Mitiate SSRF attack

Signed-off-by: Bryan Frimin <bryan@getprobo.com>

pkg/connector/apikey.go

@@ -40,7 +40,7 @@ func (c *APIKeyConnection) Client(ctx context.Context) (*http.Client, error) {
 	transport := &oauth2Transport{
 		token:      c.APIKey,
 		tokenType:  "Bearer",
-		underlying: httpclient.DefaultPooledTransport(),
+		underlying: httpclient.DefaultPooledTransport(httpclient.WithSSRFProtection()),
 	}
 	return &http.Client{Transport: transport}, nil
 }

pkg/connector/oauth2.go

@@ -49,6 +49,12 @@ type (
 		ExtraAuthParams         map[string]string // Optional: extra params for auth URL (e.g., access_type=offline for Google)
 		TokenEndpointAuth       string            // "post-form" (default), "basic-form", or "basic-json"
 		SupportsIncrementalAuth bool
+
+		// HTTPClient is used for the OAuth2 token-exchange request
+		// issued from CompleteWithState. It must be set by callers;
+		// ApplyProviderDefaults assigns an SSRF-protected client for
+		// production use. Tests may inject a loopback-friendly one.
+		HTTPClient *http.Client
 	}
 
 	OAuth2State struct {
@@ -208,7 +214,7 @@ func (c *OAuth2Connector) CompleteWithState(ctx context.Context, r *http.Request
 		return nil, nil, err
 	}
 
-	tokenResp, err := http.DefaultClient.Do(tokenRequest)
+	tokenResp, err := c.HTTPClient.Do(tokenRequest)
 	if err != nil {
 		return nil, nil, fmt.Errorf("cannot post token URL: %w", err)
 	}
@@ -363,7 +369,14 @@ func (c *OAuth2Connection) Client(ctx context.Context) (*http.Client, error) {
 
 // ClientWithOptions returns an HTTP client with the given options.
 // Use this to add logging and tracing to the HTTP client.
+//
+// SSRF protection is always enabled: the underlying connector URL
+// (for example a 1Password SCIM bridge URL) is customer-supplied,
+// so dials to private, loopback, or other reserved address ranges
+// are refused. Hardcoded provider hosts on public IPs are
+// unaffected.
 func (c *OAuth2Connection) ClientWithOptions(ctx context.Context, opts ...httpclient.Option) (*http.Client, error) {
+	opts = append(opts, httpclient.WithSSRFProtection())
 	transport := &oauth2Transport{
 		token:      c.AccessToken,
 		tokenType:  c.TokenType,
@@ -389,6 +402,11 @@ func (c *OAuth2Connection) RefreshableClient(ctx context.Context, cfg OAuth2Refr
 		return c.ClientWithOptions(ctx, opts...)
 	}
 
+	// All HTTP traffic on this path (token refresh + API calls)
+	// must reject private/loopback/reserved peer IPs because the
+	// configured TokenURL or API host can be customer-influenced.
+	opts = append(opts, httpclient.WithSSRFProtection())
+
 	// Determine auth style based on TokenEndpointAuth
 	authStyle := oauth2.AuthStyleInParams
 	switch cfg.TokenEndpointAuth {
@@ -462,6 +480,10 @@ func (c *OAuth2Connection) clientCredentialsClient(ctx context.Context, opts ...
 		return c.ClientWithOptions(ctx, opts...)
 	}
 
+	// TokenURL is stored from customer-supplied connector settings;
+	// reject dials to private/loopback/reserved peer IPs.
+	opts = append(opts, httpclient.WithSSRFProtection())
+
 	formData := url.Values{}
 	formData.Set("grant_type", "client_credentials")
 	if c.Scope != "" {

pkg/connector/oauth2_test.go

@@ -27,6 +27,7 @@ import (
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	"go.gearno.de/kit/httpclient"
 	"go.probo.inc/probo/pkg/gid"
 	"go.probo.inc/probo/pkg/statelesstoken"
 )
@@ -228,7 +229,9 @@ func TestClientCredentialsClient(t *testing.T) {
 		TokenURL:     server.URL,
 	}
 
-	client, err := conn.clientCredentialsClient(context.Background())
+	// httptest binds to loopback, which the SSRF-protected default
+	// transport refuses; relax just for this test.
+	client, err := conn.clientCredentialsClient(context.Background(), httpclient.WithSSRFAllowLoopback())
 	require.NoError(t, err)
 	require.NotNil(t, client)
 
@@ -518,6 +521,9 @@ func TestCompleteWithState_ScopeFallback(t *testing.T) {
 		RedirectURI:  "https://example.com/cb",
 		AuthURL:      "https://provider.example.com/authorize",
 		TokenURL:     server.URL,
+		// httptest binds to loopback, which the SSRF-protected
+		// default client refuses; inject a permissive client.
+		HTTPClient: httpclient.DefaultClient(httpclient.WithSSRFProtection(), httpclient.WithSSRFAllowLoopback()),
 	}
 
 	orgID := gid.New(gid.NewTenantID(), 0)

pkg/connector/providers.go

@@ -14,6 +14,8 @@
 
 package connector
 
+import "go.gearno.de/kit/httpclient"
+
 // CallbackPath is the HTTP path for the OAuth2 callback endpoint.
 const CallbackPath = "/api/console/v1/connectors/complete"
 
@@ -87,9 +89,11 @@ var (
 
 // ApplyProviderDefaults sets the redirect URI and applies static provider
 // defaults (auth URL, token URL, extra params, token endpoint auth) onto
-// an OAuth2Connector. Call this before registering the connector.
+// an OAuth2Connector, and wires an SSRF-protected HTTP client for the
+// token exchange request. Call this before registering the connector.
 func ApplyProviderDefaults(provider string, redirectURI string, c *OAuth2Connector) {
 	c.RedirectURI = redirectURI
+	c.HTTPClient = httpclient.DefaultClient(httpclient.WithSSRFProtection())
 
 	if def, ok := providerDefinitions[provider]; ok {
 		c.AuthURL = def.AuthURL