Construct an Sha256
Length padding size
Cipher block size
Obtain the digest
The digest size of Sha-256 is 32 bytes
Performs the length padding
Pads the cipher data
Initialize the cipher
Performs the cipher on a block of data
Constructs the digest
Digest block size
Length padding size
Pads the digest data
Performs the length padding
Performs the digest on a block of data
Final processing of digest.
Initialize the digest
Digest additional data
Complete the digest
Converts 8 bit to 32 bit Little Endian
Converts 8 bit to 32 bit Big Endian
Converts 8 bit to 64 bit Little Endian
Converts 8 bit to 64 bit Big Endian
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