HMAC 类

定义

表示基于哈希的消息验证代码 (HMAC) 的所有实现必须从中派生的抽象类。Represents the abstract class from which all implementations of Hash-based Message Authentication Code (HMAC) must derive.

public ref class HMAC abstract : System::Security::Cryptography::KeyedHashAlgorithm
[System.Runtime.InteropServices.ComVisible(true)]
public abstract class HMAC : System.Security.Cryptography.KeyedHashAlgorithm
type HMAC = class
    inherit KeyedHashAlgorithm
Public MustInherit Class HMAC
Inherits KeyedHashAlgorithm
继承
派生
属性

注解

如果发送方和接收方共享机密密钥,则可以使用基于哈希的消息验证代码(HMAC)来确定通过不安全通道发送的消息是否已被篡改。A Hash-based Message Authentication Code (HMAC) can be used to determine whether a message sent over an insecure channel has been tampered with, provided that the sender and receiver share a secret key. 发件人计算原始数据的哈希值,并将原始数据和 HMAC 作为单个消息发送。The sender computes the hash value for the original data and sends both the original data and the HMAC as a single message. 接收方重新计算收到的消息上的哈希值,并检查计算所得的哈希值是否与传输的哈希值匹配。The receiver recomputes the hash value on the received message and checks that the computed hash value matches the transmitted hash value.

HMAC 可以与任何迭代加密哈希函数(如 MD5 或 SHA-1)结合使用,并与机密共享密钥结合使用。HMAC can be used with any iterative cryptographic hash function, such as MD5 or SHA-1, in combination with a secret shared key. HMAC 的加密强度取决于基础哈希函数的属性。The cryptographic strength of HMAC depends on the properties of the underlying hash function.

对数据或哈希值所做的任何更改都将导致不匹配,因为更改消息和重现正确的哈希值需要使用机密密钥知识。Any change to the data or the hash value results in a mismatch, because knowledge of the secret key is required to change the message and reproduce the correct hash value. 因此,如果原始和计算所得的哈希值匹配,则将对消息进行身份验证。Therefore, if the original and computed hash values match, the message is authenticated.

由于 MD5 和 SHA-1 出现冲突,Microsoft 建议使用基于 SHA-256 或更高安全性的安全模式。Due to collision problems with MD5 and SHA-1, Microsoft recommends a security model based on SHA-256 or better.

构造函数

HMAC()

初始化 HMAC 类的新实例。Initializes a new instance of the HMAC class.

字段

HashSizeValue

表示计算所得的哈希代码的大小(以位为单位)。Represents the size, in bits, of the computed hash code.

(继承自 HashAlgorithm)
HashValue

表示计算所得的哈希代码的值。Represents the value of the computed hash code.

(继承自 HashAlgorithm)
KeyValue

用于哈希算法的密钥。The key to use in the hash algorithm.

(继承自 KeyedHashAlgorithm)
State

表示哈希计算的状态。Represents the state of the hash computation.

(继承自 HashAlgorithm)

属性

BlockSizeValue

获取或设置哈希值中使用的块大小。Gets or sets the block size to use in the hash value.

CanReuseTransform

获取一个值,该值指示是否可重复使用当前转换。Gets a value indicating whether the current transform can be reused.

(继承自 HashAlgorithm)
CanTransformMultipleBlocks

当在派生类中重写时,获取一个值,该值指示是否可以转换多个块。When overridden in a derived class, gets a value indicating whether multiple blocks can be transformed.

(继承自 HashAlgorithm)
Hash

获取计算所得的哈希代码的值。Gets the value of the computed hash code.

(继承自 HashAlgorithm)
HashName

获取或设置用于哈希计算的哈希算法的名称。Gets or sets the name of the hash algorithm to use for hashing.

HashSize

获取计算所得的哈希代码的大小(以位为单位)。Gets the size, in bits, of the computed hash code.

(继承自 HashAlgorithm)
InputBlockSize

当在派生类中重写时,获取输入块的大小。When overridden in a derived class, gets the input block size.

(继承自 HashAlgorithm)
Key

获取或设置要在 HMAC 计算中使用的密钥。Gets or sets the key to use in the HMAC calculation.

