From 0bd7e6ca675f879773a635afa711fc7ab00382d5 Mon Sep 17 00:00:00 2001
From: pk910 <philipp@zoelle1.de>
Date: Sat, 7 Jan 2012 08:14:24 +0100
Subject: [PATCH] build a better is_valid_email_addr function

---
 src/nickserv.c | 46 ++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 44 insertions(+), 2 deletions(-)

diff --git a/src/nickserv.c b/src/nickserv.c
index 27dcddf..e9aaad4 100644
--- a/src/nickserv.c
+++ b/src/nickserv.c
@@ -709,9 +709,51 @@ is_registerable_nick(const char *nick)
 }
 
 static int
-is_valid_email_addr(const char *email)
+is_valid_email_addr(const char *org_email)
 {
-    return strchr(email, '@') != NULL;
+    char email[strlen(org_email)+1];
+    strcpy(email, org_email);
+    //validate email address
+    //1st check: there need to be one @
+    char *p1 = strchr(email, '@');
+    if(!p1 || strchr(p1+1, '@')) return 0;
+    *p1 = '\0';
+    //2nd check: username (bevore @) must be at least 1 char long and out of part_chars
+    char *part_chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789._%+-";
+    int i;
+    if(p1 - email == 0) return 0;
+    for(i = 0; i < (p1 - email); i++) {
+        if(!strchr(part_chars, email[i])) return 0;
+    }
+    //3rd check: there need to be at least 1 dot in the domain part and all characters out of part_chars
+    part_chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-";
+    char *p2 = NULL;
+    p1++;
+    i = 0;
+    while(*p1) {
+        if(*p1 == '.') {
+            if(!i) return 0;
+            i = 0;
+            p2 = p1;
+        } else if(!strchr(part_chars, *p1))
+            return 0;
+        else
+            i++;
+        p1++;
+    }
+    if(!p2) return 0;
+    //4th check: TLD must be <= 5 chars, no special chars
+    i = 0;
+    p2++;
+    while(*p2) {
+        if(!isalpha(*p2))
+            return 0;
+        else
+            i++;
+        p2++;
+    }
+    if(i > 5) return 0;
+    return 1;
 }
 
 static const char *
-- 
2.20.1