mirror of
https://github.com/ZLMediaKit/ZLMediaKit.git
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882 lines
33 KiB
C++
882 lines
33 KiB
C++
/**
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ISC License
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Copyright © 2015, Iñaki Baz Castillo <ibc@aliax.net>
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Permission to use, copy, modify, and/or distribute this software for any
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purpose with or without fee is hereby granted, provided that the above
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copyright notice and this permission notice appear in all copies.
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THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*/
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#define MS_CLASS "RTC::StunPacket"
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// #define MS_LOG_DEV_LEVEL 3
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#include "StunPacket.hpp"
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#include <cstdio> // std::snprintf()
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#include <cstring> // std::memcmp(), std::memcpy()
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#include <openssl/hmac.h>
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namespace RTC
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{
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static const uint32_t crc32Table[] =
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{
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0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3,
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0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91,
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0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
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0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5,
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0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
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0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
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0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f,
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0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d,
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0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
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0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
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0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457,
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0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
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0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb,
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0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9,
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0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
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0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad,
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0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683,
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0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
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0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7,
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0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
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0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
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0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79,
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0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f,
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0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
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0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713,
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0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21,
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0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
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0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45,
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0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db,
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0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
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0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693, 0x54de5729, 0x23d967bf,
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0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d
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};
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inline uint32_t GetCRC32(const uint8_t *data, size_t size) {
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uint32_t crc{0xFFFFFFFF};
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const uint8_t *p = data;
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while (size--) {
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crc = crc32Table[(crc ^ *p++) & 0xFF] ^ (crc >> 8);
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}
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return crc ^ ~0U;
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}
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static std::string openssl_HMACsha1(const void *key, size_t key_len, const void *data, size_t data_len){
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std::string str;
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str.resize(20);
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unsigned int out_len;
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#if defined(OPENSSL_VERSION_NUMBER) && (OPENSSL_VERSION_NUMBER > 0x10100000L)
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//openssl 1.1.0新增api，老版本api作废
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HMAC_CTX *ctx = HMAC_CTX_new();
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HMAC_CTX_reset(ctx);
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HMAC_Init_ex(ctx, key, (int)key_len, EVP_sha1(), NULL);
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HMAC_Update(ctx, (unsigned char*)data, data_len);
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HMAC_Final(ctx, (unsigned char *)str.data(), &out_len);
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HMAC_CTX_reset(ctx);
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HMAC_CTX_free(ctx);
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#else
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HMAC_CTX ctx;
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HMAC_CTX_init(&ctx);
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HMAC_Init_ex(&ctx, key, key_len, EVP_sha1(), NULL);
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HMAC_Update(&ctx, (unsigned char*)data, data_len);
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HMAC_Final(&ctx, (unsigned char *)str.data(), &out_len);
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HMAC_CTX_cleanup(&ctx);
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#endif //defined(OPENSSL_VERSION_NUMBER) && (OPENSSL_VERSION_NUMBER > 0x10100000L)
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return str;
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}
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/* Class variables. */
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const uint8_t StunPacket::magicCookie[] = { 0x21, 0x12, 0xA4, 0x42 };
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/* Class methods. */
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StunPacket* StunPacket::Parse(const uint8_t* data, size_t len)
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{
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MS_TRACE();
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if (!StunPacket::IsStun(data, len))
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return nullptr;
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/*
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The message type field is decomposed further into the following
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structure:
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0 1
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2 3 4 5 6 7 8 9 0 1 2 3 4 5
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+--+--+-+-+-+-+-+-+-+-+-+-+-+-+
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|M |M |M|M|M|C|M|M|M|C|M|M|M|M|
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|11|10|9|8|7|1|6|5|4|0|3|2|1|0|
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+--+--+-+-+-+-+-+-+-+-+-+-+-+-+
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Figure 3: Format of STUN Message Type Field
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Here the bits in the message type field are shown as most significant
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(M11) through least significant (M0). M11 through M0 represent a 12-
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bit encoding of the method. C1 and C0 represent a 2-bit encoding of
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the class.
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*/
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// Get type field.
