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review.jami.net / jami-client-android / e24852d9433d165d04897751549b4a00170e37e9 / . / jni / libzrtp / sources / src / Base32.cpp
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/**
*
* Copyright (c) 2002 Bryce "Zooko" Wilcox-O'Hearn Permission is hereby
* granted, free of charge, to any person obtaining a copy of this software to
* deal in this software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of this software, and to permit persons to whom this software
* is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of this software.
*
* THIS SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THIS SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THIS SOFTWARE.
*
* Converted to C++ by:
* @author Werner Dittmann <Werner.Dittmann@t-online.de>
*/
#ifndef UNIT_TEST
#include <libzrtpcpp/Base32.h>
#else
#include "libzrtpcpp/Base32.h"
#endif
int divceil(int a, int b) {
int c;
if (a>0) {
if (b>0) c=a+b-1;
else c=a;
} else {
if (b>0) c=a;
else c=a+b+1;
}
return c/b;
}
// 1 2 3
// 01234567890123456789012345678901
static const char* const chars= "ybndrfg8ejkmcpqxot1uwisza345h769";
/*
* revchars: index into this table with the ASCII value of the char.
* The result is the value of that quintet.
*/
static const unsigned char revchars[]= {
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 18, 255, 25, 26, 27, 30, 29,
7, 31, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 24, 1, 12, 3, 8, 5, 6,
28, 21, 9, 10, 255, 11, 2, 16,
13, 14, 4, 22, 17, 19, 255, 20,
15, 0, 23, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255
};
Base32::Base32(const string encoded):
binaryResult(NULL), resultLength(0) {
a2b_l(encoded, encoded.size(), (encoded.size()*5/8)*8);
}
Base32::Base32(const string encoded, int noOfBits):
binaryResult(NULL), resultLength(0) {
a2b_l(encoded, divceil(noOfBits, 5), noOfBits);
}
Base32::Base32(const unsigned char* data, int noOfBits):
binaryResult(NULL), resultLength(0) {
b2a_l(data, (noOfBits+7)/8, noOfBits);
}
Base32::~Base32() {
if (binaryResult != NULL && binaryResult != smallBuffer) {
delete [] binaryResult;
}
binaryResult = NULL;
}
const unsigned char* Base32::getDecoded(int &length) {
length = resultLength;
return binaryResult;
}
void Base32::b2a_l(const unsigned char* os, int len,
const size_t lengthinbits) {
/* if lengthinbits is not a multiple of 8 then this is allocating
* space for 0, 1, or 2 extra quintets that will be truncated at the
* end of this function if they are not needed
*/
string result(divceil(len*8, 5), ' ');
/* index into the result buffer, initially pointing to the
* "one-past-the-end" quintet
*/
int resp = result.size();
/* pointer into the os buffer, initially pointing to the
* "one-past-the-end" octet
*/
const unsigned char* osp = os + len;
/* Now this is a real live Duff's device. You gotta love it. */
unsigned long x = 0; // to hold up to 32 bits worth of the input
switch ((osp - os) % 5) {
case 0:
do {
x = *--osp;
result[--resp] = chars[x % 32]; /* The least sig 5 bits go into the final quintet. */
x /= 32; /* ... now we have 3 bits worth in x... */
case 4:
x |= ((unsigned long)(*--osp)) << 3; /* ... now we have 11 bits worth in x... */
result[--resp] = chars[x % 32];
x /= 32; /* ... now we have 6 bits worth in x... */
result[--resp] = chars[x % 32];
x /= 32; /* ... now we have 1 bits worth in x... */
case 3:
x |= ((unsigned long)(*--osp)) << 1; /* The 8 bits from the 2-indexed octet.
So now we have 9 bits worth in x... */
result[--resp] = chars[x % 32];
x /= 32; /* ... now we have 4 bits worth in x... */
case 2:
x |= ((unsigned long)(*--osp)) << 4; /* The 8 bits from the 1-indexed octet.
So now we have 12 bits worth in x... */
result[--resp] = chars[x%32];
x /= 32; /* ... now we have 7 bits worth in x... */
result[--resp] = chars[x%32];
x /= 32; /* ... now we have 2 bits worth in x... */
case 1:
x |= ((unsigned long)(*--osp)) << 2; /* The 8 bits from the 0-indexed octet.
