PKCS11 Trace with netscape?
Antonio Andres Espallardo
developed in encrypt/decrypt methods. I can't understand the behavior
when I use it with Netscape 7.2 or Thunderbind in these operations.
Could anyone facilitate me a trace of his pkcs11 in which I could see
the input data (and length), the cipher used and the output generated by
the methods C_EncryptInit / C_DecryptInit, C_Encrypt / C_Decrypt or
C_EncryptUpdate / C_DecryptUpdate?.
Thanks in advance.
Antonio Andres Espallardo
To be more concrete. If I write a mail message (using the mail manager
of netscape 7.2) indicating it must be encrypted, netscape only uses my
pkcs11 module to do some objects search operations and to know some
attribute values, but it don't use the pkcs11 cypher operations. What
cipher algorithm uses netscape by defect to do that operation?
This is the trace I obtain when I try to decrypt the previous mail message:
C_DecryptInit.
--> Mechanism: CKM_DES3_CBC.
--> Key length: 24 bytes.
--> IV: <195> <128> <252> <112> <101> <170> <232> <250>
END C_DecryptInit.
C_DecryptUpdate.
--> Input Data(16 bytes): <22> <b2> <b5> <62> <f1> <8c> <c2> <11> <78>
<2d> <88> <bd> <31> <4> <33> <5e>
--> Output data(8 bytes): <43> <6f> <6e> <74> <65> <6e> <74> <2d>
END C_DecryptUpdate.
Now Netscape close the session and finalizes the decrypt operation.
Does anybody knows what can be happening?. Thanks in advance.
Antonio Andres Espallardo
, netscape uses its implementation and decrypts the email message OK.
I've been testing my CKM_DES3 implementation, and I don't know exactly
what its wrong, but indeed changing the lengths returned to netscape I
obtain the original message. Again, thanks a lot.
Antonio.
Bob Relyea wrote:
> Antonio Andres Espallardo wrote:
>
>> Hi everybody. I'm having some problems with a PKCS11 module I've
>> developed in encrypt/decrypt methods. I can't understand the behavior
>> when I use it with Netscape 7.2 or Thunderbind in these operations.
>> Could anyone facilitate me a trace of his pkcs11 in which I could see
>> the input data (and length), the cipher used and the output generated by
>> the methods C_EncryptInit / C_DecryptInit, C_Encrypt / C_Decrypt or
>> C_EncryptUpdate / C_DecryptUpdate?.
>
>
> To get trace information, you will need to build or pull a debug version
> of NSS. As long as you get a version of NSS which is equal to or greater
> then the version of NSS in the mozilla product you are useing you should
> be OK (I swap in newer versions of NSS to these products all the time to
> test changes in NSS).
>
> Once you have a debug version installed you can set the environment
> variable "NSS_DEBUG_PKCS11_MODULE" to the name you installed our PKCS
> #11 module as. The output will go to the NSPR Log named "nss_mod_log".
>
>>
>> To be more concrete. If I write a mail message (using the mail manager
>> of netscape 7.2) indicating it must be encrypted, netscape only uses
>> my pkcs11 module to do some objects search operations and to know some
>> attribute values, but it don't use the pkcs11 cypher operations. What
>> cipher algorithm uses netscape by defect to do that operation?
>
>
> All crypto operations for these products go through the security layer
> called NSS.
>
> For almost all operations NSS has a perfectly usable PKCS #11 module to
> provide all the operations it needs -- the soft token. Unless you
> specify at install time that you want your token to take over these
> default operations, NSS will continue to prefer using it's own
> implementation. This is because 1) in most cases it's internal
> implementation is faster, and 2) it's more likely to provide the
> functionality NSS needs.
>
> The exceptions to this rule are 1) if you register your token to take
> over these default operations, NSS will use your token whenever it
> desides to do operation XYZ, or 2) they keys needed to do the requested
> operation resides in your token.
>
> Case 1 is really to make hardware accellerators work. Vendors of
> hardware accellerators tyically implement a complete set of PKCS #11
> mechanisms, and usually do as good or better a job with those
> implementations as the soft token does. Most user tokens (those that
> would run in an application like Mozilla or Thunderbird), don't
> implement a full set of operations (nor do they need to). They also tend
> to be slower.
>
> In the email encryption case, the public key comes from the cert. NSS
> then looks at the all the default RSA devices for ones that can do RSA
> and DES3. It chooses the first one that does all these operations,
> imports the public key and encrypts the message. Since your token isn't
> registered as the default RSA device, NSS doesn't use your token for
> any of these operations, but it shouldn't matter since the software is
> able to completely handle your encryption request.
>
>>
>> This is the trace I obtain when I try to decrypt the previous mail
>> message:
>>
>> C_DecryptInit.
>> --> Mechanism: CKM_DES3_CBC.
>> --> Key length: 24 bytes.
>> --> IV: <195> <128> <252> <112> <101> <170> <232> <250>
>> END C_DecryptInit.