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uint16_t msgType = Utils::Byte::Get2Bytes(data, 0);
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// Get length field.
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uint16_t msgLength = Utils::Byte::Get2Bytes(data, 2);
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// length field must be total size minus header's 20 bytes, and must be multiple of 4 Bytes.
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if ((static_cast<size_t>(msgLength) != len - 20) || ((msgLength & 0x03) != 0))
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{
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MS_WARN_TAG(
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ice,
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"length field + 20 does not match total size (or it is not multiple of 4 bytes), "
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"packet discarded");
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return nullptr;
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}
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// Get STUN method.
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uint16_t msgMethod = (msgType & 0x000f) | ((msgType & 0x00e0) >> 1) | ((msgType & 0x3E00) >> 2);
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// Get STUN class.
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uint16_t msgClass = ((data[0] & 0x01) << 1) | ((data[1] & 0x10) >> 4);
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// Create a new StunPacket (data + 8 points to the received TransactionID field).
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auto* packet = new StunPacket(
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static_cast<Class>(msgClass), static_cast<Method>(msgMethod), data + 8, data, len);
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/*
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STUN Attributes
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After the STUN header are zero or more attributes. Each attribute
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MUST be TLV encoded, with a 16-bit type, 16-bit length, and value.
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Each STUN attribute MUST end on a 32-bit boundary. As mentioned
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above, all fields in an attribute are transmitted most significant
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bit first.
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0 1 2 3
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0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Type | Length |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Value (variable) ....
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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*/
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// Start looking for attributes after STUN header (Byte #20).
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size_t pos{ 20 };
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// Flags (positions) for special MESSAGE-INTEGRITY and FINGERPRINT attributes.
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bool hasMessageIntegrity{ false };
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bool hasFingerprint{ false };
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size_t fingerprintAttrPos; // Will point to the beginning of the attribute.
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uint32_t fingerprint; // Holds the value of the FINGERPRINT attribute.
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// Ensure there are at least 4 remaining bytes (attribute with 0 length).
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while (pos + 4 <= len)
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{
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// Get the attribute type.
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auto attrType = static_cast<Attribute>(Utils::Byte::Get2Bytes(data, pos));
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// Get the attribute length.
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uint16_t attrLength = Utils::Byte::Get2Bytes(data, pos + 2);
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// Ensure the attribute length is not greater than the remaining size.
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if ((pos + 4 + attrLength) > len)
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{
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MS_WARN_TAG(ice, "the attribute length exceeds the remaining size, packet discarded");
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delete packet;
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return nullptr;
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}
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// FINGERPRINT must be the last attribute.
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if (hasFingerprint)
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{
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MS_WARN_TAG(ice, "attribute after FINGERPRINT is not allowed, packet discarded");
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delete packet;
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return nullptr;
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}
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// After a MESSAGE-INTEGRITY attribute just FINGERPRINT is allowed.
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if (hasMessageIntegrity && attrType != Attribute::FINGERPRINT)
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{
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MS_WARN_TAG(
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ice,
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"attribute after MESSAGE-INTEGRITY other than FINGERPRINT is not allowed, "
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"packet discarded");
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delete packet;
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return nullptr;
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}
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const uint8_t* attrValuePos = data + pos + 4;
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switch (attrType)
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{
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case Attribute::USERNAME:
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{
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packet->SetUsername(
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reinterpret_cast<const char*>(attrValuePos), static_cast<size_t>(attrLength));
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break;
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}
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case Attribute::PRIORITY:
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{
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// Ensure attribute length is 4 bytes.
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if (attrLength != 4)
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{
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MS_WARN_TAG(ice, "attribute PRIORITY must be 4 bytes length, packet discarded");
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delete packet;
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return nullptr;
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}
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packet->SetPriority(Utils::Byte::Get4Bytes(attrValuePos, 0));
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break;
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}
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case Attribute::ICE_CONTROLLING:
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{
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// Ensure attribute length is 8 bytes.
