SecurityTokenHandler.ValidateToken(SecurityToken) 方法

参考

定义

命名空间:: System.IdentityModel.Tokens

程序集:: System.IdentityModel.dll

重要

一些信息与预发行产品相关，相应产品在发行之前可能会进行重大修改。对于此处提供的信息，Microsoft 不作任何明示或暗示的担保。

在派生类中重写时，验证指定安全标记。该标记必须是派生类处理的类型。

public:
 virtual System::Collections::ObjectModel::ReadOnlyCollection<System::Security::Claims::ClaimsIdentity ^> ^ ValidateToken(System::IdentityModel::Tokens::SecurityToken ^ token);

public virtual System.Collections.ObjectModel.ReadOnlyCollection<System.Security.Claims.ClaimsIdentity> ValidateToken (System.IdentityModel.Tokens.SecurityToken token);

abstract member ValidateToken : System.IdentityModel.Tokens.SecurityToken -> System.Collections.ObjectModel.ReadOnlyCollection<System.Security.Claims.ClaimsIdentity>
override this.ValidateToken : System.IdentityModel.Tokens.SecurityToken -> System.Collections.ObjectModel.ReadOnlyCollection<System.Security.Claims.ClaimsIdentity>

Public Overridable Function ValidateToken (token As SecurityToken) As ReadOnlyCollection(Of ClaimsIdentity)

参数

token: SecurityToken

要验证的标记。

ReadOnlyCollection<ClaimsIdentity>

标记中包含的值标识。

示例

下面的代码演示了安全令牌处理程序的方法的 ValidateToken 替代，该处理程序 (SWT) 处理简单 Web 令牌。代码取自示例 CustomToken 。有关此示例和可用于 WIF 的其他示例及其下载位置的信息，请参阅 WIF 代码示例索引。

/// <summary>
/// This method validates the Simple Web Token.
/// </summary>
/// <param name="token">A simple web token.</param>
/// <returns>A Claims Collection which contains all the claims from the token.</returns>
public override ReadOnlyCollection<ClaimsIdentity> ValidateToken(SecurityToken token)
{
    if ( token == null )
    {
        throw new ArgumentNullException( "token" );
    }

    SimpleWebToken simpleWebToken = token as SimpleWebToken;
    if ( simpleWebToken == null )
    {
        throw new ArgumentException("The token provided must be of type SimpleWebToken.");                    
    }

    if ( DateTime.Compare( simpleWebToken.ValidTo.Add( Configuration.MaxClockSkew ), DateTime.UtcNow ) <= 0 )
    {
        throw new SecurityTokenExpiredException("The incoming token has expired. Get a new access token from the Authorization Server.");
    }

    ValidateSignature( simpleWebToken );
 
    ValidateAudience( simpleWebToken.Audience );
 
    ClaimsIdentity claimsIdentity = CreateClaims( simpleWebToken );
   
    if (this.Configuration.SaveBootstrapContext)
    {
        claimsIdentity.BootstrapContext = new BootstrapContext(simpleWebToken.SerializedToken);
    }

    List<ClaimsIdentity> claimCollection = new List<ClaimsIdentity>(new ClaimsIdentity[] { claimsIdentity });
    return claimCollection.AsReadOnly();
}

以下代码显示了 CreateClaims 从上一示例中方法的 ValidateToken 重写调用的方法。此方法返回从 ClaimsIdentity 令牌中的声明创建的对象。代码取自示例 CustomToken 。有关此示例和可用于 WIF 的其他示例及其下载位置的信息，请参阅 WIF 代码示例索引。

/// <summary>Creates <see cref="Claim"/>'s from the incoming token.
/// </summary>
/// <param name="simpleWebToken">The incoming <see cref="SimpleWebToken"/>.</param>
/// <returns>A <see cref="ClaimsIdentity"/> created from the token.</returns>
protected virtual ClaimsIdentity CreateClaims( SimpleWebToken simpleWebToken )
{
    if ( simpleWebToken == null )
    {
        throw new ArgumentNullException( "simpleWebToken" );
    }

