hash_file

(PHP 5 >= 5.1.2, PHP 7, PECL hash >= 1.1)

hash_file — 使用给定文件的内容生成哈希值

说明

string hash_file ( string $algo , string $filename [, bool $raw_output = false ] )

参数

algo: 要使用的哈希算法的名称，例如："md5"，"sha256"，"haval160,4" 等。
filename: 要进行哈希运算的文件路径。支持 fopen 封装器。
raw_output: 设置为 TRUE，输出格式为原始的二进制数据。设置为 FALSE，输出小写的 16 进制字符串。

返回值

如果 raw_output 设置为 TRUE，则返回原始二进制数据表示的信息摘要，否则返回 16 进制小写字符串格式表示的信息摘要。

范例

Example #1 使用 hash_file()


<?php
/* 创建一个要计算哈希值的文件 */
file_put_contents('example.txt', 'The quick brown fox jumped over the lazy dog.');

echo hash_file('md5', 'example.txt');
?>

以上例程会输出：

5c6ffbdd40d9556b73a21e63c3e0e904

参见

hash() - 生成哈希值（消息摘要）
hash_hmac_file() - 使用 HMAC 方法和给定文件的内容生成带密钥的哈希值
hash_update_file() - 从文件向活跃的哈希运算上下文中填充数据
md5_file() - 计算指定文件的 MD5 散列值
sha1_file() - 计算文件的 sha1 散列值

User Contributed Notes

lnker dot ua at gmail dot com 05-Sep-2017 11:28


Link id : 6r1j-d2gs

Code description : hash_file() performance check; Table head columns are sortable by clicking;



Open the code with PhpFiddle - http://phpfiddle.org/main/code/6r1j-d2gs

Open the code with PhpFiddle Lite - http://phpfiddle.org/lite/code/6r1j-d2gs



So do not care a lot about performance! Just use what you need!