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if (attrLength != 8)
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{
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MS_WARN_TAG(ice, "attribute ICE-CONTROLLING must be 8 bytes length, packet discarded");
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delete packet;
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return nullptr;
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}
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packet->SetIceControlling(Utils::Byte::Get8Bytes(attrValuePos, 0));
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break;
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}
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case Attribute::ICE_CONTROLLED:
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{
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// Ensure attribute length is 8 bytes.
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if (attrLength != 8)
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{
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MS_WARN_TAG(ice, "attribute ICE-CONTROLLED must be 8 bytes length, packet discarded");
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delete packet;
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return nullptr;
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}
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packet->SetIceControlled(Utils::Byte::Get8Bytes(attrValuePos, 0));
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break;
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}
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case Attribute::USE_CANDIDATE:
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{
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// Ensure attribute length is 0 bytes.
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if (attrLength != 0)
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{
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MS_WARN_TAG(ice, "attribute USE-CANDIDATE must be 0 bytes length, packet discarded");
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delete packet;
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return nullptr;
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}
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packet->SetUseCandidate();
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break;
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}
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case Attribute::MESSAGE_INTEGRITY:
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{
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// Ensure attribute length is 20 bytes.
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if (attrLength != 20)
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{
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MS_WARN_TAG(ice, "attribute MESSAGE-INTEGRITY must be 20 bytes length, packet discarded");
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delete packet;
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return nullptr;
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}
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hasMessageIntegrity = true;
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packet->SetMessageIntegrity(attrValuePos);
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break;
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}
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case Attribute::FINGERPRINT:
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{
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// Ensure attribute length is 4 bytes.
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if (attrLength != 4)
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{
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MS_WARN_TAG(ice, "attribute FINGERPRINT must be 4 bytes length, packet discarded");
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delete packet;
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return nullptr;
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}
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hasFingerprint = true;
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fingerprintAttrPos = pos;
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fingerprint = Utils::Byte::Get4Bytes(attrValuePos, 0);
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packet->SetFingerprint();
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break;
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}
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case Attribute::ERROR_CODE:
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{
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// Ensure attribute length >= 4bytes.
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if (attrLength < 4)
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{
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MS_WARN_TAG(ice, "attribute ERROR-CODE must be >= 4bytes length, packet discarded");
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delete packet;
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return nullptr;
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}
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uint8_t errorClass = Utils::Byte::Get1Byte(attrValuePos, 2);
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uint8_t errorNumber = Utils::Byte::Get1Byte(attrValuePos, 3);
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auto errorCode = static_cast<uint16_t>(errorClass * 100 + errorNumber);
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packet->SetErrorCode(errorCode);
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break;
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}
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default:;
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}
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// Set next attribute position.
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pos =
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static_cast<size_t>(Utils::Byte::PadTo4Bytes(static_cast<uint16_t>(pos + 4 + attrLength)));
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}
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// Ensure current position matches the total length.
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if (pos != len)
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{
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MS_WARN_TAG(ice, "computed packet size does not match total size, packet discarded");
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delete packet;
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return nullptr;
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}
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// If it has FINGERPRINT attribute then verify it.
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if (hasFingerprint)
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{
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// Compute the CRC32 of the received packet up to (but excluding) the
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// FINGERPRINT attribute and XOR it with 0x5354554e.
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uint32_t computedFingerprint = GetCRC32(data, fingerprintAttrPos) ^ 0x5354554e;
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// Compare with the FINGERPRINT value in the packet.
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if (fingerprint != computedFingerprint)
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{
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MS_WARN_TAG(
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ice,
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"computed FINGERPRINT value does not match the value in the packet, "
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"packet discarded");
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delete packet;
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return nullptr;
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}
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}
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return packet;
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}
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/* Instance methods. */
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StunPacket::StunPacket(
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Class klass, Method method, const uint8_t* transactionId, const uint8_t* data, size_t size)
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: klass(klass), method(method), transactionId(transactionId), data(const_cast<uint8_t*>(data)),
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size(size)
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{
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MS_TRACE();
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}
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StunPacket::~StunPacket()
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{
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MS_TRACE();
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}
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#if 0
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void StunPacket::Dump() const
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{
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MS_TRACE();
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MS_DUMP("<StunPacket>");
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std::string klass;
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switch (this->klass)
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{
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case Class::REQUEST:
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klass = "Request";
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break;
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case Class::INDICATION:
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klass = "Indication";
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break;
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case Class::SUCCESS_RESPONSE:
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klass = "SuccessResponse";
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break;
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||
case Class::ERROR_RESPONSE:
|
||
klass = "ErrorResponse";
|
||
break;
|
||
}
|
||
if (this->method == Method::BINDING)
|
||
{
|
||
MS_DUMP(" Binding %s", klass.c_str());
|
||
}
|
||
else
|
||
{
|
||
// This prints the unknown method number. Example: TURN Allocate => 0x003.
