Issuer signing key validation: Remove exceptions (#2672)

* Added SigningKeyValidationResult
* Added validation failure type for signing key, removed exception throwing from ValidateIssuerSigningKey, and added tests

src/Microsoft.IdentityModel.Tokens/Validation/SigningKeyValidationResult.cs

@@ -0,0 +1,69 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+using System;
+#nullable enable
+namespace Microsoft.IdentityModel.Tokens
+{
+    /// <summary>
+    /// Contains the result of validating the <see cref="SecurityKey"/> used to sign a <see cref="SecurityToken"/>.
+    /// The <see cref="TokenValidationResult"/> contains a collection of <see cref="ValidationResult"/> for each step in the token validation.
+    /// </summary>
+    internal class SigningKeyValidationResult : ValidationResult
+    {
+        private Exception? _exception;
+
+        /// <summary>
+        /// Creates an instance of <see cref="SigningKeyValidationResult"/>
+        /// </summary>
+        /// <paramref name="signingKey"/> is the security key that was validated successfully.
+        public SigningKeyValidationResult(SecurityKey? signingKey)
+            : base(ValidationFailureType.ValidationSucceeded)
+        {
+            SigningKey = signingKey;
+            IsValid = true;
+        }
+
+        /// <summary>
+        /// Creates an instance of <see cref="SigningKeyValidationResult"/>
+        /// </summary>
+        /// <paramref name="signingKey"/> is the security key that was intended to be validated.
+        /// <paramref name="validationFailure"/> is the <see cref="ValidationFailureType"/> that occurred during validation.
+        /// <paramref name="exceptionDetail"/> is the <see cref="ExceptionDetail"/> that occurred during validation.
+        public SigningKeyValidationResult(SecurityKey? signingKey, ValidationFailureType validationFailure, ExceptionDetail exceptionDetail)
+            : base(validationFailure, exceptionDetail)
+        {
+            SigningKey = signingKey;
+            IsValid = false;
+        }
+
+        /// <summary>
+        /// Gets the <see cref="Exception"/> that occurred during validation.
+        /// </summary>
+        public override Exception? Exception
+        {
+            get
+            {
+                if (_exception != null || ExceptionDetail == null)
+                    return _exception;
+
+                HasValidOrExceptionWasRead = true;
+                _exception = ExceptionDetail.GetException();
+                if (_exception is SecurityTokenInvalidSigningKeyException securityTokenInvalidSigningKeyException)
+                {
+                    securityTokenInvalidSigningKeyException.SigningKey = SigningKey;
+                    securityTokenInvalidSigningKeyException.ExceptionDetail = ExceptionDetail;
+                    securityTokenInvalidSigningKeyException.Source = "Microsoft.IdentityModel.Tokens";
+                }
+
+                return _exception;
+            }
+        }
+
+        /// <summary>
+        /// Gets the security key that was validated or intended to be validated.
+        /// </summary>
+        public SecurityKey? SigningKey { get; }
+    }
+}
+#nullable restore

src/Microsoft.IdentityModel.Tokens/Validation/ValidationFailureType.cs

@@ -39,6 +39,12 @@ private class IssuerValidationFailure : ValidationFailureType { internal IssuerV
         public static readonly ValidationFailureType AudienceValidationFailed = new AudienceValidationFailure("AudienceValidationFailed");
         private class AudienceValidationFailure : ValidationFailureType { internal AudienceValidationFailure(string name) : base(name) { } }
 
+        /// <summary>
+        /// Defines a type that represents that signing key validation failed.
+        /// </summary>
+        public static readonly ValidationFailureType SigningKeyValidationFailed = new SigningKeyValidationFailure("SigningKeyValidationFailed");
+        private class SigningKeyValidationFailure : ValidationFailureType { internal SigningKeyValidationFailure(string name) : base(name) { } }
+
         /// <summary>
         /// Defines a type that represents that lifetime validation failed.
         /// </summary>

src/Microsoft.IdentityModel.Tokens/Validation/Validators.IssuerSecurityKey.cs

@@ -2,12 +2,37 @@
 // Licensed under the MIT License.
 
 using System;
+using System.Diagnostics;
 using System.Security.Cryptography.X509Certificates;
+using System.Threading;
+using System.Threading.Tasks;
 using Microsoft.IdentityModel.Abstractions;
 using Microsoft.IdentityModel.Logging;
 
