Two new Curve25519 implementations (generic "i31" code, and optimised code with MUL31).

This commit is contained in:
Thomas Pornin 2017-01-15 23:16:18 +01:00
parent 3655193439
commit 89ea3b1876
6 changed files with 1211 additions and 12 deletions

View file

@ -450,6 +450,20 @@ extern const br_ec_impl br_ec_p256_m15;
*/
extern const br_ec_impl br_ec_c25519_i15;
/**
* \brief EC implementation "i31" (generic code) for Curve25519.
*
* This implementation uses the generic code for modular integers (with
* 31-bit words) to support Curve25519. Due to the specificities of the
* curve definition, the following applies:
*
* - `muladd()` is not implemented (the function returns 0 systematically).
* - `order()` returns 2^255-1, since the point multiplication algorithm
* accepts any 32-bit integer as input (it clears the top bit and low
* three bits systematically).
*/
extern const br_ec_impl br_ec_c25519_i31;
/**
* \brief EC implementation "m15" (specialised code) for Curve25519.
*
@ -464,6 +478,20 @@ extern const br_ec_impl br_ec_c25519_i15;
*/
extern const br_ec_impl br_ec_c25519_m15;
/**
* \brief EC implementation "m31" (specialised code) for Curve25519.
*
* This implementation uses custom code relying on multiplication of
* integers up to 31 bits. Due to the specificities of the curve
* definition, the following applies:
*
* - `muladd()` is not implemented (the function returns 0 systematically).
* - `order()` returns 2^255-1, since the point multiplication algorithm
* accepts any 32-bit integer as input (it clears the top bit and low
* three bits systematically).
*/
extern const br_ec_impl br_ec_c25519_m31;
/**
* \brief Aggregate EC implementation "m15".
*