diff -ru squid-2.2.STABLE4/src/acl.c my2_squid-2.2.STABLE4/src/acl.c
--- squid-2.2.STABLE4/src/acl.c	Wed Jul  7 03:12:48 1999
+++ my2_squid-2.2.STABLE4/src/acl.c	Tue Jul 13 19:22:18 1999
@@ -75,7 +75,7 @@
 static IPH aclLookupDstIPforASNDone;
 static FQDNH aclLookupSrcFQDNDone;
 static FQDNH aclLookupDstFQDNDone;
-static void aclLookupProxyAuthStart(aclCheck_t * checklist);
+static void aclLookupProxyAuthStart(aclCheck_t * checklist,const char *acl_name);
 static void aclLookupProxyAuthDone(void *data, char *result);
 static wordlist *aclDumpIpList(void *);
 static wordlist *aclDumpDomainList(void *data);
@@ -1029,12 +1029,14 @@
  */
 
 static int
-aclMatchProxyAuth(wordlist * data, const char *proxy_auth, acl_proxy_auth_user * auth_user, aclCheck_t * checklist)
+aclMatchProxyAuth(acl * ae, const char *proxy_auth, acl_proxy_auth_user * auth_user, aclCheck_t * checklist)
 {
     /* checklist is used to register user name when identified, nothing else */
     LOCAL_ARRAY(char, login_buf, USER_IDENT_SZ);
     char *user, *password;
-
+    LOCAL_ARRAY(char, acl_name_buf, USER_IDENT_SZ + ACL_NAME_SZ + 1);
+    wordlist *data = ae->data;
+    
     if (!aclDecodeProxyAuth(proxy_auth, &user, &password, login_buf, sizeof(login_buf)))
 	/* No or invalid Proxy-Auth header */
 	return -2;
@@ -1072,7 +1074,8 @@
 	}
     }
     /* see if we already know this user */
-    auth_user = hash_lookup(proxy_auth_cache, user);
+    snprintf(acl_name_buf,sizeof(acl_name_buf),"%s:%s",user,ae->name);
+    auth_user = hash_lookup(proxy_auth_cache, acl_name_buf);
 
     if (!auth_user) {
 	/* user not yet known, ask external authenticator */
@@ -1102,12 +1105,12 @@
 }
 
 static void
-aclLookupProxyAuthStart(aclCheck_t * checklist)
+aclLookupProxyAuthStart(aclCheck_t * checklist,const char *acl_name)
 {
     LOCAL_ARRAY(char, login_buf, USER_IDENT_SZ);
     const char *proxy_auth;
     char *user, *password;
-    int ok;
+    int ok,len;
     acl_proxy_auth_user *auth_user;
     assert(!checklist->auth_user);
     if (!checklist->request->flags.accelerated) {
@@ -1129,8 +1132,12 @@
     debug(28, 4) ("aclLookupProxyAuthStart: going to ask authenticator on %s\n", user);
     /* we must still check this user's password */
     auth_user = memAllocate(MEM_ACL_PROXY_AUTH_USER);
+    len = strlen(user) + strlen(acl_name) + 2;
+    auth_user->user_acl_name = xmalloc(len);
+    snprintf(auth_user->user_acl_name,len,"%s:%s",user,acl_name);
     auth_user->user = xstrdup(user);
     auth_user->passwd = xstrdup(password);
+    auth_user->acl_name = xstrdup(acl_name);
     auth_user->passwd_ok = -1;
     auth_user->expiretime = -1;
     checklist->auth_user = auth_user;
@@ -1378,7 +1385,7 @@
 	 */
 	r->flags.used_proxy_auth = 1;
 	/* Check the password */
-	switch (aclMatchProxyAuth(ae->data,
+	switch (aclMatchProxyAuth(ae,
 		header,
 		checklist->auth_user,
 		checklist)) {
@@ -1478,6 +1485,7 @@
     const acl_access *A;
     int match;
     ipcache_addrs *ia;
+    acl_list *scan;
     while ((A = checklist->access_list) != NULL) {
 	/*
 	 * If the _acl_access is no longer valid (i.e. its been
@@ -1523,7 +1531,11 @@
 	    return;
 	} else if (checklist->state[ACL_PROXY_AUTH] == ACL_LOOKUP_NEEDED) {
 	    debug(28, 3) ("aclCheck: checking password via authenticator\n");
-	    aclLookupProxyAuthStart(checklist);
+	    for (scan = A->acl_list ; scan &&
+		   scan->acl->type != ACL_PROXY_AUTH; scan = scan->next) ;
+
+	    assert(scan);  /* This system works on this assumption */
+	    aclLookupProxyAuthStart(checklist,scan->acl->name);
 	    checklist->state[ACL_PROXY_AUTH] = ACL_LOOKUP_PENDING;
 	    return;
 	} else if (checklist->state[ACL_PROXY_AUTH] == ACL_PROXY_AUTH_NEEDED) {
@@ -1750,8 +1762,10 @@
 aclFreeProxyAuthUser(void *data)
 {
     acl_proxy_auth_user *u = data;
+    xfree(u->user_acl_name);
     xfree(u->user);
     xfree(u->passwd);
+    xfree(u->acl_name);
     memFree(u, MEM_ACL_PROXY_AUTH_USER);
 }
 
diff -ru squid-2.2.STABLE4/src/authenticate.c my2_squid-2.2.STABLE4/src/authenticate.c
--- squid-2.2.STABLE4/src/authenticate.c	Sat Dec  5 00:54:15 1998
+++ my2_squid-2.2.STABLE4/src/authenticate.c	Tue Jul 13 19:08:56 1999
@@ -88,8 +88,8 @@
     char buf[8192];
     assert(auth_user);
     assert(handler);
-    debug(29, 5) ("authenticateStart: '%s:%s'\n", auth_user->user,
-	auth_user->passwd);
+    debug(29, 5) ("authenticateStart: '%s:%s:%s'\n", auth_user->acl_name,
+		  auth_user->user, auth_user->passwd);
     if (Config.Program.authenticate == NULL) {
 	handler(data, NULL);
 	return;
@@ -100,7 +100,8 @@
     cbdataLock(data);
     r->data = data;
     r->auth_user = auth_user;
-    snprintf(buf, 8192, "%s %s\n", r->auth_user->user, r->auth_user->passwd);
+    snprintf(buf, 8192, "%s %s %s\n", r->auth_user->acl_name,
+	     r->auth_user->user, r->auth_user->passwd);
     helperSubmit(authenticators, buf, authenticateHandleReply, r);
 }
 
Only in my2_squid-2.2.STABLE4/src: squid.conf
diff -ru squid-2.2.STABLE4/src/structs.h my2_squid-2.2.STABLE4/src/structs.h
--- squid-2.2.STABLE4/src/structs.h	Fri Feb 19 22:35:36 1999
+++ my2_squid-2.2.STABLE4/src/structs.h	Tue Jul 13 19:08:55 1999
@@ -69,10 +69,12 @@
 
 struct _acl_proxy_auth_user {
     /* first two items must be same as hash_link */
-    char *user;
+    char *user_acl_name;
     acl_proxy_auth_user *next;
     /* extra fields for proxy_auth */
+    char *user;
     char *passwd;
+    char *acl_name;
     int passwd_ok;		/* 1 = passwd checked OK */
     long expiretime;
 };