+#nullable enable
 namespace Microsoft.IdentityModel.Tokens
 {
+    /// <summary>
+    /// Definition for delegate that will validate the <see cref="SecurityKey"/> that signed a <see cref="SecurityToken"/>.
+    /// </summary>
+    /// <param name="signingKey">The security key to validate.</param>
+    /// <param name="securityToken">The <see cref="SecurityToken"/> that is being validated.</param>
+    /// <param name="validationParameters"><see cref="TokenValidationParameters"/> required for validation.</param>
+    /// <param name="callContext"></param>
+    /// <param name="cancellationToken"></param>
+    /// <returns>A <see cref="SigningKeyValidationResult"/>that contains the results of validating the issuer.</returns>
+    /// <remarks>This delegate is not expected to throw.</remarks>
+    internal delegate Task<SigningKeyValidationResult> IssuerSecurityKeyValidationDelegate(
+        SecurityKey signingKey,
+        SecurityToken securityToken,
+        TokenValidationParameters validationParameters,
+        CallContext callContext,
+        CancellationToken cancellationToken);
+
+    /// <summary>
+    /// SigningKeyValidation
+    /// </summary>
+
     public static partial class Validators
     {
         /// <summary>
@@ -21,7 +46,7 @@ public static partial class Validators
         /// <exception cref="ArgumentNullException"> if 'validationParameters' is null.</exception>
         public static void ValidateIssuerSecurityKey(SecurityKey securityKey, SecurityToken securityToken, TokenValidationParameters validationParameters)
         {
-            ValidateIssuerSecurityKey(securityKey, securityToken, validationParameters, null);
+            ValidateIssuerSecurityKey(securityKey, securityToken, validationParameters, configuration: null);
         }
 
