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date: Thu, 5 Jun 2008 00:28:02 -0700,
group: microsoft.public.platformsdk.security
back
CardRSADecrypt succeeds but CryptDecrypt fails with NTE_BAD_DATA
Hello everyone,
I'm new to writing a card module and I have some doubts about the
implementation of the CardRSADecrypt function. I don't know if either the
documentation is not complete or if I'm making a mistake.
I came to the point of implementing the CardRSADecrypt function in my card
module, and when I test it, by calling it through the CAPI function
CryptDecrypt, it fails with a NTE_BAD_DATA error (that is CryptDecrypt fails).
CardRSADecrypt finishes well and returns SCARD_S_SUCCESS. But it seems like
CryptDecrypt (or maybe the BaseCSP in between) doesn't like the data that it
is returning.
I print the data that is being returned by CardRSADecrypt and it is fine.
The data is decrypted (in fact the data is the same as originally I ciphered
by using the certificate that is inside the smart card). Maybe I am not
inicialiting the return parameters right:
- Should the returned decrypted data include padding?
- what should pInfo->cbData return? the documentation of the CryptDecrypt
funcion in the MSDN says: "This value must always be the same as the key
modulus". According to that, If I'm using a 1024 bits key, I should return
128bytes, right?
If so, how should I fill that returned data? Because in my test, the length
of the descripted data is 117 bytes. Then, How should I filled the bytes
between 117 and 128, is there any special format? Should I fill them with
'\0' and an pattern saying the length of the zeros? Or should I return the
data in an special TLV format or blob that indicates the lenght of the data
and the padding?
Thanks in advance for your answers,
Best regards,
Gloria.
date: Thu, 5 Jun 2008 00:28:02 -0700
author: glosoria
RE: CardRSADecrypt succeeds but CryptDecrypt fails with NTE_BAD_DATA
Hi,
In the implementation of CardRSADecrypt , you should only perform a bare
bone RSA private key exponentiation (classically C^D mod N) without trying to
remove any padding from output data. All the padding verification and
removal is done by the MS Base Smart Card CSP.
Cheers,
--
Mounir IDRASSI
IDRIX
http://www.idrix.fr
to reach : mounir_idrix_fr (replace the underscores with the at and dot
characters respectively)
"glosoria" wrote:
> Hello everyone,
>
> I'm new to writing a card module and I have some doubts about the
> implementation of the CardRSADecrypt function. I don't know if either the
> documentation is not complete or if I'm making a mistake.
>
> I came to the point of implementing the CardRSADecrypt function in my card
> module, and when I test it, by calling it through the CAPI function
> CryptDecrypt, it fails with a NTE_BAD_DATA error (that is CryptDecrypt fails).
>
> CardRSADecrypt finishes well and returns SCARD_S_SUCCESS. But it seems like
> CryptDecrypt (or maybe the BaseCSP in between) doesn't like the data that it
> is returning.
>
> I print the data that is being returned by CardRSADecrypt and it is fine.
> The data is decrypted (in fact the data is the same as originally I ciphered
> by using the certificate that is inside the smart card). Maybe I am not
> inicialiting the return parameters right:
> - Should the returned decrypted data include padding?
> - what should pInfo->cbData return? the documentation of the CryptDecrypt
> funcion in the MSDN says: "This value must always be the same as the key
> modulus". According to that, If I'm using a 1024 bits key, I should return
> 128bytes, right?
> If so, how should I fill that returned data? Because in my test, the length
> of the descripted data is 117 bytes. Then, How should I filled the bytes
> between 117 and 128, is there any special format? Should I fill them with
> '\0' and an pattern saying the length of the zeros? Or should I return the
> data in an special TLV format or blob that indicates the lenght of the data
> and the padding?
>
> Thanks in advance for your answers,
> Best regards,
> Gloria.
date: Thu, 5 Jun 2008 07:31:01 -0700
author: Mounir IDRASSI am
RE: CardRSADecrypt succeeds but CryptDecrypt fails with NTE_BAD_DA
Thanks for your reply Mounir,
but I followed your tips and it's still not working.
I'm going to get a little more specific with the parameters I get as input
and the results I am obtaining to see if you can help me out.
This is the original data that I have to cypher and decypher:
"OpenSSL - Frequently Asked Questions Which is the current version of
OpenSSL? Where is the documentation? How can I contact the OpenSSL
developers? Do I " ...and it goes on, but I wont post the whole buffer.
