gpmp::nt::RC5 Class Reference

RC5 encryption and decryption class. More...

#include <rc5.hpp>

Public Member Functions
	RC5 (uint32_t rounds=12, uint32_t wordSize=32, uint32_t blockSize=16)
	Constructs an RC5 object. More...
void	encrypt (uint32_t &A, uint32_t &B)
	Encrypts the given block. More...
void	decrypt (uint32_t &A, uint32_t &B)
	Decrypts the given block. More...

Private Member Functions
uint32_t	rotl (uint32_t value, uint32_t shift)
uint32_t	rotr (uint32_t value, uint32_t shift)
void	init ()

Private Attributes
uint32_t	w
uint32_t	r
uint32_t	b
std::vector< uint32_t >	S
const uint32_t	P = 0xB7E15163
const uint32_t	Q = 0x9E3779B9

Detailed Description

RC5 encryption and decryption class.

Definition at line 47 of file rc5.hpp.

Constructor & Destructor Documentation

RC5()

gpmp::nt::RC5::RC5	(	uint32_t	rounds = 12,
		uint32_t	wordSize = 32,
		uint32_t	blockSize = 16
	)

Constructs an RC5 object.

Parameters

rounds	Number of rounds
wordSize	Size of the word in bits
blockSize	Size of the block in bytes

Definition at line 36 of file rc5.cpp.

    : w(wordSize), r(rounds), b(blockSize) {
    init();
}

References init().

Member Function Documentation

decrypt()

void gpmp::nt::RC5::decrypt	(	uint32_t &	A,
		uint32_t &	B
	)

Decrypts the given block.

Parameters

A	First half of the block
B	Second half of the block

Definition at line 58 of file rc5.cpp.

                                                {
    for (uint32_t i = r; i > 0; --i) {
        B = rotr(B - S[2 * i + 1], A) ^ A;
        A = rotr(A - S[2 * i], B) ^ B;
    }
    B -= S[1];
    A -= S[0];
}

References python.linalg::A, and python.linalg::B.

encrypt()

void gpmp::nt::RC5::encrypt	(	uint32_t &	A,
		uint32_t &	B
	)

Encrypts the given block.

Parameters

A	First half of the block
B	Second half of the block

Definition at line 49 of file rc5.cpp.

                                                {
    A += S[0];
    B += S[1];
    for (uint32_t i = 1; i <= r; ++i) {
        A = rotl((A ^ B), B) + S[2 * i];
        B = rotl((B ^ A), A) + S[2 * i + 1];
    }
}

References python.linalg::A, and python.linalg::B.

init()

void gpmp::nt::RC5::init ( )

private

Definition at line 41 of file rc5.cpp.

                     {
    S.resize(2 * r + 2);
    S[0] = P;
    for (uint32_t i = 1; i < 2 * r + 2; ++i) {
        S[i] = S[i - 1] + Q;
    }
}

Referenced by RC5().

rotl()

uint32_t gpmp::nt::RC5::rotl ( uint32_t  value, uint32_t  shift  )

private

Definition at line 67 of file rc5.cpp.

                                                       {
    return (value << shift) | (value >> (w - shift));
}

rotr()

uint32_t gpmp::nt::RC5::rotr ( uint32_t  value, uint32_t  shift  )

private

Definition at line 71 of file rc5.cpp.

                                                       {
    return (value >> shift) | (value << (w - shift));
}

Member Data Documentation

b

uint32_t gpmp::nt::RC5::b

private

Definition at line 79 of file rc5.hpp.

P

const uint32_t gpmp::nt::RC5::P = 0xB7E15163

private

Definition at line 82 of file rc5.hpp.

Q

const uint32_t gpmp::nt::RC5::Q = 0x9E3779B9

private

Definition at line 83 of file rc5.hpp.

r

uint32_t gpmp::nt::RC5::r

private

Definition at line 79 of file rc5.hpp.

S

std::vector<uint32_t> gpmp::nt::RC5::S

private

Definition at line 80 of file rc5.hpp.

w

uint32_t gpmp::nt::RC5::w

private

Definition at line 79 of file rc5.hpp.

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

• include/openGPMP/nt/rc5.hpp
• modules/nt/rc5.cpp