Discrete Logarithm Cryptography (DLC)
[API]

Fundamental declarations and definitions for algorithms based on discrete logarithm problem. More...

Data Structures
struct	C4eDlcDomain
	Discrete logarithm (DL) domain parameters (public). More...
Modules
	DLC Temp. Space Qualifiers
	Temp. space qualifiers for DL based cryptography (exclusive RSA).
	Diffie-Hellman (DH)
	Diffie-Hellman shared secret computation in discrete logarithm (DL) domain.
	Digital Signature Algorithm (DSA)
	Digital Signature Algorithm (DSA) in discrete logarithm (DL) domain.
Defines
#define	C4E_DLC_GF_BYTES_MAX
	Maximum allowed size (in bytes) of a discrete logarithm (DL) domain modulus in C4eDlcDomain::m.
Functions
C4eSysStatus	c4e_dlc_domchk (C4eArchUint algos, C4E_CONST C4eDlcDomain *dom)
	A simple (and fast) discrete logarithm domain parameters validity test.
C4eSysStatus	c4e_dlc_keychk_prv (C4eArchUint algos, C4E_CONST C4eDlcDomain C4E_RESTRICT dom, C4E_CONST C4eElement C4E_RESTRICT key, C4eArchDigit tmp[C4E_RESTRICT])
	Discrete logarithm (DL) domain private key validity test.
C4eSysStatus	c4e_dlc_keychk_pub (C4eArchUint algos, C4E_CONST C4eDlcDomain C4E_RESTRICT dom, C4E_CONST C4eElement C4E_RESTRICT key, C4eArchDigit tmp[C4E_RESTRICT])
	Discrete logarithm (DL) domain public key validity test.
DLC Algorithm Identifiers
Algorithm identifiers for Discrete Logarithm Cryptography (DLC), to be used as parameter to c4e_dlc_domchk().
#define	C4E_DLC_ALGO_NONE
	"unspecific" algorithm identifier.
#define	C4E_DLC_ALGO_DH
	DH algorithm identifier.
#define	C4E_DLC_ALGO_DSA
	DSA algorithm identifier.
#define	C4E_DLC_ALGO_RSA
	RSA algorithm identifier.
#define	C4E_DLC_ALGO_ALL
	"all" algorithm identifier.

Detailed Description

Fundamental declarations and definitions for algorithms based on discrete logarithm problem.

Define Documentation

#define C4E_DLC_GF_BYTES_MAX

Maximum allowed size (in bytes) of a discrete logarithm (DL) domain modulus in C4eDlcDomain::m.

Customize:: Simply undefine C4E_DLC_GF_BYTES_MAX to support longer (unlimited) modulus sizes. Modify it if you want to limit the size of a modulus to this value (recommended for static memory reservation).

Definition at line 158 of file c4e_dlc.h.

Function Documentation

C4eSysStatus c4e_dlc_domchk	(	C4eArchUint	algos,
		C4E_CONST C4eDlcDomain *	dom
	)

A simple (and fast) discrete logarithm domain parameters validity test.

Function c4e_dlc_domchk() checks the following conditions:

The modulus dom->m.val must be odd and greater than zero.
The size of modulus dom->m.val must be less than C4E_ELEM_DIGITS_NUM(dom->m.len).
The field size dom->m.len must be less/equal C4E_DLC_GF_BYTES_MAX (if defined).

If algos does contain C4E_DLC_ALGO_DSA then the following additional conditions are checked:

, q an odd number;
;
the size dom->q.val.size fits C4E_ELEM_DIGITS_NUM(dom->q.len);

the size of dom->m.val is at least:

 2U * C4E_MODN_POW_SPACE(dom->q.val.size)

Note:: This test is not fully conforming to IEEE Std 1363, annex A.16.2, FIPS 186-4, annex A.1.2.2 and NIST SP800-89, section 4. Especially condition #7 of FIPS 186-4, annex A.1.2.2 is not checked: $p-1 \bmod q = 0$ .

Precondition:: All big numbers in dom must be normalized, for example by using functions c4e_elem_norm() or c4e_elem_os2e().

Bibliography:

Standard Specifications For Public-Key Cryptography. Std 1363-2000, IEEE, 2000.

Digitale Signature Standard (DSS). FIPS Publication 186-4, National Institute of Standards and Technology, 2013.

NIST Special Publication 800-56A Revision 2: Recommendation for Pair-Wise Key Establishment Schemes Using Discrete Logarithm Cryptography. 2013.