When the CardRSADecrypt function of my card module gets called these are the
input parameters I receive in the CARD_RSA_DECRYPT_INFO structure:
pInfo->dwVersion: 1,
pInfo->bContainerIndex: 00,
pInfo->dwKeyspec: 1,
pInfo->cbData: 128,
pInfo->pbData: af 36 42 fc 64 01 32 fb c4 da 25 e7 95 04 77 de 92 b3 44 89
29 2f 6e 78 32 63 a8 62 d9 7c 5d 34 f3 45 7b 1f 23 48 2d 09 e0 76 10 d4 d9 58
14 94 ff 42 de 62 26 0c 99 44 53 4f 11 0f d4 c5 0a d4 f5 b1 ae ea e8 e9 bf c9
1d 2c 20 54 84 18 69 c6 20 04 eb b7 f3 89 87 7a eb a3 63 cb cf 4f 79 d5 2b cf
3f 0e 65 f8 77 d7 61 23 5e e9 fc 4d fa 18 e4 b4 21 1b a2 38 a0 a0 3b 0c 99 94
75 e4 f8 7c
Inside the function I decrypt the data with the openssl RSA_private_decrypt
function, using the private key that my smartcard holds (because my card is
not a cryptographic one). After I process the input cypher, the prior
structure looks like this:
dwVersion: 1 ,
pInfo->bContainerIndex: 00 ,
pInfo->dwKeySpec: 1 ,
pInfo->cbData: 128 ,
pInfo->pbData: 4f 70 65 6e 53 53 4c 20 20 2d 20 20 46 72 65 71 75 65 6e 74
6c 79 20 41 73 6b 65 64 20 51 75 65 73 74 69 6f 6e 73 20 57 68 69 63 68 20 69
73 20 74 68 65 20 63 75 72 72 65 6e 74 20 76 65 72 73 69 6f 6e 20 6f 66 20 4f
70 65 6e 53 53 4c 3f 20 57 68 65 72 65 20 69 73 20 74 68 65 20 64 6f 63 75 6d
65 6e 74 61 74 69 6f 6e 3f 20 48 6f 77 20 63 61 6e 20 49 38 a0 a0 3b 0c 99 94
75 e4 f8 7c
If I edit the deciphered data (in pInfo->pbData) using an hexadecimal editor
I get the following:
"OpenSSL - Frequently Asked Questions Which is the current version of
OpenSSL? Where is the documentation? How can I"
...and 11 weird characters which I suppose are the padding bytes: 38 a0 a0
3b 0c 99 94 75 e4 f8 7c
That is exactly what my function returns, and I am still getting the ugly
NTE_BAD_DATA error in the CAPI CryptDecrypt function.
Do yo see anything wrong here? I just don't understand what I'm doing wrong.
"Mounir IDRASSI" wrote:
> Hi,
>
> In the implementation of CardRSADecrypt , you should only perform a bare
> bone RSA private key exponentiation (classically C^D mod N) without trying to
> remove any padding from output data. All the padding verification and
> removal is done by the MS Base Smart Card CSP.
>
> Cheers,
> --
> Mounir IDRASSI
> IDRIX
> http://www.idrix.fr
>
> to reach : mounir_idrix_fr (replace the underscores with the at and dot
> characters respectively)
>
>
> "glosoria" wrote:
>
> > Hello everyone,
> >
> > I'm new to writing a card module and I have some doubts about the
> > implementation of the CardRSADecrypt function. I don't know if either the
> > documentation is not complete or if I'm making a mistake.
> >
> > I came to the point of implementing the CardRSADecrypt function in my card
> > module, and when I test it, by calling it through the CAPI function
> > CryptDecrypt, it fails with a NTE_BAD_DATA error (that is CryptDecrypt fails).
> >
> > CardRSADecrypt finishes well and returns SCARD_S_SUCCESS. But it seems like
> > CryptDecrypt (or maybe the BaseCSP in between) doesn't like the data that it
> > is returning.
> >
> > I print the data that is being returned by CardRSADecrypt and it is fine.
> > The data is decrypted (in fact the data is the same as originally I ciphered
> > by using the certificate that is inside the smart card). Maybe I am not
> > inicialiting the return parameters right:
> > - Should the returned decrypted data include padding?
> > - what should pInfo->cbData return? the documentation of the CryptDecrypt
> > funcion in the MSDN says: "This value must always be the same as the key
> > modulus". According to that, If I'm using a 1024 bits key, I should return
> > 128bytes, right?
> > If so, how should I fill that returned data? Because in my test, the length
> > of the descripted data is 117 bytes. Then, How should I filled the bytes
> > between 117 and 128, is there any special format? Should I fill them with
> > '\0' and an pattern saying the length of the zeros? Or should I return the
> > data in an special TLV format or blob that indicates the lenght of the data
> > and the padding?
