Bounds checking for LeaseSet2

[chadf]

This replaces pull request #1939.

[chadf]

Buffer overflow still in LeaseSet2 decoder:

==66929==ERROR: AddressSanitizer: global-buffer-overflow on address 0x00000048f56b at pc 0x000000ba6402 bp 0x7fffffffc3b0 sp 0x7fffffffbb68
READ of size 2 at 0x00000048f56b thread T0
    #0 0x000000ba6401 in __asan_memcpy /usr/src/contrib/llvm-project/compiler-rt/lib/asan/asan_interceptors_memintrinsics.cpp:63:3
    #1 0x000000c42053 in buf16toh(void const*) /XXXX/i2pd/libi2pd/I2PEndian.h:96:2
    #2 0x000000c02b7a in bufbe16toh(void const*) /XXXX/i2pd/libi2pd/I2PEndian.h:116:9
    #3 0x000000c04d93 in i2p::data::LeaseSet2::ReadStandardLS2TypeSpecificPart(unsigned char const*, unsigned long, std::__1::shared_ptr<i2p::data::LocalDestination>) /XXXX/i2pd/libi2pd/LeaseSet.cpp:402:28
    #4 0x000000bff5af in i2p::data::LeaseSet2::ReadFromBuffer(unsigned char const*, unsigned long, std::__1::shared_ptr<i2p::data::LocalDestination>, bool, bool) /XXXX/i2pd/libi2pd/LeaseSet.cpp:355:9
    #5 0x000000bf9964 in i2p::data::LeaseSet2::LeaseSet2(unsigned char, unsigned char const*, unsigned long, bool, std::__1::shared_ptr<i2p::data::LocalDestination>, unsigned short) /XXXX/i2pd/libi2pd/LeaseSet.cpp:292:4
    #6 0x000000bdfa51 in main /XXXX/i2pd/fuzzing/LeaseSet2_crasher.cpp:64:2
    #7 0x000802630e33 in __libc_start1 /usr/src/lib/libc/csu/libc_start1.c:157:7
    #8 0x000000b37323 in _start /usr/src/lib/csu/amd64/crt1_s.S:80

0x00000048f56b is located 0 bytes after global variable 'main::input' defined in '/XXXX/i2pd/fuzzing/LeaseSet2_crasher.cpp:8' (0x00000048f3e0) of size 395
SUMMARY: AddressSanitizer: global-buffer-overflow /XXXX/i2pd/libi2pd/I2PEndian.h:96:2 in buf16toh(void const*)

---

Standalone crasher code:

#include <LeaseSet.h>


int
main()
{
        static const uint8_t input[] =
        {
                      0xfb, 0x30, 0x99, 0x35, 0x89, 0x60, 0x61,
                0xf2, 0x01, 0x00, 0xf6, 0x00, 0x5c, 0xab, 0x7c,
                0xa0, 0x06, 0x58, 0xf1, 0x52, 0x97, 0xf5, 0x3b,
                0x20, 0xce, 0xc9, 0x42, 0x3f, 0xe7, 0x20, 0x9b,
                0x03, 0xfb, 0x30, 0x99, 0x35, 0x89, 0x60, 0x61,
                0xf2, 0x5f, 0x6a, 0x04, 0xad, 0x5c, 0xab, 0x7c,
                0xa0, 0x06, 0x58, 0xf1, 0x52, 0x97, 0xf5, 0x3b,
                0x20, 0xce, 0xc9, 0x42, 0x3f, 0xe7, 0x20, 0x9b,
                0x03, 0xfb, 0x30, 0x99, 0x35, 0x89, 0x60, 0x61,
                0xf2, 0x5f, 0x6a, 0x04, 0xad, 0x5c, 0xab, 0x7c,
                0xa0, 0x06, 0x11, 0xa4, 0xed, 0x12, 0x32, 0x6e,
                0x20, 0x61, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
                0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
                0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
                0x01, 0x01, 0x01, 0x01, 0x01, 0x00, 0x00, 0x01,
                0x00, 0x9e, 0xab, 0x7c, 0xa0, 0x06, 0x11, 0xa4,
                0xed, 0x05, 0x00, 0x07, 0x00, 0x00, 0x00, 0x00,
                0x01, 0x83, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
                0xff, 0xff, 0xfb, 0x82, 0x80, 0x80, 0x80, 0x80,
                0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
                0x80, 0x05, 0x07, 0x2a, 0x00, 0x83, 0x01, 0x83,
                0xff, 0x9f, 0x00, 0x22, 0x9f, 0x57, 0x4f, 0x30,
                0x96, 0xe0, 0x32, 0x0a, 0xff, 0xff, 0xff, 0xff,
                0xff, 0xff, 0x00, 0x96, 0x52, 0x24, 0xb9, 0x2a,
                0x71, 0xf8, 0x7e, 0x15, 0x06, 0x02, 0xc4, 0x5f,
                0xd6, 0xbc, 0x3b, 0x1a, 0x4a, 0x22, 0xdb, 0x58,
                0x50, 0x44, 0x52, 0xc4, 0x6f, 0x45, 0x22, 0xac,
                0x4c, 0x58, 0x3e, 0x63, 0xca, 0xf6, 0x37, 0xfb,
                0x58, 0xe6, 0x06, 0xf8, 0x3c, 0xdb, 0x58, 0x7f,
                0xc8, 0x41, 0x5e, 0x6f, 0x74, 0x06, 0x99, 0xa4,
                0xf1, 0x5b, 0x06, 0xf3, 0x61, 0xb9, 0x73, 0x50,
                0xb1, 0xfa, 0x75, 0x7b, 0x44, 0x40, 0x63, 0x2a,
                0xff, 0x18, 0xd3, 0x17, 0x13, 0x23, 0x68, 0x55,
                0x8d, 0x09, 0x9d, 0x52, 0x40, 0xc9, 0x8b, 0x32,
                0x3a, 0x6b, 0x54, 0x84, 0x5e, 0x9a, 0xbc, 0x0e,
                0x15, 0x72, 0x7c, 0x86, 0xa6, 0x04, 0xb8, 0xc8,
                0x50, 0x9e, 0x80, 0x64, 0xe7, 0xa5, 0x6f, 0x37,
                0xd3, 0x62, 0xc8, 0xc8, 0x4e, 0x2b, 0xd4, 0x59,
                0x35, 0x1e, 0x0e, 0x22, 0x41, 0xd1, 0xa8, 0x80,
                0xd0, 0x6c, 0xcd, 0x8c, 0x8b, 0x35, 0xbc, 0xe9,
                0xe2, 0x1a, 0x4d, 0x55, 0xd2, 0xc5, 0xda, 0x7c,
                0x39, 0x7f, 0xae, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x8a, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x98,
                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0xea, 0xea, 0xea, 0xea, 0xea, 0xea, 0xea,
                0xea, 0xea, 0xea, 0xea, 0xea, 0xea, 0xea, 0xea,
                0xea, 0xea, 0xea, 0xea, 0xea, 0xea, 0xea, 0xea,
                0xea, 0xea, 0xea, 0xea, 0xea, 0xea, 0xea, 0xea,
                0xea, 0xea, 0xea, 0xea,
        };

        uint8_t storeType = 0x03;

        i2p::data::LeaseSet2(storeType, input, sizeof(input), false);
}

[chadf]

Updated the branch to be mergeable and removed HandleDatabaseSearchReplyMsg() bound check [for now].