Summary:

The changes made in this pull request are focused on improving the handling of multi-valued attributes in SQL filters within the SqlFilterConverter class. The key security-related aspects of these changes are:

1. Handling of Multi-valued Attributes: The code now supports converting LDAP filters with multi-valued attributes to their SQL equivalents, which is an important feature for applications that need to query data with complex filter conditions.

2. Support for PostgreSQL: The patch includes specific handling for PostgreSQL databases, using PostgreSQL-specific operators to efficiently handle multi-valued attributes in SQL filters.

3. Escaping of Special Characters: The code includes a method to escape special regular expression characters when building SQL LIKE expressions, which is an important security measure to prevent SQL injection attacks.

4. Handling of Null Values: The code correctly handles the case where the filter's assertion value is null by generating a SQL IS NULL expression.

5. Attribute Type Resolution: The code attempts to resolve the attribute type for the filter's attribute name, which is important for ensuring that the correct SQL data type is used when generating the filter expression.

Overall, the changes in this patch demonstrate a focus on improving the robustness and security of the SQL filter conversion process, particularly in the handling of multi-valued attributes and the prevention of SQL injection vulnerabilities.

Files Changed:

• jans-orm/sql/src/main/java/io/jans/orm/sql/impl/SqlFilterConverter.java: This file contains the SqlFilterConverter class, which is responsible for converting LDAP filters to SQL filters. The changes in this patch focus on improving the handling of multi-valued attributes in SQL filters, supporting PostgreSQL-specific syntax, escaping special characters to prevent SQL injection, handling null values, and resolving attribute types.