SQL Server Connector Maintenance & Troubleshooting

Applies to: SQL Server

Supplemental information about the SQL Server Connector is provided in this article. For more information about the SQL Server connector, see Extensible Key Management Using Azure Key Vault (SQL Server), Setup Steps for Extensible Key Management Using the Azure Key Vault, and Use SQL Server Connector with SQL Encryption Features.

Note

While Microsoft Entra ID is the new name for Azure Active Directory (Azure AD), to prevent disrupting existing environments, Azure AD still remains in some hardcoded elements such as UI fields, connection providers, error codes, and cmdlets. In this article, the two names are interchangeable.

A. Maintenance Instructions for SQL Server Connector

Key Rotation

Azure Key Vault supports key rotation, which is the process of creating a new key and updating the applications to use the new key. Key rotation is a security best practice that helps protect data in case the key is compromised. The SQL Server Connector supports key rotation. Old keys shouldn't be deleted since it might be required to restore a database using an old key. To rotate a key, follow the steps in Rotate asymmetric key with a new AKV key or a new AKV key version.

Upgrade of SQL Server Connector

Versions 1.0.0.440 and older have been replaced and are no longer supported in production environments. Versions 1.0.1.0 and newer are supported in production environments. Use the following instructions to upgrade to the latest version available on the Microsoft Download Center.

Upgrade

  1. Stop SQL Server service using SQL Server Configuration Manager
  2. Uninstall the old version using Control Panel\Programs\Programs and Features
    1. Application name: SQL Server Connector for Microsoft Azure Key Vault
    2. Version: 15.0.300.96 (or older)
    3. DLL file date: 01/30/2018 (or older)
  3. Install (upgrade) new SQL Server Connector for Microsoft Azure Key Vault
    1. Version: 15.0.2000.440
    2. DLL file date: 09/11/2020
  4. Start SQL Server service
  5. Test encrypted databases are accessible

Rollback

  1. Stop SQL Server service using SQL Server Configuration Manager

  2. Uninstall the new version using Control Panel\Programs\Programs and Features

    1. Application name: SQL Server Connector for Microsoft Azure Key Vault
    2. Version: 15.0.2000.440
    3. DLL file date: 11/24/2020
  3. Install old version of SQL Server Connector for Microsoft Azure Key Vault

    1. Version: 15.0.300.96
    2. DLL file date: 01/30/2018
  4. Start SQL Server service

  5. Check that the databases using TDE are accessible

  6. After validating that the update works, you can delete the old SQL Server Connector folder (if you chose to rename it instead of uninstalling in Step 3)

Older versions of the SQL Server Connector

Deep links to older versions of the SQL Server Connector

Rolling the SQL Server service principal

SQL Server uses service principals created in Microsoft Entra ID (formerly Azure Active Directory) as credentials to access the Key Vault. The service principal has a Client ID and Authentication Key. A SQL Server credential is set up with the VaultName, Client ID, and Authentication Key. The Authentication Key is valid for a certain period of time (one or two years). Before the time period expires a new key must be generated in Microsoft Entra ID for the service principal. Then the credential has to be changed in SQL Server. Management Studio maintains a cache for the credential in the current session, so when a credential is changed, Management Studio should be restarted.

Key Backup and Recovery

The Key vault should be regularly backed up. If an asymmetric key in the vault is lost, it can be restored from backup. The key must be restored using the same name as before, which the Restore PowerShell command does (see below steps).
If the vault has been lost, you'll need to recreate a vault and restore the asymmetric key to the vault using the same name as before. The vault name can be different (or the same as before). Set the access permissions on the new vault to grant to the SQL Server service principal the access that is needed for the SQL Server encryption scenarios, and then adjust the SQL Server credential so that the new vault name is reflected.

In summary, here are the steps:

  • Back up the vault key (using the Backup-AzureKeyVaultKey PowerShell cmdlet).
  • In the case of vault failure, create a new vault in the same geographic region. The user creating the vault should be in the same default directory as the service principal setup for SQL Server.
  • Restore the key to the new vault using the Restore-AzureKeyVaultKey PowerShell cmdlet, which restores the key using the same name as before. If there's already a key with the same name, the restore fails.
  • Grant permissions to the SQL Server service principal to use this new vault.
  • Modify the SQL Server credential used by the Database Engine to reflect the new vault name (if needed).

