Remove the old in_commasep_string system.

It's just silly to have _two_ systems for traversing a string of
comma-separated protocol ids. I think the new get_commasep_word
technique for looping over the elements of a string is simpler and
more general than the old membership-testing approach, and also it's
necessary for the modern KEX untangling system (which has to be able
to loop over one string, even if it used a membership test to check
things in the other). So this commit rewrites the two remaining uses
of in_commasep_string to use get_commasep_word instead, and deletes
the former.

ssh.h

@@ -1529,9 +1529,6 @@ unsigned alloc_channel_id_general(tree234 *channels, size_t localid_offset);
     TYPECHECK(&((type *)0)->localid == (unsigned *)0, \
               alloc_channel_id_general(tree, offsetof(type, localid)))
 
-bool first_in_commasep_string(char const *needle, char const *haystack,
-                              int haylen);
-bool in_commasep_string(char const *needle, char const *haystack, int haylen);
 void add_to_commasep(strbuf *buf, const char *data);
 bool get_commasep_word(ptrlen *list, ptrlen *word);
 

ssh2transport.c

@@ -940,11 +940,14 @@ static bool ssh2_scan_kexinits(
          */
         *n_server_hostkeys = 0;
 
+        ptrlen list = slists[KEXLIST_HOSTKEY];
+        for (ptrlen word; get_commasep_word(&list, &word) ;) {
             for (i = 0; i < lenof(ssh2_hostkey_algs); i++)
-            if (in_commasep_string(ssh2_hostkey_algs[i].alg->ssh_id,
+                if (ptrlen_eq_string(word, ssh2_hostkey_algs[i].alg->ssh_id)) {
-                                   slists[KEXLIST_HOSTKEY].ptr,
-                                   slists[KEXLIST_HOSTKEY].len))
                     server_hostkeys[(*n_server_hostkeys)++] = i;
+                    break;
+                }
+        }
     }
 
     return true;

ssh2userauth.c

@@ -575,26 +575,36 @@ static void ssh2_userauth_process_queue(PacketProtocolLayer *ppl)
                 /*
                  * Scan it for method identifiers we know about.
                  */
-                s->can_pubkey =
+                bool srv_pubkey = false, srv_passwd = false;
-                    in_commasep_string("publickey", methods.ptr, methods.len);
+                bool srv_keyb_inter = false, srv_gssapi = false;
-                s->can_passwd =
+                bool srv_gssapi_keyex_auth = false;
-                    in_commasep_string("password", methods.ptr, methods.len);
+
-                s->can_keyb_inter =
+                for (ptrlen method; get_commasep_word(&methods, &method) ;) {
-                    s->try_ki_auth &&
+                    if (ptrlen_eq_string(method, "publickey"))
-                    in_commasep_string("keyboard-interactive",
+                        srv_pubkey = true;
-                                       methods.ptr, methods.len);
+                    else if (ptrlen_eq_string(method, "password"))
+                        srv_passwd = true;
+                    else if (ptrlen_eq_string(method, "keyboard-interactive"))
+                        srv_keyb_inter = true;
+                    else if (ptrlen_eq_string(method, "gssapi-with-mic"))
+                        srv_gssapi = true;
+                    else if (ptrlen_eq_string(method, "gssapi-keyex"))
+                        srv_gssapi_keyex_auth = true;
+                }
+
+                /*
+                 * And combine those flags with our own configuration
+                 * and context to set the main can_foo variables.
+                 */
+                s->can_pubkey = srv_pubkey;
+                s->can_passwd = srv_passwd;
+                s->can_keyb_inter = s->try_ki_auth && srv_keyb_inter;
 #ifndef NO_GSSAPI
-                s->can_gssapi =
+                s->can_gssapi = s->try_gssapi_auth && srv_gssapi &&
-                    s->try_gssapi_auth &&
-                    in_commasep_string("gssapi-with-mic",
-                                       methods.ptr, methods.len) &&
                     s->shgss->libs->nlibraries > 0;
-                s->can_gssapi_keyex_auth =
+                s->can_gssapi_keyex_auth = s->try_gssapi_kex_auth &&
-                    s->try_gssapi_kex_auth &&
+                    srv_gssapi_keyex_auth &&
-                    in_commasep_string("gssapi-keyex",
+                    s->shgss->libs->nlibraries > 0 && s->shgss->ctx;
-                                       methods.ptr, methods.len) &&
-                    s->shgss->libs->nlibraries > 0 &&
-                    s->shgss->ctx;
 #endif
             }
 

sshcommon.c

@@ -687,45 +687,6 @@ unsigned alloc_channel_id_general(tree234 *channels, size_t localid_offset)
  * lists of protocol identifiers in SSH-2.
  */
 
-bool first_in_commasep_string(char const *needle, char const *haystack,
-                              int haylen)
-{
-    int needlen;
-    if (!needle || !haystack)          /* protect against null pointers */
-        return false;
-    needlen = strlen(needle);
-
-    if (haylen >= needlen &&       /* haystack is long enough */
-        !memcmp(needle, haystack, needlen) &&   /* initial match */
-        (haylen == needlen || haystack[needlen] == ',')
-        /* either , or EOS follows */
-        )
-        return true;
-    return false;
-}
-
-bool in_commasep_string(char const *needle, char const *haystack, int haylen)
-{
-    char *p;
-
-    if (!needle || !haystack)          /* protect against null pointers */
-        return false;
-    /*
-     * Is it at the start of the string?
-     */
-    if (first_in_commasep_string(needle, haystack, haylen))
-        return true;
-    /*
-     * If not, search for the next comma and resume after that.
-     * If no comma found, terminate.
-     */
-    p = memchr(haystack, ',', haylen);
-    if (!p)
-        return false;
-    /* + 1 to skip over comma */
-    return in_commasep_string(needle, p + 1, haylen - (p + 1 - haystack));
-}
-
 void add_to_commasep(strbuf *buf, const char *data)
 {
     if (buf->len > 0)