1f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project/* LibTomCrypt, modular cryptographic library -- Tom St Denis 2f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project * 3f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project * LibTomCrypt is a library that provides various cryptographic 4f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project * algorithms in a highly modular and flexible manner. 5f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project * 6f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project * The library is free for all purposes without any express 7f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project * guarantee it works. 8f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project * 9f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project * Tom St Denis, tomstdenis@gmail.com, http://libtomcrypt.com 10f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project */ 11f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 12f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project/* Implements ECC over Z/pZ for curve y^2 = x^3 - 3x + b 13f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project * 14f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project * All curves taken from NIST recommendation paper of July 1999 15f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project * Available at http://csrc.nist.gov/cryptval/dss.htm 16f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project */ 17f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project#include "tomcrypt.h" 18f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 19f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project/** 20f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project @file ecc_encrypt_key.c 21f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project ECC Crypto, Tom St Denis 22f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project*/ 23f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 24f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project#ifdef MECC 25f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 26f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project/** 27f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project Encrypt a symmetric key with ECC 28f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project @param in The symmetric key you want to encrypt 29f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project @param inlen The length of the key to encrypt (octets) 30f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project @param out [out] The destination for the ciphertext 31f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project @param outlen [in/out] The max size and resulting size of the ciphertext 32f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project @param prng An active PRNG state 33f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project @param wprng The index of the PRNG you wish to use 34f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project @param hash The index of the hash you want to use 35f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project @param key The ECC key you want to encrypt to 36f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project @return CRYPT_OK if successful 37f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project*/ 38f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Projectint ecc_encrypt_key(const unsigned char *in, unsigned long inlen, 39f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project unsigned char *out, unsigned long *outlen, 40f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project prng_state *prng, int wprng, int hash, 41f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project ecc_key *key) 42f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project{ 43f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project unsigned char *pub_expt, *ecc_shared, *skey; 44f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project ecc_key pubkey; 45f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project unsigned long x, y, pubkeysize; 46f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project int err; 47f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 48f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project LTC_ARGCHK(in != NULL); 49f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project LTC_ARGCHK(out != NULL); 50f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project LTC_ARGCHK(outlen != NULL); 51f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project LTC_ARGCHK(key != NULL); 52f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 53f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project /* check that wprng/cipher/hash are not invalid */ 54f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project if ((err = prng_is_valid(wprng)) != CRYPT_OK) { 55f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project return err; 56f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project } 57f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 58f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project if ((err = hash_is_valid(hash)) != CRYPT_OK) { 59f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project return err; 60f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project } 61f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 62f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project if (inlen > hash_descriptor[hash].hashsize) { 63f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project return CRYPT_INVALID_HASH; 64f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project } 65f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 66f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project /* make a random key and export the public copy */ 67f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project if ((err = ecc_make_key_ex(prng, wprng, &pubkey, key->dp)) != CRYPT_OK) { 68f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project return err; 69f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project } 70f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 71f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project pub_expt = XMALLOC(ECC_BUF_SIZE); 72f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project ecc_shared = XMALLOC(ECC_BUF_SIZE); 73f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project skey = XMALLOC(MAXBLOCKSIZE); 74f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project if (pub_expt == NULL || ecc_shared == NULL || skey == NULL) { 75f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project if (pub_expt != NULL) { 76f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project XFREE(pub_expt); 77f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project } 78f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project if (ecc_shared != NULL) { 79f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project XFREE(ecc_shared); 80f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project } 81f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project if (skey != NULL) { 82f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project XFREE(skey); 83f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project } 84f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project ecc_free(&pubkey); 85f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project return CRYPT_MEM; 86f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project } 87f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 88f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project pubkeysize = ECC_BUF_SIZE; 89f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project if ((err = ecc_export(pub_expt, &pubkeysize, PK_PUBLIC, &pubkey)) != CRYPT_OK) { 90f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project ecc_free(&pubkey); 91f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project goto LBL_ERR; 92f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project } 93f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 94f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project /* make random key */ 95f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project x = ECC_BUF_SIZE; 96f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project if ((err = ecc_shared_secret(&pubkey, key, ecc_shared, &x)) != CRYPT_OK) { 97f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project ecc_free(&pubkey); 98f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project goto LBL_ERR; 99f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project } 100f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project ecc_free(&pubkey); 101f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project y = MAXBLOCKSIZE; 102f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project if ((err = hash_memory(hash, ecc_shared, x, skey, &y)) != CRYPT_OK) { 103f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project goto LBL_ERR; 104f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project } 105f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 106f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project /* Encrypt key */ 107f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project for (x = 0; x < inlen; x++) { 108f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project skey[x] ^= in[x]; 109f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project } 110f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 111f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project err = der_encode_sequence_multi(out, outlen, 112f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project LTC_ASN1_OBJECT_IDENTIFIER, hash_descriptor[hash].OIDlen, hash_descriptor[hash].OID, 113f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project LTC_ASN1_OCTET_STRING, pubkeysize, pub_expt, 114f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project LTC_ASN1_OCTET_STRING, inlen, skey, 115f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project LTC_ASN1_EOL, 0UL, NULL); 116f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 117f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source ProjectLBL_ERR: 118f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project#ifdef LTC_CLEAN_STACK 119f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project /* clean up */ 120f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project zeromem(pub_expt, ECC_BUF_SIZE); 121f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project zeromem(ecc_shared, ECC_BUF_SIZE); 122f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project zeromem(skey, MAXBLOCKSIZE); 123f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project#endif 124f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 125f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project XFREE(skey); 126f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project XFREE(ecc_shared); 127f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project XFREE(pub_expt); 128f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 129f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project return err; 130f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project} 131f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 132f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project#endif 133f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project/* $Source: /cvs/libtom/libtomcrypt/src/pk/ecc/ecc_encrypt_key.c,v $ */ 134f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project/* $Revision: 1.4 $ */ 135f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project/* $Date: 2006/11/21 00:10:18 $ */ 136f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 137