AES/CTR IV custom increment

[Jan-126]

Hello,

I am trying to implement AES in CTR mode but with the custom IV
increment. CryptoPP implementation increments IV over the whole vector
but I would like to have increment only over the lowest 4 bytes (with
modulo).

E.g. 00 .... AB FF FF FF FE -> 00 .... AB FF FF FF FF -> 00 .... AB 00
00 00 00

Is there any easy way how to do it? Only solution which I currently
found is to increment IV by myself after each block and then call
Resynchronize and then encrypt another block.

Thank you for your help,
Jan

--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the "Crypto++ Users" Google Group.
To unsubscribe, send an email to cryptopp-users-unsubscribe@....
More information about Crypto++ and this group is available at http://www.cryptopp.com.
-~----------~----~----~----~------~----~------~--~---

[Wei Dai]

Hi, take a look at GCM_Base::GCTR in gcm.h. It does what you want, but is a
protected member of GCM_Base, so just copy its code.

--------------------------------------------------
From: "Jan" <honza.smrcek@...>
Sent: Tuesday, June 16, 2009 2:40 AM
To: "Crypto++ Users" <cryptopp-users@...>
Subject: AES/CTR IV custom increment

>
> Hello,
>
> I am trying to implement AES in CTR mode but with the custom IV
> increment. CryptoPP implementation increments IV over the whole vector
> but I would like to have increment only over the lowest 4 bytes (with
> modulo).
>
> E.g. 00 .... AB FF FF FF FE -> 00 .... AB FF FF FF FF -> 00 .... AB 00
> 00 00 00
>
> Is there any easy way how to do it? Only solution which I currently
> found is to increment IV by myself after each block and then call
> Resynchronize and then encrypt another block.
>
> Thank you for your help,
> Jan
>
> >
>

--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the "Crypto++ Users" Google Group.
To unsubscribe, send an email to cryptopp-users-unsubscribe@....
More information about Crypto++ and this group is available at http://www.cryptopp.com.
-~----------~----~----~----~------~----~------~--~---

[Jan-126]

Hi,

thank you for pointing me.

I have tried it to implement it by a new template and new class
(inspired by modes.h):

class CTR_TPM_ModePolicy : public CTR_ModePolicy
{
protected:
        virtual void IncrementCounterBy256() { IncrementCounterByOne
(m_counterArray, 3); }
};

CRYPTOPP_DLL_TEMPLATE_CLASS
AdditiveCipherTemplate<AbstractPolicyHolder<AdditiveCipherAbstractPolicy,
CTR_TPM_ModePolicy> >;

template <class CIPHER>
struct CTR_TPM_Mode : public CipherModeDocumentation
{
        typedef CipherModeFinalTemplate_CipherHolder<CPP_TYPENAME
CIPHER::Encryption, ConcretePolicyHolder<Empty,
AdditiveCipherTemplate<AbstractPolicyHolder<AdditiveCipherAbstractPolicy,
CTR_TPM_ModePolicy> > > > Encryption;
        typedef Encryption Decryption;
};

and then I tried to create proper variable:

CTR_TPM_Mode<AES>::Encryption aes(key.data, key.size, iv.data,
iv.size);

Unfortunately linker (VC++ 8.0 Express) returned few errors:

"public: virtual void __thiscall
CryptoPP::AdditiveCipherTemplate<class
CryptoPP::AbstractPolicyHolder<struct
CryptoPP::AdditiveCipherAbstractPolicy,class
CryptoPP::CTR_TPM_ModePolicy> >::Resynchronize(unsigned char const
*,int)"
"protected: virtual void __thiscall
CryptoPP::AdditiveCipherTemplate<class
CryptoPP::AbstractPolicyHolder<struct
CryptoPP::AdditiveCipherAbstractPolicy,class
CryptoPP::CTR_TPM_ModePolicy> >::UncheckedSetKey(unsigned char const
*,unsigned int,class CryptoPP::NameValuePairs const &)"
"public: virtual void __thiscall
CryptoPP::AdditiveCipherTemplate<class
CryptoPP::AbstractPolicyHolder<struct
CryptoPP::AdditiveCipherAbstractPolicy,class
CryptoPP::CTR_TPM_ModePolicy> >::ProcessData(unsigned char *,unsigned
char const *,unsigned int)"
"public: virtual void __thiscall
CryptoPP::AdditiveCipherTemplate<class
CryptoPP::AbstractPolicyHolder<struct
CryptoPP::AdditiveCipherAbstractPolicy,class
CryptoPP::CTR_TPM_ModePolicy> >::Seek(unsigned __int64)"
"public: virtual void __thiscall
CryptoPP::AdditiveCipherTemplate<class
CryptoPP::AbstractPolicyHolder<struct
CryptoPP::AdditiveCipherAbstractPolicy,class
CryptoPP::CTR_TPM_ModePolicy> >::GenerateBlock(unsigned char
*,unsigned int)"

Do you know what could be origin of them?