> >
> > Thanks in advance for your answers,
> > Best regards,
> > Gloria.
date: Sat, 7 Jun 2008 03:06:03 -0700
author: glosoria
RE: CardRSADecrypt succeeds but CryptDecrypt fails with NTE_BAD_DA
Hi Gloria,
From what I see, the sequence of 11 bytes you mention are already present on
the input buffer. So I guess that in your code you copied the output of
OpenSSL function RSA_private_decrypt without checking its returned length
which is clearly lesser than 128 in your case.
My deduction is that, in your code, you are calling RSA_private_decrypt with
a padding parameter value other than RSA_NO_PADDING. In order to have the
correct behavior, you must call RSA_private_decrypt by specifying
RSA_NO_PADDING in its last parameter. Thus, OpenSSL will do the raw RSA
exponentiation without removing any padding and you will obtain the 128 bytes
of data that you will copy to the output buffer.
Conclusion: always check the return value of RSA_private_decrypt and use it
to manipulate the recovered data.
Cheers,
--
Mounir IDRASSI
IDRIX
http://www.idrix.fr
to reach : mounir_idrix_fr (replace the underscores with the at and dot
characters respectively)
"glosoria" wrote:
> Thanks for your reply Mounir,
> but I followed your tips and it's still not working.
> I'm going to get a little more specific with the parameters I get as input
> and the results I am obtaining to see if you can help me out.
>
> This is the original data that I have to cypher and decypher:
> "OpenSSL - Frequently Asked Questions Which is the current version of
> OpenSSL? Where is the documentation? How can I contact the OpenSSL
> developers? Do I " ...and it goes on, but I wont post the whole buffer.
>
> When the CardRSADecrypt function of my card module gets called these are the
> input parameters I receive in the CARD_RSA_DECRYPT_INFO structure:
> pInfo->dwVersion: 1,
> pInfo->bContainerIndex: 00,
> pInfo->dwKeyspec: 1,
> pInfo->cbData: 128,
> pInfo->pbData: af 36 42 fc 64 01 32 fb c4 da 25 e7 95 04 77 de 92 b3 44 89
> 29 2f 6e 78 32 63 a8 62 d9 7c 5d 34 f3 45 7b 1f 23 48 2d 09 e0 76 10 d4 d9 58
> 14 94 ff 42 de 62 26 0c 99 44 53 4f 11 0f d4 c5 0a d4 f5 b1 ae ea e8 e9 bf c9
> 1d 2c 20 54 84 18 69 c6 20 04 eb b7 f3 89 87 7a eb a3 63 cb cf 4f 79 d5 2b cf
> 3f 0e 65 f8 77 d7 61 23 5e e9 fc 4d fa 18 e4 b4 21 1b a2 38 a0 a0 3b 0c 99 94
> 75 e4 f8 7c
>
> Inside the function I decrypt the data with the openssl RSA_private_decrypt
> function, using the private key that my smartcard holds (because my card is
> not a cryptographic one). After I process the input cypher, the prior
> structure looks like this:
> dwVersion: 1 ,
> pInfo->bContainerIndex: 00 ,
> pInfo->dwKeySpec: 1 ,
> pInfo->cbData: 128 ,
> pInfo->pbData: 4f 70 65 6e 53 53 4c 20 20 2d 20 20 46 72 65 71 75 65 6e 74
> 6c 79 20 41 73 6b 65 64 20 51 75 65 73 74 69 6f 6e 73 20 57 68 69 63 68 20 69
> 73 20 74 68 65 20 63 75 72 72 65 6e 74 20 76 65 72 73 69 6f 6e 20 6f 66 20 4f
> 70 65 6e 53 53 4c 3f 20 57 68 65 72 65 20 69 73 20 74 68 65 20 64 6f 63 75 6d
> 65 6e 74 61 74 69 6f 6e 3f 20 48 6f 77 20 63 61 6e 20 49 38 a0 a0 3b 0c 99 94
> 75 e4 f8 7c
>
> If I edit the deciphered data (in pInfo->pbData) using an hexadecimal editor
> I get the following:
> "OpenSSL - Frequently Asked Questions Which is the current version of
> OpenSSL? Where is the documentation? How can I"
> ...and 11 weird characters which I suppose are the padding bytes: 38 a0 a0
> 3b 0c 99 94 75 e4 f8 7c
>
> That is exactly what my function returns, and I am still getting the ugly
> NTE_BAD_DATA error in the CAPI CryptDecrypt function.
> Do yo see anything wrong here? I just don't understand what I'm doing wrong.
>
date: Sat, 7 Jun 2008 04:12:00 -0700
author: Mounir IDRASSI am
RE: CardRSADecrypt succeeds but CryptDecrypt fails with NTE_BAD_DA
Thank you very much Mounir. I think that did the trick for me. You were right
about me missusing the RSA_Private_Decrypt parameter (I was using
RSA_PKCS1_PADDING). I changed it to RSA_NO_PADDING and it seems to work now.
