AuroraMiddleware/mbedtls
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Add doxygen documentation to the new ECP interface

Browse Source 
Document the functions in the Elliptic Curve Point module hardware
acceleration to guide silicon vendors when implementing the drivers.
This commit is contained in:
Janos Follath 2016-12-02 13:49:21 +00:00 committed by Simon Butcher
parent 6c8ccd5be4
commit aab9efb4ce
1 changed files with 192 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

192
include/mbedtls/ecp_internal.h
View File

@ -21,61 +21,253 @@
*
* This file is part of mbed TLS (https://tls.mbed.org)
*/
/*
* References:
*
* SEC1 http://www.secg.org/index.php?action=secg,docs_secg
* GECC = Guide to Elliptic Curve Cryptography - Hankerson, Menezes, Vanstone
* FIPS 186-3 http://csrc.nist.gov/publications/fips/fips186-3/fips_186-3.pdf
* RFC 4492 for the related TLS structures and constants
*
* [Curve25519] http://cr.yp.to/ecdh/curve25519-20060209.pdf
*
* [2] CORON, Jean-S'ebastien. Resistance against differential power analysis
* for elliptic curve cryptosystems. In : Cryptographic Hardware and
* Embedded Systems. Springer Berlin Heidelberg, 1999. p. 292-302.
* <http://link.springer.com/chapter/10.1007/3-540-48059-5_25>
*
* [3] HEDABOU, Mustapha, PINEL, Pierre, et B'EN'ETEAU, Lucien. A comb method to
* render ECC resistant against Side Channel Attacks. IACR Cryptology
* ePrint Archive, 2004, vol. 2004, p. 342.
* <http://eprint.iacr.org/2004/342.pdf>
*/
#ifndef MBEDTLS_ECP_INTERNAL_H
#define MBEDTLS_ECP_INTERNAL_H
#if defined(MBEDTLS_ECP_INTERNAL_ALT)
/**
* \brief Tell if the cryptographic hardware can handle the group.
*
* \param grp The pointer to the group.
*
* \return Non-zero if successful.
*/
unsigned char mbedtls_internal_ecp_grp_capable( const mbedtls_ecp_group *grp );
/**
* \brief Initialise the crypto hardware accelerator.
*
* If mbedtls_internal_ecp_grp_capable returns true for a
* group, this function has to be able to initialise the
* hardware for it.
*
* \param grp The pointer to the group the hardware needs to be
* initialised for.
*
* \return 0 if successful.
*/
int mbedtls_internal_ecp_init( const mbedtls_ecp_group *grp );
/**
* \brief Reset the crypto hardware accelerator to an uninitialised
* state.
*
* \param grp The pointer to the group the hardware was initialised for.
*/
void mbedtls_internal_ecp_free( const mbedtls_ecp_group *grp );
#if defined(ECP_SHORTWEIERSTRASS)
#if defined(MBEDTLS_ECP_RANDOMIZE_JAC_ALT)
/**
* \brief Randomize jacobian coordinates:
* (X, Y, Z) -> (l^2 X, l^3 Y, l Z) for random l.
*
* This is sort of the reverse operation of
* ecp_normalize_jac().
*
* \param grp Pointer to the group representing the curve.
*
* \param pt The point on the curve to be randomised, given with Jacobian
* coordinates.
*
* \param f_rng A function pointer to the random number generator.
*
* \param p_rng A pointer to the random number generator state.
*
* \return 0 if successful.
*/
int mbedtls_internal_ecp_randomize_jac( const mbedtls_ecp_group *grp,
mbedtls_ecp_point *pt, int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng );
#endif
#if defined(MBEDTLS_ECP_ADD_MIXED_ALT)
/**
* \brief Addition: R = P + Q, mixed affine-Jacobian coordinates.
*
* The coordinates of Q must be normalized (= affine),
* but those of P don't need to. R is not normalized.
*
* Special cases: (1) P or Q is zero, (2) R is zero,
* (3) P == Q.
* None of these cases can happen as intermediate step in
* ecp_mul_comb():
* - at each step, P, Q and R are multiples of the base
* point, the factor being less than its order, so none of
* them is zero;
* - Q is an odd multiple of the base point, P an even
* multiple, due to the choice of precomputed points in the
* modified comb method.
* So branches for these cases do not leak secret information.
*
* We accept Q->Z being unset (saving memory in tables) as
* meaning 1.
*
* Cost in field operations if done by GECC 3.22:
* 1A := 8M + 3S
*
* \param grp Pointer to the group representing the curve.
