Respect TVP.RequireAudience when set to false (#3055)

* Fix AudienceValidationTheoryData to include testId

* respect TVP.RequireAudience if false, unit test

* add more details to TVP.RequireAudience flag

* add test cases

* specify TVP.RequireAudiences is used for SAML or JWT tokens

src/Microsoft.IdentityModel.Tokens/InternalAPI.Unshipped.txt

@@ -8,6 +8,7 @@ const Microsoft.IdentityModel.Tokens.LogMessages.IDX10273 = "IDX10273: Algorithm
 const Microsoft.IdentityModel.Tokens.LogMessages.IDX10274 = "IDX10274: IssuerSigningKeyValidationDelegate threw an exception, see inner exception." -> string
 const Microsoft.IdentityModel.Tokens.LogMessages.IDX10275 = "IDX10275: TokenTypeValidationDelegate threw an exception, see inner exception." -> string
 const Microsoft.IdentityModel.Tokens.LogMessages.IDX10276 = "IDX10276: TokenReplayValidationDelegate threw an exception, see inner exception." -> string
+const Microsoft.IdentityModel.Tokens.LogMessages.IDX10277 = "IDX10277: RequireAudience property on ValidationParameters is set to false. Exiting without validating the audience." -> string
 Microsoft.IdentityModel.Tokens.AlgorithmValidationError
 Microsoft.IdentityModel.Tokens.AlgorithmValidationError.AlgorithmValidationError(Microsoft.IdentityModel.Tokens.MessageDetail messageDetail, Microsoft.IdentityModel.Tokens.ValidationFailureType validationFailureType, System.Type exceptionType, System.Diagnostics.StackFrame stackFrame, string invalidAlgorithm, System.Exception innerException = null) -> void
 Microsoft.IdentityModel.Tokens.AlgorithmValidationError.InvalidAlgorithm.get -> string

src/Microsoft.IdentityModel.Tokens/LogMessages.cs

@@ -95,6 +95,7 @@ internal static class LogMessages
         public const string IDX10274 = "IDX10274: IssuerSigningKeyValidationDelegate threw an exception, see inner exception.";
         public const string IDX10275 = "IDX10275: TokenTypeValidationDelegate threw an exception, see inner exception.";
         public const string IDX10276 = "IDX10276: TokenReplayValidationDelegate threw an exception, see inner exception.";
+        public const string IDX10277 = "IDX10277: RequireAudience property on ValidationParameters is set to false. Exiting without validating the audience.";
 
         // 10500 - SignatureValidation
         public const string IDX10500 = "IDX10500: Signature validation failed. No security keys were provided to validate the signature.";

src/Microsoft.IdentityModel.Tokens/TokenValidationParameters.cs

@@ -459,9 +459,13 @@ public string NameClaimType
         public bool RefreshBeforeValidation { get; set; }
 
         /// <summary>
-        /// Gets or sets a value indicating whether SAML tokens must have at least one AudienceRestriction.
+        /// Gets or sets a value indicating whether SAML or JWT tokens must have at least one AudienceRestriction.
         /// The default is <c>true</c>.
         /// </summary>
+        /// <remarks>
+        /// If set to false and the Audience is null, Audience validation will be skipped.
+        /// If set to false and the Audience is not null, the Audience will still be validated.
+        /// </remarks>
         [DefaultValue(true)]
         public bool RequireAudience { get; set; }
 

src/Microsoft.IdentityModel.Tokens/Validators.cs

@@ -87,6 +87,12 @@ public static void ValidateAudience(IEnumerable<string> audiences, SecurityToken
                 return;
             }
 
+            if (!validationParameters.RequireAudience && !audiences.Any())
+            {
+                LogHelper.LogWarning(LogMessages.IDX10277);
+                return;
+            }
+
             if (audiences == null)
                 throw LogHelper.LogExceptionMessage(new SecurityTokenInvalidAudienceException(LogMessages.IDX10207) { InvalidAudience = null });