I'm sure I tried that parameter before, in one of the many tests I did, but I
must have had something else wrong.
Cheers.
"Mounir IDRASSI" wrote:
> Hi Gloria,
>
> From what I see, the sequence of 11 bytes you mention are already present on
> the input buffer. So I guess that in your code you copied the output of
> OpenSSL function RSA_private_decrypt without checking its returned length
> which is clearly lesser than 128 in your case.
> My deduction is that, in your code, you are calling RSA_private_decrypt with
> a padding parameter value other than RSA_NO_PADDING. In order to have the
> correct behavior, you must call RSA_private_decrypt by specifying
> RSA_NO_PADDING in its last parameter. Thus, OpenSSL will do the raw RSA
> exponentiation without removing any padding and you will obtain the 128 bytes
> of data that you will copy to the output buffer.
> Conclusion: always check the return value of RSA_private_decrypt and use it
> to manipulate the recovered data.
>
> Cheers,
> --
> Mounir IDRASSI
> IDRIX
> http://www.idrix.fr
>
> to reach : mounir_idrix_fr (replace the underscores with the at and dot
> characters respectively)
>
>
> "glosoria" wrote:
>
> > Thanks for your reply Mounir,
> > but I followed your tips and it's still not working.
> > I'm going to get a little more specific with the parameters I get as input
> > and the results I am obtaining to see if you can help me out.
> >
> > This is the original data that I have to cypher and decypher:
> > "OpenSSL - Frequently Asked Questions Which is the current version of
> > OpenSSL? Where is the documentation? How can I contact the OpenSSL
> > developers? Do I " ...and it goes on, but I wont post the whole buffer.
> >
> > When the CardRSADecrypt function of my card module gets called these are the
> > input parameters I receive in the CARD_RSA_DECRYPT_INFO structure:
> > pInfo->dwVersion: 1,
> > pInfo->bContainerIndex: 00,
> > pInfo->dwKeyspec: 1,
> > pInfo->cbData: 128,
> > pInfo->pbData: af 36 42 fc 64 01 32 fb c4 da 25 e7 95 04 77 de 92 b3 44 89
> > 29 2f 6e 78 32 63 a8 62 d9 7c 5d 34 f3 45 7b 1f 23 48 2d 09 e0 76 10 d4 d9 58
> > 14 94 ff 42 de 62 26 0c 99 44 53 4f 11 0f d4 c5 0a d4 f5 b1 ae ea e8 e9 bf c9
> > 1d 2c 20 54 84 18 69 c6 20 04 eb b7 f3 89 87 7a eb a3 63 cb cf 4f 79 d5 2b cf
> > 3f 0e 65 f8 77 d7 61 23 5e e9 fc 4d fa 18 e4 b4 21 1b a2 38 a0 a0 3b 0c 99 94
> > 75 e4 f8 7c
> >
> > Inside the function I decrypt the data with the openssl RSA_private_decrypt
> > function, using the private key that my smartcard holds (because my card is
> > not a cryptographic one). After I process the input cypher, the prior
> > structure looks like this:
> > dwVersion: 1 ,
> > pInfo->bContainerIndex: 00 ,
> > pInfo->dwKeySpec: 1 ,
> > pInfo->cbData: 128 ,
> > pInfo->pbData: 4f 70 65 6e 53 53 4c 20 20 2d 20 20 46 72 65 71 75 65 6e 74
> > 6c 79 20 41 73 6b 65 64 20 51 75 65 73 74 69 6f 6e 73 20 57 68 69 63 68 20 69
> > 73 20 74 68 65 20 63 75 72 72 65 6e 74 20 76 65 72 73 69 6f 6e 20 6f 66 20 4f
> > 70 65 6e 53 53 4c 3f 20 57 68 65 72 65 20 69 73 20 74 68 65 20 64 6f 63 75 6d
> > 65 6e 74 61 74 69 6f 6e 3f 20 48 6f 77 20 63 61 6e 20 49 38 a0 a0 3b 0c 99 94
> > 75 e4 f8 7c
> >
> > If I edit the deciphered data (in pInfo->pbData) using an hexadecimal editor
> > I get the following:
> > "OpenSSL - Frequently Asked Questions Which is the current version of
> > OpenSSL? Where is the documentation? How can I"
> > ...and 11 weird characters which I suppose are the padding bytes: 38 a0 a0
> > 3b 0c 99 94 75 e4 f8 7c
> >
> > That is exactly what my function returns, and I am still getting the ugly
> > NTE_BAD_DATA error in the CAPI CryptDecrypt function.
> > Do yo see anything wrong here? I just don't understand what I'm doing wrong.
> >
date: Sat, 7 Jun 2008 07:06:00 -0700
author: glosoria
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