synnus at gmail dot com 17-Jun-2015 08:57


bench 476 Mo, win is 'haval160,4' : 0.037002



ALGO: md2, time: 74.702272891998

ALGO: md4, time: 9.2155270576477

ALGO: md5, time: 9.0815191268921

ALGO: sha1, time: 9.0945210456848

ALGO: sha224, time: 9.1465229988098

ALGO: sha256, time: 9.143522977829

ALGO: sha384, time: 14.065804004669

ALGO: sha512, time: 13.990800857544

ALGO: ripemd128, time: 9.3185329437256

ALGO: ripemd160, time: 9.3165328502655

ALGO: ripemd256, time: 9.2495288848877

ALGO: ripemd320, time: 9.2395279407501

ALGO: whirlpool, time: 27.779588937759

ALGO: tiger128,3, time: 9.3075330257416

ALGO: tiger160,3, time: 9.1875250339508

ALGO: tiger192,3, time: 9.3875370025635

ALGO: tiger128,4, time: 9.1755249500275

ALGO: tiger160,4, time: 9.355535030365

ALGO: tiger192,4, time: 9.2025260925293

ALGO: snefru, time: 42.781446218491

ALGO: snefru256, time: 42.613437175751

ALGO: gost, time: 18.606064081192

ALGO: gost-crypto, time: 18.664067983627

ALGO: adler32, time: 9.1535229682922

ALGO: crc32, time: 10.126579999924

ALGO: crc32b, time: 10.01757311821

ALGO: fnv132, time: 9.7505569458008

ALGO: fnv1a32, time: 9.7935597896576

ALGO: fnv164, time: 9.8945660591125

ALGO: fnv1a64, time: 9.3025319576263

ALGO: joaat, time: 9.7175559997559

ALGO: haval128,3, time: 9.6855540275574

ALGO: haval160,3, time: 10.10857796669

ALGO: haval192,3, time: 9.6765530109406

ALGO: haval224,3, time: 20.636180877686

ALGO: haval256,3, time: 10.641607999802

ALGO: haval128,4, time: 7.5594329833984

ALGO: haval160,4, time: 7.2884171009064

ALGO: haval192,4, time: 7.2934169769287

ALGO: haval224,4, time: 7.2964169979095

ALGO: haval256,4, time: 7.3034179210663

ALGO: haval128,5, time: 8.3244760036469

ALGO: haval160,5, time: 8.3174757957458

ALGO: haval192,5, time: 8.3204758167267

ALGO: haval224,5, time: 8.3234758377075

ALGO: haval256,5, time: 8.3254759311676



bench 13,0 Mo, win is 'adler32'  : 0.037002



ALGO: md2, time: 2.0341160297394

ALGO: md4, time: 0.062004089355469

ALGO: md5, time: 0.071003913879395

ALGO: sha1, time: 0.086004972457886

ALGO: sha224, time: 0.18301010131836

ALGO: sha256, time: 0.18301105499268

ALGO: sha384, time: 0.36102104187012

ALGO: sha512, time: 0.3610200881958

ALGO: ripemd128, time: 0.15900897979736

ALGO: ripemd160, time: 0.20701193809509

ALGO: ripemd256, time: 0.16500997543335

ALGO: ripemd320, time: 0.22501301765442

ALGO: whirlpool, time: 0.74204206466675

ALGO: tiger128,3, time: 0.12200689315796

ALGO: tiger160,3, time: 0.12100696563721

ALGO: tiger192,3, time: 0.12200713157654

ALGO: tiger128,4, time: 0.15700888633728

ALGO: tiger160,4, time: 0.15700888633728

ALGO: tiger192,4, time: 0.15600895881653

ALGO: snefru, time: 1.1520659923553

ALGO: snefru256, time: 1.151065826416

ALGO: gost, time: 0.48902797698975

ALGO: gost-crypto, time: 0.49202799797058

ALGO: adler32, time: 0.037002086639404

ALGO: crc32, time: 0.10300588607788

ALGO: crc32b, time: 0.093006134033203

ALGO: fnv132, time: 0.043002128601074

ALGO: fnv1a32, time: 0.045002937316895

ALGO: fnv164, time: 0.12800693511963

ALGO: fnv1a64, time: 0.12800693511963

ALGO: joaat, time: 0.070003986358643

ALGO: haval128,3, time: 0.12900686264038

ALGO: haval160,3, time: 0.12800693511963

ALGO: haval192,3, time: 0.12900805473328

ALGO: haval224,3, time: 0.12800693511963

ALGO: haval256,3, time: 0.12800693511963

ALGO: haval128,4, time: 0.19901204109192

ALGO: haval160,4, time: 0.1990110874176

ALGO: haval192,4, time: 0.20001196861267

ALGO: haval224,4, time: 0.20001101493835

ALGO: haval256,4, time: 0.20001220703125

ALGO: haval128,5, time: 0.22601294517517

ALGO: haval160,5, time: 0.2270131111145

ALGO: haval192,5, time: 0.2270131111145

ALGO: haval224,5, time: 0.2270131111145

ALGO: haval256,5, time: 0.22701287269592

holdoffhunger at gmail dot com 30-Jun-2012 10:03


The Hash_File() function returns the same value as if the function Hash() had been performed on the same exact piece of data.  At first, I was uncertain if Hash_File() used the filename, or even the permission settings, when defining the data to be hashed for the given algorithm.  If it did work that way, then that means the same exact files would have different HASH values when you moved or renamed them on your system.  Anyway, fortunately, it does not work that way.  Hash() and Hash_File() produce identical results for the same pieces of data.  This is also true for the relationship between the Hash_HMAC() and Hash_HMAC_File() functions: the same pieces of data, the same keys, produce identical results.  It was a wise, design principle.



Some sample code to demonstrate this principle :



<?php



            // Author: holdoffhunger@gmail.com



        // Preset Data

        // ------------------------------------------------

        

    $test_data = "php-hashing";

    $test_file = "test.txt";

    $test_file_read = file_get_contents($test_file);

    

        // Hash Data

        // ------------------------------------------------

    

    $test_data_hash = hash("md2", $test_data, FALSE);

    $test_file_hash = hash_file("md2", $test_file, FALSE);

    

        // Print Hash Results

        // ------------------------------------------------

    

    print("Data Hash ($test_data): $test_data_hash<br><br>");

    print("File Hash ($test_file_read): $test_file_hash");

    

?>



    Expected Results

    ..................................

    

Data Hash (php-hashing): 457d84e1d69e519a7b73348db21477d3



File Hash (php-hashing): 457d84e1d69e519a7b73348db21477d3

apm at domain itsmee.co.uk 10-Jul-2011 01:56


I have verified that the output of the "crc32" is the ITU I.363.5 algorithm (a.k.a. AAL5 CRC - popularised by BZIP2 but also used in ATM transmissions - the algorithm is the same as that in POSIX 1003.2-1992 in Cksum but that stuffs the size into the CRC at the end for extra measure).  However, the output is expressed in reverse order to many CRC programs.  Using the "standard" crctest.txt (numbers 1 to 9 in sequence - google it, it's not hard to find), php will output 181989fc - many other (Intel little endian) programs would output this as fc891918, hence the confusion (that I have had, at least).



The crc32b is the 32-bit Frame Check Sequence of ITU V.42 (used in Ethernet and popularised by PKZip).  The output from this CRC is popularised in Intel little endian format and would produce cbf43926 on the same file.

Anonymous 26-Apr-2011 06:55


Please take note that hash-file will throw error on files >=2GB.

chernyshevsky at hotmail dot com 23-Sep-2010 01:01


If you want to use hash_file() to get the CRC32 value of a file, use the following to unpack the hex string returned by the function to an integer (similar to crc32()):



$hash = hash_file('crc32b', $filepath);

$array = unpack('N', pack('H*', $hash));

$crc32 = $array[1];

Keisial at gmail dot com 11-Sep-2008 08:46


The 'octets reversed' you are seeing is the bug 45028 which has been fixed. http://bugs.php.net/bug.php?id=45028



The difference between crc32 and crc32b is explained on mhash man page. crc32 is the one used on ethernet, while crc32b is the one used on zip, png... They differ on the table used.

allaryin at gmail dot com 24-Jul-2008 12:16


For those who are wondering, there appears to be no fundamental difference between hash_file('md5')/hash_file('sha1') and md5_file()/sha1_file(). They produce identical output and have comparable performance.



There is, however, a difference between hash_file('crc32') and something silly like crc32(file_get_contents()).



crc32(file_get_contents())'s results are most similar to those of hash_file('crc32b'), just with the octets reversed:



<?php

$fname = "something.png";



$hash = hash_file( 'crc32', $fname );

echo "crc32  = $hash\n";



$hash = hash_file( 'crc32b', $fname );

echo "crc32b = $hash\n";



$hash = sprintf("%x",crc32(file_get_contents($fname)));

echo "manual = $hash\n";

?>



crc32  = f41d7f4e

crc32b = 7dafbba4

manual = a4bbaf7d