What solution can be recommended to restrict access key retrieval while allowing legacy applications to function?

The recommended solution to restrict access key retrieval while allowing legacy applications to function is to apply read-only locks on the storage accounts. This approach helps in reducing the risk associated with access key exposure while still accommodating legacy applications that may rely on those access keys for certain functionalities.

Applying read-only locks prevents any modifications to the storage account configuration, which includes the access keys. Therefore, while the legacy applications can continue to operate without interruption, the keys themselves are protected from unauthorized retrieval or changes. As a result, you maintain both the operational continuity for existing applications and the integrity of access control.

Legacy applications often have hard-coded access keys, making it challenging to switch to more secure access methods without significant rework. By using read-only locks, organizations can temporarily secure these credentials while they work towards implementing more robust identity and access management solutions.

In contrast, disabling access keys altogether could disrupt the functioning of those legacy applications, which depend on those keys. Implementing Azure Active Directory typically enhances access management but may not suit scenarios where applications require straightforward key access. Shared Access Signatures, while a viable option for generating temporary access permissions, do not entirely prevent access key retrieval and do not help legacy systems unless modified to use the new method.