Manage storage account access keys
When you create a storage account, Azure generates two 512-bit storage account access keys. These keys can be used to authorize access to data in your storage account via Shared Key authorization.
Microsoft recommends that you use Azure Key Vault to manage your access keys, and that you regularly rotate and regenerate your keys. Using Azure Key Vault makes it easy to rotate your keys without interruption to your applications. You can also manually rotate your keys.
Protect your access keys
Your storage account access keys are similar to a root password for your storage account. Always be careful to protect your access keys. Use Azure Key Vault to manage and rotate your keys securely. Avoid distributing access keys to other users, hard-coding them, or saving them anywhere in plain text that is accessible to others. Rotate your keys if you believe they may have been compromised.
Microsoft recommends using Azure Active Directory (Azure AD) to authorize requests against blob and queue data if possible, instead of Shared Key. Azure AD provides superior security and ease of use over Shared Key. For more information about authorizing access to data with Azure AD, see Authorize access to Azure blobs and queues using Azure Active Directory.
View account access keys
You can view and copy your account access keys with the Azure portal, PowerShell, or Azure CLI. The Azure portal also provides a connection string for your storage account that you can copy.
To view and copy your storage account access keys or connection string from the Azure portal:
Navigate to your storage account in the Azure portal.
Under Settings, select Access keys. Your account access keys appear, as well as the complete connection string for each key.
Locate the Key value under key1, and click the Copy button to copy the account key.
Alternately, you can copy the entire connection string. Find the Connection string value under key1, and click the Copy button to copy the connection string.
You can use either of the two keys to access Azure Storage, but in general it's a good practice to use the first key, and reserve the use of the second key for when you are rotating keys.
To view or read an account's access keys, the user must either be a Service Administrator, or must be assigned an Azure role that includes the Microsoft.Storage/storageAccounts/listkeys/action. Some Azure built-in roles that include this action are the Owner, Contributor, and Storage Account Key Operator Service Role roles. For more information about the Service Administrator role, see Classic subscription administrator roles, Azure roles, and Azure AD roles. For detailed information about built-in roles for Azure Storage, see the Storage section in Azure built-in roles for Azure RBAC.
Use Azure Key Vault to manage your access keys
Microsoft recommends using Azure Key Vault to manage and rotate your access keys. Your application can securely access your keys in Key Vault, so that you can avoid storing them with your application code. For more information about using Key Vault for key management, see the following articles:
- Manage storage account keys with Azure Key Vault and PowerShell
- Manage storage account keys with Azure Key Vault and the Azure CLI
Manually rotate access keys
Microsoft recommends that you rotate your access keys periodically to help keep your storage account secure. If possible, use Azure Key Vault to manage your access keys. If you are not using Key Vault, you will need to rotate your keys manually.
Two access keys are assigned so that you can rotate your keys. Having two keys ensures that your application maintains access to Azure Storage throughout the process.
Regenerating your access keys can affect any applications or Azure services that are dependent on the storage account key. Any clients that use the account key to access the storage account must be updated to use the new key, including media services, cloud, desktop and mobile applications, and graphical user interface applications for Azure Storage, such as Azure Storage Explorer.
If you plan to manually rotate access keys, Microsoft recommends that you set a key expiration policy, and then use queries in Azure Monitor to determine when it's time to rotate an access key.
Create a key expiration policy
The ability to set a key expiration policy by using the Azure portal is not yet available. You can use either PowerShell or Azure CLI.
Query for policy violations
If you create a diagnostic setting that sends logs to Azure Log Analytics workspace, then you can use an Azure Monitor log query to determine whether a key has expired.
To determine if a key has expired, enter the following query in the Log search bar.
StorageBlobLogs | where KeyExpiryStatus startsWith "Policy Violated".
You can also create a query that helps you determine if a query is nearing expiration. The following query provides this information.
resources | where type =~ 'microsoft.storage/storageAccounts' | extend days = datetime_diff('day', now(), todatetime(parse_json(properties).keyCreationTime)) | extend KeyExpiryStatus = iff(days > 180, "Policy Violated", "") | project name, days, KeyExpiryStatus
Rotate access keys
To rotate your storage account access keys in the Azure portal:
Update the connection strings in your application code to reference the secondary access key for the storage account.
Navigate to your storage account in the Azure portal.
Under Settings, select Access keys.
To regenerate the primary access key for your storage account, select the Regenerate button next to the primary access key.
Update the connection strings in your code to reference the new primary access key.
Regenerate the secondary access key in the same manner.
Microsoft recommends using only one of the keys in all of your applications at the same time. If you use Key 1 in some places and Key 2 in others, you will not be able to rotate your keys without some application losing access.
To rotate an account's access keys, the user must either be a Service Administrator, or must be assigned an Azure role that includes the Microsoft.Storage/storageAccounts/regeneratekey/action. Some Azure built-in roles that include this action are the Owner, Contributor, and Storage Account Key Operator Service Role roles. For more information about the Service Administrator role, see Classic subscription administrator roles, Azure roles, and Azure AD roles. For detailed information about Azure built-in roles for Azure Storage, see the Storage section in Azure built-in roles for Azure RBAC.