONSE_LENGTH + 2) ||
 	    strncmp((char *)msg, "S=", 2) != 0) {
@@ -349,7 +414,7 @@ chapms2_check_success(unsigned char *msg, int len, unsigned char *private)
 	msg += 2;
 	len -= 2;
 	if (len < MS_AUTH_RESPONSE_LENGTH
-	    || memcmp(msg, private, MS_AUTH_RESPONSE_LENGTH)) {
+	    || !chapms2_find_in_response_cache(id, NULL /* challenge */, msg)) {
 		/* Authenticator Response did not match expected. */
 		error("MS-CHAPv2 mutual authentication failed.");
 		return 0;