|
||
MS_DUMP(" %s with unknown method %#.3x", klass.c_str(), static_cast<uint16_t>(this->method));
|
||
}
|
||
MS_DUMP(" size: %zu bytes", this->size);
|
||
|
||
static char transactionId[25];
|
||
|
||
for (int i{ 0 }; i < 12; ++i)
|
||
{
|
||
// NOTE: n must be 3 because snprintf adds a \0 after printed chars.
|
||
std::snprintf(transactionId + (i * 2), 3, "%.2x", this->transactionId[i]);
|
||
}
|
||
MS_DUMP(" transactionId: %s", transactionId);
|
||
if (this->errorCode != 0u)
|
||
MS_DUMP(" errorCode: %" PRIu16, this->errorCode);
|
||
if (!this->username.empty())
|
||
MS_DUMP(" username: %s", this->username.c_str());
|
||
if (this->priority != 0u)
|
||
MS_DUMP(" priority: %" PRIu32, this->priority);
|
||
if (this->iceControlling != 0u)
|
||
MS_DUMP(" iceControlling: %" PRIu64, this->iceControlling);
|
||
if (this->iceControlled != 0u)
|
||
MS_DUMP(" iceControlled: %" PRIu64, this->iceControlled);
|
||
if (this->hasUseCandidate)
|
||
MS_DUMP(" useCandidate");
|
||
if (this->xorMappedAddress != nullptr)
|
||
{
|
||
int family;
|
||
uint16_t port;
|
||
std::string ip;
|
||
|
||
Utils::IP::GetAddressInfo(this->xorMappedAddress, family, ip, port);
|
||
|
||
MS_DUMP(" xorMappedAddress: %s : %" PRIu16, ip.c_str(), port);
|
||
}
|
||
if (this->messageIntegrity != nullptr)
|
||
{
|
||
static char messageIntegrity[41];
|
||
|
||
for (int i{ 0 }; i < 20; ++i)
|
||
{
|
||
std::snprintf(messageIntegrity + (i * 2), 3, "%.2x", this->messageIntegrity[i]);
|
||
}
|
||
|
||
MS_DUMP(" messageIntegrity: %s", messageIntegrity);
|
||
}
|
||
if (this->hasFingerprint)
|
||
MS_DUMP(" has fingerprint");
|
||
|
||
MS_DUMP("</StunPacket>");
|
||
}
|
||
#endif
|
||
|
||
StunPacket::Authentication StunPacket::CheckAuthentication(
|
||
const std::string& localUsername, const std::string& localPassword)
|
||
{
|
||
MS_TRACE();
|
||
|
||
switch (this->klass)
|
||
{
|
||
case Class::REQUEST:
|
||
case Class::INDICATION:
|
||
{
|
||
// Both USERNAME and MESSAGE-INTEGRITY must be present.
|
||
if (!this->messageIntegrity || this->username.empty())
|
||
return Authentication::BAD_REQUEST;
|
||
|
||
// Check that USERNAME attribute begins with our local username plus ":".
|
||
size_t localUsernameLen = localUsername.length();
|
||
|
||
if (
|
||
this->username.length() <= localUsernameLen || this->username.at(localUsernameLen) != ':' ||
|
||
(this->username.compare(0, localUsernameLen, localUsername) != 0))
|
||
{
|
||
return Authentication::UNAUTHORIZED;
|
||
}
|
||
|
||
break;
|
||
}
|
||
// This method cannot check authentication in received responses (as we
|
||
// are ICE-Lite and don't generate requests).
