From c7f53e193aa173ccfe9c052c706d3ebe2818a2b3 Mon Sep 17 00:00:00 2001
From: belliash <belliash@codingworkshop.eu.org>
Date: Mon, 26 Sep 2022 16:53:58 +0200
Subject: [PATCH] Implement RtlWideStringLength() routine

---
 sdk/xtdk/rtlfuncs.h    |  5 +++++
 xtoskrnl/rtl/widestr.c | 44 +++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 48 insertions(+), 1 deletion(-)

diff --git a/sdk/xtdk/rtlfuncs.h b/sdk/xtdk/rtlfuncs.h
index 01c0bd3..e74d710 100644
--- a/sdk/xtdk/rtlfuncs.h
+++ b/sdk/xtdk/rtlfuncs.h
@@ -73,6 +73,11 @@ RtlWideStringCompare(IN CONST PWCHAR String1,
                      IN CONST PWCHAR String2,
                      IN CONST ULONG Length);
 
+XTCDECL
+SIZE_T
+RtlWideStringLength(IN CONST PWCHAR String,
+                    IN SIZE_T MaxLength);
+
 XTCDECL
 PWCHAR
 RtlWideStringTokenize(IN PWCHAR String,
diff --git a/xtoskrnl/rtl/widestr.c b/xtoskrnl/rtl/widestr.c
index 8e6baa6..b75b19d 100644
--- a/xtoskrnl/rtl/widestr.c
+++ b/xtoskrnl/rtl/widestr.c
@@ -19,7 +19,7 @@
  *        Wide string to be compared.
  *
  * @param Length
- *        Maximum number of characters to compare.
+ *        Maximum number of characters to compare. If no limit set, it compares whole strings.
  *
  * @return Integral value indicating the relationship between the wide strings.
  *
@@ -61,6 +61,48 @@ RtlWideStringCompare(IN CONST PWCHAR String1,
     return 0;
 }
 
+/**
+ * Calculates the length of a given wide string.
+ *
+ * @param String
+ *        Pointer to the null-terminated wide string to be examined.
+ *
+ * @param MaxLength
+ *        Maximum number of wide characters to examine. If no limit set, it examines whole string.
+ *
+ * @return The length of the null-terminated wide string.
+ *
+ * @since: XT 1.0
+ */
+XTCDECL
+SIZE_T
+RtlWideStringLength(IN CONST PWCHAR String,
+                    IN SIZE_T MaxLength)
+{
+    SIZE_T Length;
+
+    /* Check if NULL pointer passed */
+    if(String == NULL)
+    {
+        return 0;
+    }
+
+    /* Iterate through the wide string */
+    for(Length = 0; ; Length++)
+    {
+
+        /* Check if NULL found or max length limit reached */
+        if((Length != 0 && Length == MaxLength) || !String[Length])
+        {
+            /* Finish examination */
+            break;
+        }
+    }
+
+    /* Return wide string length */
+    return Length;
+}
+
 /**
  * Finds the next token in a null-terminated wide string.
  *