Add support for authenticating using azureauth cli (#1464)

sdk/identity/Cargo.toml

@@ -50,6 +50,7 @@ development = []
 test_e2e = []
 client_certificate = ["openssl"]
 vendored_openssl = ["openssl/vendored"]
+azureauth_cli = []
 
 [[example]]
 name="client_certificate_credentials"

sdk/identity/src/token_credentials/azureauth_cli_credentials.rs

@@ -0,0 +1,209 @@
+use azure_core::{
+    auth::{AccessToken, TokenCredential, TokenResponse},
+    error::{Error, ErrorKind, ResultExt},
+};
+use oauth2::ClientId;
+use serde::Deserialize;
+use std::process::Command;
+use std::str;
+use time::OffsetDateTime;
+
+mod unix_date_string {
+    use azure_core::error::{Error, ErrorKind};
+    use serde::{Deserialize, Deserializer};
+    use time::OffsetDateTime;
+
+    pub fn parse(s: &str) -> azure_core::Result<OffsetDateTime> {
+        let as_i64 = s.parse().map_err(|_| {
+            Error::with_message(ErrorKind::DataConversion, || {
+                format!("unable to parse expiration_date '{s}")
+            })
+        })?;
+
+        OffsetDateTime::from_unix_timestamp(as_i64).map_err(|_| {
+            Error::with_message(ErrorKind::DataConversion, || {
+                format!("unable to parse expiration_date '{s}")
+            })
+        })
+    }
+
+    pub fn deserialize<'de, D>(deserializer: D) -> Result<OffsetDateTime, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        let s = String::deserialize(deserializer)?;
+        parse(&s).map_err(serde::de::Error::custom)
+    }
+}
+
+#[derive(Debug, Clone, Deserialize)]
+struct CliTokenResponse {
+    pub token: AccessToken,
+    #[serde(with = "unix_date_string")]
+    pub expiration_date: OffsetDateTime,
+}
+
+/// Authentication Mode
+///
+/// Note: While the azureauth CLI supports devicecode, users wishing to use
+/// devicecode should use `azure_identity::device_code_flow`
+#[derive(Debug, Clone, Copy)]
+pub enum AzureauthCliMode {
+    All,
+    IntegratedWindowsAuth,
+    Broker,
+    Web,
+}
+
+/// Enables authentication to Azure Active Directory using Azure CLI to obtain an access token.
+pub struct AzureauthCliCredential {
+    tenant_id: String,
+    client_id: ClientId,
+    modes: Vec<AzureauthCliMode>,
+    prompt_hint: Option<String>,
+}
+
+impl AzureauthCliCredential {
+    /// Create a new `AzureCliCredential`
+    pub fn new<T, C>(tenant_id: T, client_id: C) -> Self
+    where
+        T: Into<String>,
+        C: Into<ClientId>,
+    {
+        Self {
+            tenant_id: tenant_id.into(),
+            client_id: client_id.into(),
+            modes: Vec::new(),
+            prompt_hint: None,
+        }
+    }
+
+    pub fn add_mode(mut self, mode: AzureauthCliMode) -> Self {
+        self.modes.push(mode);
+        self
+    }
+
+    pub fn with_modes(mut self, modes: Vec<AzureauthCliMode>) -> Self {
+        self.modes = modes;
+        self
+    }
+
+    pub fn with_prompt_hint<S>(mut self, hint: S) -> Self
+    where
+        S: Into<String>,
+    {
+        self.prompt_hint = Some(hint.into());
+        self
+    }
+
+    fn get_access_token(&self, resource: &str) -> azure_core::Result<CliTokenResponse> {
+        // try using azureauth.exe first, such that azureauth through WSL is
+        // used first if possible.
+        let (cmd_name, use_windows_features) = if Command::new("azureauth.exe")
+            .arg("--version")
+            .output()
+            .map(|x| x.status.success())
+            .unwrap_or(false)
+        {
+            ("azureauth.exe", true)
+        } else {
+            ("azureauth", false)
+        };
+
+        let mut cmd = Command::new(cmd_name);
+        cmd.args([
+            "aad",
+            "--scope",
