Corrupted RouterInfo's will crash i2pd

[meeh420]

Tried to find exception, or error handling in CryptoPP. No luck.

Maybe verify data before Verifier::VerifyMessage ?

GDB backtrace.

Program received signal SIGSEGV, Segmentation fault.
0x00007ffff7a4efe0 in CryptoPP::IteratedHashBase<unsigned int, CryptoPP::HashTransformation>::HashMultipleBlocks(unsigned int const*, unsigned long) () from /usr/lib/libcrypto++.so.9
(gdb) bt
#0  0x00007ffff7a4efe0 in CryptoPP::IteratedHashBase<unsigned int, CryptoPP::HashTransformation>::HashMultipleBlocks(unsigned int const*, unsigned long) () from /usr/lib/libcrypto++.so.9
#1  0x00007ffff7a4f83c in CryptoPP::IteratedHashBase<unsigned int, CryptoPP::HashTransformation>::Update(unsigned char const*, unsigned long) () from /usr/lib/libcrypto++.so.9
#2  0x000000000043b990 in CryptoPP::PK_MessageAccumulatorBase::Update (this=0x76c4a0, input=0x76b0f0 "", length=18446744073709551576)
    at /usr/include/cryptopp/pubkey.h:292
#3  0x00007ffff799ce2c in CryptoPP::PK_Verifier::VerifyMessage(unsigned char const*, unsigned long, unsigned char const*, unsigned long) const () from /usr/lib/libcrypto++.so.9
#4  0x000000000045c3fc in i2p::data::RouterInfo::ReadFromBuffer (this=0x76aef0) at RouterInfo.cpp:74
#5  0x000000000045c192 in i2p::data::RouterInfo::ReadFromFile (this=0x76aef0, 
    filename=0x754898 "/home/meeh/.i2pd/netDb/rt/routerInfo-tNtnzINKGef6lVhj0BlM-t8-~8iW6~g249w7~KwJegQ=.dat") at RouterInfo.cpp:54
#6  0x000000000045be68 in i2p::data::RouterInfo::RouterInfo (this=0x76aef0, 
    filename=0x754898 "/home/meeh/.i2pd/netDb/rt/routerInfo-tNtnzINKGef6lVhj0BlM-t8-~8iW6~g249w7~KwJegQ=.dat") at RouterInfo.cpp:23
#7  0x000000000046fea9 in i2p::data::NetDb::Load (this=0x74b4e0 <i2p::data::netdb>, 
    directory=0x4d6bf0 <i2p::data::NetDb::m_NetDbPath> "/netDb") at NetDb.cpp:243
#8  0x000000000046f2e0 in i2p::data::NetDb::Start (this=0x74b4e0 <i2p::data::netdb>) at NetDb.cpp:69
#9  0x0000000000433d3b in main (argc=1, argv=0x7fffffffe028) at i2p.cpp:42
(gdb) f
#0  0x00007ffff7a4efe0 in CryptoPP::IteratedHashBase<unsigned int, CryptoPP::HashTransformation>::HashMultipleBlocks(unsigned int const*, unsigned long) () from /usr/lib/libcrypto++.so.9

[orignal]

Yes, I have noticed it. Usually it happens if file is zero length, I just delete such files.
Basically this line causes the problem:
int l = m_BufferLen - 40;
l might be negative, that's not supposed to.

[meeh420]

Maybe we should set this. Not sure if it helps much doh.

if (l < 0)
    l = 0;

[orignal]

line 48 m_BufferLen = s.tellg ();
if (m_BufleLen < 40)
{
LogPrint ("File ", filename, " is malformed");
return;
}

[meeh420]

ok, pull request :)