*
* \param R Pointer to a point structure to hold the result.
*
* \param P Pointer to the first summand, given with Jacobian
* coordinates
*
* \param Q Pointer to the second summand, given with affine
* coordinates.
*
* \return 0 if successful.
*/
int mbedtls_internal_ecp_add_mixed( const mbedtls_ecp_group *grp,
mbedtls_ecp_point *R, const mbedtls_ecp_point *P,
const mbedtls_ecp_point *Q );
#endif
/**
* \brief Point doubling R = 2 P, Jacobian coordinates.
*
* Cost: 1D := 3M + 4S (A == 0)
* 4M + 4S (A == -3)
* 3M + 6S + 1a otherwise
* when the implementation is based on
* http://www.hyperelliptic.org/EFD/g1p/
* auto-shortw-jacobian.html#doubling-dbl-1998-cmo-2
* and standard optimizations are applied when curve parameter
* A is one of { 0, -3 }.
*
* \param grp Pointer to the group representing the curve.
*
* \param R Pointer to a point structure to hold the result.
*
* \param P Pointer to the point that has to be doubled, given with
* Jacobian coordinates.
*
* \return 0 if successful.
*/
#if defined(MBEDTLS_ECP_DOUBLE_JAC_ALT)
int mbedtls_internal_ecp_double_jac( const mbedtls_ecp_group *grp,
mbedtls_ecp_point *R, const mbedtls_ecp_point *P );
#endif
/**
* \brief Normalize jacobian coordinates of an array of (pointers to)
* points.
*
* Using Montgomery's trick to perform only one inversion mod P
* the cost is:
* 1N(t) := 1I + (6t - 3)M + 1S
* (See for example Cohen's "A Course in Computational
* Algebraic Number Theory", Algorithm 10.3.4.)
*
* Warning: fails (returning an error) if one of the points is
* zero!
* This should never happen, see choice of w in ecp_mul_comb().
*
* \param grp Pointer to the group representing the curve.
*
* \param T Array of pointers to the points to normalise.
*
* \param t_len Number of elements in the array.
*
* \return 0 if successful,
* an error if one of the points is zero.
*/
#if defined(MBEDTLS_ECP_NORMALIZE_JAC_MANY_ALT)
int mbedtls_internal_ecp_normalize_jac_many( const mbedtls_ecp_group *grp,
mbedtls_ecp_point *T[], size_t t_len );
#endif
/**
* \brief Normalize jacobian coordinates so that Z == 0 || Z == 1.
*
* Cost in field operations if done by GECC 3.2.1:
* 1N := 1I + 3M + 1S
*
* \param grp Pointer to the group representing the curve.
*
* \param pt pointer to the point to be normalised. This is an
* input/output parameter.
*
* \return 0 if successful.
*/
#if defined(MBEDTLS_ECP_NORMALIZE_JAC_ALT)
int mbedtls_internal_ecp_normalize_jac( const mbedtls_ecp_group *grp,
mbedtls_ecp_point *pt );
#endif
#endif /* ECP_SHORTWEIERSTRASS */
#if defined(ECP_MONTGOMERY)
#if defined(MBEDTLS_ECP_DOUBLE_ADD_MXZ_ALT)
int mbedtls_internal_ecp_double_add_mxz( const mbedtls_ecp_group *grp,
mbedtls_ecp_point *R, mbedtls_ecp_point *S, const mbedtls_ecp_point *P,
const mbedtls_ecp_point *Q, const mbedtls_mpi *d );
#endif
/**
* \brief Randomize projective x/z coordinates:
* (X, Z) -> (l X, l Z) for random l
* This is sort of the reverse operation of ecp_normalize_mxz().
*
* \param grp pointer to the group representing the curve
*
* \param P the point on the curve to be randomised given with
* projective coordinates. This is an input/output parameter.
*
* \param f_rng a function pointer to the random number generator
*
* \param p_rng a pointer to the random number generator state
*
* \return 0 if successful
*/
#if defined(MBEDTLS_ECP_RANDOMIZE_MXZ_ALT)
int mbedtls_internal_ecp_randomize_mxz( const mbedtls_ecp_group *grp,
mbedtls_ecp_point *P, int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng );
#endif
/**
* \brief Normalize Montgomery x/z coordinates: X = X/Z, Z = 1.
*
* \param grp pointer to the group representing the curve
*
* \param P pointer to the point to be normalised. This is an
* input/output parameter.
*
* \return 0 if successful
*/
#if defined(MBEDTLS_ECP_NORMALIZE_MXZ_ALT)
int mbedtls_internal_ecp_normalize_mxz( const mbedtls_ecp_group *grp,
mbedtls_ecp_point *P );
#endif
#endif /* ECP_MONTGOMERY */
#endif /* MBEDTLS_ECP_INTERNAL_ALT */
#endif /* ecp_internal.h */