|
||
case Class::SUCCESS_RESPONSE:
|
||
case Class::ERROR_RESPONSE:
|
||
{
|
||
MS_ERROR("cannot check authentication for a STUN response");
|
||
|
||
return Authentication::BAD_REQUEST;
|
||
}
|
||
}
|
||
|
||
// If there is FINGERPRINT it must be discarded for MESSAGE-INTEGRITY calculation,
|
||
// so the header length field must be modified (and later restored).
|
||
if (this->hasFingerprint)
|
||
// Set the header length field: full size - header length (20) - FINGERPRINT length (8).
|
||
Utils::Byte::Set2Bytes(this->data, 2, static_cast<uint16_t>(this->size - 20 - 8));
|
||
|
||
// Calculate the HMAC-SHA1 of the message according to MESSAGE-INTEGRITY rules.
|
||
auto computedMessageIntegrity = openssl_HMACsha1(
|
||
localPassword.data(),localPassword.size(), this->data, (this->messageIntegrity - 4) - this->data);
|
||
|
||
Authentication result;
|
||
|
||
// Compare the computed HMAC-SHA1 with the MESSAGE-INTEGRITY in the packet.
|
||
if (std::memcmp(this->messageIntegrity, computedMessageIntegrity.data(), computedMessageIntegrity.size()) == 0)
|
||
result = Authentication::OK;
|
||
else
|
||
result = Authentication::UNAUTHORIZED;
|
||
|
||
// Restore the header length field.
|
||
if (this->hasFingerprint)
|
||
Utils::Byte::Set2Bytes(this->data, 2, static_cast<uint16_t>(this->size - 20));
|
||
|
||
return result;
|
||
}
|
||
|
||
StunPacket* StunPacket::CreateSuccessResponse()
|
||
{
|
||
MS_TRACE();
|
||
|
||
MS_ASSERT(
|
||
this->klass == Class::REQUEST,
|
||
"attempt to create a success response for a non Request STUN packet");
|
||
|
||
return new StunPacket(Class::SUCCESS_RESPONSE, this->method, this->transactionId, nullptr, 0);
|
||
}
|
||
|
||
StunPacket* StunPacket::CreateErrorResponse(uint16_t errorCode)
|
||
{
|
||
MS_TRACE();
|
||
|
||
MS_ASSERT(
|
||
this->klass == Class::REQUEST,
|
||
"attempt to create an error response for a non Request STUN packet");
|
||
|
||
auto* response =
|
||
new StunPacket(Class::ERROR_RESPONSE, this->method, this->transactionId, nullptr, 0);
|
||
|
||
response->SetErrorCode(errorCode);
|
||
|
||
return response;
|
||
}
|
||
|
||
void StunPacket::Authenticate(const std::string& password)
|
||
{
|
||
// Just for Request, Indication and SuccessResponse messages.
|
||
if (this->klass == Class::ERROR_RESPONSE)
|
||
{
|
||
MS_ERROR("cannot set password for ErrorResponse messages");
|
||
|
||
return;
|
||
}
|
||
|
||
this->password = password;
|
||
}
|
||
|
||
void StunPacket::Serialize(uint8_t* buffer)
|
||
{
|
||
MS_TRACE();
|
||
|
||
// Some useful variables.
|
||
uint16_t usernamePaddedLen{ 0 };
|
||
uint16_t xorMappedAddressPaddedLen{ 0 };
|
||
bool addXorMappedAddress =
|
||
((this->xorMappedAddress != nullptr) && this->method == StunPacket::Method::BINDING &&
|
||
this->klass == Class::SUCCESS_RESPONSE);
|
||
bool addErrorCode = ((this->errorCode != 0u) && this->klass == Class::ERROR_RESPONSE);
|
||
bool addMessageIntegrity = (this->klass != Class::ERROR_RESPONSE && !this->password.empty());
|
||
bool addFingerprint{ true }; // Do always.
|
||
|
||
// Update data pointer.
|
||
this->data = buffer;
|
||
|
||
// First calculate the total required size for the entire packet.
|
||
this->size = 20; // Header.
