From e673c3eab00b64ddf1a70b0835c8c1a282e90211 Mon Sep 17 00:00:00 2001
From: Johan Wikman <johan.wikman@mariadb.com>
Date: Thu, 5 Dec 2019 13:44:18 +0200
Subject: [PATCH] MXS-2788 Use case-insensitive string comparisons

When names are matched in rules and in resultsets, case insensitive
matching must be used.
---
 server/modules/filter/masking/maskingrules.cc | 23 +++++++---
 server/modules/filter/masking/mysql.hh        | 44 +++++++++++++++++--
 2 files changed, 58 insertions(+), 9 deletions(-)

diff --git a/server/modules/filter/masking/maskingrules.cc b/server/modules/filter/masking/maskingrules.cc
index e0a4485d6..e2d856c3e 100644
--- a/server/modules/filter/masking/maskingrules.cc
+++ b/server/modules/filter/masking/maskingrules.cc
@@ -430,6 +430,17 @@ bool create_rules_from_root(json_t* pRoot,
 
     return parsed;
 }
+
+inline bool is_same_name(const std::string& s, const char* zS)
+{
+    return strcasecmp(s.c_str(), zS) == 0;
+}
+
+inline bool is_same_name(const std::string& lhs, const LEncString& rhs)
+{
+    return rhs.case_eq(lhs);
+}
+
 }
 
 //
@@ -1063,9 +1074,9 @@ bool MaskingRules::Rule::matches(const ComQueryResponse::ColumnDef& column_def,
     // Otherwise it would be easy to bypass a table/database rule.
 
     bool match =
-        (m_column == column_def.org_name())
-        && (m_table.empty() || table.empty() || (m_table == table))
-        && (m_database.empty() || database.empty() || (m_database == database));
+        is_same_name(m_column, column_def.org_name())
+        && (m_table.empty() || table.empty() || is_same_name(m_table, table))
+        && (m_database.empty() || database.empty() || is_same_name(m_database, database));
 
     if (match)
     {
@@ -1094,9 +1105,9 @@ bool MaskingRules::Rule::matches(const QC_FIELD_INFO& field,
     // Otherwise it would be easy to bypass a table/database rule.
 
     bool match =
-        (m_column == zColumn)
-        && (m_table.empty() || !zTable || (m_table == zTable))
-        && (m_database.empty() || !zDatabase || (m_database == zDatabase));
+        is_same_name(m_column, zColumn)
+        && (m_table.empty() || !zTable || is_same_name(m_table, zTable))
+        && (m_database.empty() || !zDatabase || is_same_name(m_database, zDatabase));
 
     if (match)
     {
diff --git a/server/modules/filter/masking/mysql.hh b/server/modules/filter/masking/mysql.hh
index b25d45ebc..4920b8fd1 100644
--- a/server/modules/filter/masking/mysql.hh
+++ b/server/modules/filter/masking/mysql.hh
@@ -294,7 +294,7 @@ public:
     }
 
     /**
-     * Compare for equality.
+     * Compare for equality in a case-sensitive fashion.
      *
      * @param s  The string to compare with.
      *
@@ -306,7 +306,19 @@ public:
     }
 
     /**
-     * Compare for equality.
+     * Compare for equality in case-insensitive fashion.
+     *
+     * @param s  The string to compare with.
+     *
+     * @return True, if the strings are equal.
+     */
+    bool case_eq(const LEncString& s) const
+    {
+        return m_length == s.m_length ? (strncasecmp(m_pString, s.m_pString, m_length) == 0) : false;
+    }
+
+    /**
+     * Compare for equality in a case-sensitive fashion
      *
      * @param s  The string to compare with.
      *
@@ -320,7 +332,21 @@ public:
     }
 
     /**
-     * Compare for equality.
+     * Compare for equality in a case-insensitive fashion.
+     *
+     * @param s  The string to compare with.
+     *
+     * @return True, if the strings are equal.
+     */
+    bool case_eq(const char* zString) const
+    {
+        size_t length = strlen(zString);
+
+        return m_length == length ? (strncasecmp(m_pString, zString, m_length) == 0) : false;
+    }
+
+    /**
+     * Compare for equality in a case-sensitive fashion
      *
      * @param s  The string to compare with.
      *
@@ -331,6 +357,18 @@ public:
         return m_length == s.length() ? (memcmp(m_pString, s.data(), m_length) == 0) : false;
     }
 
+    /**
+     * Compare for equality in a case-insensitive fashion
+     *
+     * @param s  The string to compare with.
+     *
+     * @return True, if the strings are equal.
+     */
+    bool case_eq(const std::string& s) const
+    {
+        return m_length == s.length() ? (strncasecmp(m_pString, s.data(), m_length) == 0) : false;
+    }
+
     /**
      * Convert a @c LEncString to the equivalent @c std::string.
      *