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CryptX-0.085
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/ Crypt::PRNG

NAME

Crypt::PRNG - Cryptographically secure random number generator

SYNOPSIS


            

              
              
### Functional interface:
use Crypt::PRNG qw(random_bytes random_bytes_hex random_bytes_b64 random_bytes_b64u
                   random_string random_string_from rand irand);
$octets = random_bytes(45);
$hex_string = random_bytes_hex(45);
$base64_string = random_bytes_b64(45);
$base64url_string = random_bytes_b64u(45);
$alphanumeric_string = random_string(30);
$string = random_string_from('ACGT', 64);
$floating_point_number_0_to_1 = rand;
$floating_point_number_0_to_88 = rand(88);
$unsigned_32bit_int = irand;
### OO interface:
use Crypt::PRNG;
$prng = Crypt::PRNG->new;  # defaults to ChaCha20
#or
$prng = Crypt::PRNG->new("RC4");
#or
$prng = Crypt::PRNG->new("RC4", "some data used for seeding PRNG");
$octets = $prng->bytes(45);
$hex_string = $prng->bytes_hex(45);
$base64_string = $prng->bytes_b64(45);
$base64url_string = $prng->bytes_b64u(45);
$alphanumeric_string = $prng->string(30);
$string = $prng->string_from('ACGT', 64);
$floating_point_number_0_to_1 = $prng->double;
$floating_point_number_0_to_88 = $prng->double(88);
$unsigned_32bit_int = $prng->int32;

DESCRIPTION

Provides an interface to the ChaCha20 based pseudo random number generator (thread-safe and fork-safe).

FUNCTIONS

random_bytes


            

              
              
$octets = random_bytes($length);

Returns $length random octects.

random_bytes_hex


            

              
              
$hex_string = random_bytes_hex($length);

Returns $length random octects encoded as hexadecimal string.

random_bytes_b64


            

              
              
$base64_string = random_bytes_b64($length);

Returns $length random octects Base64 encoded.

random_bytes_b64u


            

              
              
$base64url_string = random_bytes_b64u($length);

Returns $length random octects Base64 URL Safe (RFC 4648 section 5) encoded.

random_string_from


            

              
              
$string = random_string_from($range, $length);
#e.g.
$string = random_string_from("ABCD", 10);

Returns a random string made of $length chars randomly chosen from $range string.

random_string


            

              
              
$alphanumeric_string = random_string($length);
#or
$alphanumeric_string = random_string;  # default length = 20

Similar to random_string_from, only $range is fixed to 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789'.

rand


            

              
              
$n = rand;
#or
$n = rand($limit);

Returns a random floating point number from range [0,1) (if called without parameter) or [0,$limit).

irand


            

              
              
$i = irand;

Returns a random unsigned 32bit integer - range 0 .. 0xFFFFFFFF.

METHODS

new


            

              
              
$prng = Crypt::PRNG->new;  # defaults to ChaCha20
#or
$prng = Crypt::PRNG->new($alg);
#or
$prng = Crypt::PRNG->new($alg, $seed);
# $alg  ... algorithm name 'ChaCha20' (DEFAULT), 'Fortuna', 'RC4', 'Sober128' or 'Yarrow'
# $seed ... will be used as an initial entropy for seeding PRNG

If $seed is not specified the PRNG is automatically seeded with 32bytes random data taken from /dev/random (UNIX) or CryptGenRandom (Win32)

add_entropy


            

              
              
$prng->add_entropy($random_data);
#or
$prng->add_entropy();

If called without parameter it uses 32bytes random data taken from /dev/random (UNIX) or CryptGenRandom (Win32).

BEWARE: you probably do not need this function at all as the module does automatic seeding on initialization as well as reseeding after fork and thread creation.

bytes


            

              
              
$octets = $prng->bytes($length);

See random_bytes

bytes_hex


            

              
              
$hex_string = $prng->bytes_hex($length);

See random_bytes_hex

bytes_b64


            

              
              
$base64_string = $prng->bytes_b64($length);

See random_bytes_b64

bytes_b64u


            

              
              
$base64url_string = $prng->bytes_b64u($length);

See random_bytes_b64u

string


            

              
              
$alphanumeric_string = $prng->string($length);
#or
$alphanumeric_string = $prng->string;

See random_string

string_from


            

              
              
$string = $prng->string_from($range, $length);

See random_string_from

double


            

              
              
$n = $prng->double;
#or
$n = $prng->double($limit);

See rand

int32


            

              
              
$i = $prng->int32;

See irand

SEE ALSO

Crypt::PRNG::Fortuna, Crypt::PRNG::RC4, Crypt::PRNG::Sober128, Crypt::PRNG::Yarrow