SHA / SHA1 seed data and password encryption

[mwepper_zyres]

Dear ,

hopefully I miss a point, but
today we are experiencing a quite interesting issue which might heavily
influence the security of many ofbiz installations - but I'm not
mathematician enough to see how/if this lowers the security of the saved
hashes

Please have  a look at this:

I'm simply listing hashes  let's start with the hash in seed/demo for
"ofbiz":
 
47b56994cbc2b6d10aa1be30f70165adb305a41a = ofbiz hashed by debian4/sha1sum
47b56994cbc2b6d10aa1be30f70165adb305a41a = ofbiz hashed by php
47b56994cbc2b6d10aa1be30f70165adb305a41a = ofbiz by  java - Jacksum 1.7.0,
algorithm=sha1
but:
47ca69ebb4bdc9ae0adec130880165d2cc05db1a = ofbiz password for admin in
demo-seed-data
__xx__xxxxxxxxxx  xxxx  xx____xxxx__xx__    here the ofbiz hash differs to
other sha1 implementations

Other examples:
xxxx________xxxxxx____xxxx__xx__________
8cb2237d0679ca88db6464eac60da96345513964 = 12345 by "others"
f3cd237d0679b5f7a4646495b90dd66345513964 = 12345 by ofbiz

______xxxx__xxxxxxx_______xxxx__xx______  
7c222fb2927d828af22f592134e8932480637c0d = 12345678 by others
7c222fcded7dfdf58d2f59213497ec24ff637c0d = 12345678 by ofbiz

__xxxx____xxxx______xxxx__xx__xx____xx__  
2fb5e13419fc89246865e7a324f476ec624e8740 = abcdefg by others
2fca9e341983f624686598dc248b7693624ef840 = abcdefg by ofbiz


A brief analysis shows that the implementation might start here being
problematic:

getDigestHash trunk/base/src/base/org/ofbiz/base/crypto/HashCrypt.java

...
int i1 = digestBytes[l];
if (i1 < 0)
    i1 = 127 + i1 * -1;
StringUtil.encodeInt(i1, k, digestChars);
...

The bit operations introduced in encodeInt do not comply to the way the int
is calculated before.

Example:
Digest of -116 should result in 0x8c but in our ofbiz code it is resulting
in 0xf3
But:
-116 = 0b10001100 = 0x8c  for sha1
127 + -116*-1 =  243 = 0b11110011 = 0xf3 for obfiz-sha  

The digest is calculated properly, but when converting to hex string the
function seems to fail on negative byte/int values, only.

This has been introduced in 2004-09-09 21:06:36 UTC (rev 3317)  

Conclusion: the hashes in customer dbs are not really compatible with other
sha1 implementations today, bad for SSO.
Is there any impact on vulnerability of stored hashes created by ofbiz?

Martin

 


--
Martin Wepper
ZYRES digital media systems GmbH
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http://www.zyres.com/
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