feat: [CI-19349]: Added oidc support for ACR (#154)

* feat: [CI-18693]: Added oidc support for ACR * feat: [CI-19349]: error handling * feat: [CI-19349]: Refactored the code and added cli flags * feat: [CI-19349]: Added test cases * Update cmd/kaniko-acr/main.go * Update cmd/kaniko-acr/main.go * Update cmd/kaniko-acr/main.go * feat: [CI-19349]: changed the variable names * feat: [CI-18693]: Added error handling * feat: [CI-19349]: removed redundant code --------- Co-authored-by: OP (oppenheimer) <21008429+Ompragash@users.noreply.github.com>
2026-06-04 18:23:49 +08:00 · 2025-10-23 12:25:13 +05:30
parent a1d07a3262
commit f83970e37a
4 changed files with 281 additions and 31 deletions
@@ -0,0 +1,72 @@
+package azure
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"strings"
+	"time"
+)
+
+const DefaultResource = "https://management.azure.com/"
+const defaultAuthorityHost = "https://login.microsoftonline.com"
+const defaultHTTPTimeout = 30 * time.Second
+
+// GetAADAccessTokenViaClientAssertion exchanges an external OIDC ID token for an Azure AD access token
+
+func GetAADAccessTokenViaClientAssertion(ctx context.Context, tenantID, clientID, oidcToken, authorityHost string) (string, error) {
+	resource := DefaultResource
+
+	form := url.Values{
+		"client_id":             {clientID},
+		"scope":                 {resource + ".default"},
+		"grant_type":            {"client_credentials"},
+		"client_assertion_type": {"urn:ietf:params:oauth:client-assertion-type:jwt-bearer"},
+		"client_assertion":      {oidcToken},
+	}
+	base := authorityHost
+	if strings.TrimSpace(base) == "" {
+		base = defaultAuthorityHost
+	}
+	base = strings.TrimRight(base, "/")
+	endpoint := fmt.Sprintf("%s/%s/oauth2/v2.0/token", base, tenantID)
+	client := &http.Client{Timeout: defaultHTTPTimeout}
+	req, err := http.NewRequestWithContext(ctx, "POST", endpoint, strings.NewReader(form.Encode()))
+	if err != nil {
+		return "", err
+	}
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+	req.Header.Set("Accept", "application/json")
+	resp, err := client.Do(req)
+	if err != nil {
+		return "", err
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		var aadErr struct {
+			Error            string `json:"error"`
+			ErrorDescription string `json:"error_description"`
+		}
+		limited := io.LimitedReader{R: resp.Body, N: 4096}
+		_ = json.NewDecoder(&limited).Decode(&aadErr)
+		if aadErr.Error != "" {
+			return "", fmt.Errorf("AAD token request failed: status=%d, error=%s", resp.StatusCode, aadErr.Error)
+		}
+		return "", fmt.Errorf("AAD token request failed: status=%d", resp.StatusCode)
+	}
+	var payload struct {
+		AccessToken string `json:"access_token"`
+		TokenType   string `json:"token_type"`
+		ExpiresIn   int    `json:"expires_in"`
+	}
+	if err := json.NewDecoder(resp.Body).Decode(&payload); err != nil {
+		return "", err
+	}
+	if payload.AccessToken == "" {
+		return "", fmt.Errorf("AAD token response missing access_token")
+	}
+	return payload.AccessToken, nil
+}
@@ -0,0 +1,103 @@
+package azure
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+)
+
+func TestGetAADAccessTokenViaClientAssertion_Success(t *testing.T) {
+
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodPost {
+			t.Fatalf("expected POST, got %s", r.Method)
+		}
+		if ct := r.Header.Get("Content-Type"); !strings.Contains(ct, "application/x-www-form-urlencoded") {
+			t.Fatalf("expected form content-type, got %s", ct)
+		}
+		if err := r.ParseForm(); err != nil {
+			t.Fatalf("failed parsing form: %v", err)
+		}
+		assertEq(t, r.Form.Get("client_id"), "client")
+		assertEq(t, r.Form.Get("grant_type"), "client_credentials")
+		assertEq(t, r.Form.Get("client_assertion_type"), "urn:ietf:params:oauth:client-assertion-type:jwt-bearer")
+		assertEq(t, r.Form.Get("client_assertion"), "idtoken")
+		assertEq(t, r.Form.Get("scope"), DefaultResource+".default")
+
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(http.StatusOK)
+		_, _ = w.Write([]byte(`{"access_token":"AT","token_type":"Bearer","expires_in":3600}`))
+	}))
+	defer ts.Close()
+
+	tok, err := GetAADAccessTokenViaClientAssertion(context.Background(), "tenant", "client", "idtoken", ts.URL)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if tok != "AT" {
+		t.Fatalf("expected access token AT, got %q", tok)
+	}
+}
+
+func TestGetAADAccessTokenViaClientAssertion_400WithErrorField(t *testing.T) {
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(http.StatusBadRequest)
+		_, _ = w.Write([]byte(`{"error":"invalid_client","error_description":"bad"}`))
+	}))
+	defer ts.Close()
+
+	_, err := GetAADAccessTokenViaClientAssertion(context.Background(), "tenant", "client", "idtoken", ts.URL)
+	if err == nil || !strings.Contains(err.Error(), "status=400") || !strings.Contains(err.Error(), "invalid_client") {
+		t.Fatalf("expected 400 with invalid_client error, got %v", err)
+	}
+}
+
+func TestGetAADAccessTokenViaClientAssertion_400WithoutErrorField(t *testing.T) {
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusBadRequest)
+		_, _ = w.Write([]byte("{}"))
+	}))
+	defer ts.Close()
+
+	_, err := GetAADAccessTokenViaClientAssertion(context.Background(), "tenant", "client", "idtoken", ts.URL)
+	if err == nil || !strings.Contains(err.Error(), "status=400") {
+		t.Fatalf("expected 400 error, got %v", err)
+	}
+}
+
+func TestGetAADAccessTokenViaClientAssertion_MalformedJSON(t *testing.T) {
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusOK)
+		_, _ = w.Write([]byte("not-json"))
+	}))
+	defer ts.Close()
+
+	_, err := GetAADAccessTokenViaClientAssertion(context.Background(), "tenant", "client", "idtoken", ts.URL)
+	if err == nil {
+		t.Fatalf("expected JSON decode error, got nil")
+	}
+}
+
+func TestGetAADAccessTokenViaClientAssertion_MissingAccessToken(t *testing.T) {
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(http.StatusOK)
+		_, _ = w.Write([]byte(`{"token_type":"Bearer","expires_in":3600}`))
+	}))
+	defer ts.Close()
+
+	_, err := GetAADAccessTokenViaClientAssertion(context.Background(), "tenant", "client", "idtoken", ts.URL)
+	if err == nil || !strings.Contains(err.Error(), "missing access_token") {
+		t.Fatalf("expected missing access_token error, got %v", err)
+	}
+}
+
+func assertEq(t *testing.T, got, want string) {
+	t.Helper()
+	if got != want {
+		t.Fatalf("mismatch: got=%q want=%q", got, want)
+	}
+}