X-Git-Url: https://www.bearssl.org/gitweb//home/git/?p=BearSSL;a=blobdiff_plain;f=inc%2Fbearssl_ec.h;h=533296dcaca0d99db1d34e06e087f7841cfe824a;hp=1ecb4cdcffe54b9347cc9f3454e0773c63e8c31e;hb=8e86598b33f9df81d1f77d6cc32568d9ae119d67;hpb=693d2a0085f4c1d289cb6d79c02ddd23f18d9478 diff --git a/inc/bearssl_ec.h b/inc/bearssl_ec.h index 1ecb4cd..533296d 100644 --- a/inc/bearssl_ec.h +++ b/inc/bearssl_ec.h @@ -28,6 +28,10 @@ #include #include +#ifdef __cplusplus +extern "C" { +#endif + /** \file bearssl_ec.h * * # Elliptic Curves @@ -65,6 +69,11 @@ * Callback method that returns a pointer to the subgroup order for * that curve. That value uses unsigned big-endian encoding. * + * - `xoff()` + * + * Callback method that returns the offset and length of the X + * coordinate in an encoded point. + * * - `mul()` * * Multiply a curve point with an integer. @@ -294,6 +303,18 @@ typedef struct { */ const unsigned char *(*order)(int curve, size_t *len); + /** + * \brief Get the offset and length for the X coordinate. + * + * This function returns the offset and length (in bytes) of + * the X coordinate in an encoded non-zero point. + * + * \param curve curve identifier. + * \param len receiver for the X coordinate length (in bytes). + * \return the offset for the X coordinate (in bytes). + */ + size_t (*xoff)(int curve, size_t *len); + /** * \brief Multiply a curve point by an integer. * @@ -419,23 +440,103 @@ extern const br_ec_impl br_ec_prime_i15; */ extern const br_ec_impl br_ec_p256_m15; +/** + * \brief EC implementation "m31" for P-256. + * + * This implementation uses specialised code for curve secp256r1 (also + * known as NIST P-256), relying on multiplications of 31-bit values + * (MUL31). + */ +extern const br_ec_impl br_ec_p256_m31; + /** * \brief EC implementation "i15" (generic code) for Curve25519. * * This implementation uses the generic code for modular integers (with - * 15-bit words) to support Curve25519. The `muladd()` method is not - * implemented. + * 15-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_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. * * This implementation uses custom code relying on multiplication of - * integers up to 15 bits. The `muladd()` method is not implemented. + * integers up to 15 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_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". + * + * This implementation is a wrapper for: + * + * - `br_ec_c25519_m15` for Curve25519 + * - `br_ec_p256_m15` for NIST P-256 + * - `br_ec_prime_i15` for other curves (NIST P-384 and NIST-P512) + */ +extern const br_ec_impl br_ec_all_m15; + +/** + * \brief Aggregate EC implementation "m31". + * + * This implementation is a wrapper for: + * + * - `br_ec_c25519_m31` for Curve25519 + * - `br_ec_p256_m31` for NIST P-256 + * - `br_ec_prime_i31` for other curves (NIST P-384 and NIST-P512) + */ +extern const br_ec_impl br_ec_all_m31; + +/** + * \brief Get the "default" EC implementation for the current system. + * + * This returns a pointer to the preferred implementation on the + * current system. + * + * \return the default EC implementation. + */ +const br_ec_impl *br_ec_get_default(void); + /** * \brief Convert a signature from "raw" to "asn1". * @@ -656,4 +757,48 @@ uint32_t br_ecdsa_i15_vrfy_raw(const br_ec_impl *impl, const void *hash, size_t hash_len, const br_ec_public_key *pk, const void *sig, size_t sig_len); +/** + * \brief Get "default" ECDSA implementation (signer, asn1 format). + * + * This returns the preferred implementation of ECDSA signature generation + * ("asn1" output format) on the current system. + * + * \return the default implementation. + */ +br_ecdsa_sign br_ecdsa_sign_asn1_get_default(void); + +/** + * \brief Get "default" ECDSA implementation (signer, raw format). + * + * This returns the preferred implementation of ECDSA signature generation + * ("raw" output format) on the current system. + * + * \return the default implementation. + */ +br_ecdsa_sign br_ecdsa_sign_raw_get_default(void); + +/** + * \brief Get "default" ECDSA implementation (verifier, asn1 format). + * + * This returns the preferred implementation of ECDSA signature verification + * ("asn1" output format) on the current system. + * + * \return the default implementation. + */ +br_ecdsa_vrfy br_ecdsa_vrfy_asn1_get_default(void); + +/** + * \brief Get "default" ECDSA implementation (verifier, raw format). + * + * This returns the preferred implementation of ECDSA signature verification + * ("raw" output format) on the current system. + * + * \return the default implementation. + */ +br_ecdsa_vrfy br_ecdsa_vrfy_raw_get_default(void); + +#ifdef __cplusplus +} +#endif + #endif