Crypto++  8.2
Free C++ class library of cryptographic schemes
Public Member Functions | Static Public Member Functions | Static Public Attributes | List of all members
CRC32 Class Reference

CRC-32 Checksum Calculation. More...

+ Inheritance diagram for CRC32:

Public Member Functions

void Update (const byte *input, size_t length)
 Updates a hash with additional input. More...
 
void TruncatedFinal (byte *hash, size_t size)
 Computes the hash of the current message. More...
 
unsigned int DigestSize () const
 Provides the digest size of the hash. More...
 
std::string AlgorithmName () const
 Provides the name of this algorithm. More...
 
void UpdateByte (byte b)
 
byte GetCrcByte (size_t i) const
 
std::string AlgorithmProvider () const
 Retrieve the provider of this algorithm. More...
 
- Public Member Functions inherited from HashTransformation
HashTransformationRef ()
 Provides a reference to this object. More...
 
virtual byte * CreateUpdateSpace (size_t &size)
 Request space which can be written into by the caller. More...
 
virtual void Final (byte *digest)
 Computes the hash of the current message. More...
 
virtual void Restart ()
 Restart the hash. More...
 
unsigned int TagSize () const
 Provides the tag size of the hash. More...
 
virtual unsigned int BlockSize () const
 Provides the block size of the compression function. More...
 
virtual unsigned int OptimalBlockSize () const
 Provides the input block size most efficient for this hash. More...
 
virtual unsigned int OptimalDataAlignment () const
 Provides input and output data alignment for optimal performance. More...
 
virtual void CalculateDigest (byte *digest, const byte *input, size_t length)
 Updates the hash with additional input and computes the hash of the current message. More...
 
virtual bool Verify (const byte *digest)
 Verifies the hash of the current message. More...
 
virtual bool VerifyDigest (const byte *digest, const byte *input, size_t length)
 Updates the hash with additional input and verifies the hash of the current message. More...
 
virtual void CalculateTruncatedDigest (byte *digest, size_t digestSize, const byte *input, size_t length)
 Updates the hash with additional input and computes the hash of the current message. More...
 
virtual bool TruncatedVerify (const byte *digest, size_t digestLength)
 Verifies the hash of the current message. More...
 
virtual bool VerifyTruncatedDigest (const byte *digest, size_t digestLength, const byte *input, size_t length)
 Updates the hash with additional input and verifies the hash of the current message. More...
 
- Public Member Functions inherited from Algorithm
 Algorithm (bool checkSelfTestStatus=true)
 Interface for all crypto algorithms. More...
 
- Public Member Functions inherited from Clonable
virtual ClonableClone () const
 Copies this object. More...
 

Static Public Member Functions

static const char * StaticAlgorithmName ()
 

Static Public Attributes

static const int DIGESTSIZE = 4
 

Detailed Description

CRC-32 Checksum Calculation.

Uses CRC polynomial 0xEDB88320

Definition at line 25 of file crc.h.

Member Function Documentation

◆ Update()

void CRC32::Update ( const byte *  input,
size_t  length 
)
virtual

Updates a hash with additional input.

Parameters
inputthe additional input as a buffer
lengththe size of the buffer, in bytes

Implements HashTransformation.

Definition at line 147 of file crc.cpp.

◆ TruncatedFinal()

void CRC32::TruncatedFinal ( byte *  digest,
size_t  digestSize 
)
virtual

Computes the hash of the current message.

Parameters
digesta pointer to the buffer to receive the hash
digestSizethe size of the truncated digest, in bytes

TruncatedFinal() call Final() and then copies digestSize bytes to digest. The hash is restarted the hash for the next message.

Implements HashTransformation.

Definition at line 178 of file crc.cpp.

◆ DigestSize()

unsigned int CRC32::DigestSize ( ) const
inlinevirtual

Provides the digest size of the hash.

Returns
the digest size of the hash.

Implements HashTransformation.

Definition at line 32 of file crc.h.

◆ AlgorithmName()

std::string CRC32::AlgorithmName ( ) const
inlinevirtual

Provides the name of this algorithm.

Returns
the standard algorithm name

The standard algorithm name can be a name like AES or AES/GCM. Some algorithms do not have standard names yet. For example, there is no standard algorithm name for Shoup's ECIES.

Note
AlgorithmName is not universally implemented yet.

Reimplemented from Algorithm.

Definition at line 34 of file crc.h.

◆ AlgorithmProvider()

std::string CRC32::AlgorithmProvider ( ) const
virtual

Retrieve the provider of this algorithm.

Returns
the algorithm provider

The algorithm provider can be a name like "C++", "SSE", "NEON", "AESNI", "ARMv8" and "Power8". C++ is standard C++ code. Other labels, like SSE, usually indicate a specialized implementation using instructions from a higher instruction set architecture (ISA). Future labels may include external hardware like a hardware security module (HSM).

Generally speaking Wei Dai's original IA-32 ASM code falls under "SSE2". Labels like "SSSE3" and "SSE4.1" follow after Wei's code and use intrinsics instead of ASM.

Algorithms which combine different instructions or ISAs provide the dominant one. For example on x86 AES/GCM returns "AESNI" rather than "CLMUL" or "AES+SSE4.1" or "AES+CLMUL" or "AES+SSE4.1+CLMUL".

Note
Provider is not universally implemented yet.
Since
Crypto++ 8.0

Reimplemented from Algorithm.

Definition at line 133 of file crc.cpp.


The documentation for this class was generated from the following files: