HASH_EQUALS(3) 1 HASH_EQUALS(3)hash_equals - Timing attack safe string comparisonSYNOPSIS
bool hash_equals (string $known_string, string $user_string)
DESCRIPTION
Compares two strings using the same time whether they're equal or not.
This function should be used to mitigate timing attacks; for instance, when testing crypt(3) password hashes.
PARAMETERS
o $known_string
- The string of known length to compare against
o $user_string
- The user-supplied string
RETURN VALUES
Returns TRUE when the two strings are equal, FALSE otherwise.
ERRORS /EXCEPTIONS
Emits an E_WARNING message when either of the supplied parameters is not a string.
EXAMPLES
Example #1
example
<?php
$expected = crypt('12345', '$2a$07$usesomesillystringforsalt$');
$correct = crypt('12345', '$2a$07$usesomesillystringforsalt$');
$incorrect = crypt('apple', '$2a$07$usesomesillystringforsalt$');
var_dump(hash_equals($expected, $correct));
var_dump(hash_equals($expected, $incorrect));
?>
The above example will output:
bool(true)
bool(false)
NOTES
Note
Both arguments must be of the same length to be compared successfully. When arguments of differing length are supplied, FALSE is
returned immediately and the length of the known string may be leaked in case of a timing attack.
Note
It is important to provide the user-supplied string as the second parameter, rather than the first.
PHP Documentation Group HASH_EQUALS(3)
Check Out this Related Man Page
CLASS_ALIAS(3) 1 CLASS_ALIAS(3)class_alias - Creates an alias for a classSYNOPSIS
bool class_alias TRUE (string $original, string $alias, [bool $autoload])
DESCRIPTION
Creates an alias named $alias based on the user defined class $original. The aliased class is exactly the same as the original class.
PARAMETERS
o $original
- The original class.
o $alias
- The alias name for the class.
o $autoload
- Whether to autoload if the original class is not found.
RETURN VALUES
Returns TRUE on success or FALSE on failure.
EXAMPLES
Example #1
class_alias(3) example
<?php
class foo { }
class_alias('foo', 'bar');
$a = new foo;
$b = new bar;
// the objects are the same
var_dump($a == $b, $a === $b);
var_dump($a instanceof $b);
// the classes are the same
var_dump($a instanceof foo);
var_dump($a instanceof bar);
var_dump($b instanceof foo);
var_dump($b instanceof bar);
?>
The above example will output:
bool(true)
bool(false)
bool(true)
bool(true)
bool(true)
bool(true)
bool(true)
SEE ALSO get_parent_class(3), is_subclass_of(3).
PHP Documentation Group CLASS_ALIAS(3)
I am using a Korn Shell script..
I need to verify the length of a variable..
ie number=12345
I need then to check 12345 to make sure its no longer than 5 digits...
Can you help? (4 Replies)
Hi
I have got a log file which is like:
id status
---------------------
12345 status1.true
12345 status2.true
12345 status3.false
12345 status4.true
23452 status5.true
23452 status6.true
23452 status7.false
65243 ... (2 Replies)
I have a file of 1000 rows , I need to format it to be coulmn seperatred by TAB , and print it
Ex:
12345
12345
12343
32232
23432
34242
43224
to like
12345 TAB 12345
12343 TAB 32232
23432 TAB 34242
43224 TAB .........
Thanks alot for your helping and care... (9 Replies)
All,
I have a file ABC.TXT which has two records:
12345 19.93 34.94
12345 94.84 10.48
If do the following command and
grep '12345' ABC.TXT >> test1.txt
If I look at the output of test1.txt I appears as follows:
12345 19.93 34.94 12345 94.84 10.48
I... (5 Replies)
I'm at a total loss how to attack this problem.
I have a file that contains
ab
What I need to do is if
1)if the string "ab" doesn't contain a newline, I need to insert one back into the buffer.
2)If the file contains two consecutive blank lines, skip over it.
Here is what I started
... (5 Replies)
Hi,
I need to delete repeated nos in a file and finally list the count. Can some one assist me?
file:
12345
12345
56345
12345
23896
Output needed:
12345
56345
23896
Total count:3
Thanks (2 Replies)
Hi,
I am trying to use awk to split line before the pattern:
abcde 12345 67890 abcde 12345 67890 abcde 12345 67890 abcde 12345 67890 abcde 12345 67890 abcde 12345 67890 abcde 12345 67890
I need it to be like this:
abcde 12345 67890
abcde 12345 67890
abcde 12345 67890
abcde... (7 Replies)
I have a criteria like bloew.
user entered the uid like <START_UID>-<END_UID>
it menas if he enter 00001-12345
START_UID=00001 and END_UID=12345
both are separated by `-`.
I need to validate whether user entered uids like above, he should have to enter '-', otherwise error msg has to... (4 Replies)
field 12345 12345
field 12345
field 12345 123456
last fleld (from three) is optional, but if it occures It has to be composed only of nummbers and maximum 5 positions long.
If I use:
grep "^field \{5\}"
I get:
field 12345 12345
field 12345
field 12345 123456
But I wont... (11 Replies)
A server I host is having very rare glitches where a file the user downloads will have incorrect contents. This almost never happens when I am looking, I caught it once and only once -- a user messaged me saying his antivirus had given him a warning about an image file downloaded from his... (2 Replies)
Hello,
Does anyone have a one-liner to remove lines of a csv file if the value in a specific column is zero? For example, I have this file,
12345,COM,5,0,N,29.95,Y
12345,MOM,1,0,N,29.95,Y
12345,COM,4,0,N,9.99,Y
12345,MOM,0,2,N,9.99,Y
12345,REN,0,1,N,9.99,Y
and I want to remove lines... (4 Replies)
Hi,
I have the input file with the below data:
12345|12|34
12345|13|23
3456|12|90
15670|12|13
12345|10|14
3456|12|13
I need to remove the duplicates based on the first field only.
I need the output like:
12345|12|34
3456|12|90
15670|12|13
The first field needs to be unique . (4 Replies)
Hello,
I have files with fixed length fields.
12345 12345 12345671234567 10 1234567
12345 12345 123456 1234567 10 1234567
I want to take 1st, 3rd, 4th and 6th string.
Usually 3rd and 4th string are coming as it is on the first row /1234567 and... (3 Replies)
Dear All,
We were hit with a denial of service (DOS) attack today beginning around June 12th 2019 @ 01:27:51 PM from an IP address registered to "RACKWEB-NET" in Bulgaria.
I was notified about this around June 12th 2019 @ 03:05 PM and did some log file analysis and discovered how the attack... (4 Replies)