ARM Shanghai IoT Team (Internal) / newMiniTLS-GPL

change some parameters in the library to meet the needs of the website httpbin.org

Fork of MiniTLS-GPL by Donatien Garnier

crypto/crypto_prng.c@5:95f70ebfe61f, 2015-02-06 (annotated)

Committer:
shiyilei
Date:
Fri Feb 06 06:17:33 2015 +0000
Revision:
5:95f70ebfe61f
Parent:
2:527a66d0a1a9 
change some parameters in the library to meet the needs of httpbin.org

Who changed what in which revision?

UserRevisionLine numberNew contents of line
MiniTLS 2:527a66d0a1a9 1 /*
MiniTLS 2:527a66d0a1a9 2 MiniTLS - A super trimmed down TLS/SSL Library for embedded devices
MiniTLS 2:527a66d0a1a9 3 Author: Donatien Garnier
MiniTLS 2:527a66d0a1a9 4 Copyright (C) 2013-2014 AppNearMe Ltd
MiniTLS 2:527a66d0a1a9 5
MiniTLS 2:527a66d0a1a9 6 This program is free software; you can redistribute it and/or
MiniTLS 2:527a66d0a1a9 7 modify it under the terms of the GNU General Public License
MiniTLS 2:527a66d0a1a9 8 as published by the Free Software Foundation; either version 2
MiniTLS 2:527a66d0a1a9 9 of the License, or (at your option) any later version.
MiniTLS 2:527a66d0a1a9 10
MiniTLS 2:527a66d0a1a9 11 This program is distributed in the hope that it will be useful,
MiniTLS 2:527a66d0a1a9 12 but WITHOUT ANY WARRANTY; without even the implied warranty of
MiniTLS 2:527a66d0a1a9 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
MiniTLS 2:527a66d0a1a9 14 GNU General Public License for more details.
MiniTLS 2:527a66d0a1a9 15
MiniTLS 2:527a66d0a1a9 16 You should have received a copy of the GNU General Public License
MiniTLS 2:527a66d0a1a9 17 along with this program; if not, write to the Free Software
MiniTLS 2:527a66d0a1a9 18 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
MiniTLS 2:527a66d0a1a9 19 *//**
MiniTLS 2:527a66d0a1a9 20 * \file crypto_prng.c
MiniTLS 2:527a66d0a1a9 21 * \copyright Copyright (c) AppNearMe Ltd 2013
MiniTLS 2:527a66d0a1a9 22 * \author Donatien Garnier
MiniTLS 2:527a66d0a1a9 23 */
MiniTLS 2:527a66d0a1a9 24
MiniTLS 2:527a66d0a1a9 25 #define __DEBUG__ 0//4
MiniTLS 2:527a66d0a1a9 26 #ifndef __MODULE__
MiniTLS 2:527a66d0a1a9 27 #define __MODULE__ "crypto_prng.c"
MiniTLS 2:527a66d0a1a9 28 #endif
MiniTLS 2:527a66d0a1a9 29
MiniTLS 2:527a66d0a1a9 30 #include "core/fwk.h"
MiniTLS 2:527a66d0a1a9 31 #include "inc/minitls_errors.h"
MiniTLS 2:527a66d0a1a9 32 #include "crypto_prng.h"
MiniTLS 2:527a66d0a1a9 33
MiniTLS 2:527a66d0a1a9 34 #include "crypto_aes_128.h"
MiniTLS 2:527a66d0a1a9 35 #include "crypto_sha1.h"
MiniTLS 2:527a66d0a1a9 36
MiniTLS 2:527a66d0a1a9 37 #define YARROW_REGENERATE_VALUE 10
MiniTLS 2:527a66d0a1a9 38
MiniTLS 2:527a66d0a1a9 39 static void crypto_prng_update_internal(crypto_prng_t* prng);
MiniTLS 2:527a66d0a1a9 40
MiniTLS 2:527a66d0a1a9 41 void crypto_prng_init(crypto_prng_t* prng, rtos_mtx_t* mtx)
MiniTLS 2:527a66d0a1a9 42 {
MiniTLS 2:527a66d0a1a9 43 memset(prng->pool, 0, SHA1_SIZE);
MiniTLS 2:527a66d0a1a9 44 prng->counter = 0xFFFFFFFFUL; //Will force update
MiniTLS 2:527a66d0a1a9 45 prng->mtx = mtx;
MiniTLS 2:527a66d0a1a9 46 prng->buf_pos = AES_128_BLOCK_SIZE; //invalidate buffer
MiniTLS 2:527a66d0a1a9 47 prng->fed = false;
MiniTLS 2:527a66d0a1a9 48 }
MiniTLS 2:527a66d0a1a9 49
MiniTLS 2:527a66d0a1a9 50 #define LOCK() do{ if(prng->mtx) { rtos_mtx_lock(prng->mtx); } }while(0)
MiniTLS 2:527a66d0a1a9 51 #define UNLOCK() do{ if(prng->mtx) { rtos_mtx_unlock(prng->mtx); } }while(0)
MiniTLS 2:527a66d0a1a9 52