Key backups can be restored across Azure regions, as long as they remain in the same geographic region or national cloud: USA, Canada, Japan, Australia, India, APAC, Europe Brazil, China, US Government, or Germany.

B. Frequently Asked Questions

On Azure Key Vault

How do key operations work with Azure Key Vault?
The asymmetric key in the key vault is used to protect SQL Server encryption keys. Only the public portion of the asymmetric key ever leaves the vault; the private portion is never exported by the vault. All cryptographic operations using the asymmetric key are done within the Azure Key Vault service, and are protected by the service's security.

What is a Key URI?
Every key in Azure Key Vault has a Uniform Resource Identifier (URI), which you can use to reference the key in your application. Use the format https://ContosoKeyVault.vault.azure.net/keys/ContosoFirstKey to get the current version, and use the format https://ContosoKeyVault.vault.azure.net/keys/ContosoFirstKey/cgacf4f763ar42ffb0a1gca546aygd87 to get a specific version.

On Configuring SQL Server

What are the endpoints that the SQL Server Connector needs access to? The Connector talks to two endpoints, which need to be allowed. The only port required for outbound communication to these other services is 443 for Https:

  • login.microsoftonline.com/*:443
  • .vault.azure.net/:443

Additionally, checking the certificate revocation list might create HTTP traffic on port 80.

Note

Using the SQL Server Connector for Azure Key Vault behind a firewall or proxy server can affect performance if traffic is delayed or blocked. Familiarize yourself with Access Azure Key Vault behind a firewall to ensure the correct rules are in place.

How do I connect to Azure Key Vault through an HTTP(S) Proxy Server? The Connector uses Internet Explorer's Proxy configuration settings. These settings can be controlled via Group Policy or via the Registry, but it's important to note that they aren't system-wide settings and will need to be targeted to the service account running the SQL Server instance. If a Database Administrator views or edits the settings in Internet Explorer, they'll only affect the Database Administrator's account rather than the SQL Server engine. Logging on to the server interactively using the service account isn't recommended and is blocked in many secure environments. Changes to the configured proxy settings might require restarting the SQL Server instance to take effect as they're cached when the Connector first attempts to connect to a key vault.

Which key sizes in Azure Key Vault are supported by the SQL Server Connector? The latest build of SQL Server Connector supports Azure Key Vault keys of sizes 2048 and 3072.

Note

The "sys.asymmetric_keys" view reports the key size as 2048 even if key size 3072 is used. This is a known gap in this view and the SQL Server product team will address this in a future release.

What are the minimum permission levels required for each configuration step in SQL Server?
Though you could perform all the configuration steps as a member of the sysadmin fixed server role, Microsoft encourages you to minimize the permissions you use. The following list defines the minimum permission level for each action.

  • To create a cryptographic provider, requires CONTROL SERVER permission or membership in the sysadmin fixed server role.

  • To change a configuration option and run the RECONFIGURE statement, you must be granted the ALTER SETTINGS server-level permission. The ALTER SETTINGS permission is implicitly held by the sysadmin and serveradmin fixed server roles.

  • To create a credential, requires ALTER ANY CREDENTIAL permission.

  • To add a credential to a login, requires ALTER ANY LOGIN permission.

  • To create an asymmetric key, requires CREATE ASYMMETRIC KEY permission.

How do I change my default Microsoft Entra directory so my key vault is created in the same subscription and directory as the service principal I created for the SQL Server Connector?

Screenshot showing Microsoft Entra ID change default directory help steps.

  1. Go to the Azure portal.

  2. On the upper-right corner of the page, select the settings icon, or your user profile.

  3. On the Directories + subscriptions page, select All Directories to see all the Microsoft Entra directories that you belong to.

  4. You can change your Startup directory, or switch to a different directory if you have multiple directories.

    Note

    You may not have permissions to actually change the default directory on your Azure subscription. In this case, create the Microsoft Entra service principal within your default directory so that it is in the same directory as the Azure Key Vault used later.

To learn more about Microsoft Entra ID, read How Azure subscriptions are related to Microsoft Entra ID.

C. Error Code Explanations for SQL Server Connector

Note

While Microsoft Entra ID is the new name for Azure Active Directory (Azure AD), to prevent disrupting existing environments, Azure AD still remains in some hardcoded elements such as UI fields, connection providers, error codes, and cmdlets. In this article, the two names are interchangeable.

