sha1 hash from as3crypto differs from the one made with PHP

Question

Make SHA1 hash from string '12345' with as3crypto in as3 the same way how it is done in there example:

var sha1:SHA1 = new SHA1;
var src:ByteArray = Hex.toArray("12345");
var digest:ByteArray = sha1.hash(src);
trace('SHA:' + Hex.fromArray(digest));

result : ec60c0fd70d82a7785f6c9a02dbe16f2e40b1344

Make SHA1 from the same string in PHP:

print "SHA:".sha1("12345");

result : 8cb2237d0679ca88db6464eac60da96345513964

If I try other tools to obtain hash I get the second result, so it looks like the result from PHP is correct.

Question: How can I get the same hash with as3crypto?

BTW: when testing I found that another way with as3crypto gives me another (wrong?) result:

var src:ByteArray = new ByteArray();
src.writeUTF("12345");
var digest:ByteArray = sha1.hash(src);
trace('SHA:' + Hex.fromArray(digest));

result : b98cfbc53daec4029895585ab198f7403d0d0506

Can you not pass in a simple string in AS3? `var src = '12345'`? I'm suspecting that however those ByteArrays get stringified for the hash function, they're nothing coming out as '12345' anymore. — Marc B, Feb 17 '11 at 16:22
@MarcB - apparently not, according to the source that function only takes a byte array as input. It's an unusual crypto library, though - most allow you to continually "update" the input stream, and then get a final digest. This one appears to require the entire input to be in memory first and then digests it in one fell swoop. — Alnitak, Feb 17 '11 at 16:28
Thanks to A. R. Younce. It works with src.writeUTFBytes("12345"); — user621684, Feb 18 '11 at 07:13

score 2 · Answer 1 · answered Apr 14 '12 at 23:18

The correct way to match a php sha1 using as3crypto lib is to do the following:

var src:ByteArray = Hex.toArray(Hex.fromString(srcString));
var sha1:SHA1 = new SHA1();
var hashedString:String = Hex.fromArray(sha1.hash( src ));

The first additional Hex.fromString avoids your decimal conversion as others have mentioned.

Note: The as3corelib version is much simpler: as3corelib SHA1

var hashedString:String = SHA1.hash( srcString );

score 2 · Answer 2 · answered Feb 17 '11 at 16:38

2

The hexadecimal (you're converting it with Hex.toArray) value of 12345 is not the same as the string "12345".

You are converting a decimal number to a hexadecimal byte array and hashing it, and then comparing it to a hash of a string generated in PHP. These will never match.

If you absolutely need to compare two hex number together then a change to your PHP like this should probably work.

print "SHA:" . sha1(dechex(12345));

See the dechex PHP documentation for more.

answered Feb 17 '11 at 16:38

A. R. Younce

1,913
17
22

Right, I converted it with Hex.toArray in the first example. The problem is that in the second example (see after BTW) I do not use this function and still have wrong hash. – user621684 Feb 17 '11 at 17:08
3

Are you checking the output of writeUTF to see exactly what you're hashing? I've seen suggestions that it prefixes the string with its length. See: http://symmetri.blogsome.com/2008/12/17/flex-writeutf-vs-writeutfbytes/ Try writeUTFBytes() instead. – A. R. Younce Feb 17 '11 at 18:43
Thanks for your help. Now it works with src.writeUTFBytes("12345"); – user621684 Feb 18 '11 at 07:12

score 1 · Answer 3 · answered Aug 04 '16 at 05:08

1

var sha1:SHA1 = new SHA1(); 
var src:ByteArray = new ByteArray(); 
src.writeUTFBytes("12345"); 
trace( Hex.fromArray( sha1.hash( src ) ) );

using writeUTFBytes, this method write the string into bytesarray object without BOM.

answered Aug 04 '16 at 05:08

dainan13

11
2

score 1 · Answer 4 · answered Feb 17 '11 at 16:25

The PHP output is definitely correct. I tested it against MySQL's sha1 function:

mysql> select sha1('12345');
+------------------------------------------+
| sha1('12345')                            |
+------------------------------------------+
| 8cb2237d0679ca88db6464eac60da96345513964 |
+------------------------------------------+

The likely culprit is this - you're using Hex.toArray() on the input data in this line:

var src:ByteArray = Hex.toArray("12345");

When you need the original string to be in the byte array. I don't know AS3, though, so can't answer why your second attempt also failed.

sha1 hash from as3crypto differs from the one made with PHP

4 Answers4

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