>>
>> C_DecryptUpdate.
>> --> Input Data(16 bytes): <22> <b2> <b5> <62> <f1> <8c> <c2> <11> <78>
>> <2d> <88> <bd> <31> <4> <33> <5e>
>> --> Output data(8 bytes): <43> <6f> <6e> <74> <65> <6e> <74> <2d>
>> END C_DecryptUpdate.
>>
>> Now Netscape close the session and finalizes the decrypt operation.
>>
>> Does anybody knows what can be happening?. Thanks in advance.
>
>
>
> So now it's time to decrypt the message. The only certificate NSS found
> that it could use to decrypt the message had it's private key in your
> token (I'm presuming you have a C_Unwrap call to your PKCS #11 module
> before the C_DecryptInit). In this case the only way to accomplish its
> task is for NSS to use your CKM_RSA_PKCS mechanism with the private key
> in that token. Once NSS has started using a token, NSS tries to keep all
> the rest of the operations in that token. This is because many tokens do
> not give up their keys easily. NSS noticed that 1) your token had the
> private key, 2) your token supported unwrap, and 3) your token supported
> CKM_DES3_CBC. Because of all of this, NSS not only uses your token to
> unwrap the key, but also uses your implementation of CKM_DES3_CBC.
> Unfortunately you're implementation is incorrect as you can clearly see
> that even though NSS provided a proper multiple of the Blocksize (3
> blocks) to your PKCS #11 module as input, your module only returned one
> block on output.
>
> The first thing I would do would be turn off CKM_DES3_CBC in your module
> temporarily. This will cause NSS to use your token to decrypt the S/MIME
> key, then use the internal soft token to decrypt the message. It looks
> like everything would work since you look like you are starting to
> decrypt good data (the Output when converted back to ascii of this dump
> reads 'Content-').
>
> The other thing you could do is fix your C_DecryptUpdate function to
> return the correct number of bytes.
>
> I would try both fixes and see what the performance is for a large
> document. Then you can decide which you would rather ship with.
>
> bob
>
>> _______________________________________________
>> mozilla-crypto mailing list
>> mozilla...@mozilla.org
>> http://mail.mozilla.org/listinfo/mozilla-crypto
>
>
>
Nelson B
> Hi everybody. I'm having some problems with a PKCS11 module I've
> developed in encrypt/decrypt methods. I can't understand the behavior
> C_DecryptUpdate.
> --> Input Data(16 bytes): <22> <b2> <b5> <62> <f1> <8c> <c2> <11> <78>
> <2d> <88> <bd> <31> <4> <33> <5e>
> --> Output data(8 bytes): <43> <6f> <6e> <74> <65> <6e> <74> <2d>
> END C_DecryptUpdate.
>
> Now Netscape close the session and finalizes the decrypt operation.
That last DecryptUpdate returned the wrong amount of output information
IINM.
--
Nelson B
Antonio Andrés Espallardo
correct length, but I'm having a problem with the last block caused by
PADDING I think. This is what I obtain when I try to decrypt a mail
mesagge using 3DES mechanism:
C_DecryptInit.
--> Mechanism: CKM_DES3_CBC.
--> Key length: 24 bytes.
--> IV: <195> <128> <252> <112> <101> <170> <232> <250>
END C_DecryptInit.
C_DecryptUpdate.
-->Input Data(16 bytes): <71> <66> <47> <b9> <9> <b4> <9e> <fc> <61>
<4c> <55> <ca> <8e> <39> <c> <93>
--> Output Data (16 bytes): <43> <6f> <6e> <74> <65> <6e> <74> <2d> <54>
<79> <70> <65> <3a> <20> <74> <65>
END C_DecryptUpdate.
C_DecryptUpdate.
-->Input Data(8 bytes): <1b> <5f> <14> <8> <be> <8a> <7d> <6>
--> Output Data (8 bytes): <78> <74> <2f> <70> <6c> <61> <69> <6e>
END C_DecryptUpdate.
C_DecryptUpdate.
-->Input Data(48 bytes): <8> <86> <89> <15> <c1> <87> <c3> <58> <45>
<fe> <35> <ba> <dd> <67> <71> <be> <15> <e2> <39> <1d> <39> <91> <37>
<58> <bc> <7d> <81> <f4> <af> <aa> <63> <db> <f> <ce> <49> <7a> <e> <72>
<16> <e1> <df> <59> <f9> <81> <84> <bc> <6b> <97>
--> Output Data (48 bytes): <3b> <20> <63> <68> <61> <72> <73> <65> <74>
<3d> <49> <53> <4f> <2d> <38> <38> <35> <39> <2d> <31> <3b> <20> <66>
<6f> <72> <6d> <61> <74> <3d> <66> <6c> <6f> <77> <65> <64> <d> <a> <43>
<6f> <6e> <74> <65> <6e> <74> <2d> <54> <72> <61>
END C_DecryptUpdate.
..........
And the last C_DecryptUpdate call:
C_DecryptUpdate.