Provider Error Codes:

Error code Symbol Description
0 scp_err_Success The operation has succeeded.
1 scp_err_Failure The operation has failed.
2 scp_err_InsufficientBuffer This error tells engine to allocate more memory for the buffer.
3 scp_err_NotSupported The operation is not supported. For example, the key type or algorithm specified isn't supported by the EKM provider.
4 scp_err_NotFound The specified key or algorithm couldn't be found by the EKM provider.
5 scp_err_AuthFailure The authentication has failed with EKM provider.
6 scp_err_InvalidArgument The provided argument is invalid.
7 scp_err_ProviderError There is an unspecified error happened in EKM provider that is caught by SQL engine.
401 acquireToken Server responded 401 for the request. Make sure the client ID and secret are correct, and the credential string is a concatenation of AAD client ID and secret without hyphens.
404 getKeyByName The server responded 404, because the key name was not found. Please make sure the key name exists in your vault.
2049 scp_err_KeyNameDoesNotFitThumbprint The key name is too long to fit into SQL engine's thumbprint. The key name must not exceed 26 characters.
2050 scp_err_PasswordTooShort The secret string that is the concatenation of AAD client ID and secret is shorter than 32 characters.
2051 scp_err_OutOfMemory SQL engine has run out of memory and failed to allocate memory for EKM provider.
2052 scp_err_ConvertKeyNameToThumbprint Failed to convert key name to thumbprint.
2053 scp_err_ConvertThumbprintToKeyName Failed to convert thumbprint to key name.
2057 scp_err_ThumbprintExistedInRegistry The key thumbprint already exists in Windows registry mapped to a different key URI.
2058 scp_err_FailureInRegistry Failed to perform the operation in registry. SQL Server service account does not have permission to create the registry key.
3000 ErrorSuccess The AKV operation has succeeded.
3001 ErrorUnknown The AKV operation has failed with an unspecified error.
3002 ErrorHttpCreateHttpClientOutOfMemory Cannot create an HttpClient for AKV operation due to out of memory.
3003 ErrorHttpOpenSession Cannot open an Http session because of network error.
3004 ErrorHttpConnectSession Cannot connect an Http session because of network error.
3005 ErrorHttpAttemptConnect Cannot attempt a connect because of network error.
3006 ErrorHttpOpenRequest Cannot open a request due to network error.
3007 ErrorHttpAddRequestHeader Cannot add request header.
3008 ErrorHttpSendRequest Cannot send a request due to network error.
3009 ErrorHttpGetResponseCode Cannot get a response code due to network error.
3010 ErrorHttpResponseCodeUnauthorized Server responded 401 for the request.
3011 ErrorHttpResponseCodeThrottled Server has throttled the request.
3012 ErrorHttpResponseCodeClientError The request sent from the connector is invalid. This usually means the key name is invalid or contains invalid characters.
3013 ErrorHttpResponseCodeServerError Server responded a response code between 500 and 600.
3014 ErrorHttpQueryHeader Cannot query for response header.
3015 ErrorHttpQueryHeaderOutOfMemoryCopyHeader Cannot copy the response header due to out of memory.
3016 ErrorHttpQueryHeaderOutOfMemoryReallocBuffer Cannot query the response header due to out of memory when reallocating a buffer.
3017 ErrorHttpQueryHeaderNotFound Cannot find the query header in the response.
3018 ErrorHttpQueryHeaderUpdateBufferLength Cannot update the buffer length when querying the response header.
3019 ErrorHttpReadData Cannot read response data due to network error.
3076 ErrorHttpResourceNotFound The server responded 404, because the key name was not found. Make sure the key name exists in your vault.
3077 ErrorHttpOperationForbidden The server responded 403, because the user doesn't have proper permission to perform the action. Make sure you have the permission for the specified operation. At minimum, the connector requires 'get, list, wrapKey, unwrapKey' permissions to function properly.
3100 ErrorHttpCreateHttpClientOutOfMemory Cannot create a HttpClient for AKV operation due to out of memory.
3101 ErrorHttpOpenSession Cannot open a Http session due to network error.
3102 ErrorHttpConnectSession Cannot connect a Http session due to network error.
3103 ErrorHttpAttemptConnect Cannot attempt a connect due to network error.
3104 ErrorHttpOpenRequest Cannot open a request due to network error.
3105 ErrorHttpAddRequestHeader Cannot add request header.
3106 ErrorHttpSendRequest Cannot send a request due to network error.
3107 ErrorHttpGetResponseCode Cannot get a response code due to network error.
3108 ErrorHttpResponseCodeUnauthorized Server responded 401 for the request. Make sure the client Id and secret are correct, and the credential string is a concatenation of AAD client Id and secret without hyphens.
3109 ErrorHttpResponseCodeThrottled Server has throttled the request.
3110 ErrorHttpResponseCodeClientError The request is invalid. This usually means the key name is invalid or contains invalid characters.
3111 ErrorHttpResponseCodeServerError Server responded a response code between 500 and 600.
