Enum Credentials 

#[non_exhaustive]
pub enum Credentials {
    SqlServer {
        username: Cow<'static, str>,
        password: Cow<'static, str>,
    },
    AzureAccessToken {
        token: Cow<'static, str>,
    },
    AzureManagedIdentity {
        client_id: Option<Cow<'static, str>>,
    },
    AzureServicePrincipal {
        tenant_id: Cow<'static, str>,
        client_id: Cow<'static, str>,
        client_secret: Cow<'static, str>,
    },
    AzureDefault,
    Certificate {
        tenant_id: Cow<'static, str>,
        client_id: Cow<'static, str>,
        cert_path: Cow<'static, str>,
        password: Option<Cow<'static, str>>,
    },
}

Credentials for SQL Server authentication.

This enum represents the various authentication methods supported. Credentials are designed to minimize copying of sensitive data.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

SqlServer

SQL Server authentication with username and password.

Fields

username: Cow<'static, str>

Username.

password: Cow<'static, str>

Password.

AzureAccessToken

Azure Active Directory / Entra ID access token.

Fields

token: Cow<'static, str>

The access token string.

AzureManagedIdentity

Azure Managed Identity (for VMs and containers).

Fields

client_id: Option<Cow<'static, str>>

Optional client ID for user-assigned identity.

AzureServicePrincipal

Azure Service Principal.

Fields

tenant_id: Cow<'static, str>

Tenant ID.

client_id: Cow<'static, str>

Client ID.

client_secret: Cow<'static, str>

Client secret.

AzureDefault

Azure default credential chain (managed identity, then the signed-in az / azd CLI session). Maps to Authentication=ActiveDirectoryDefault.

Certificate

Client certificate authentication (Azure AD service principal with an X.509 certificate).

The certificate authenticates to Microsoft Entra, which issues the access token used for the FEDAUTH login. This is NOT TDS-level mutual TLS — SQL Server does not accept client certificates at the protocol level.

Fields

tenant_id: Cow<'static, str>

Azure AD tenant ID.

client_id: Cow<'static, str>

Application (client) ID of the service principal.

cert_path: Cow<'static, str>

Path to the certificate file: PKCS#12 (.pfx), or a PEM file containing both the certificate and its private key.

password: Option<Cow<'static, str>>

Optional password protecting the certificate’s private key.

Implementations

impl Credentials

pub fn sql_server( username: impl Into<Cow<'static, str>>, password: impl Into<Cow<'static, str>>, ) -> Credentials

Create SQL Server credentials.

pub fn azure_token(token: impl Into<Cow<'static, str>>) -> Credentials

Create Azure access token credentials.

pub fn azure_default() -> Credentials

Create Azure default-credential-chain credentials (Authentication=ActiveDirectoryDefault): managed identity, then the signed-in az / azd CLI session.

Requires the azure-identity feature.

pub fn certificate( tenant_id: impl Into<Cow<'static, str>>, client_id: impl Into<Cow<'static, str>>, cert_path: impl Into<Cow<'static, str>>, password: Option<Cow<'static, str>>, ) -> Credentials

Create client-certificate (Azure AD service principal) credentials.

cert_path points at a PKCS#12 (.pfx) file, or a PEM file containing both the certificate and its private key. The certificate authenticates to Microsoft Entra, which issues the access token used for login.

Requires the cert-auth feature.

pub fn is_sql_auth(&self) -> bool

Check if these credentials use SQL authentication.

pub fn is_azure_ad(&self) -> bool

Check if these credentials use Azure AD.

pub fn method_name(&self) -> &'static str

Get the authentication method name.

Trait Implementations

impl Clone for Credentials

fn clone(&self) -> Credentials

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Credentials

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl From<Credentials> for SecureCredentials

Available on crate feature zeroize only.

Convert from non-secure credentials to secure credentials.

fn from(creds: Credentials) -> SecureCredentials

Converts to this type from the input type.