OutputBlockSize

当在派生类中重写时,获取输出块的大小。When overridden in a derived class, gets the output block size.

(继承自 HashAlgorithm)

方法

Clear()

释放 HashAlgorithm 类使用的所有资源。Releases all resources used by the HashAlgorithm class.

(继承自 HashAlgorithm)
ComputeHash(Byte[])

计算指定字节数组的哈希值。Computes the hash value for the specified byte array.

(继承自 HashAlgorithm)
ComputeHash(Byte[], Int32, Int32)

计算指定字节数组的指定区域的哈希值。Computes the hash value for the specified region of the specified byte array.

(继承自 HashAlgorithm)
ComputeHash(Stream)

计算指定 Stream 对象的哈希值。Computes the hash value for the specified Stream object.

(继承自 HashAlgorithm)
Create()

创建基于哈希的消息验证代码 (HMAC) 默认实现的实例。Creates an instance of the default implementation of a Hash-based Message Authentication Code (HMAC).

Create(String)

创建基于哈希的消息验证代码 (HMAC) 指定实现的实例。Creates an instance of the specified implementation of a Hash-based Message Authentication Code (HMAC).

Dispose()

释放 HashAlgorithm 类的当前实例所使用的所有资源。Releases all resources used by the current instance of the HashAlgorithm class.

(继承自 HashAlgorithm)
Dispose(Boolean)

密钥更改合法时释放由 HMAC 类使用的非托管资源,并可选择释放托管资源。Releases the unmanaged resources used by the HMAC class when a key change is legitimate and optionally releases the managed resources.

Equals(Object)

确定指定的对象是否等于当前对象。Determines whether the specified object is equal to the current object.

(继承自 Object)
GetHashCode()

用作默认哈希函数。Serves as the default hash function.

(继承自 Object)
GetType()

获取当前实例的 TypeGets the Type of the current instance.

(继承自 Object)
HashCore(Byte[], Int32, Int32)

在派生类中重写时,将写入对象的数据路由到 HMAC 算法以计算 HMAC 值。When overridden in a derived class, routes data written to the object into the HMAC algorithm for computing the HMAC value.

HashCore(ReadOnlySpan<Byte>)

将写入对象的数据路由到 HMAC 算法以计算 HMAC 。Routes data written to the object into the HMAC algorithm for computing the HMAC.

HashFinal()

在派生类中重写时,在算法处理最后一个数据后结束 HMAC 计算。When overridden in a derived class, finalizes the HMAC computation after the last data is processed by the algorithm.

Initialize()

初始化默认 HMAC 实现的实例。Initializes an instance of the default implementation of HMAC.

MemberwiseClone()

创建当前 Object 的浅表副本。Creates a shallow copy of the current Object.

(继承自 Object)
ToString()

返回一个表示当前对象的 string。Returns a string that represents the current object.

(继承自 Object)
TransformBlock(Byte[], Int32, Int32, Byte[], Int32)

计算输入字节数组指定区域的哈希值,并将输入字节数组指定区域复制到输出字节数组的指定区域。Computes the hash value for the specified region of the input byte array and copies the specified region of the input byte array to the specified region of the output byte array.

(继承自 HashAlgorithm)
TransformFinalBlock(Byte[], Int32, Int32)

计算指定字节数组的指定区域的哈希值。Computes the hash value for the specified region of the specified byte array.

(继承自 HashAlgorithm)
TryComputeHash(ReadOnlySpan<Byte>, Span<Byte>, Int32)

尝试计算指定字节数组的哈希值。Attempts to compute the hash value for the specified byte array.

(继承自 HashAlgorithm)
TryHashFinal(Span<Byte>, Int32)

在 HMAC 算法处理最后一个数据后,尝试结束 HMAC 计算。Attempts to finalize the HMAC computation after the last data is processed by the HMAC algorithm.

显式接口实现

IDisposable.Dispose()

释放 HashAlgorithm 使用的非托管资源,并选择性地释放托管资源。Releases the unmanaged resources used by the HashAlgorithm and optionally releases the managed resources.

(继承自 HashAlgorithm)

适用于

另请参阅