3112 ErrorHttpResourceNotFound The server responded 404, because the key name was not found. Please make sure the key name exists in your vault.
3113 ErrorHttpOperationForbidden The server responded 403, because the user does not have proper permission to perform the action. Please make sure you have the permission for the specified operation. At minimum,'get, wrapKey, unwrapKey' permissions are required.
3114 ErrorHttpQueryHeader Cannot query for response header.
3115 ErrorHttpQueryHeaderOutOfMemoryCopyHeader Cannot copy the response header due to out of memory.
3116 ErrorHttpQueryHeaderOutOfMemoryReallocBuffer Cannot query the response header due to out of memory when reallocating a buffer.
3117 ErrorHttpQueryHeaderNotFound Cannot find the query header in the response.
3118 ErrorHttpQueryHeaderUpdateBufferLength Cannot update the buffer length when querying the response header.
3119 ErrorHttpReadData Cannot read response data due to network error.
3120 ErrorHttpGetResponseOutOfMemoryCreateTempBuffer Cannot get response body due to out of memory when creating a temp buffer.
3121 ErrorHttpGetResponseOutOfMemoryGetResultString Cannot get response body due to out of memory when get result string.
3122 ErrorHttpGetResponseOutOfMemoryAppendResponse Cannot get response body due to out of memory when appending response.
3200 ErrorGetAADValuesOutOfMemoryConcatPath Cannot get Azure Active Directory challenge header values due to out of memory when concatenating the path.
3201 ErrorGetAADDomainUrlStartPosition Cannot find the starting position for Azure Active Directory domain Url in malformatted response challenge header.
3202 ErrorGetAADDomainUrlStopPosition Cannot find the ending position for Azure Active Directory domain Url in malformatted response challenge header.
3203 ErrorGetAADDomainUrlMalformatted The Azure Active Directory response challenge header is malformatted and doesn't contain the AAD domain Url.
3204 ErrorGetAADDomainUrlOutOfMemoryAlloc Out of memory when allocating buffer for Azure Active Directory domain Url.
3205 ErrorGetAADTenantIdOutOfMemoryAlloc Out of memory when allocating buffer for Azure Active Directory tenantId.
3206 ErrorGetAKVResourceUrlStartPosition Cannot find the starting position for Azure Key Vault resource Url in malformatted response challenge header.
3207 ErrorGetAKVResourceUrlStopPosition Cannot find the ending position for Azure Key Vault resource Url in malformatted response challenge header.
3208 ErrorGetAKVResourceUrlOutOfMemoryAlloc Out of memory when allocating buffer for Azure Key Vault resource Url.
3300 ErrorGetTokenOutOfMemoryConcatPath Cannot get token due to out of memory when concatenating the request path.
3301 ErrorGetTokenOutOfMemoryConcatBody Cannot get token due to out of memory when concatenating the response body.
3302 ErrorGetTokenOutOfMemoryConvertResponseString Cannot get token due to out of memory when converting the response string.
3303 ErrorGetTokenBadCredentials Cannot get token due to incorrect credentials. Make sure the credential string or certificate is valid.
3304 ErrorGetTokenFailedToGetToken While the credentials are correct, the operation still failed to get a valid token.
3305 ErrorGetTokenRejected The token is valid but is rejected by server.
3306 ErrorGetTokenNotFound Cannot find the token in response.
3307 ErrorGetTokenJsonParser Cannot parse the JSON response of server.
3308 ErrorGetTokenExtractToken Cannot extract the token from the JSON response.
3400 ErrorGetKeyByNameOutOfMemoryConvertResponseString Cannot get the key by name due to out of memory converting the response string.
3401 ErrorGetKeyByNameOutOfMemoryConcatPath Cannot get the key by name due to out of memory when concatenating the path.
3402 ErrorGetKeyByNameOutOfMemoryConcatHeader Cannot get the key by name due to out of memory when concatenating the header.
3403 ErrorGetKeyByNameNoResponse Cannot get the key by name due to no response from server.
3404 ErrorGetKeyByNameJsonParser Cannot get the key by name due to failed to parse the JSON response.
3405 ErrorGetKeyByNameExtractKeyNode Cannot get the key by name due to failed to extract the key node from the response.
3406 ErrorGetKeyByNameExtractKeyId Cannot get the key by name due to failed to extract the key Id from the response.
3407 ErrorGetKeyByNameExtractKeyType Cannot get the key by name due to failed to extract the key type from the response.
3408 ErrorGetKeyByNameExtractKeyN Cannot get the key by name due to failed to extract the key N from the response.
3409 ErrorGetKeyByNameBase64DecodeN Cannot get the key by name due to failed to Base64 decode the N.
3410 ErrorGetKeyByNameExtractKeyE Cannot get the key by name due to failed to extract the key E from the response.
3411 ErrorGetKeyByNameBase64DecodeE Cannot get the key by name due to failed to Base64 decode the E.
3412 ErrorGetKeyByNameExtractKeyUri Cannot extract the key Uri from the response.
3500 ErrorBackupKeyOutOfMemoryConvertResponseString Cannot back up key due to out of memory when converting the response string.
3501 ErrorBackupKeyOutOfMemoryConcatPath Cannot back up key due to out of memory when concatenating the path.
3502 ErrorBackupKeyOutOfMemoryConcatHeader Cannot back up key due to out of memory when concatenating the request header.