+            &format!("{resource}/.default"),
+            resource,
+            "--client",
+            self.client_id.as_str(),
+            "--tenant",
+            self.tenant_id.as_str(),
+            "--output",
+            "json",
+        ]);
+
+        if let Some(prompt_hint) = &self.prompt_hint {
+            cmd.args(["--prompt-hint", prompt_hint]);
+        }
+
+        for mode in &self.modes {
+            match mode {
+                AzureauthCliMode::All => {
+                    cmd.args(["--mode", "all"]);
+                }
+                AzureauthCliMode::IntegratedWindowsAuth => {
+                    if use_windows_features {
+                        cmd.args(["--mode", "iwa"]);
+                    }
+                }
+                AzureauthCliMode::Broker => {
+                    if use_windows_features {
+                        cmd.args(["--mode", "broker"]);
+                    }
+                }
+                AzureauthCliMode::Web => {
+                    cmd.args(["--mode", "web"]);
+                }
+            };
+        }
+
+        let result = cmd.output();
+
+        let output = result.map_err(|e| match e.kind() {
+            std::io::ErrorKind::NotFound => {
+                Error::message(ErrorKind::Other, "azureauth CLI not installed")
+            }
+            error_kind => Error::with_message(ErrorKind::Other, || {
+                format!("Unknown error of kind: {error_kind:?}")
+            }),
+        })?;
+
+        if !output.status.success() {
+            let output = String::from_utf8_lossy(&output.stderr);
+            return Err(Error::with_message(ErrorKind::Credential, || {
+                format!("'azureauth' command failed: {output}")
+            }));
+        }
+
+        let output = String::from_utf8(output.stdout)?;
+
+        let token_response = serde_json::from_str::<CliTokenResponse>(&output)
+            .map_kind(ErrorKind::DataConversion)?;
+        Ok(token_response)
+    }
+}
+
+#[cfg_attr(target_arch = "wasm32", async_trait::async_trait(?Send))]
+#[cfg_attr(not(target_arch = "wasm32"), async_trait::async_trait)]
+impl TokenCredential for AzureauthCliCredential {
+    async fn get_token(&self, resource: &str) -> azure_core::Result<TokenResponse> {
+        let tr = self.get_access_token(resource)?;
+        Ok(TokenResponse::new(tr.token, tr.expiration_date))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn parse_example() -> azure_core::Result<()> {
+        let src = r#"{
+            "user": "[email protected]",
+            "display_name": "Example User",
+            "token": "security token here",
+            "expiration_date": "1700166595"
+        }"#;
+
+        let response: CliTokenResponse = serde_json::from_str(src)?;
+        assert_eq!(response.token.secret(), "security token here");
+        assert_eq!(
+            response.expiration_date,
+            OffsetDateTime::from_unix_timestamp(1700166595).expect("known valid date")
+        );
+
+        Ok(())
+    }
+}

sdk/identity/src/token_credentials/mod.rs

@@ -7,6 +7,8 @@
 //! * Client secret
 mod auto_refreshing_credentials;
 mod azure_cli_credentials;
+#[cfg(feature = "azureauth-cli")]
+mod azureauth_cli_credentials;
 #[cfg(feature = "client_certificate")]
 mod client_certificate_credentials;
 mod client_secret_credentials;
@@ -17,6 +19,8 @@ mod workload_identity_credentials;
 
 pub use auto_refreshing_credentials::*;
 pub use azure_cli_credentials::*;
+#[cfg(feature = "azureauth-cli")]
+pub use azureauth_cli_credentials::*;
 #[cfg(feature = "client_certificate")]
 pub use client_certificate_credentials::*;
 pub use client_secret_credentials::*;