MD5

Implements the Message-Digest algorithm 5.

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Interface

#include <codecogs/computing/security/md5.h>

using namespace Computing::Security;

inline uint32_t md5AddRotate(uint32_t value, uint32_t B, char shiftCount)
inline uint32_t md5F(uint32_t A, uint32_t B, uint32_t C, uint32_t D, uint32_t blockItem, char shiftCount, uint32_t sineValue)
inline uint32_t md5G(uint32_t A, uint32_t B, uint32_t C, uint32_t D, uint32_t blockItem, char shiftCount, uint32_t sineValue)
inline uint32_t md5H(uint32_t A, uint32_t B, uint32_t C, uint32_t D, uint32_t blockItem, char shiftCount, uint32_t sineValue)
inline uint32_t md5I(uint32_t A, uint32_t B, uint32_t C, uint32_t D, uint32_t blockItem, char shiftCount, uint32_t sineValue)
inline std::string md5(std::string &str)

Overview

This module implements the MD5 (Message-Digest algorithm 5) algorithm, which is a 128-bit valued hash function designed by Ron Rivest in 1991. Its main application is to check the integrity of data, but it can also be used in conjunction with cryptosystems like RSA.

The idea of the algorithm is to encode the input message using four 32-bit registers and by going through a series of bitwise operations, based on the following four functions:

$$F(x, y, z) := (x \wedge y) \vee (\neg x \wedge z)$$

(1)

$$G(x, y, z) := (x \wedge z) \vee (y \wedge \neg z),$$

(2)

$$H(x, y, z) := x \oplus y \oplus z,$$

(3)

$$I(x, y, z) := y \oplus (x \vee \neg z).$$

(4)

The algorithm also uses a number of 64 constants $c_0$, $c_1$, ..., $c_{63}$ defined through:

$$c_i := \left\lfloor 2^{32} \left| \sin(i + 1) \right| \right\rfloor, \qquad 0 \leq i \leq 63,$$

(5)

where $\lfloor \cdot \rfloor$ denotes the floor function.

The following example displays the MD5 code for the string "somewhere over the rainbow".

Example 1

#include <iostream>
#include <codecogs/computing/security/md5.h>

int main()
{
  std::string data = "somewhere over the rainbow";

  std::cout << "Input: " << data << std::endl;
  std::cout << "  MD5: " << Computing::Security::md5(data) << std::endl;

  return 0;
}

Output

Input: somewhere over the rainbow
  MD5: fe6acc5bea48d66ac6baa60ff73f6d62

References

The MD5 Message-Digest Algorithm (RFC1321), http://tools.ietf.org/html/rfc1321
The description of the MD5 algorithm on Wikipedia, http://en.wikipedia.org/wiki/MD5
Free online MD5 hash calculator based on PHP, http://md5-hash-online.waraxe.us

FUNCTION

md5AddRotate

FUNCTION

md5F

FUNCTION

md5G

FUNCTION

md5H

FUNCTION

md5I

FUNCTION

This function generates the unique MD5 code corresponding to the given string, in the form of a 32 digits hexadecimal number.

For example, to obtain the MD5 code of the string "Hello World", you would write something similar to:

std::string md5Code = Computing::Security::Hash::md5("Hello World");

Parameters

str

the string to be hashed

Returns

the MD5 code corresponding to str, as a 32 digits hexadecimal number stored as a string

Interactive Calculator

str

Result –