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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