Fix SSL hostname verification bug and update env var names

[taylorleese]

Summary

This PR fixes a bug that causes SSL connections to fail with the error "Cannot set verify_mode to CERT_NONE when check_hostname is enabled" when using REDIS_SSL_CERT_REQS=none. It also corrects inconsistent environment variable naming in the documentation.

1. SSL Hostname Verification Bug Fix

Problem: When setting REDIS_SSL_CERT_REQS=none, the server would crash with:

ValueError: Cannot set verify_mode to CERT_NONE when check_hostname is enabled

This happens because Python's SSL library requires that when verify_mode=ssl.CERT_NONE, the check_hostname parameter must also be set to False.

Use Case: This is essential for scenarios like AWS SSM port forwarding, where:

• The connection goes to localhost:6379 (via the tunnel)
• But the SSL certificate is issued for the actual AWS hostname
• Hostname verification fails because localhost ≠ aws-hostname.amazonaws.com

Solution: Added REDIS_SSL_CHECK_HOSTNAME configuration that:

• Automatically defaults to False when REDIS_SSL_CERT_REQS=none
• Matches the behavior of redis-cli --insecure
• Can be explicitly overridden if needed

2. Environment Variable Naming Fixes

Fixed inconsistencies in .env.example, README.md, and smithery.yaml where some SSL variables were missing the SSL_ prefix:

• REDIS_CA_PATH → REDIS_SSL_CA_PATH
• REDIS_CERT_REQS → REDIS_SSL_CERT_REQS
• REDIS_CA_CERTS → REDIS_SSL_CA_CERTS

These now match the actual variable names used in src/common/config.py.

Changes

• ✅ Added REDIS_SSL_CHECK_HOSTNAME configuration option to config.py
• ✅ Automatically disable hostname checking when cert_reqs="none"
• ✅ Added ssl_check_hostname support in parse_redis_uri() for URI-based config
• ✅ Pass ssl_check_hostname to both Redis and RedisCluster connections
• ✅ Added comprehensive tests for the new functionality
• ✅ Updated all documentation to reflect correct variable names

Test Plan

• Verified SSL connection with REDIS_SSL_CERT_REQS=none no longer crashes
• Tested that redis-cli --tls --insecure behavior is matched
• Added unit tests for the new ssl_check_hostname configuration
• Verified default behavior (cert_reqs=required → check_hostname=true)
• Verified auto-disable behavior (cert_reqs=none → check_hostname=false)
• Verified explicit override works (cert_reqs=none + CHECK_HOSTNAME=true)

Related

This addresses the issue discovered while debugging AWS SSM port forwarding connections where the certificate hostname doesn't match the forwarded localhost address.

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[vchomakov]

when REDIS_SSL_CERT_REQS=none

[codecov-commenter]

Codecov Report

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Additional details and impacted files

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