Andrew Boyson / crypto

A simple library to support serving https.

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tls/tls-session.c@22:af0b5ceb556e, 2019-10-23 (annotated)

Committer:
andrewboyson
Date:
Wed Oct 23 08:44:50 2019 +0000
Revision:
22:af0b5ceb556e
Parent:
14:03a0b8fd6ddc 
Removed error if passing a 0 id to TlsSessionGetFromIdOrNull; now it just returns NULL without complaining.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
andrewboyson 5:ee5489ee1117 1 #include <stdlib.h>
andrewboyson 2:82268409e83f 2 #include <stdint.h>
andrewboyson 2:82268409e83f 3 #include <stdbool.h>
andrewboyson 2:82268409e83f 4
andrewboyson 2:82268409e83f 5 #include "tls-session.h"
andrewboyson 2:82268409e83f 6 #include "mstimer.h"
andrewboyson 10:e269fd7b9500 7 #include "hrtimer.h"
andrewboyson 13:0a80b49a5e78 8 #include "log.h"
andrewboyson 2:82268409e83f 9
andrewboyson 2:82268409e83f 10 #define TLS_MAX_SESSIONS 4
andrewboyson 2:82268409e83f 11
andrewboyson 2:82268409e83f 12 static struct TlsSession sessions[TLS_MAX_SESSIONS];
andrewboyson 2:82268409e83f 13
andrewboyson 10:e269fd7b9500 14 static void zeroSession(struct TlsSession* p)
andrewboyson 2:82268409e83f 15 {
andrewboyson 10:e269fd7b9500 16 p->id = 0;
andrewboyson 10:e269fd7b9500 17 p->lastUsed = 0;
andrewboyson 10:e269fd7b9500 18 p->valid = false;
andrewboyson 10:e269fd7b9500 19 for (int i = 0; i < TLS_KEY_SIZE_MASTER; i++) p->masterSecret[i] = 0;
andrewboyson 10:e269fd7b9500 20 }
andrewboyson 10:e269fd7b9500 21
andrewboyson 10:e269fd7b9500 22 struct TlsSession* TlsSessionNew() //Never fails so never returns NULL
andrewboyson 10:e269fd7b9500 23 {
andrewboyson 10:e269fd7b9500 24 struct TlsSession* p;
andrewboyson 10:e269fd7b9500 25
andrewboyson 10:e269fd7b9500 26 //look for an empty connection
andrewboyson 2:82268409e83f 27 struct TlsSession* pOldest = 0;
andrewboyson 2:82268409e83f 28 uint32_t ageOldest = 0;
andrewboyson 10:e269fd7b9500 29 for (p = sessions; p < sessions + TLS_MAX_SESSIONS; p++)
andrewboyson 2:82268409e83f 30 {
andrewboyson 10:e269fd7b9500 31 if (!p->id) goto end; //Found an empty slot so just return it
andrewboyson 5:ee5489ee1117 32 uint32_t age = MsTimerCount - p->lastUsed;
andrewboyson 2:82268409e83f 33 if (age >= ageOldest)
andrewboyson 2:82268409e83f 34 {
andrewboyson 2:82268409e83f 35 ageOldest = age;
andrewboyson 5:ee5489ee1117 36 pOldest = p;
andrewboyson 2:82268409e83f 37 }
andrewboyson 2:82268409e83f 38 }
andrewboyson 10:e269fd7b9500 39
andrewboyson 10:e269fd7b9500 40 //No empty ones found so use the oldest
andrewboyson 10:e269fd7b9500 41 p = pOldest;
andrewboyson 10:e269fd7b9500 42
andrewboyson 10:e269fd7b9500 43 end:
andrewboyson 10:e269fd7b9500 44 zeroSession(p);
andrewboyson 10:e269fd7b9500 45 uint32_t id = 0;
andrewboyson 10:e269fd7b9500 46 while (!id) id = HrTimerCount(); //This is used as a convenient unique identifier which is never zero;
andrewboyson 10:e269fd7b9500 47 p->id = id;
andrewboyson 10:e269fd7b9500 48 p->lastUsed = MsTimerCount;
andrewboyson 10:e269fd7b9500 49 return p;
andrewboyson 2:82268409e83f 50 }
andrewboyson 2:82268409e83f 51
andrewboyson 10:e269fd7b9500 52 struct TlsSession* TlsSessionOrNull(uint32_t id)
andrewboyson 2:82268409e83f 53 {
andrewboyson 22:af0b5ceb556e 54 if (!id) return NULL;
andrewboyson 10:e269fd7b9500 55 for (struct TlsSession* p = sessions; p < sessions + TLS_MAX_SESSIONS; p++)
andrewboyson 10:e269fd7b9500 56 {
andrewboyson 10:e269fd7b9500 57 if (p->id == id) return p;
andrewboyson 10:e269fd7b9500 58 }
andrewboyson 22:af0b5ceb556e 59 return NULL;
andrewboyson 2:82268409e83f 60 }
andrewboyson 10:e269fd7b9500 61 void TlsSessionReset(uint32_t id)
andrewboyson 2:82268409e83f 62 {
andrewboyson 22:af0b5ceb556e 63 if (!id) return;
andrewboyson 10:e269fd7b9500 64 for (struct TlsSession* p = sessions; p < sessions + TLS_MAX_SESSIONS; p++)
andrewboyson 10:e269fd7b9500 65 {
andrewboyson 10:e269fd7b9500 66 if (p->id == id) zeroSession(p);
andrewboyson 10:e269fd7b9500 67 }
andrewboyson 2:82268409e83f 68 }