| 33 | } |
| 34 | |
| 35 | bool StunMessageParse(const unsigned char *pMessage, size_t MessageSize, const CStunData *pData, bool *pSuccess, NETADDR *pAddr) |
| 36 | { |
| 37 | *pSuccess = false; |
| 38 | mem_zero(pAddr, sizeof(*pAddr)); |
| 39 | if(MessageSize < 20) |
| 40 | { |
| 41 | return true; |
| 42 | } |
| 43 | bool Parsed = true; |
| 44 | // STUN Success/Error Response Type 1: Binding |
| 45 | Parsed = Parsed && pMessage[0] == 0x01 && (pMessage[1] == 0x01 || pMessage[1] == 0x11); |
| 46 | uint16_t MessageLength = (pMessage[2] << 8) | pMessage[3]; |
| 47 | Parsed = Parsed && MessageSize >= 20 + (size_t)MessageLength && MessageLength % 4 == 0; |
| 48 | // Magic Cookie: 0x2112A442 |
| 49 | Parsed = Parsed && pMessage[4] == 0x21 && pMessage[5] == 0x12; |
| 50 | Parsed = Parsed && pMessage[6] == 0xA4 && pMessage[7] == 0x42; |
| 51 | // Transaction ID |
| 52 | Parsed = Parsed && mem_comp(pMessage + 8, pData->m_aSecret, sizeof(pData->m_aSecret)) == 0; |
| 53 | if(!Parsed) |
| 54 | { |
| 55 | return true; |
| 56 | } |
| 57 | |
| 58 | *pSuccess = pMessage[1] == 0x01; |
| 59 | |
| 60 | MessageSize = 20 + MessageLength; |
| 61 | size_t Offset = 20; |
| 62 | bool FoundAddr = false; |
| 63 | while(true) |
| 64 | { |
| 65 | // STUN attribute format (from RFC 5389, section 15, figure 4): |
| 66 | // |
| 67 | // 0 1 2 3 |
| 68 | // 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 |
| 69 | // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 70 | // | Type | Length | |
| 71 | // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 72 | // | Value (variable) .... |
| 73 | // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 74 | if(MessageSize == Offset) |
| 75 | { |
| 76 | break; |
| 77 | } |
| 78 | else if(MessageSize < Offset + 4) |
| 79 | { |
| 80 | return true; |
| 81 | } |
| 82 | uint16_t Type = (pMessage[Offset] << 8) | pMessage[Offset + 1]; |
| 83 | uint16_t Length = (pMessage[Offset + 2] << 8) | pMessage[Offset + 3]; |
| 84 | if(MessageSize < Offset + 4 + Length) |
| 85 | { |
| 86 | return true; |
| 87 | } |
| 88 | if(*pSuccess && Type == 0x0020) // XOR-MAPPED-ADDRESS |
| 89 | { |
| 90 | // STUN XOR-MAPPED-ADDRESS attribute format (from RFC 5389, section 15, |
| 91 | // figure 6): |
| 92 | // |