Security Scol plugin
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ChaCha stream cipher implementation. More...
#include <chacha.h>
Protected Member Functions | |
void | CipherSetKey (const NameValuePairs ¶ms, const byte *key, size_t length) |
Key the cipher. | |
void | OperateKeystream (KeystreamOperation operation, byte *output, const byte *input, size_t iterationCount) |
Operates the keystream. | |
void | CipherResynchronize (byte *keystreamBuffer, const byte *IV, size_t length) |
Resynchronize the cipher. | |
bool | CipherIsRandomAccess () const |
Flag indicating random access. | |
void | SeekToIteration (lword iterationCount) |
Seeks to a random position in the stream. | |
unsigned int | GetAlignment () const |
Provides data alignment requirements. | |
unsigned int | GetOptimalBlockSize () const |
Provides number of ideal bytes to process. | |
std::string | AlgorithmName () const |
std::string | AlgorithmProvider () const |
Retrieve the provider of this algorithm. | |
CRYPTOPP_CONSTANT (ROUNDS=20) | |
Protected Attributes | |
FixedSizeAlignedSecBlock< word32, 16 > | m_state |
unsigned int | m_rounds |
Additional Inherited Members | |
Public Types inherited from AdditiveCipherConcretePolicy< word32, 16 > | |
typedef word32 | WordType |
Word type for the cipher. | |
Public Member Functions inherited from AdditiveCipherConcretePolicy< word32, 16 > | |
CRYPTOPP_CONSTANT (BYTES_PER_ITERATION=sizeof(WordType) *W) | |
Number of bytes for an iteration. | |
unsigned int | GetBytesPerIteration () const |
Provides number of bytes operated upon during an iteration. | |
unsigned int | GetIterationsToBuffer () const |
Provides buffer size based on iterations. | |
bool | CanOperateKeystream () const |
Flag indicating. | |
Public Member Functions inherited from AdditiveCipherAbstractPolicy | |
virtual void | WriteKeystream (byte *keystream, size_t iterationCount) |
Generate the keystream. | |
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protected |
Definition at line 311 of file chacha.cpp.
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protectedvirtual |
Retrieve the provider of this algorithm.
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".
Reimplemented from AdditiveCipherAbstractPolicy.
Definition at line 316 of file chacha.cpp.
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inlineprotectedvirtual |
Flag indicating random access.
Implements AdditiveCipherAbstractPolicy.
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protectedvirtual |
Resynchronize the cipher.
keystreamBuffer | the keystream buffer |
iv | a byte array used to resynchronize the cipher |
length | the size of the IV array |
Reimplemented from AdditiveCipherAbstractPolicy.
Definition at line 347 of file chacha.cpp.
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protectedvirtual |
Key the cipher.
params | set of NameValuePairs use to initialize this object |
key | a byte array used to key the cipher |
length | the size of the key array |
Implements AdditiveCipherAbstractPolicy.
Definition at line 321 of file chacha.cpp.
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protectedvirtual |
Provides data alignment requirements.
Internally, the default implementation returns 1. If the stream cipher is implemented using an SSE2 ASM or intrinsics, then the value returned is usually 16.
Reimplemented from AdditiveCipherConcretePolicy< word32, 16 >.
Definition at line 363 of file chacha.cpp.
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protectedvirtual |
Provides number of ideal bytes to process.
Internally, the default implementation returns GetBytesPerIteration()
Reimplemented from AdditiveCipherAbstractPolicy.
Definition at line 368 of file chacha.cpp.
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protectedvirtual |
Operates the keystream.
operation | the operation with additional flags |
output | the output buffer |
input | the input buffer |
iterationCount | the number of iterations to perform on the input |
OperateKeystream() will attempt to operate upon GetOptimalBlockSize() buffer, which will be derived from GetBytesPerIteration().
Implements AdditiveCipherConcretePolicy< word32, 16 >.
Definition at line 373 of file chacha.cpp.
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protectedvirtual |
Seeks to a random position in the stream.
Reimplemented from AdditiveCipherAbstractPolicy.
Definition at line 357 of file chacha.cpp.
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protected |