-->Input Data(8 bytes): <12> <65> <bc> <d2> <4> <17> <89> <20>
--> Output Data (8 bytes): <d> <a> <6> <6> <6> <6> <6> <6>
END C_DecryptUpdate.
Now I don't know what happens but Netscape don't finalize the decrypt
operation correctly calling C_DecryptFinal, but he close the session.
The message is showed decrypted in the mail manager, but Netscape hasn't
finalized correctly the decrypt operation.
Always, in the last block decrypted, appear some bytes which I think it
doesn't must appear (STX, SOH...). What can be happening?
Appart of this, How could I specify in a Windows 2000 operating system
that netscape uses my pkcs11 module by default to develop all the
operations needed?.
Thanks in advance.
Antonio.
Antonio Andres Espallardo
if that is a nss bug or the problem is in my pkcs11?.
Antonio.
Bob Relyea wrote:
> Antonio Andrés Espallardo wrote:
>
>> Hi. I've modified my C_DecryptUpdate method, and now it's returning
>> the correct length, but I'm having a problem with the last block
>> caused by PADDING I think. This is what I obtain when I try to decrypt
>> a mail mesagge using 3DES mechanism:
>>
>>
>> And the last C_DecryptUpdate call:
>>
>> C_DecryptUpdate.
>> -->Input Data(8 bytes): <12> <65> <bc> <d2> <4> <17> <89> <20>
>> --> Output Data (8 bytes): <d> <a> <6> <6> <6> <6> <6> <6>
>> END C_DecryptUpdate.
>>
>>
>> Now I don't know what happens but Netscape don't finalize the decrypt
>> operation correctly calling C_DecryptFinal, but he close the session.
>> The message is showed decrypted in the mail manager, but Netscape
>> hasn't finalized correctly the decrypt operation.
>
>
> It's probably a bug in NSS. Once the session is closed, though, you
> should throw away all your decryptions state.
>
>>
>> Always, in the last block decrypted, appear some bytes which I think
>> it doesn't must appear (STX, SOH...). What can be happening?
>
>
> Looks like the end of a message to me. <d><a> is \r\n (normal line
> termination) and the <6>'s are the padding bytes (you'll note
> six of them).
>
>>
>> Appart of this, How could I specify in a Windows 2000 operating system
>> that netscape uses my pkcs11 module by default to develop all the
>> operations needed?.
>
>
> It's specified when you install your token into NSS. You'll have to use
> javascript or Modutil to do the actual install. I don't have the
> javascript instructions in front of me. For modultil is the -ciphers flag.
>
> bob
>
>>
>> Thanks in advance.
>>
>> Antonio.
>>
>>
>>
>> Nelson B wrote:
>>
>>> Antonio Andres Espallardo wrote:
>>>
>>>> Hi everybody. I'm having some problems with a PKCS11 module I've
>>>> developed in encrypt/decrypt methods. I can't understand the behavior
>>>
>>>
>>>
>>>
>>>> C_DecryptUpdate.
>>>> --> Input Data(16 bytes): <22> <b2> <b5> <62> <f1> <8c> <c2> <11>
>>>> <78> <2d> <88> <bd> <31> <4> <33> <5e>
>>>> --> Output data(8 bytes): <43> <6f> <6e> <74> <65> <6e> <74> <2d>
>>>> END C_DecryptUpdate.
>>>>
>>>> Now Netscape close the session and finalizes the decrypt operation.
>>>
>>>
>>>
>>>
>>> That last DecryptUpdate returned the wrong amount of output information
>>> IINM.
>>>
Nelson B
> Antonio Andrés Espallardo wrote:
>> Now I don't know what happens but Netscape don't finalize the decrypt
>> operation correctly calling C_DecryptFinal, but he close the session.
>> The message is showed decrypted in the mail manager, but Netscape
>> hasn't finalized correctly the decrypt operation.
>
>
> It's probably a bug in NSS. Once the session is closed, though, you
> should throw away all your decryptions state.
libsmime calls
PK11_CreateContextBySymKey
PK11_CipherOp (repeatedly)
PK11_DestroyContext
libsmime should call PK11_Finalize before calling PK11_DestroyContext,
but doesn't. That would be a small fix to a single source file.
PK11_DestroyContext starts by destroying the session.
Later it destroys the key. I believe that is the wrong order.
I believe the key handle is invalid after the session is destroyed,
and so the call to PK11_FreeSymKey probably sends a invalid key handle
(or potentially a reused key handle!) to C_DestroyObject.
I will file bugs about these findings.
--
Nelson B
Nelson B
> Thanks again. One question, where could I notify this problem to confirm
> if that is a nss bug or the problem is in my pkcs11?.
I have filed these bugs about your report:
https://bugzilla.mozilla.org/show_bug.cgi?id=283654
https://bugzilla.mozilla.org/show_bug.cgi?id=283658
If you have a bugzilla account, you may add yourself to the CC list
for those bugs, if you wish.
--
Nelson B