Extract nickname-checking functions from router.c

3 files changed, 86 insertions, 0 deletions

diff --git a/src/feature/nodelist/describe.c b/src/feature/nodelist/describe.c
index ccf27e02d6..0ef9e3e7f7 100644
--- a/src/feature/nodelist/describe.c
+++ b/src/feature/nodelist/describe.c
@@ -4,6 +4,11 @@
  * Copyright (c) 2007-2018, The Tor Project, Inc. */
 /* See LICENSE for licensing information */
 
+/**
+ * \file describe.c
+ * \brief Format short descriptions of relays.
+ */
+
 #include "core/or/or.h"
 #include "feature/nodelist/describe.h"
 #include "feature/relay/router.h"
diff --git a/src/feature/nodelist/nickname.c b/src/feature/nodelist/nickname.c
new file mode 100644
index 0000000000..7b0b29a934
--- /dev/null
+++ b/src/feature/nodelist/nickname.c
@@ -0,0 +1,62 @@
+/* Copyright (c) 2001 Matej Pfajfar.
+ * Copyright (c) 2001-2004, Roger Dingledine.
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2018, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * \file nickname.c
+ * \brief Check and manipulate relay nicknames.
+ */
+
+#include "core/or/or.h"
+#include "feature/nodelist/nickname.h"
+
+/** Return true iff <b>s</b> is a valid server nickname. (That is, a string
+ * containing between 1 and MAX_NICKNAME_LEN characters from
+ * LEGAL_NICKNAME_CHARACTERS.) */
+int
+is_legal_nickname(const char *s)
+{
+  size_t len;
+  tor_assert(s);
+  len = strlen(s);
+  return len > 0 && len <= MAX_NICKNAME_LEN &&
+    strspn(s,LEGAL_NICKNAME_CHARACTERS) == len;
+}
+
+/** Return true iff <b>s</b> is a valid server nickname or
+ * hex-encoded identity-key digest. */
+int
+is_legal_nickname_or_hexdigest(const char *s)
+{
+  if (*s!='$')
+    return is_legal_nickname(s);
+  else
+    return is_legal_hexdigest(s);
+}
+
+/** Return true iff <b>s</b> is a valid hex-encoded identity-key
+ * digest. (That is, an optional $, followed by 40 hex characters,
+ * followed by either nothing, or = or ~ followed by a nickname, or
+ * a character other than =, ~, or a hex character.)
+ */
+int
+is_legal_hexdigest(const char *s)
+{
+  size_t len;
+  tor_assert(s);
+  if (s[0] == '$') s++;
+  len = strlen(s);
+  if (len > HEX_DIGEST_LEN) {
+    if (s[HEX_DIGEST_LEN] == '=' ||
+        s[HEX_DIGEST_LEN] == '~') {
+      if (!is_legal_nickname(s+HEX_DIGEST_LEN+1))
+        return 0;
+    } else {
+      return 0;
+    }
+  }
+  return (len >= HEX_DIGEST_LEN &&
+          strspn(s,HEX_CHARACTERS)==HEX_DIGEST_LEN);
+}
diff --git a/src/feature/nodelist/nickname.h b/src/feature/nodelist/nickname.h
new file mode 100644
index 0000000000..86d4309918
--- /dev/null
+++ b/src/feature/nodelist/nickname.h
@@ -0,0 +1,19 @@
+/* Copyright (c) 2001 Matej Pfajfar.
+ * Copyright (c) 2001-2004, Roger Dingledine.
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2018, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * \file nickname.h
+ * \brief Header file for nickname.c.
+ **/
+
+#ifndef TOR_NICKNAME_H
+#define TOR_NICKNAME_H
+
+int is_legal_nickname(const char *s);
+int is_legal_nickname_or_hexdigest(const char *s);
+int is_legal_hexdigest(const char *s);
+
+#endif