|
||
|
||
if (!this->username.empty())
|
||
{
|
||
usernamePaddedLen = Utils::Byte::PadTo4Bytes(static_cast<uint16_t>(this->username.length()));
|
||
this->size += 4 + usernamePaddedLen;
|
||
}
|
||
|
||
if (this->priority != 0u)
|
||
this->size += 4 + 4;
|
||
|
||
if (this->iceControlling != 0u)
|
||
this->size += 4 + 8;
|
||
|
||
if (this->iceControlled != 0u)
|
||
this->size += 4 + 8;
|
||
|
||
if (this->hasUseCandidate)
|
||
this->size += 4;
|
||
|
||
if (addXorMappedAddress)
|
||
{
|
||
switch (this->xorMappedAddress->sa_family)
|
||
{
|
||
case AF_INET:
|
||
{
|
||
xorMappedAddressPaddedLen = 8;
|
||
this->size += 4 + 8;
|
||
|
||
break;
|
||
}
|
||
|
||
case AF_INET6:
|
||
{
|
||
xorMappedAddressPaddedLen = 20;
|
||
this->size += 4 + 20;
|
||
|
||
break;
|
||
}
|
||
|
||
default:
|
||
{
|
||
MS_ERROR("invalid inet family in XOR-MAPPED-ADDRESS attribute");
|
||
|
||
addXorMappedAddress = false;
|
||
}
|
||
}
|
||
}
|
||
|
||
if (addErrorCode)
|
||
this->size += 4 + 4;
|
||
|
||
if (addMessageIntegrity)
|
||
this->size += 4 + 20;
|
||
|
||
if (addFingerprint)
|
||
this->size += 4 + 4;
|
||
|
||
// Merge class and method fields into type.
|
||
uint16_t typeField = (static_cast<uint16_t>(this->method) & 0x0f80) << 2;
|
||
|
||
typeField |= (static_cast<uint16_t>(this->method) & 0x0070) << 1;
|
||
typeField |= (static_cast<uint16_t>(this->method) & 0x000f);
|
||
typeField |= (static_cast<uint16_t>(this->klass) & 0x02) << 7;
|
||
typeField |= (static_cast<uint16_t>(this->klass) & 0x01) << 4;
|
||
|
||
// Set type field.
|
||
Utils::Byte::Set2Bytes(buffer, 0, typeField);
|
||
// Set length field.
|
||
Utils::Byte::Set2Bytes(buffer, 2, static_cast<uint16_t>(this->size) - 20);
|
||
// Set magic cookie.
|
||
std::memcpy(buffer + 4, StunPacket::magicCookie, 4);
|
||
// Set TransactionId field.
|
||
std::memcpy(buffer + 8, this->transactionId, 12);
|
||
// Update the transaction ID pointer.
|
||
this->transactionId = buffer + 8;
|
||
// Add atributes.
|
||
size_t pos{ 20 };
|
||
|
||
// Add USERNAME.
|
||
if (usernamePaddedLen != 0u)
|
||
{
|
||
Utils::Byte::Set2Bytes(buffer, pos, static_cast<uint16_t>(Attribute::USERNAME));
|
||
Utils::Byte::Set2Bytes(buffer, pos + 2, static_cast<uint16_t>(this->username.length()));
|
||
std::memcpy(buffer + pos + 4, this->username.c_str(), this->username.length());
|
||
pos += 4 + usernamePaddedLen;
|
||
}
|
||
|
||
// Add PRIORITY.
|
||
if (this->priority != 0u)
|
||
{
|
||
Utils::Byte::Set2Bytes(buffer, pos, static_cast<uint16_t>(Attribute::PRIORITY));
|
||
Utils::Byte::Set2Bytes(buffer, pos + 2, 4);
|
||
Utils::Byte::Set4Bytes(buffer, pos + 4, this->priority);
|
||
pos += 4 + 4;
|
||
}
|
||
|
||
// Add ICE-CONTROLLING.