Best regards,
Jan



On Jun 16, 7:52 pm, "Wei Dai" <wei...@...> wrote:

> Hi, take a look at GCM_Base::GCTR in gcm.h. It does what you want, but is a
> protected member of GCM_Base, so just copy its code.
>
> --------------------------------------------------
> From: "Jan" <honza.smr...@...>
> Sent: Tuesday, June 16, 2009 2:40 AM
> To: "Crypto++ Users" <cryptopp-users@...>
> Subject: AES/CTR IV custom increment
>
>
>
> > Hello,
>
> > I am trying to implement AES in CTR mode but with the custom IV
> > increment. CryptoPP implementation increments IV over the whole vector
> > but I would like to have increment only over the lowest 4 bytes (with
> > modulo).
>
> > E.g. 00 .... AB FF FF FF FE -> 00 .... AB FF FF FF FF -> 00 .... AB 00
> > 00 00 00
>
> > Is there any easy way how to do it? Only solution which I currently
> > found is to increment IV by myself after each block and then call
> > Resynchronize and then encrypt another block.
>
> > Thank you for your help,
> > Jan

--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the "Crypto++ Users" Google Group.
To unsubscribe, send an email to cryptopp-users-unsubscribe@....
More information about Crypto++ and this group is available at http://www.cryptopp.com.
-~----------~----~----~----~------~----~------~--~---

[Jeffrey Walton-3]

Hi Jan,

>  Do you know what could be origin of them?
Verify VC++ 8.0 Express *has not* changed the settings of static
linking to dynamic linking. I seem to remember something similar in
the academic versions of the compiler. In these versions, only dynamic
linking to libraries (any library, not just Crypto++) was supported.

Jeff

On 6/18/09, Jan <honza.smrcek@...> wrote:

>
>  Hi,
>
>  thank you for pointing me.
>
>  I have tried it to implement it by a new template and new class
>  (inspired by modes.h):
>
>  class CTR_TPM_ModePolicy : public CTR_ModePolicy
>  {
>  protected:
>         virtual void IncrementCounterBy256() { IncrementCounterByOne
>  (m_counterArray, 3); }
>  };
>
>  CRYPTOPP_DLL_TEMPLATE_CLASS
>  AdditiveCipherTemplate<AbstractPolicyHolder<AdditiveCipherAbstractPolicy,
>  CTR_TPM_ModePolicy> >;
>
>  template <class CIPHER>
>  struct CTR_TPM_Mode : public CipherModeDocumentation
>  {
>         typedef CipherModeFinalTemplate_CipherHolder<CPP_TYPENAME
>  CIPHER::Encryption, ConcretePolicyHolder<Empty,
>  AdditiveCipherTemplate<AbstractPolicyHolder<AdditiveCipherAbstractPolicy,
>  CTR_TPM_ModePolicy> > > > Encryption;
>         typedef Encryption Decryption;
>  };
>
>  and then I tried to create proper variable:
>
>  CTR_TPM_Mode<AES>::Encryption aes(key.data, key.size, iv.data,
>  iv.size);
>
>  Unfortunately linker (VC++ 8.0 Express) returned few errors:
>
>  "public: virtual void __thiscall
>  CryptoPP::AdditiveCipherTemplate<class
>  CryptoPP::AbstractPolicyHolder<struct
>  CryptoPP::AdditiveCipherAbstractPolicy,class
>  CryptoPP::CTR_TPM_ModePolicy> >::Resynchronize(unsigned char const
>  *,int)"
>  "protected: virtual void __thiscall
>  CryptoPP::AdditiveCipherTemplate<class
>  CryptoPP::AbstractPolicyHolder<struct
>  CryptoPP::AdditiveCipherAbstractPolicy,class
>  CryptoPP::CTR_TPM_ModePolicy> >::UncheckedSetKey(unsigned char const
>  *,unsigned int,class CryptoPP::NameValuePairs const &)"
>  "public: virtual void __thiscall
>  CryptoPP::AdditiveCipherTemplate<class
>  CryptoPP::AbstractPolicyHolder<struct
>  CryptoPP::AdditiveCipherAbstractPolicy,class
>  CryptoPP::CTR_TPM_ModePolicy> >::ProcessData(unsigned char *,unsigned
>  char const *,unsigned int)"
>  "public: virtual void __thiscall
>  CryptoPP::AdditiveCipherTemplate<class
>  CryptoPP::AbstractPolicyHolder<struct
>  CryptoPP::AdditiveCipherAbstractPolicy,class
>  CryptoPP::CTR_TPM_ModePolicy> >::Seek(unsigned __int64)"
>  "public: virtual void __thiscall
>  CryptoPP::AdditiveCipherTemplate<class
>  CryptoPP::AbstractPolicyHolder<struct
>  CryptoPP::AdditiveCipherAbstractPolicy,class
>  CryptoPP::CTR_TPM_ModePolicy> >::GenerateBlock(unsigned char
>  *,unsigned int)"
>
>  Do you know what could be origin of them?
>
>  Best regards,
>  Jan
>
>  On Jun 16, 7:52 pm, "Wei Dai" <wei...@...> wrote:
>  > Hi, take a look at GCM_Base::GCTR in gcm.h. It does what you want, but is a
>  > protected member of GCM_Base, so just copy its code.
>  >
>  [SNIP]

--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the "Crypto++ Users" Google Group.
To unsubscribe, send an email to cryptopp-users-unsubscribe@....
More information about Crypto++ and this group is available at http://www.cryptopp.com.
-~----------~----~----~----~------~----~------~--~---

[Jan-126]

Hi Jeff,

I have checked it and it has static linking.