MiniTLS 2:527a66d0a1a9 53 void crypto_prng_feed(crypto_prng_t* prng, uint8_t* data, size_t size)
MiniTLS 2:527a66d0a1a9 54 {
MiniTLS 2:527a66d0a1a9 55 LOCK();
MiniTLS 2:527a66d0a1a9 56 //Update pool
MiniTLS 2:527a66d0a1a9 57 crypto_sha1_t hash;
MiniTLS 2:527a66d0a1a9 58 crypto_sha1_init(&hash);
MiniTLS 2:527a66d0a1a9 59 crypto_sha1_update(&hash, prng->pool, SHA1_SIZE);
MiniTLS 2:527a66d0a1a9 60 crypto_sha1_update(&hash, data, size);
MiniTLS 2:527a66d0a1a9 61 crypto_sha1_end(&hash, prng->pool);
MiniTLS 2:527a66d0a1a9 62 prng->fed = true;
MiniTLS 2:527a66d0a1a9 63 UNLOCK();
MiniTLS 2:527a66d0a1a9 64 }
MiniTLS 2:527a66d0a1a9 65
MiniTLS 2:527a66d0a1a9 66 void crypto_prng_update_internal(crypto_prng_t* prng)
MiniTLS 2:527a66d0a1a9 67 {
MiniTLS 2:527a66d0a1a9 68 if(!prng->fed)
MiniTLS 2:527a66d0a1a9 69 {
MiniTLS 2:527a66d0a1a9 70 //Rehash the pool to "rotate" key
MiniTLS 2:527a66d0a1a9 71 crypto_sha1_t hash;
MiniTLS 2:527a66d0a1a9 72 crypto_sha1_init(&hash);
MiniTLS 2:527a66d0a1a9 73 crypto_sha1_update(&hash, prng->pool, SHA1_SIZE);
MiniTLS 2:527a66d0a1a9 74 crypto_sha1_end(&hash, prng->pool);
MiniTLS 2:527a66d0a1a9 75 }
MiniTLS 2:527a66d0a1a9 76 prng->fed = false;
MiniTLS 2:527a66d0a1a9 77 //Generate key from pool
MiniTLS 2:527a66d0a1a9 78 crypto_aes_128_init(&prng->cipher, prng->pool, expand_encryption_key); //OK because AES_128_BLOCK_SIZE < SHA1_SIZE
MiniTLS 2:527a66d0a1a9 79 prng->counter = 0;
MiniTLS 2:527a66d0a1a9 80 }
MiniTLS 2:527a66d0a1a9 81
MiniTLS 2:527a66d0a1a9 82 void crypto_prng_update(crypto_prng_t* prng)
MiniTLS 2:527a66d0a1a9 83 {
MiniTLS 2:527a66d0a1a9 84 LOCK();
MiniTLS 2:527a66d0a1a9 85 crypto_prng_update_internal(prng);
MiniTLS 2:527a66d0a1a9 86 UNLOCK();
MiniTLS 2:527a66d0a1a9 87 }
MiniTLS 2:527a66d0a1a9 88
MiniTLS 2:527a66d0a1a9 89 void crypto_prng_get(crypto_prng_t* prng, uint8_t* data, size_t size)
MiniTLS 2:527a66d0a1a9 90 {
MiniTLS 2:527a66d0a1a9 91 LOCK();
MiniTLS 2:527a66d0a1a9 92
MiniTLS 2:527a66d0a1a9 93 //Regenerate data as needed
MiniTLS 2:527a66d0a1a9 94 while(size > 0)
MiniTLS 2:527a66d0a1a9 95 {
MiniTLS 2:527a66d0a1a9 96 if(prng->counter > YARROW_REGENERATE_VALUE)
MiniTLS 2:527a66d0a1a9 97 {
MiniTLS 2:527a66d0a1a9 98 crypto_prng_update_internal(prng);
MiniTLS 2:527a66d0a1a9 99 }
MiniTLS 2:527a66d0a1a9 100
MiniTLS 2:527a66d0a1a9 101 //Copy any remaining data from buffer
MiniTLS 2:527a66d0a1a9 102 size_t cpy_size = MIN(size, AES_128_BLOCK_SIZE - prng->buf_pos);
MiniTLS 2:527a66d0a1a9 103 memcpy(data, prng->buf + prng->buf_pos, cpy_size);
MiniTLS 2:527a66d0a1a9 104 data += cpy_size;
MiniTLS 2:527a66d0a1a9 105 size -= cpy_size;
MiniTLS 2:527a66d0a1a9 106 prng->buf_pos += cpy_size;
MiniTLS 2:527a66d0a1a9 107
MiniTLS 2:527a66d0a1a9 108 if(prng->buf_pos >= AES_128_BLOCK_SIZE)
MiniTLS 2:527a66d0a1a9 109 {
MiniTLS 2:527a66d0a1a9 110 memset(prng->buf + sizeof(uint32_t), 0, AES_128_BLOCK_SIZE - sizeof(uint32_t));
MiniTLS 2:527a66d0a1a9 111 memcpy(prng->buf, &prng->counter, sizeof(uint32_t)); //We do not care about endianness as long as it's consistent (don't know of any system which would swap endianness during the execution of a program...)
MiniTLS 2:527a66d0a1a9 112 crypto_aes_128_encrypt(&prng->cipher, prng->buf, prng->buf);
MiniTLS 2:527a66d0a1a9 113 prng->counter++;
MiniTLS 2:527a66d0a1a9 114 prng->buf_pos = 0;
MiniTLS 2:527a66d0a1a9 115 }
MiniTLS 2:527a66d0a1a9 116 }
MiniTLS 2:527a66d0a1a9 117
MiniTLS 2:527a66d0a1a9 118 UNLOCK();
MiniTLS 2:527a66d0a1a9 119 }
MiniTLS 2:527a66d0a1a9 120
MiniTLS 2:527a66d0a1a9 121