Andrew Boyson / crypto

A simple library to support serving https.

Dependents:   oldheating gps motorhome heating

rsa/rsa-slow.c@10:e269fd7b9500, 2019-09-24 (annotated)

Committer:
andrewboyson
Date:
Tue Sep 24 18:11:02 2019 +0000
Revision:
10:e269fd7b9500
Parent:
bignum/bn-async.c@2:82268409e83f
Child:
12:2c342345b3db
Got padlock and some application data through. Now need to use China remainder theorem to speed up decryption and things up and the session id to avoid having to do the decryption.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
andrewboyson 0:be515c9019e3 1 #include <stdint.h>
andrewboyson 0:be515c9019e3 2 #include <stdbool.h>
andrewboyson 10:e269fd7b9500 3 #include "rsa.h"
andrewboyson 0:be515c9019e3 4 #include "bignum.h"
andrewboyson 0:be515c9019e3 5 #include "hrtimer.h"
andrewboyson 2:82268409e83f 6 #include "log.h"
andrewboyson 0:be515c9019e3 7
andrewboyson 10:e269fd7b9500 8 #define STATUS_NONE 0
andrewboyson 10:e269fd7b9500 9 #define STATUS_STARTED 1
andrewboyson 10:e269fd7b9500 10 #define STATUS_FINISHED 2
andrewboyson 10:e269fd7b9500 11
andrewboyson 2:82268409e83f 12 #define MAX_COUNT 4
andrewboyson 2:82268409e83f 13
andrewboyson 2:82268409e83f 14 static uint32_t m[MAX_COUNT][32];
andrewboyson 2:82268409e83f 15 static uint32_t e[MAX_COUNT][32];
andrewboyson 2:82268409e83f 16 static uint32_t n[MAX_COUNT][32];
andrewboyson 2:82268409e83f 17 static uint32_t r[MAX_COUNT][32];
andrewboyson 2:82268409e83f 18
andrewboyson 10:e269fd7b9500 19 static int status[MAX_COUNT];
andrewboyson 0:be515c9019e3 20
andrewboyson 10:e269fd7b9500 21 bool RsaSlowFinished(int slot)
andrewboyson 10:e269fd7b9500 22 {
andrewboyson 10:e269fd7b9500 23 return status[slot] == STATUS_FINISHED;
andrewboyson 10:e269fd7b9500 24 }
andrewboyson 10:e269fd7b9500 25
andrewboyson 10:e269fd7b9500 26 uint32_t* RsaSlowResult(int slot)
andrewboyson 2:82268409e83f 27 {
andrewboyson 2:82268409e83f 28 return r[slot];
andrewboyson 2:82268409e83f 29 }
andrewboyson 10:e269fd7b9500 30 void RsaSlowClear(int slot) //This is for security - call it as soon as you no longer need the result.
andrewboyson 2:82268409e83f 31 {
andrewboyson 10:e269fd7b9500 32 status[slot] = STATUS_NONE;
andrewboyson 2:82268409e83f 33 BnZer1024(m[slot]);
andrewboyson 2:82268409e83f 34 BnZer1024(e[slot]);
andrewboyson 2:82268409e83f 35 BnZer1024(n[slot]);
andrewboyson 2:82268409e83f 36 BnZer1024(r[slot]);
andrewboyson 2:82268409e83f 37 }
andrewboyson 10:e269fd7b9500 38 int RsaSlowStart(uint32_t* message, uint32_t* exponent, uint32_t* modulus) //Returns the slot or -1 on failure - you must check!
andrewboyson 0:be515c9019e3 39 {
andrewboyson 2:82268409e83f 40 //If the exponent is empty then bomb out
andrewboyson 2:82268409e83f 41 if (BnIse1024(exponent))
andrewboyson 2:82268409e83f 42 {
andrewboyson 10:e269fd7b9500 43 LogTime("RsaSlowStart - empty exponent\r\n");
andrewboyson 2:82268409e83f 44 return -1;
andrewboyson 2:82268409e83f 45 }
andrewboyson 2:82268409e83f 46
andrewboyson 2:82268409e83f 47 //Look for an empty slot
andrewboyson 2:82268409e83f 48 int slot = 0;
andrewboyson 2:82268409e83f 49 while (slot < MAX_COUNT)
andrewboyson 2:82268409e83f 50 {
andrewboyson 10:e269fd7b9500 51 if (status[slot] == STATUS_NONE) goto found;
andrewboyson 2:82268409e83f 52 slot++;
andrewboyson 2:82268409e83f 53 }
andrewboyson 0:be515c9019e3 54
andrewboyson 2:82268409e83f 55 //Look for a slot whch has been used and not cleared
andrewboyson 2:82268409e83f 56 slot = 0;
andrewboyson 2:82268409e83f 57 while (slot < MAX_COUNT)
andrewboyson 2:82268409e83f 58 {
andrewboyson 10:e269fd7b9500 59 if (status[slot] == STATUS_FINISHED) goto found;
andrewboyson 2:82268409e83f 60 slot++;
andrewboyson 2:82268409e83f 61 }
andrewboyson 2:82268409e83f 62
andrewboyson 2:82268409e83f 63 //No available slot so bomb out
andrewboyson 10:e269fd7b9500 64 LogTimeF("RsaSlowStart - no available slots out of %d\r\n", MAX_COUNT);
andrewboyson 2:82268409e83f 65 return -1;
andrewboyson 2:82268409e83f 66
andrewboyson 2:82268409e83f 67 //Start the calculation
andrewboyson 2:82268409e83f 68 found:
andrewboyson 10:e269fd7b9500 69 BnModExpStart1024(m[slot], e[slot], n[slot], r[slot], message, exponent, modulus);
andrewboyson 10:e269fd7b9500 70 status[slot] = STATUS_STARTED;
andrewboyson 2:82268409e83f 71 return slot;
andrewboyson 0:be515c9019e3 72 }
andrewboyson 10:e269fd7b9500 73 void RsaSlowMain()
andrewboyson 0:be515c9019e3 74 {
andrewboyson 2:82268409e83f 75 int slot = 0;
andrewboyson 2:82268409e83f 76 while (slot < MAX_COUNT)
andrewboyson 2:82268409e83f 77 {
andrewboyson 10:e269fd7b9500 78 if (status[slot] == STATUS_STARTED) goto found;
andrewboyson 2:82268409e83f 79 slot++;
andrewboyson 2:82268409e83f 80 }
andrewboyson 2:82268409e83f 81 return;
andrewboyson 2:82268409e83f 82
andrewboyson 2:82268409e83f 83 found:
andrewboyson 10:e269fd7b9500 84 ;
andrewboyson 10:e269fd7b9500 85 bool finished = BnModExpIterate1024(m[slot], e[slot], n[slot], r[slot]);
andrewboyson 10:e269fd7b9500 86
andrewboyson 10:e269fd7b9500 87 if (finished) status[slot] = STATUS_FINISHED;
andrewboyson 2:82268409e83f 88 }
andrewboyson 2:82268409e83f 89
andrewboyson 10:e269fd7b9500 90 void RsaSlowInit(void)
andrewboyson 2:82268409e83f 91 {
andrewboyson 10:e269fd7b9500 92 for (int i = 0; i < MAX_COUNT; i++) status[i] = STATUS_NONE;
andrewboyson 0:be515c9019e3 93 }