add http language header & remove format from credential response

Signed-off-by: Johannes Tuerk <[email protected]>

src/Hyperledger.Aries/Features/OpenID4VC/VCI/Models/CredentialResponse/OidCredentialResponse.cs

@@ -17,12 +17,6 @@ public class OidCredentialResponse
         [JsonProperty("c_nonce_expires_in")]
         public int? CNonceExpiresIn { get; set; }
 
-        /// <summary>
-        ///     REQUIRED. JSON string denoting the format of the issued Credential.
-        /// </summary>
-        [JsonProperty("format")]
-        public string Format { get; set; } = null!;
-
         /// <summary>
         ///     OPTIONAL. A JSON string containing a security token subsequently used to obtain a Credential.
         ///     MUST be present when credential is not returned.

src/Hyperledger.Aries/Features/OpenID4VC/VCI/Services/Oid4VciClientService/IOid4VciClientService.cs

@@ -17,8 +17,9 @@ public interface IOid4VciClientService
         ///     Fetches the metadata related to the OID issuer from the specified endpoint.
         /// </summary>
         /// <param name="endpoint">The endpoint URL to retrieve the issuer metadata.</param>
+        /// <param name="preferredLanguage">The preferred language of the wallet in which it would like to retrieve the issuer metadata. The default is "en"</param>
         /// <returns>A task that represents the asynchronous operation. The task result contains the OID issuer metadata.</returns>
-        Task<OidIssuerMetadata> FetchIssuerMetadataAsync(Uri endpoint);
+        Task<OidIssuerMetadata> FetchIssuerMetadataAsync(Uri endpoint, string preferredLanguage = "en");
 
         /// <summary>
         ///     Requests a verifiable credential using the provided parameters.

src/Hyperledger.Aries/Features/OpenID4VC/VCI/Services/Oid4VciClientService/Oid4VciClientService.cs

@@ -40,7 +40,7 @@ public Oid4VciClientService(
         private readonly IKeyStore _keyStore;
 
         /// <inheritdoc />
-        public async Task<OidIssuerMetadata> FetchIssuerMetadataAsync(Uri endpoint)
+        public async Task<OidIssuerMetadata> FetchIssuerMetadataAsync(Uri endpoint, string preferredLanguage)
         {
             var baseEndpoint = endpoint
                 .AbsolutePath
@@ -50,9 +50,10 @@ public async Task<OidIssuerMetadata> FetchIssuerMetadataAsync(Uri endpoint)
 
             var metadataUrl = new Uri(baseEndpoint, ".well-known/openid-credential-issuer");
 
-            var response = await _httpClientFactory
-                .CreateClient()
-                .GetAsync(metadataUrl);
+            var client = _httpClientFactory.CreateClient();
+            client.DefaultRequestHeaders.Add("Accept-Language", preferredLanguage);
+
+            var response = await client.GetAsync(metadataUrl);
 
             if (!response.IsSuccessStatusCode)
             {