HashAlgorithm Class

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Represents the base class from which all implementations of cryptographic hash algorithms must derive.

Namespace:  System.Security.Cryptography
Assembly:  System.Security (in System.Security.dll)

public class HashAlgorithm : SessionContainer, 
	ICryptoTransform, IDisposable

The HashAlgorithm type exposes the following members.

  NameDescription
Public methodHashAlgorithm(HashAlgorithmType, Session)Initializes a new instance of the HashAlgorithm class with the specified algorithm and session context.
Public methodHashAlgorithm(HashAlgorithmType, String)Initializes a new instance of the HashAlgorithm class with the specified algorithm and service provider.
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  NameDescription
Public propertyCanReuseTransformGets a value indicating whether the current transform can be reused.
Public propertyCanTransformMultipleBlocksWhen overridden in a derived class, gets a value indicating whether multiple blocks can be transformed.
Public propertyHashGets the value of the computed hash code.
Public propertyHashSizeGets the size, in bits, of the computed hash code.
Public propertyHashTypeGets the hash algorithm type.
Public propertyInputBlockSizeWhen overridden in a derived class, gets the input block size.
Public propertyIsDisposed (Inherited from SessionContainer.)
Public propertyOutputBlockSizeWhen overridden in a derived class, gets the output block size.
Public propertySession (Inherited from SessionContainer.)
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  NameDescription
Public methodClearReleases all resources used by the HashAlgorithm class.
Public methodComputeHash(array<Byte>[]()[][])Computes the hash value for the specified byte array.
Public methodComputeHash(Stream)Computes the hash value for the specified Stream object.
Public methodComputeHash(array<Byte>[]()[][], Int32, Int32)Computes the hash value for the specified region of the specified byte array.
Public methodDispose()()()() (Inherited from SessionContainer.)
Protected methodDispose(Boolean)Releases the unmanaged resources used by the HashAlgorithm and optionally releases the managed resources. (Overrides SessionContainer..::..Dispose(Boolean).)
Public methodEquals(Object)Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Protected methodFinalize (Inherited from SessionContainer.)
Public methodGetHashCodeServes as a hash function for a particular type. (Inherited from Object.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Public methodInitializeInitializes an implementation of the HashAlgorithm class.
Protected methodMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Public methodToStringReturns a string that represents the current object. (Inherited from Object.)
Public methodTransformBlockComputes 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.
Public methodTransformFinalBlockComputes the hash value for the specified region of the specified byte array.
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  NameDescription
Protected fieldHashValueRepresents the value of the computed hash code.
Protected fieldm_digestContains the digest.
Protected fieldm_hashSizeContains the hash size.
Protected fieldm_isDisposed (Inherited from SessionContainer.)
Protected fieldm_isSessionClosing (Inherited from SessionContainer.)
Protected fieldm_mechanismContains the mechanism.
Protected fieldm_ownsSession (Inherited from SessionContainer.)
Protected fieldm_session (Inherited from SessionContainer.)
Protected fieldStateRepresents the state of the hash computation.
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Hash functions are fundamental to modern cryptography. These functions map binary strings of an arbitrary length to small binary strings of a fixed length, known as hash values. A cryptographic hash function has the property that it is computationally infeasible to find two distinct inputs that hash to the same value. Hash functions are commonly used with digital signatures and for data integrity.

The hash is used as a unique value of fixed size representing a large amount of data. Hashes of two sets of data should match if the corresponding data also matches. Small changes to the data result in large unpredictable changes in the hash.

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
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