|
||
if (this->iceControlling != 0u)
|
||
{
|
||
Utils::Byte::Set2Bytes(buffer, pos, static_cast<uint16_t>(Attribute::ICE_CONTROLLING));
|
||
Utils::Byte::Set2Bytes(buffer, pos + 2, 8);
|
||
Utils::Byte::Set8Bytes(buffer, pos + 4, this->iceControlling);
|
||
pos += 4 + 8;
|
||
}
|
||
|
||
// Add ICE-CONTROLLED.
|
||
if (this->iceControlled != 0u)
|
||
{
|
||
Utils::Byte::Set2Bytes(buffer, pos, static_cast<uint16_t>(Attribute::ICE_CONTROLLED));
|
||
Utils::Byte::Set2Bytes(buffer, pos + 2, 8);
|
||
Utils::Byte::Set8Bytes(buffer, pos + 4, this->iceControlled);
|
||
pos += 4 + 8;
|
||
}
|
||
|
||
// Add USE-CANDIDATE.
|
||
if (this->hasUseCandidate)
|
||
{
|
||
Utils::Byte::Set2Bytes(buffer, pos, static_cast<uint16_t>(Attribute::USE_CANDIDATE));
|
||
Utils::Byte::Set2Bytes(buffer, pos + 2, 0);
|
||
pos += 4;
|
||
}
|
||
|
||
// Add XOR-MAPPED-ADDRESS
|
||
if (addXorMappedAddress)
|
||
{
|
||
Utils::Byte::Set2Bytes(buffer, pos, static_cast<uint16_t>(Attribute::XOR_MAPPED_ADDRESS));
|
||
Utils::Byte::Set2Bytes(buffer, pos + 2, xorMappedAddressPaddedLen);
|
||
|
||
uint8_t* attrValue = buffer + pos + 4;
|
||
|
||
switch (this->xorMappedAddress->sa_family)
|
||
{
|
||
case AF_INET:
|
||
{
|
||
// Set first byte to 0.
|
||
attrValue[0] = 0;
|
||
// Set inet family.
|
||
attrValue[1] = 0x01;
|
||
// Set port and XOR it.
|
||
std::memcpy(
|
||
attrValue + 2,
|
||
&(reinterpret_cast<const sockaddr_in*>(this->xorMappedAddress))->sin_port,
|
||
2);
|
||
attrValue[2] ^= StunPacket::magicCookie[0];
|
||
attrValue[3] ^= StunPacket::magicCookie[1];
|
||
// Set address and XOR it.
|
||
std::memcpy(
|
||
attrValue + 4,
|
||
&(reinterpret_cast<const sockaddr_in*>(this->xorMappedAddress))->sin_addr.s_addr,
|
||
4);
|
||
attrValue[4] ^= StunPacket::magicCookie[0];
|
||
attrValue[5] ^= StunPacket::magicCookie[1];
|
||
attrValue[6] ^= StunPacket::magicCookie[2];
|
||
attrValue[7] ^= StunPacket::magicCookie[3];
|
||
|
||
pos += 4 + 8;
|
||
|
||
break;
|
||
}
|
||
|
||
case AF_INET6:
|
||
{
|
||
// Set first byte to 0.
|
||
attrValue[0] = 0;
|
||
// Set inet family.
|
||
attrValue[1] = 0x02;
|
||
// Set port and XOR it.
|
||
std::memcpy(
|
||
attrValue + 2,
|
||
&(reinterpret_cast<const sockaddr_in6*>(this->xorMappedAddress))->sin6_port,
|
||
2);
|
||
attrValue[2] ^= StunPacket::magicCookie[0];
|
||
attrValue[3] ^= StunPacket::magicCookie[1];
|
||
// Set address and XOR it.