    NameValueCollection tokenProperties = simpleWebToken.GetAllProperties();
    if ( tokenProperties == null )
    {
        throw new SecurityTokenValidationException( "No claims can be created from this Simple Web Token." );
    }

    if ( Configuration.IssuerNameRegistry == null )
    {
        throw new InvalidOperationException( "The Configuration.IssuerNameRegistry property of this SecurityTokenHandler is set to null. Tokens cannot be validated in this state." );
    }

    string normalizedIssuer = Configuration.IssuerNameRegistry.GetIssuerName( simpleWebToken );

    ClaimsIdentity identity = new ClaimsIdentity(AuthenticationTypes.Federation);
    
    foreach ( string key in tokenProperties.Keys )
    {
        if ( ! IsReservedKeyName(key) &&  !string.IsNullOrEmpty( tokenProperties[key] ) )
        {
            identity.AddClaim( new Claim( key, tokenProperties[key], ClaimValueTypes.String, normalizedIssuer ) );
            if ( key == AcsNameClaimType )
            {
                // add a default name claim from the Name identifier claim.
                identity.AddClaim( new Claim( DefaultNameClaimType, tokenProperties[key], ClaimValueTypes.String, normalizedIssuer ) );
            }
        }
    }

    return identity;
}

以下代码显示了 ValidateSignature 从简单 Web 令牌处理程序中方法的 ValidateToken 重写调用的方法。此方法使用配置的 IssuerTokenResolver来验证令牌上的签名。代码取自示例 CustomToken 。有关此示例和可用于 WIF 的其他示例及其下载位置的信息，请参阅 WIF 代码示例索引。

/// <summary>
/// Validates the signature on the incoming token.
/// </summary>
/// <param name="simpleWebToken">The incoming <see cref="SimpleWebToken"/>.</param>
protected virtual void ValidateSignature( SimpleWebToken simpleWebToken )
{
    if ( simpleWebToken == null )
    {
        throw new ArgumentNullException( "simpleWebToken" );
    }

    if ( String.IsNullOrEmpty( simpleWebToken.SerializedToken ) || String.IsNullOrEmpty( simpleWebToken.Signature ) )
    {
        throw new SecurityTokenValidationException( "The token does not have a signature to verify" );
    }

    string serializedToken = simpleWebToken.SerializedToken;           
    string unsignedToken = null;

    // Find the last parameter. The signature must be last per SWT specification.
    int lastSeparator = serializedToken.LastIndexOf( ParameterSeparator );

    // Check whether the last parameter is an hmac.
    if ( lastSeparator > 0 )
    {
        string lastParamStart = ParameterSeparator + SimpleWebTokenConstants.Signature + "=";
        string lastParam = serializedToken.Substring( lastSeparator );

        // Strip the trailing hmac to obtain the original unsigned string for later hmac verification.               
        if ( lastParam.StartsWith( lastParamStart, StringComparison.Ordinal ) )
        {
            unsignedToken = serializedToken.Substring( 0, lastSeparator );
        }
    }

    SimpleWebTokenKeyIdentifierClause clause = new SimpleWebTokenKeyIdentifierClause(simpleWebToken.Audience);
    InMemorySymmetricSecurityKey securityKey = null;
    try
    {
        securityKey = (InMemorySymmetricSecurityKey)this.Configuration.IssuerTokenResolver.ResolveSecurityKey(clause);
    }
    catch (InvalidOperationException)
    {
        throw new SecurityTokenValidationException( "A Symmetric key was not found for the given key identifier clause.");
    }

    string generatedSignature = GenerateSignature( unsignedToken, securityKey.GetSymmetricKey() );

    if ( string.CompareOrdinal( generatedSignature, simpleWebToken.Signature ) != 0 )
    {
        throw new SecurityTokenValidationException( "The signature on the incoming token is invalid.") ;
    }
}