         /// <summary>
@@ -34,7 +59,7 @@ public static void ValidateIssuerSecurityKey(SecurityKey securityKey, SecurityTo
         /// <exception cref="ArgumentNullException"> if 'securityKey' is null and ValidateIssuerSigningKey is true.</exception>
         /// <exception cref="ArgumentNullException"> if 'securityToken' is null and ValidateIssuerSigningKey is true.</exception>
         /// <exception cref="ArgumentNullException"> if 'validationParameters' is null.</exception>
-        internal static void ValidateIssuerSecurityKey(SecurityKey securityKey, SecurityToken securityToken, TokenValidationParameters validationParameters, BaseConfiguration configuration)
+        internal static void ValidateIssuerSecurityKey(SecurityKey securityKey, SecurityToken securityToken, TokenValidationParameters validationParameters, BaseConfiguration? configuration)
         {
             if (validationParameters == null)
                 throw LogHelper.LogArgumentNullException(nameof(validationParameters));
@@ -84,7 +109,7 @@ internal static void ValidateIssuerSecurityKey(SecurityKey securityKey, Security
         /// <param name="validationParameters">The <see cref="TokenValidationParameters"/> that are used to validate the token.</param>
         internal static void ValidateIssuerSigningKeyLifeTime(SecurityKey securityKey, TokenValidationParameters validationParameters)
         {
-            X509SecurityKey x509SecurityKey = securityKey as X509SecurityKey;
+            X509SecurityKey? x509SecurityKey = securityKey as X509SecurityKey;
             if (x509SecurityKey?.Certificate is X509Certificate2 cert)
             {
                 DateTime utcNow = DateTime.UtcNow;
@@ -104,5 +129,186 @@ internal static void ValidateIssuerSigningKeyLifeTime(SecurityKey securityKey, T
                     LogHelper.LogInformation(LogMessages.IDX10251, LogHelper.MarkAsNonPII(notAfterUtc), LogHelper.MarkAsNonPII(utcNow));
             }
         }
+
+        /// <summary>
+        /// Validates the <see cref="SecurityKey"/> that signed a <see cref="SecurityToken"/>.
+        /// </summary>
+        /// <param name="securityKey">The <see cref="SecurityKey"/> that signed the <see cref="SecurityToken"/>.</param>
+        /// <param name="securityToken">The <see cref="SecurityToken"/> being validated.</param>
+        /// <param name="validationParameters"><see cref="TokenValidationParameters"/> required for validation.</param>
+        /// <param name="callContext"></param>
+        /// <exception cref="ArgumentNullException"> if 'securityKey' is null and ValidateIssuerSigningKey is true.</exception>
+        /// <exception cref="ArgumentNullException"> if 'securityToken' is null and ValidateIssuerSigningKey is true.</exception>
+        /// <exception cref="ArgumentNullException"> if 'validationParameters' is null.</exception>
+        internal static SigningKeyValidationResult ValidateIssuerSecurityKey(SecurityKey securityKey, SecurityToken securityToken, TokenValidationParameters validationParameters, CallContext callContext)
+        {
+            return ValidateIssuerSecurityKey(securityKey, securityToken, validationParameters, null, callContext);
+        }
+
+        /// <summary>
+        /// Validates the <see cref="SecurityKey"/> that signed a <see cref="SecurityToken"/>.
+        /// </summary>
+        /// <param name="securityKey">The <see cref="SecurityKey"/> that signed the <see cref="SecurityToken"/>.</param>
+        /// <param name="securityToken">The <see cref="SecurityToken"/> being validated.</param>
+        /// <param name="validationParameters"><see cref="TokenValidationParameters"/> required for validation.</param>
+        /// <param name="configuration">The <see cref="BaseConfiguration"/> required for issuer and signing key validation.</param>
+        /// <param name="callContext"></param>
+        /// <exception cref="ArgumentNullException"> if 'securityKey' is null and ValidateIssuerSigningKey is true.</exception>
+        /// <exception cref="ArgumentNullException"> if 'securityToken' is null and ValidateIssuerSigningKey is true.</exception>
+        /// <exception cref="ArgumentNullException"> if 'validationParameters' is null.</exception>
+        internal static SigningKeyValidationResult ValidateIssuerSecurityKey(SecurityKey securityKey, SecurityToken securityToken, TokenValidationParameters validationParameters, BaseConfiguration? configuration, CallContext callContext)
+        {
+            if (validationParameters == null)
+                return new SigningKeyValidationResult(
+                    securityKey,
+                    ValidationFailureType.NullArgument,
+                    new ExceptionDetail(
+                        new MessageDetail(
+                            LogMessages.IDX10000,
+                            LogHelper.MarkAsNonPII(nameof(validationParameters))),
+                        typeof(ArgumentNullException),
+                        new StackFrame(true)));
+
+            if (validationParameters.IssuerSigningKeyValidatorUsingConfiguration != null)
+            {
+                return ValidateSigningKeyUsingDelegateAndConfiguration(securityKey, securityToken, validationParameters, configuration);
+            }
+
+            if (validationParameters.IssuerSigningKeyValidator != null)
+            {
+                return ValidateSigningKeyUsingDelegateAndConfiguration(securityKey, securityToken, validationParameters, null);
+            }
+
+            if (!validationParameters.ValidateIssuerSigningKey)
+            {
+                LogHelper.LogVerbose(LogMessages.IDX10237);
+                return new SigningKeyValidationResult(securityKey);
+            }
+
+            if (!validationParameters.RequireSignedTokens && securityKey == null)
+            {
+                LogHelper.LogInformation(LogMessages.IDX10252);
+                return new SigningKeyValidationResult(securityKey);
+            }
+            else if (securityKey == null)
+            {
+                return new SigningKeyValidationResult(
+                    securityKey,
+                    ValidationFailureType.NullArgument,
