| /** |
| * |
| * 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 |