NIST Special Publication 800-89: Recommendation for Obtaining Assurances for Digital Signature Applications. 2006.

Parameters:

`[in]`	algos	Algorithm identifiers to check domain parameters for (or'ed together).
`[in]`	dom	Pointer to domain parameters.

Returns:: Validity status of dom.

Return values:

	C4E_STATUS_OK	If the domain parameters are usable for all calculations (valid in the sense of this implementation).
	other	If one of the domain parameters is invalid.

See also:: C4eDlcDomain

Todo:: If CRY4E supports key generation (may be in the future) then implement additional tests according to IEEE Std 1363, annex A.16.2.

C4eSysStatus c4e_dlc_keychk_prv	(	C4eArchUint	algos,
		C4E_CONST C4eDlcDomain *C4E_RESTRICT	dom,
		C4E_CONST C4eElement *C4E_RESTRICT	key,
		C4eArchDigit	tmp[C4E_RESTRICT]
	)

Discrete logarithm (DL) domain private key validity test.

The function validates a private key d with respect to:

;
if algos does contain C4E_DLC_ALGO_DSA then additionally: .

Note:: According to PKCS #3, section 7.1 the allowed range for a private key is: . This has to be required because of Fermats little theorem, which for results in: $e^{p-1} \equiv 1 \pmod p$ .

Precondition:: The validity of the DL domain parameters in dom must be assured by the caller, either implicit or by using function c4e_dlc_domchk().; All big numbers in key and dom must be normalized, e.g. by using functions c4e_elem_norm() or c4e_elem_os2e().

Bibliography:: Standard Specifications For Public-Key Cryptography. Std 1363-2000, IEEE, 2000.

Bibliography:: Public Key Cryptography for the Financial Services Industry: Agreement of Symmetric Keys Using Diffie-Hellman and MQV Algorithms (draft), ANSI X9.42, 1998.

Bibliography:: NIST Special Publication 800-56A Revision 2: Recommendation for Pair-Wise Key Establishment Schemes Using Discrete Logarithm Cryptography. 2013.

Bibliography:: Digitale Signature Standard (DSS). FIPS Publication 186-4, National Institute of Standards and Technology, 2013.

Parameters:

`[in]`	algos	Algorithm identifiers to check the private key for (or'ed together).
`[in]`	dom	Pointer to DL domain parameters.
`[in]`	key	Private DL key to be tested.
	tmp	Array of `dom->m.val.size` temporary space elements.

Returns:: Validity status of key.

Return values:

	C4E_STATUS_OK	If the key seems to be valid.
	other	If the key is invalid.

See also:: C4eDlcDomain, C4eElement

Todo:: If CRY4E supports key generation (may be in the future) then implement additional tests according to NIST SP800-56A.

C4eSysStatus c4e_dlc_keychk_pub	(	C4eArchUint	algos,
		C4E_CONST C4eDlcDomain *C4E_RESTRICT	dom,
		C4E_CONST C4eElement *C4E_RESTRICT	key,
		C4eArchDigit	tmp[C4E_RESTRICT]
	)

Discrete logarithm (DL) domain public key validity test.

The function validates parameter key with respect to:

the allowed range: .

Precondition:: The validity of the DL domain parameters in dom must be assured by the caller, either implicit or by using function c4e_dlc_domchk().; All big numbers in key and dom must be normalized, e.g. by using functions c4e_elem_norm() or c4e_elem_os2e().

Bibliography:: Standard Specifications For Public-Key Cryptography. Std 1363-2000, IEEE, 2000.

Bibliography:: NIST Special Publication 800-56A Revision 2: Recommendation for Pair-Wise Key Establishment Schemes Using Discrete Logarithm Cryptography. 2013.

Parameters:

`[in]`	algos	Algorithm identifiers to check the public key for (or'ed together).
`[in]`	dom	Pointer to DL domain parameters.
`[in]`	key	Public DL key to be tested.
	tmp	Array of temporary space elements (unused at the moment).

Returns:: Validity status of key.

Return values:

	C4E_STATUS_OK	If the key seems to be valid.
	other	If the key is invalid.

See also:: C4eDlcDomain, C4eElement

Todo:: If CRY4E supports key generation (may be in the future) then implement additional tests according to NIST SP800-56A.

Discrete Logarithm Cryptography (DLC) [API]

Data Structures

Modules

Defines

Functions

DLC Algorithm Identifiers

Detailed Description

Define Documentation

Function Documentation

Discrete Logarithm Cryptography (DLC)
[API]