+                    new ExceptionDetail(
+                        new MessageDetail(
+                            LogMessages.IDX10253,
+                            LogHelper.MarkAsNonPII(nameof(securityKey))),
+                        typeof(ArgumentNullException),
+                        new StackFrame(true)));
+            }
+
+            if (securityToken == null)
+                return new SigningKeyValidationResult(
+                    securityKey,
+                    ValidationFailureType.NullArgument,
+                    new ExceptionDetail(
+                        new MessageDetail(
+                            LogMessages.IDX10000,
+                            LogHelper.MarkAsNonPII(nameof(securityToken))),
+                        typeof(ArgumentNullException),
+                        new StackFrame(true)));
+
+            return ValidateIssuerSigningKeyLifeTime(securityKey, validationParameters, callContext);
+        }
+
+        /// <summary>
+        /// Given a signing key, when it's derived from a certificate, validates that the certificate is already active and non-expired
+        /// </summary>
+        /// <param name="securityKey">The <see cref="SecurityKey"/> that signed the <see cref="SecurityToken"/>.</param>
+        /// <param name="validationParameters">The <see cref="TokenValidationParameters"/> that are used to validate the token.</param>
+        /// <param name="callContext"></param>
+#pragma warning disable CA1801 // Review unused parameters
+        internal static SigningKeyValidationResult ValidateIssuerSigningKeyLifeTime(SecurityKey securityKey, TokenValidationParameters validationParameters, CallContext callContext)
+#pragma warning restore CA1801 // Review unused parameters
+        {
+            X509SecurityKey? x509SecurityKey = securityKey as X509SecurityKey;
+            if (x509SecurityKey?.Certificate is X509Certificate2 cert)
+            {
+                DateTime utcNow = DateTime.UtcNow;
+                var notBeforeUtc = cert.NotBefore.ToUniversalTime();
+                var notAfterUtc = cert.NotAfter.ToUniversalTime();
+
+                if (notBeforeUtc > DateTimeUtil.Add(utcNow, validationParameters.ClockSkew))
+                    return new SigningKeyValidationResult(
+                        securityKey,
+                        ValidationFailureType.SigningKeyValidationFailed,
+                        new ExceptionDetail(
+                            new MessageDetail(
+                                LogHelper.FormatInvariant(
+                                    LogMessages.IDX10248,
+                                    LogHelper.MarkAsNonPII(notBeforeUtc),
+                                    LogHelper.MarkAsNonPII(utcNow))),
+                            typeof(SecurityTokenInvalidSigningKeyException),
+                            new StackFrame(true)));
+
+                if (LogHelper.IsEnabled(EventLogLevel.Informational))
+                    LogHelper.LogInformation(LogMessages.IDX10250, LogHelper.MarkAsNonPII(notBeforeUtc), LogHelper.MarkAsNonPII(utcNow));
+
+                if (notAfterUtc < DateTimeUtil.Add(utcNow, validationParameters.ClockSkew.Negate()))
+                    return new SigningKeyValidationResult(
+                        securityKey,
+                        ValidationFailureType.SigningKeyValidationFailed,
+                        new ExceptionDetail(
+                            new MessageDetail(
+                                LogHelper.FormatInvariant(
+                                    LogMessages.IDX10249,
+                                    LogHelper.MarkAsNonPII(notAfterUtc),
+                                    LogHelper.MarkAsNonPII(utcNow))),
+                            typeof(SecurityTokenInvalidSigningKeyException),
+                            new StackFrame(true)));
+
+                if (LogHelper.IsEnabled(EventLogLevel.Informational))
+                    LogHelper.LogInformation(LogMessages.IDX10251, LogHelper.MarkAsNonPII(notAfterUtc), LogHelper.MarkAsNonPII(utcNow));
+            }
+
+            return new SigningKeyValidationResult(securityKey);
+        }
+
+        private static SigningKeyValidationResult ValidateSigningKeyUsingDelegateAndConfiguration(SecurityKey securityKey, SecurityToken securityToken, TokenValidationParameters validationParameters, BaseConfiguration? configuration)
+        {
+            try
+            {
+                bool success;
+                if (configuration != null)
+                    success = validationParameters.IssuerSigningKeyValidatorUsingConfiguration(securityKey, securityToken, validationParameters, configuration);
+                else
+                    success = validationParameters.IssuerSigningKeyValidator(securityKey, securityToken, validationParameters);
+
+                if (!success)
+                    return new SigningKeyValidationResult(
+                        securityKey,
+                        ValidationFailureType.SigningKeyValidationFailed,
+                        new ExceptionDetail(
+                            new MessageDetail(
+                                LogMessages.IDX10232,
+                                securityKey),
+                            typeof(SecurityTokenInvalidSigningKeyException),
+                            new StackFrame(true)));
+
+                return new SigningKeyValidationResult(securityKey);
+            }
+#pragma warning disable CA1031 // Do not catch general exception types
+            catch (Exception exception)
+#pragma warning restore CA1031 // Do not catch general exception types
+            {
+                return new SigningKeyValidationResult(
+                    securityKey,
+                    ValidationFailureType.SigningKeyValidationFailed,
+                    new ExceptionDetail(
+                        new MessageDetail(
+                            LogMessages.IDX10232,
+                            securityKey),
+                        exception.GetType(),
+                        new StackFrame(true),
+                        exception));
+            }
+        }
     }
 }
+#nullable restore