3503 ErrorBackupKeyNoResponse Cannot back up key due to no response from server.
3504 ErrorBackupKeyJsonParser Cannot back up key due to failed to parse the JSON response.
3505 ErrorBackupKeyExtractValue Cannot back up key due to failed to extract the value from JSON response.
3506 ErrorBackupKeyBase64DecodeValue Cannot back up key due to failed to Base64 decode the value field.
3600 ErrorWrapKeyOutOfMemoryConvertResponseString Cannot wrap key due to out of memory when converting response string.
3601 ErrorWrapKeyOutOfMemoryConcatPath Cannot wrap key due to out of memory when concatenating the path.
3602 ErrorWrapKeyOutOfMemoryConcatHeader Cannot wrap key due to out of memory when concatenating the header.
3603 ErrorWrapKeyOutOfMemoryConcatBody Cannot wrap key due to out of memory when concatenating the body.
3604 ErrorWrapKeyOutOfMemoryConvertEncodedBody Cannot wrap key due to out of memory when converting the encoded body.
3605 ErrorWrapKeyBase64EncodeKey Cannot wrap key due to failed to Base64 encode the key.
3606 ErrorWrapKeyBase64DecodeValue Cannot wrap key due to failed to Base64 decode the response value.
3607 ErrorWrapKeyJsonParser Cannot wrap key due to failed to parse the JSON response.
3608 ErrorWrapKeyExtractValue Cannot wrap key due to failed to extract value from response.
3609 ErrorWrapKeyNoResponse Cannot wrap key due to no response from server.
3700 ErrorUnwrapKeyOutOfMemoryConvertResponseString Cannot unwrap key due to out of memory when converting response string.
3701 ErrorUnwrapKeyOutOfMemoryConcatPath Cannot unwrap key due to out of memory when concatenating the path.
3702 ErrorUnwrapKeyOutOfMemoryConcatHeader Cannot unwrap key due to out of memory when concatenating the header.
3703 ErrorUnwrapKeyOutOfMemoryConcatBody Cannot unwrap key due to out of memory when concatenating the body.
3704 ErrorUnwrapKeyOutOfMemoryConvertEncodedBody Cannot unwrap key due to out of memory when converting the encoded body.
3705 ErrorUnwrapKeyBase64EncodeKey Cannot unwrap key due to failed to Base64 encode the key.
3706 ErrorUnwrapKeyBase64DecodeValue Cannot unwrap key due to failed to Base64 decode the response value.
3707 ErrorUnwrapKeyJsonParser Cannot unwrap key due to failed to extract value from response.
3708 ErrorUnwrapKeyExtractValue Cannot unwrap key due to failed to extract value from response.
3709 ErrorUnwrapKeyNoResponse Cannot unwrap key due to no response from server.
3800 ErrorSecretAuthParamsGetRequestBody Error creating request body using AAD clientId and secret.
3801 ErrorJWTTokenCreateHeader Error creating JWT token header for authentication with AAD.
3802 ErrorJWTTokenCreatePayloadGUID Error creating GUID for JWT token payload for authentication with AAD.
3803 ErrorJWTTokenCreatePayload Error creating JWT token payload for authentication with AAD.
3804 ErrorJWTTokenCreateSignature Error creating JWT token signature for authentication with AAD.
3805 ErrorJWTTokenSignatureHashAlg Error getting SHA256 hash algorithm for authentication with AAD.
3806 ErrorJWTTokenSignatureHash Error creating SHA256 hash for JWT token authentication with AAD.
3807 ErrorJWTTokenSignatureSignHash Error signing JWT token hash for authentication with AAD.
3808 ErrorJWTTokenCreateToken Error creating JWT token for authentication with AAD.
3809 ErrorPfxCertAuthParamsImportPfx Error importing Pfx certificate for authentication with AAD.
3810 ErrorPfxCertAuthParamsGetThumbprint Error getting thumbprint from Pfx certificate for authentication with AAD.
3811 ErrorPfxCertAuthParamsGetPrivateKey Error getting private key from Pfx certificate for authentication with AAD.
3812 ErrorPfxCertAuthParamsSignAlg Error getting RSA signing algorithm for Pfx certificate authentication with AAD.
3813 ErrorPfxCertAuthParamsImportForSign Error importing Pfx private key for RSA signing for authentication with AAD.
3814 ErrorPfxCertAuthParamsCreateRequestBody Error creating request body from Pfx certificate for authentication with AAD.
3815 ErrorPEMCertAuthParamsGetThumbprint Error Base64 decoding Thumbprint for authentication with AAD.
3816 ErrorPEMCertAuthParamsGetPrivateKey Error getting RSA private key from PEM for authentication with AAD.
3817 ErrorPEMCertAuthParamsSignAlg Error getting RSA signing algorithm for PEM private key authentication with AAD.
3818 ErrorPEMCertAuthParamsImportForSign Error importing PEM private key for RSA signing for authentication with AAD.
3819 ErrorPEMCertAuthParamsCreateRequestBody Error creating request body from PEM private key for authentication with AAD.
3820 ErrorLegacyPrivateKeyAuthParamsSignAlg Error getting RSA signing algorithm for Legacy private key authentication with AAD.
3821 ErrorLegacyPrivateKeyAuthParamsImportForSign Error importing Legacy private key for RSA signing for authentication with AAD.
3822 ErrorLegacyPrivateKeyAuthParamsCreateRequestBody Error creating request body from Legacy private key for authentication with AAD.
3900 ErrorAKVDoesNotExist Error internet name not resolved. This typically indicates the Azure Key Vault is deleted.
4000 ErrorCreateKeyVaultRetryManagerOutOfMemory Cannot create a RetryManager for AKV operation due to out of memory.