|
||
std::memcpy(
|
||
attrValue + 4,
|
||
&(reinterpret_cast<const sockaddr_in6*>(this->xorMappedAddress))->sin6_addr.s6_addr,
|
||
16);
|
||
attrValue[4] ^= StunPacket::magicCookie[0];
|
||
attrValue[5] ^= StunPacket::magicCookie[1];
|
||
attrValue[6] ^= StunPacket::magicCookie[2];
|
||
attrValue[7] ^= StunPacket::magicCookie[3];
|
||
attrValue[8] ^= this->transactionId[0];
|
||
attrValue[9] ^= this->transactionId[1];
|
||
attrValue[10] ^= this->transactionId[2];
|
||
attrValue[11] ^= this->transactionId[3];
|
||
attrValue[12] ^= this->transactionId[4];
|
||
attrValue[13] ^= this->transactionId[5];
|
||
attrValue[14] ^= this->transactionId[6];
|
||
attrValue[15] ^= this->transactionId[7];
|
||
attrValue[16] ^= this->transactionId[8];
|
||
attrValue[17] ^= this->transactionId[9];
|
||
attrValue[18] ^= this->transactionId[10];
|
||
attrValue[19] ^= this->transactionId[11];
|
||
|
||
pos += 4 + 20;
|
||
|
||
break;
|
||
}
|
||
}
|
||
}
|
||
|
||
// Add ERROR-CODE.
|
||
if (addErrorCode)
|
||
{
|
||
Utils::Byte::Set2Bytes(buffer, pos, static_cast<uint16_t>(Attribute::ERROR_CODE));
|
||
Utils::Byte::Set2Bytes(buffer, pos + 2, 4);
|
||
|
||
auto codeClass = static_cast<uint8_t>(this->errorCode / 100);
|
||
uint8_t codeNumber = static_cast<uint8_t>(this->errorCode) - (codeClass * 100);
|
||
|
||
Utils::Byte::Set2Bytes(buffer, pos + 4, 0);
|
||
Utils::Byte::Set1Byte(buffer, pos + 6, codeClass);
|
||
Utils::Byte::Set1Byte(buffer, pos + 7, codeNumber);
|
||
pos += 4 + 4;
|
||
}
|
||
|
||
// Add MESSAGE-INTEGRITY.
|
||
if (addMessageIntegrity)
|
||
{
|
||
// Ignore FINGERPRINT.
|
||
if (addFingerprint)
|
||
Utils::Byte::Set2Bytes(buffer, 2, static_cast<uint16_t>(this->size - 20 - 8));
|
||
|
||
// Calculate the HMAC-SHA1 of the packet according to MESSAGE-INTEGRITY rules.
|
||
auto computedMessageIntegrity = openssl_HMACsha1(this->password.data(), this->password.size(), buffer, pos);
|
||
|
||
Utils::Byte::Set2Bytes(buffer, pos, static_cast<uint16_t>(Attribute::MESSAGE_INTEGRITY));
|
||
Utils::Byte::Set2Bytes(buffer, pos + 2, 20);
|
||
std::memcpy(buffer + pos + 4, computedMessageIntegrity.data(), computedMessageIntegrity.size());
|
||
|
||
// Update the pointer.
|
||
this->messageIntegrity = buffer + pos + 4;
|
||
pos += 4 + 20;
|
||
|
||
// Restore length field.
|
||
if (addFingerprint)
|
||
Utils::Byte::Set2Bytes(buffer, 2, static_cast<uint16_t>(this->size - 20));
|
||
}
|
||
else
|
||
{
|
||
// Unset the pointer (if it was set).
|
||
this->messageIntegrity = nullptr;
|
||
}
|
||
|
||
// Add FINGERPRINT.
|
||
if (addFingerprint)
|
||
{
|
||
// Compute the CRC32 of the packet up to (but excluding) the FINGERPRINT
|
||
// attribute and XOR it with 0x5354554e.
|
||
uint32_t computedFingerprint = GetCRC32(buffer, pos) ^ 0x5354554e;
|
||
|
||
Utils::Byte::Set2Bytes(buffer, pos, static_cast<uint16_t>(Attribute::FINGERPRINT));
|
||
Utils::Byte::Set2Bytes(buffer, pos + 2, 4);
|
||
Utils::Byte::Set4Bytes(buffer, pos + 4, computedFingerprint);
|
||
pos += 4 + 4;
|
||
|
||
// Set flag.
|
||
this->hasFingerprint = true;
|
||
}
|
||
else
|
||
{
|
||
this->hasFingerprint = false;
|
||
}
|
||
|
||
MS_ASSERT(pos == this->size, "pos != this->size");
|
||
}
|
||
} // namespace RTC
|