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#include "tomcrypt.h" 12f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 13f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project/** 14f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project @file katja_encrypt_key.c 15f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project Katja PKCS-style OAEP encryption, Tom St Denis 16f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project*/ 17f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 18f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project#ifdef MKAT 19f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 20f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project/** 21f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project (PKCS #1 v2.0) OAEP pad then encrypt 22f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project @param in The plaintext 23f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project @param inlen The length of the plaintext (octets) 24f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project @param out [out] The ciphertext 25f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project @param outlen [in/out] The max size and resulting size of the ciphertext 26f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project @param lparam The system "lparam" for the encryption 27f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project @param lparamlen The length of lparam (octets) 28f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project @param prng An active PRNG 29f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project @param prng_idx The index of the desired prng 30f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project @param hash_idx The index of the desired hash 31f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project @param key The Katja key to encrypt to 32f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project @return CRYPT_OK if successful 33f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project*/ 34f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Projectint katja_encrypt_key(const unsigned char *in, unsigned long inlen, 35f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project unsigned char *out, unsigned long *outlen, 36f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project const unsigned char *lparam, unsigned long lparamlen, 37f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project prng_state *prng, int prng_idx, int hash_idx, katja_key *key) 38f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project{ 39f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project unsigned long modulus_bitlen, modulus_bytelen, x; 40f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project int err; 41f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 42f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project LTC_ARGCHK(in != NULL); 43f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project LTC_ARGCHK(out != NULL); 44f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project LTC_ARGCHK(outlen != NULL); 45f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project LTC_ARGCHK(key != NULL); 46f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 47f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project /* valid prng and hash ? */ 48f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project if ((err = prng_is_valid(prng_idx)) != CRYPT_OK) { 49f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project return err; 50f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project } 51f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project if ((err = hash_is_valid(hash_idx)) != CRYPT_OK) { 52f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project return err; 53f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project } 54f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 55f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project /* get modulus len in bits */ 56f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project modulus_bitlen = mp_count_bits((key->N)); 57f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 58f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project /* payload is upto pq, so we know q is 1/3rd the size of N and therefore pq is 2/3th the size */ 59f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project modulus_bitlen = ((modulus_bitlen << 1) / 3); 60f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 61f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project /* round down to next byte */ 62f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project modulus_bitlen -= (modulus_bitlen & 7) + 8; 63f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 64f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project /* outlen must be at least the size of the modulus */ 65f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project modulus_bytelen = mp_unsigned_bin_size((key->N)); 66f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project if (modulus_bytelen > *outlen) { 67f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project *outlen = modulus_bytelen; 68f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project return CRYPT_BUFFER_OVERFLOW; 69f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project } 70f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 71f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project /* OAEP pad the key */ 72f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project x = *outlen; 73f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project if ((err = pkcs_1_oaep_encode(in, inlen, lparam, 74f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project lparamlen, modulus_bitlen, prng, prng_idx, hash_idx, 75f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project out, &x)) != CRYPT_OK) { 76f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project return err; 77f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project } 78f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 79f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project /* Katja exptmod the OAEP pad */ 80f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project return katja_exptmod(out, x, out, outlen, PK_PUBLIC, key); 81f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project} 82f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 83f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project#endif /* MRSA */ 84f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 85f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project/* $Source: /cvs/libtom/libtomcrypt/src/pk/katja/katja_encrypt_key.c,v $ */ 86f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project/* $Revision: 1.5 $ */ 87f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project/* $Date: 2006/06/16 21:53:41 $ */ 88