So now we have 10 bits worth in x... */
result[--resp] = chars[x%32];
x /= 32; /* ... now we have 5 bits worth in x... */
result[--resp] = chars[x];
} while (osp > os);
} /* switch ((osp - os.buf) % 5) */
/* truncate any unused trailing zero quintets */
encoded = result.substr(0, divceil(lengthinbits, 5));
return;
}
void Base32::a2b_l(const string cs, size_t size, const size_t lengthinbits ) {
unsigned long x = 0; // to hold up to 32 bits worth of the input
int len = divceil(size*5, 8);
/* if lengthinbits is not a multiple of 5 then this is
* allocating space for 0 or 1 extra octets that will be
* truncated at the end of this function if they are
* not needed
*/
if (len < 128) {
binaryResult = smallBuffer;
}
else {
binaryResult = new unsigned char[len];
}
/* pointer into the result buffer, initially pointing to
* the "one-past-the-end" octet
*/
unsigned char* resp = binaryResult + len;
/* index into the input buffer, initially pointing to the
* "one-past-the-end" character
*/
int csp = size;
/* Now this is a real live Duff's device. You gotta love it. */
switch (csp % 8) {
case 0:
do {
x = revchars[cs[--csp]&0xff]; /* 5 bits... */
case 7:
x |= revchars[cs[--csp]&0xff] << 5; /* 10 bits... */
*--resp = x % 256;
x /= 256; /* 2 bits... */
case 6:
x |= revchars[cs[--csp]&0xff] << 2; /* 7 bits... */
case 5:
x |= revchars[cs[--csp]&0xff] << 7; /* 12 bits... */
*--resp = x % 256;
x /= 256; /* 4 bits... */
case 4:
x |= revchars[cs[--csp]&0xff] << 4; /* 9 bits... */
*--resp = x % 256;
x /= 256; /* 1 bit... */
case 3:
x |= revchars[cs[--csp]&0xff] << 1; /* 6 bits... */
case 2:
x |= revchars[cs[--csp]&0xff] << 6; /* 11 bits... */
*--resp = x % 256;
x /= 256; /* 3 bits... */
case 1:
x |= revchars[cs[--csp]&0xff] << 3; /* 8 bits... */
*--resp = x % 256;
} while (csp);
} /* switch ((csp - cs.buf) % 8) */
/* truncate any unused trailing zero octets */
resultLength = divceil(lengthinbits, 8);
return;
}
#ifdef UNIT_TEST
#include <math.h>
static uint8_t *randz(const size_t len)
{
uint8_t* result = (uint8_t*)malloc(len);
size_t i;
for (i=0; i<len; i++) {
result[i] = rand() % 256;
}
return result;
}
int main(int argc, char *argv[]) {
int32_t resLen;
string a;
const uint8_t* zrecovered;
uint8_t ones[] = {1, 1, 1, 1, 1};
uint8_t zrtpVec01[] = {0x00, 0x00, 0x00, 0x00};
uint8_t zrtpVec02[] = {0x80, 0x00, 0x00, 0x00};
uint8_t zrtpVec03[] = {0x40, 0x00, 0x00, 0x00};
uint8_t zrtpVec04[] = {0xc0, 0x00, 0x00, 0x00};
uint8_t zrtpVec05[] = {0x00, 0x00, 0x00, 0x00};
uint8_t zrtpVec06[] = {0x80, 0x80, 0x00, 0x00};
uint8_t zrtpVec07[] = {0x8b, 0x88, 0x80, 0x00};
uint8_t zrtpVec08[] = {0xf0, 0xbf, 0xc7, 0x00};
uint8_t zrtpVec09[] = {0xd4, 0x7a, 0x04, 0x00};
uint8_t zrtpVec10[] = {0xf5, 0x57, 0xbb, 0x0c};
// Encode all bits of the 5 one bytes (= 40 bits)
a = Base32(ones, 5*8).getEncoded();
// The string should be: "yryonyeb"
cout << "Encoded 5 ones: '" << a << "', Expected: 'yryonyeb'" << endl;
// Now decode all bits and check
Base32 *y = new Base32(a);
zrecovered = y->getDecoded(resLen);
if (resLen != 5 && memcmp(ones, zrecovered, 5)) {
printf("Failed basic 5 ones recovery test.\n");
return -1;
}
delete y;
a = Base32(ones, 15).getEncoded();
cout << "Encoded 5 ones, 15 bits only: '" << a << "', Expected: 'yry'" << endl;
// now decode 15 bits (out of 40 possible)
y = new Base32(a, 15);
zrecovered = y->getDecoded(resLen);
printf("Decoded 15 bits, result length: %d (should be 2)\n", resLen);
printf("Decoded bytes: %x %x (should be 1 0)\n", zrecovered[0], zrecovered[1]);
delete y;
// Encode 20 bits of the test vectors
a = Base32(zrtpVec01, 20).getEncoded();
cout << "Encoded ZRTP vector 01: '" << a << "', Expected: 'yyyy'" << endl;
a = Base32(zrtpVec02, 20).getEncoded();
cout << "Encoded ZRTP vector 02: '" << a << "', Expected: 'oyyy'" << endl;
a = Base32(zrtpVec03, 20).getEncoded();
cout << "Encoded ZRTP vector 02: '" << a << "', Expected: 'eyyy'" << endl;
a = Base32(zrtpVec04, 20).getEncoded();
cout << "Encoded ZRTP vector 04: '" << a << "', Expected: 'ayyy'" << endl;
a = Base32(zrtpVec05, 20).getEncoded();
cout << "Encoded ZRTP vector 05: '" << a << "', Expected: 'yyyy'" << endl;
a = Base32(zrtpVec06, 20).getEncoded();
cout << "Encoded ZRTP vector 06: '" << a << "', Expected: 'onyy'" << endl;
a = Base32(zrtpVec07, 20).getEncoded();
cout << "Encoded ZRTP vector 07: '" << a << "', Expected: 'tqre'" << endl;
a = Base32(zrtpVec08, 20).getEncoded();
cout << "Encoded ZRTP vector 08: '" << a << "', Expected: '6n9h'" << endl;
a = Base32(zrtpVec09, 20).getEncoded();
cout << "Encoded ZRTP vector 09: '" << a << "', Expected: '4t7y'" << endl;
a = Base32(zrtpVec10, 20).getEncoded();
cout << "Encoded ZRTP vector 10: '" << a << "', Expected: '6im5'" << endl;
// test the 30 bit output of same data as 20 bit
a = Base32(zrtpVec10, 30).getEncoded();
cout << "Encoded ZRTP vector 10 (30bit): '" << a << "', Expected: '6im5sd'" << endl;
for (int i = 0; i < 2; i++) {
uint8_t* z = randz(16);
a = Base32(z, 16*8).getEncoded();
// cout << "Result: " << a << endl;
assert (a.size() == Base32::b2alen(16*8));
zrecovered = Base32(a).getDecoded(resLen);
if (resLen != 16 && memcmp(z, zrecovered, 16)) {
printf("Failed basic recovery test.\n");
return -1;
}
free((void*)z);
}
}
#endif