Add SAML 2.0 metadata export for dynamic SPs (#1094)

bitwarden_license/src/Sso/Controllers/MetadataController.cs

@@ -0,0 +1,72 @@
+using System;
+using System.Threading.Tasks;
+using Bit.Core.Enums;
+using Bit.Sso.Utilities;
+using Microsoft.AspNetCore.Authentication;
+using Microsoft.AspNetCore.Mvc;
+using Sustainsys.Saml2.AspNetCore2;
+using Sustainsys.Saml2.WebSso;
+
+namespace Bit.Sso.Controllers
+{
+    public class MetadataController : Controller
+    {
+        private readonly IAuthenticationSchemeProvider _schemeProvider;
+
+        public MetadataController(
+            IAuthenticationSchemeProvider schemeProvider)
+        {
+            _schemeProvider = schemeProvider;
+        }
+
+        [HttpGet("saml2/{scheme}")]
+        public async Task<IActionResult> ViewAsync(string scheme)
+        {
+            if (string.IsNullOrWhiteSpace(scheme))
+            {
+                return NotFound();
+            }
+
+            var authScheme = await _schemeProvider.GetSchemeAsync(scheme);
+            if (authScheme == null ||
+                !(authScheme is DynamicAuthenticationScheme dynamicAuthScheme) ||
+                dynamicAuthScheme?.SsoType != SsoType.Saml2)
+            {
+                return NotFound();
+            }
+
+            if (!(dynamicAuthScheme.Options is Saml2Options options))
+            {
+                return NotFound();
+            }
+
+            var uri = new Uri(
+                Request.Scheme
+                + "://"
+                + Request.Host
+                + Request.Path
+                + Request.QueryString);
+
+            var pathBase = Request.PathBase.Value;
+            pathBase = string.IsNullOrEmpty(pathBase) ? "/" : pathBase;
+
+            var requestdata = new HttpRequestData(
+                Request.Method,
+                uri,
+                pathBase,
+                null,
+                Request.Cookies,
+                (data) => data);
+
+            var metadataResult = CommandFactory
+                .GetCommand(CommandFactory.MetadataCommand)
+                .Run(requestdata, options);
+            //Response.Headers.Add("Content-Disposition", $"filename= bitwarden-saml2-meta-{scheme}.xml");
+            return new ContentResult
+            {
+                Content = metadataResult.Content,
+                ContentType = "text/xml",
+            };
+        }
+    }
+}