I have solution with 5 projects. 4 of them generates dll files and one
of them is cryptlib (from CryptoPP solution) that has static linking
and it is linked to the one of the dll. Without my new classes it
worked fine but with them I get these linker errors. Maybe it is
somehow related to the templates, but I don't know how to solve it.

Jan

On Jun 18, 7:26 pm, Jeffrey Walton <noloa...@...> wrote:

> Hi Jan,
>
> >  Do you know what could be origin of them?
>
> Verify VC++ 8.0 Express *has not* changed the settings of static
> linking to dynamic linking. I seem to remember something similar in
> the academic versions of the compiler. In these versions, only dynamic
> linking to libraries (any library, not just Crypto++) was supported.
>
> Jeff
>
> On 6/18/09, Jan <honza.smr...@...> wrote:
>
>
>
> >  Hi,
>
> >  thank you for pointing me.
>
> >  I have tried it to implement it by a new template and new class
> >  (inspired by modes.h):
>
> >  class CTR_TPM_ModePolicy : public CTR_ModePolicy
> >  {
> >  protected:
> >         virtual void IncrementCounterBy256() { IncrementCounterByOne
> >  (m_counterArray, 3); }
> >  };
>
> >  CRYPTOPP_DLL_TEMPLATE_CLASS
> >  AdditiveCipherTemplate<AbstractPolicyHolder<AdditiveCipherAbstractPolicy,
> >  CTR_TPM_ModePolicy> >;
>
> >  template <class CIPHER>
> >  struct CTR_TPM_Mode : public CipherModeDocumentation
> >  {
> >         typedef CipherModeFinalTemplate_CipherHolder<CPP_TYPENAME
> >  CIPHER::Encryption, ConcretePolicyHolder<Empty,
> >  AdditiveCipherTemplate<AbstractPolicyHolder<AdditiveCipherAbstractPolicy,
> >  CTR_TPM_ModePolicy> > > > Encryption;
> >         typedef Encryption Decryption;
> >  };
>
> >  and then I tried to create proper variable:
>
> >  CTR_TPM_Mode<AES>::Encryption aes(key.data, key.size, iv.data,
> >  iv.size);
>
> >  Unfortunately linker (VC++ 8.0 Express) returned few errors:
>
> >  "public: virtual void __thiscall
> >  CryptoPP::AdditiveCipherTemplate<class
> >  CryptoPP::AbstractPolicyHolder<struct
> >  CryptoPP::AdditiveCipherAbstractPolicy,class
> >  CryptoPP::CTR_TPM_ModePolicy> >::Resynchronize(unsigned char const
> >  *,int)"
> >  "protected: virtual void __thiscall
> >  CryptoPP::AdditiveCipherTemplate<class
> >  CryptoPP::AbstractPolicyHolder<struct
> >  CryptoPP::AdditiveCipherAbstractPolicy,class
> >  CryptoPP::CTR_TPM_ModePolicy> >::UncheckedSetKey(unsigned char const
> >  *,unsigned int,class CryptoPP::NameValuePairs const &)"
> >  "public: virtual void __thiscall
> >  CryptoPP::AdditiveCipherTemplate<class
> >  CryptoPP::AbstractPolicyHolder<struct
> >  CryptoPP::AdditiveCipherAbstractPolicy,class
> >  CryptoPP::CTR_TPM_ModePolicy> >::ProcessData(unsigned char *,unsigned
> >  char const *,unsigned int)"
> >  "public: virtual void __thiscall
> >  CryptoPP::AdditiveCipherTemplate<class
> >  CryptoPP::AbstractPolicyHolder<struct
> >  CryptoPP::AdditiveCipherAbstractPolicy,class
> >  CryptoPP::CTR_TPM_ModePolicy> >::Seek(unsigned __int64)"
> >  "public: virtual void __thiscall
> >  CryptoPP::AdditiveCipherTemplate<class
> >  CryptoPP::AbstractPolicyHolder<struct
> >  CryptoPP::AdditiveCipherAbstractPolicy,class
> >  CryptoPP::CTR_TPM_ModePolicy> >::GenerateBlock(unsigned char
> >  *,unsigned int)"
>
> >  Do you know what could be origin of them?
>
> >  Best regards,
> >  Jan
>
> >  On Jun 16, 7:52 pm, "Wei Dai" <wei...@...> wrote:
> >  > Hi, take a look at GCM_Base::GCTR in gcm.h. It does what you want, but is a
> >  > protected member of GCM_Base, so just copy its code.
>
> >  [SNIP]

--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the "Crypto++ Users" Google Group.
To unsubscribe, send an email to cryptopp-users-unsubscribe@....
More information about Crypto++ and this group is available at http://www.cryptopp.com.
-~----------~----~----~----~------~----~------~--~---