Generate 128 Bit Key Php
/windows-2008-product-key-generator.html. Generating Keys for Encryption and Decryption.; 3 minutes to read +7; In this article. Creating and managing keys is an important part of the cryptographic process. Symmetric algorithms require the creation of a key and an initialization vector (IV). The key must be kept secret from anyone who should not decrypt your data.
- For example, AES has 3 choices: 128-bit, 192-bit, // or 256-bit. In the ChaCha20 algorithm, the key size must always be 256-bits (32-bytes). // Both sides (encryptor and decryptor) must be in possession of the same secret key // in order to communicate. Whichever side generates the key, it must somehow // deliver the key to the other side.
- Oct 14, 2008 Length of 128-bit? Leaked screenshots show new Inbox tabs for Outlook on the web in. To decipher an SSL communication, one simply needs to generate the correct decoding key.
Hello,
I need to generate a 128-bit random number, so I wrote the following code:
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include 'polarssl/config.h'
#include 'polarssl/bignum.h'
#define ciL ((int) sizeof(t_int))
#define biL (ciL << 3)
#define BITS_TO_LIMBS(i) (((i) + biL - 1) / biL)
// in bytes
#define RANDOM_NUMBER_LENGTH 16
static int my_rand(void) {
srand( (unsigned int) time(0) );
return( rand() );
}
int main (void) {
#if defined(POLARSSL_BIGNUM_C)
int i, n;
mpi N;
unsigned char *p;
mpi_init(&N, NULL);
n = BITS_TO_LIMBS(RANDOM_NUMBER_LENGTH*8);
mpi_grow(&N, n);
mpi_lset(&N, 0);
p = (unsigned char *) N.p;
for (i = 0; i <N.n * ciL; i++)
*p++ = (unsigned char) my_rand();
mpi_write_file('nThe 128-bit RN is: ', &N, 2, NULL);
mpi_write_file('nThe 128-bit RN is: ', &N, 10, NULL);
mpi_free(&N, NULL);
#endif
return 0;
}
It seems to be working fine (different runs produce different sequence of 128-bits).
I am new to mpi and rng so I am curious to know if there some way to check if the above code is logically correct? Or if there are some changes that could be made to improve it (e.g. in terms of robustness or execution time)?
Thanxs
I need to generate a 128-bit random number, so I wrote the following code:
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include 'polarssl/config.h'
#include 'polarssl/bignum.h'
#define ciL ((int) sizeof(t_int))
#define biL (ciL << 3)
#define BITS_TO_LIMBS(i) (((i) + biL - 1) / biL)
// in bytes
#define RANDOM_NUMBER_LENGTH 16
static int my_rand(void) {
srand( (unsigned int) time(0) );
return( rand() );
}
int main (void) {
#if defined(POLARSSL_BIGNUM_C)
int i, n;
mpi N;
unsigned char *p;
mpi_init(&N, NULL);
n = BITS_TO_LIMBS(RANDOM_NUMBER_LENGTH*8);
mpi_grow(&N, n);
mpi_lset(&N, 0);
p = (unsigned char *) N.p;
for (i = 0; i <N.n * ciL; i++)
*p++ = (unsigned char) my_rand();
mpi_write_file('nThe 128-bit RN is: ', &N, 2, NULL);
mpi_write_file('nThe 128-bit RN is: ', &N, 10, NULL);
mpi_free(&N, NULL);
#endif
return 0;
}
It seems to be working fine (different runs produce different sequence of 128-bits).
I am new to mpi and rng so I am curious to know if there some way to check if the above code is logically correct? Or if there are some changes that could be made to improve it (e.g. in terms of robustness or execution time)?
Thanxs
Hi,
This code seems correct to me (although you might want to use a true random source like /dev/random). Paul, maybe a new function in the mpi library would be useful to users of the library who need to quickly generate random mpintegers?
This code seems correct to me (although you might want to use a true random source like /dev/random). Paul, maybe a new function in the mpi library would be useful to users of the library who need to quickly generate random mpintegers?
Seems like a good idea. I'll place it in the issue list, which is now publicly available.
(http://polarssl.org/trac)
Paul
(http://polarssl.org/trac)
Paul
Generate 128 Bit Key Php Password
Hi,
This code does not work correctly. The output is not random as shown below:
run 1:
The 128-bit modifier is: 1100000011000000110000001100000011000000110000001100000011000000110000001100000011000000110000001100000011000000110000001100
run 2:
The 128-bit modifier is: 1001011010010110100101101001011010010110100101101001011010010110100101101001011010010110100101101001011010010110100101101001011
It is obvious that a bit pattern is repeating within each 128-bit sequence (e.g. 11000000 in run 1 and 10010110 in run 2)
Any suggestions on how to overcome this problem?
thanks
This code does not work correctly. The output is not random as shown below:
run 1:
The 128-bit modifier is: 1100000011000000110000001100000011000000110000001100000011000000110000001100000011000000110000001100000011000000110000001100
run 2:
The 128-bit modifier is: 1001011010010110100101101001011010010110100101101001011010010110100101101001011010010110100101101001011010010110100101101001011
It is obvious that a bit pattern is repeating within each 128-bit sequence (e.g. 11000000 in run 1 and 10010110 in run 2)
Any suggestions on how to overcome this problem?
thanks
Generate 128 Bit Key Php Download
Hi Bluebottle,
You are correct. The random function used in the example is not written correctly. As suggested in posts more down, you should use a real random function (like for instance the HAVEGE code in PolarSSL).
To fix this example, you should move the:
from the my_rand() function to the top of main().
That fixes the repeating sequences, but still does not give you the best random. using HAVEGE would give you solid results:
You are correct. The random function used in the example is not written correctly. As suggested in posts more down, you should use a real random function (like for instance the HAVEGE code in PolarSSL).
To fix this example, you should move the:
from the my_rand() function to the top of main().
That fixes the repeating sequences, but still does not give you the best random. using HAVEGE would give you solid results: