Re: found a weird bug....

[Chris R. <Chr...@me...>]

On Wed, 10 May 2000 05:30:13 PDT, "Kurt D. Zeilenga" wrote:
> At 02:59 AM 5/10/00 -0700, Pythagoras Watson wrote:
> >This appears to be a decoding error on Net::LDAP's part.  When the
> >operation number (5th byte of response) reaches 128 (0x80), the
> >resulting message code changes to two.
> >
> >To wit:
> >  searching 126
> >  ...
> >  30 38 02 01 7F 64 33 04 2F 75 69 64 3D 70 79 2C 08...d3./uid=py,
> >  ...
> >  0002 02    1:   INTEGER = 127
> >  ...
> >  searching 127
> >  ...
> >  30 38 02 01 80 64 33 04 2F 75 69 64 3D 70 79 2C 08...d3./uid=py,
> >  ...
> >  0002 02    1:   INTEGER = -128
> >  search failed: 2
> >
> 
> 	02 01 7F ==  127
> 	02 01 80 == -128
> 
> 02 INTEGER
> 01 length of 1
> xx 2-complement base-256 value
> 
> From RSA's Layman's Guide:
> > Some example BER encodings (which also happen to be DER
> > encodings) are given in Table 3.
> >
> >                   Integer   BER encoding
> >                   value
> >                   0         02 01 00
> >                   127       02 01 7F
> >                   128       02 02 00 80
> >                   256       02 02 01 00
> >                   -128      02 01 80
> >                   -129      02 02 FF 7F
> 
> Appears to me that your server is broke.
> 

Kurt is quite right.

X.208 (BER) says:

------------
8 Encoding of an integer value

8.1 The encoding of an integer value shall be primitive. The contents 
octets shall consist of one or more octets.

8.2 If the contents octets of an integer value encoding consist of more 
than one octet, then the bits of the first octet and bit 8 of the 
second octet

a) shall not all be ones; and

b) shall not all be zero.

Note - These rules ensure that an integer value is always encoded in 
the smallest possible number of octets.

8.3 The contents octets shall be a two's, complement binary number 
equal to the integer value, and consisting of bits 8 to 1 of the first 
octet, followed by bits 8 to 1 of the second octet, followed by bits 8 
to 1 of each octet in turn up to and including the last octet of the 
contents octets.

------------

So 0x80 is -128.

This is a common encoding error made by Microsoft software. (Read 
http://www.cs.auckland.ac.nz/~pgut001/pubs/x509guide.txt and search for 
INTEGER.)

Are you using an MS server, Pythagoras?

Cheers,

Chris