Andrew Boyson / crypto

A simple library to support serving https.

Dependents:   oldheating gps motorhome heating

pki/base64.c@24:cb43290fc439, 2020-04-01 (annotated)

Committer:
andrewboyson
Date:
Wed Apr 01 12:48:52 2020 +0000
Revision:
24:cb43290fc439
Parent:
0:be515c9019e3 
Added check so that if the client closes the TCP connection before the TLS connection is established then respond that we have finished and the TCP connection is to be closed.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
andrewboyson 0:be515c9019e3 1 #include <stdbool.h>
andrewboyson 0:be515c9019e3 2 #include <stdio.h>
andrewboyson 0:be515c9019e3 3 #include "base64.h"
andrewboyson 0:be515c9019e3 4
andrewboyson 0:be515c9019e3 5 char (*Base64ReadNextCharFunctionPointer)(void) = NULL;
andrewboyson 0:be515c9019e3 6
andrewboyson 0:be515c9019e3 7 static int get6bits()
andrewboyson 0:be515c9019e3 8 {
andrewboyson 0:be515c9019e3 9 while (true)
andrewboyson 0:be515c9019e3 10 {
andrewboyson 0:be515c9019e3 11 char c = Base64ReadNextCharFunctionPointer();
andrewboyson 0:be515c9019e3 12 if (c == 0 ) return -1; //EOF or an error
andrewboyson 0:be515c9019e3 13 else if (c == '-') return -1; //Finished
andrewboyson 0:be515c9019e3 14 else if (c == '=') return -1; //Padding
andrewboyson 0:be515c9019e3 15 else if (c == '/') return 63;
andrewboyson 0:be515c9019e3 16 else if (c == '+') return 62;
andrewboyson 0:be515c9019e3 17 else if (c >= 'a') return c - 'a' + 26;
andrewboyson 0:be515c9019e3 18 else if (c >= 'A') return c - 'A' + 0;
andrewboyson 0:be515c9019e3 19 else if (c >= '0') return c - '0' + 52;
andrewboyson 0:be515c9019e3 20 else continue;
andrewboyson 0:be515c9019e3 21 }
andrewboyson 0:be515c9019e3 22 }
andrewboyson 0:be515c9019e3 23
andrewboyson 0:be515c9019e3 24 static int last6 = 0;
andrewboyson 0:be515c9019e3 25 static int posn = 0;
andrewboyson 0:be515c9019e3 26 static bool finished = false;
andrewboyson 0:be515c9019e3 27 int Base64ReadByte()
andrewboyson 0:be515c9019e3 28 {
andrewboyson 0:be515c9019e3 29 if (finished) return -1;
andrewboyson 0:be515c9019e3 30
andrewboyson 0:be515c9019e3 31 /*
andrewboyson 0:be515c9019e3 32 L = last
andrewboyson 0:be515c9019e3 33 T = this
andrewboyson 0:be515c9019e3 34 out
andrewboyson 0:be515c9019e3 35 case 0 TTTTTTLL
andrewboyson 0:be515c9019e3 36 case 1 LLLLTTTT
andrewboyson 0:be515c9019e3 37 case 2 LLTTTTTT
andrewboyson 0:be515c9019e3 38 */
andrewboyson 0:be515c9019e3 39 int this6 = 0;
andrewboyson 0:be515c9019e3 40 int bits8 = 0;
andrewboyson 0:be515c9019e3 41
andrewboyson 0:be515c9019e3 42 switch (posn)
andrewboyson 0:be515c9019e3 43 {
andrewboyson 0:be515c9019e3 44 case 0: //We have no bits leftover
andrewboyson 0:be515c9019e3 45 {
andrewboyson 0:be515c9019e3 46 this6 = get6bits(); if (this6 == -1) return -1; //EOF or an error
andrewboyson 0:be515c9019e3 47 last6 = get6bits();
andrewboyson 0:be515c9019e3 48 if (last6 == -1)
andrewboyson 0:be515c9019e3 49 {
andrewboyson 0:be515c9019e3 50 last6 = 0;
andrewboyson 0:be515c9019e3 51 finished = true;
andrewboyson 0:be515c9019e3 52 }
andrewboyson 0:be515c9019e3 53 bits8 = this6 << 2;
andrewboyson 0:be515c9019e3 54 bits8 &= 0xFF;
andrewboyson 0:be515c9019e3 55 bits8 |= last6 >> 4;
andrewboyson 0:be515c9019e3 56
andrewboyson 0:be515c9019e3 57 posn = 1;
andrewboyson 0:be515c9019e3 58 break;
andrewboyson 0:be515c9019e3 59 }
andrewboyson 0:be515c9019e3 60 case 1: //We have 4 bits leftover
andrewboyson 0:be515c9019e3 61 {
andrewboyson 0:be515c9019e3 62 this6 = get6bits(); if (this6 == -1) return -1; //EOF or an error
andrewboyson 0:be515c9019e3 63
andrewboyson 0:be515c9019e3 64 bits8 = last6 << 4;
andrewboyson 0:be515c9019e3 65 bits8 &= 0xFF;
andrewboyson 0:be515c9019e3 66 bits8 |= this6 >> 2;
andrewboyson 0:be515c9019e3 67
andrewboyson 0:be515c9019e3 68 last6 = this6;
andrewboyson 0:be515c9019e3 69
andrewboyson 0:be515c9019e3 70 posn = 2;
andrewboyson 0:be515c9019e3 71 break;
andrewboyson 0:be515c9019e3 72 }
andrewboyson 0:be515c9019e3 73 case 2: //We have 2 bits leftover
andrewboyson 0:be515c9019e3 74 {
andrewboyson 0:be515c9019e3 75 this6 = get6bits(); if (this6 == -1) return -1; //EOF or an error
andrewboyson 0:be515c9019e3 76
andrewboyson 0:be515c9019e3 77 bits8 = last6 << 6;
andrewboyson 0:be515c9019e3 78 bits8 &= 0xFF;
andrewboyson 0:be515c9019e3 79 bits8 |= this6;
andrewboyson 0:be515c9019e3 80
andrewboyson 0:be515c9019e3 81 posn = 0;
andrewboyson 0:be515c9019e3 82 break;
andrewboyson 0:be515c9019e3 83 }
andrewboyson 0:be515c9019e3 84 }
andrewboyson 0:be515c9019e3 85
andrewboyson 0:be515c9019e3 86 return bits8;
andrewboyson 0:be515c9019e3 87 }
andrewboyson 0:be515c9019e3 88 int Base64SkipLine()
andrewboyson 0:be515c9019e3 89 {
andrewboyson 0:be515c9019e3 90 last6 = 0;
andrewboyson 0:be515c9019e3 91 posn = 0;
andrewboyson 0:be515c9019e3 92 finished = false;
andrewboyson 0:be515c9019e3 93
andrewboyson 0:be515c9019e3 94 while (true)
andrewboyson 0:be515c9019e3 95 {
andrewboyson 0:be515c9019e3 96 char c = Base64ReadNextCharFunctionPointer();
andrewboyson 0:be515c9019e3 97 if (c == 0 ) return -1; //EOF or an error
andrewboyson 0:be515c9019e3 98 else if (c == '\n') return 0; //EOL
andrewboyson 0:be515c9019e3 99 }
andrewboyson 0:be515c9019e3 100 }