/// <summary>
/// Generates an HMACSHA256 signature for a given string and key.
/// </summary>
/// <param name="unsignedToken">The token to be signed.</param>
/// <param name="signingKey">The key used to generate the signature.</param>
/// <returns>The generated signature.</returns>
protected static string GenerateSignature(string unsignedToken, byte[] signingKey)
{
    using (HMACSHA256 hmac = new HMACSHA256(signingKey))
    {
        byte[] signatureBytes = hmac.ComputeHash(Encoding.ASCII.GetBytes(unsignedToken));
        string signature = HttpUtility.UrlEncode(Convert.ToBase64String(signatureBytes));

        return signature;
    }
}

以下代码显示了 ValidateAudience 从简单 Web 令牌处理程序中方法的 ValidateToken 重写调用的方法。此方法根据配置中指定的访问群体 URI 验证令牌中包含的访问群体。代码取自示例 CustomToken 。有关此示例和可用于 WIF 的其他示例及其下载位置的信息，请参阅 WIF 代码示例索引。

/// <summary>
/// Validates the audience of the incoming token with those specified in configuration.
/// </summary>
/// <param name="tokenAudience">The audience of the incoming token.</param>
protected virtual void ValidateAudience( string tokenAudience )
{
    if ( Configuration.AudienceRestriction.AudienceMode != AudienceUriMode.Never )
    {
        if ( String.IsNullOrEmpty( tokenAudience ) )
        {
            throw new SecurityTokenValidationException("The incoming token does not have a valid audience Uri and the Audience Restriction is not set to 'None'.");
        }

        if ( Configuration.AudienceRestriction.AllowedAudienceUris.Count == 0 )
        {
            throw new InvalidOperationException( " Audience Restriction is not set to 'None' but no valid audience URI's are configured." );
        }

        IList<Uri> allowedAudienceUris = Configuration.AudienceRestriction.AllowedAudienceUris;
        
        Uri audienceUri = null;

        Uri.TryCreate(tokenAudience, UriKind.RelativeOrAbsolute, out audienceUri);
        
        // Strip off any query string or fragment. 
        Uri audienceLeftPart;

        if ( audienceUri.IsAbsoluteUri )
        {
            audienceLeftPart = new Uri( audienceUri.GetLeftPart( UriPartial.Path ) );
        }
        else
        {
            Uri baseUri = new Uri( "http://www.example.com" );
            Uri resolved = new Uri( baseUri, tokenAudience );
            audienceLeftPart = baseUri.MakeRelativeUri( new Uri( resolved.GetLeftPart( UriPartial.Path ) ) );
        }

        if ( !allowedAudienceUris.Contains( audienceLeftPart ) )
        {
            throw new AudienceUriValidationFailedException(
                    "The Audience Uri of the incoming token is not present in the list of permitted Audience Uri's.");
        }
    }
}

注解

默认情况下，此方法引发 NotImplementedException 异常。

基础结构 ValidateToken 调用方法以验证和提取反序列化安全令牌中的声明。这些声明在方法返回的 ClaimsIdentity 对象的集合中返回。在典型情况下，此集合将包含单个标识。

在派生类中，验证通常包括根据属性上指定的令牌处理程序配置对象的属性中指定的 SecurityTokenHandlerConfiguration.AudienceRestriction 访问群体 URI 验证令牌中指定的 Configuration 目标受众。这些 URI 通常在 audienceUris> 元素下的<配置文件中设置。如果无法验证受众， AudienceUriValidationFailedException 应引发异常。

处理令牌时，通常会通过 Configuration 属性将颁发者令牌传递给对象上IssuerNameRegistry为处理程序配置的方法之一GetIssuerName来验证颁发者。颁发者名称注册表通常通过配置文件中的 <issuerNameRegistry> 元素进行配置。返回 GetIssuerName 颁发者的名称。应使用此名称在令牌中包含的声明中设置 Claim.Issuer 属性。如果颁发者名称注册表不包含颁发者令牌的条目， GetIssuerName 则 null返回。在这种情况下，通常会在派生类中引发， SecurityTokenException 但此行为由类的设计器决定。

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SecurityTokenHandler.ValidateToken(SecurityToken) 方法

定义

参数

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示例

注解

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