/* | |

* Copyright (c) 2013, Kenneth MacKay | |

* All rights reserved. | |

* | |

* Redistribution and use in source and binary forms, with or without | |

* modification, are permitted provided that the following conditions are | |

* met: | |

* * Redistributions of source code must retain the above copyright | |

* notice, this list of conditions and the following disclaimer. | |

* * Redistributions in binary form must reproduce the above copyright | |

* notice, this list of conditions and the following disclaimer in the | |

* documentation and/or other materials provided with the distribution. | |

* | |

* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | |

* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | |

* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR | |

* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT | |

* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | |

* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT | |

* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |

* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |

* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |

* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE | |

* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |

*/ | |

#ifndef _CRYPTO_ECC_H | |

#define _CRYPTO_ECC_H | |

#define ECC_MAX_DIGITS 4 /* 256 */ | |

#define ECC_DIGITS_TO_BYTES_SHIFT 3 | |

/** | |

* ecc_is_key_valid() - Validate a given ECDH private key | |

* | |

* @curve_id: id representing the curve to use | |

* @ndigits: curve's number of digits | |

* @private_key: private key to be used for the given curve | |

* @private_key_len: private key length | |

* | |

* Returns 0 if the key is acceptable, a negative value otherwise | |

*/ | |

int ecc_is_key_valid(unsigned int curve_id, unsigned int ndigits, | |

const u64 *private_key, unsigned int private_key_len); | |

/** | |

* ecc_gen_privkey() - Generates an ECC private key. | |

* The private key is a random integer in the range 0 < random < n, where n is a | |

* prime that is the order of the cyclic subgroup generated by the distinguished | |

* point G. | |

* @curve_id: id representing the curve to use | |

* @ndigits: curve number of digits | |

* @private_key: buffer for storing the generated private key | |

* | |

* Returns 0 if the private key was generated successfully, a negative value | |

* if an error occurred. | |

*/ | |

int ecc_gen_privkey(unsigned int curve_id, unsigned int ndigits, u64 *privkey); | |

/** | |

* ecc_make_pub_key() - Compute an ECC public key | |

* | |

* @curve_id: id representing the curve to use | |

* @ndigits: curve's number of digits | |

* @private_key: pregenerated private key for the given curve | |

* @public_key: buffer for storing the generated public key | |

* | |

* Returns 0 if the public key was generated successfully, a negative value | |

* if an error occurred. | |

*/ | |

int ecc_make_pub_key(const unsigned int curve_id, unsigned int ndigits, | |

const u64 *private_key, u64 *public_key); | |

/** | |

* crypto_ecdh_shared_secret() - Compute a shared secret | |

* | |

* @curve_id: id representing the curve to use | |

* @ndigits: curve's number of digits | |

* @private_key: private key of part A | |

* @public_key: public key of counterpart B | |

* @secret: buffer for storing the calculated shared secret | |

* | |

* Note: It is recommended that you hash the result of crypto_ecdh_shared_secret | |

* before using it for symmetric encryption or HMAC. | |

* | |

* Returns 0 if the shared secret was generated successfully, a negative value | |

* if an error occurred. | |

*/ | |

int crypto_ecdh_shared_secret(unsigned int curve_id, unsigned int ndigits, | |

const u64 *private_key, const u64 *public_key, | |

u64 *secret); | |

#endif |