If you don't see your error code in this table, here are some other reasons the error may be happening:

  • You may not have Internet access and cannot access your Azure Key Vault. Check your Internet connection.

  • The Azure Key Vault service may be down. Try again at another time.

  • You may have dropped the asymmetric key from Azure Key Vault or SQL Server. Restore the key.

  • If you receive a "Cannot load library" error, make sure you have the appropriate version of the Visual Studio C++ redistributable installed based on the version of SQL Server that you're running. The table below specifies which version to install from the Microsoft Download Center.

The Windows event log also logs errors associated with the SQL Server Connector, which can help with additional context on why the error is actually happening. The source in the Windows Application Event Log will be "SQL Server Connector for Microsoft Azure Key Vault".

C++ Runtime Libraries for SQL Server Connector 1.0.5.0

SQL Server Version Redistributable Install Link if using SQL Server Connector 1.0.5.0
2008, 2008 R2, 2012, 2014 Visual C++ Redistributable Packages for Visual Studio 2013
2016, 2017, 2019 Visual C++ Redistributable for Visual Studio 2015

C++ Runtime Libraries for SQL Server Connector 1.0.4.0

SQL Server Version Redistributable Install Link if using SQL Server Connector 1.0.4.0
2008, 2008 R2, 2012, 2014, 2016, 2017, 2019 Visual C++ Redistributable Packages for Visual Studio 2013

Additional References

More About Extensible Key Management:

SQL Encryptions supporting EKM:

Related Transact-SQL Commands:

Azure Key Vault documentation: