I got it working by implementing the raw Integer method. See my code below,
previous encryption is commented out. I don't know why but it wasn't
working otherwise and *I think it has something to do with memory
allocation maybe it works with -static flag because some references are
staying in scope as the entire library is loaded into RAM ? *
I had to implement the PKCS1v15 again but I would like to know what is
wrong so I can write the code accordingly.
I have the Integer c.
1) If I use snippet 1, get the vector and then read it into a string "res"
and return it, this works.
2) If I use snippet 2, aka do the exact same thing in the function. It
doesn't work. I am trying to think whether the Vector needs to be declared
with *new *? I am passing back the whole object not a pointer, so it should
not go out of scope ?? But maybe the resarr2 is not a deep copy and when it
goes out of scope the string data is also destroyed ?? On the other side,
the serve complains with Snippet 2 and not with Snippet 1.
Snippet 1: (works)
std::vector<byte> resarr2 = convert_cryptopp_integer(c);
string res(resarr2.begin(), resarr2.end());
return res;
Snippet 2: (doesn't work)
string res = convert_cryptopp_integer_str(c);
return res;
Functions:
std::vector<byte> convert_cryptopp_integer(Integer n){
const size_t len = n.MinEncodedSize(Integer::UNSIGNED);
std::vector<byte> v;
v.resize(len);
n.Encode((byte*)&v[0], v.size(), Integer::UNSIGNED);
//std::cout << "Iostream: " << std::hex << n << std::endl;
std::cout << "Iostream: " << n << std::endl;
std::cout << " Vector: ";
for(size_t i : v) { std::cout << (i & 0xff); }
std::cout << " Done vector: " << endl;
for(size_t i : v) { std::cout << int(i) << " "; }
std::cout << " Done cout: " << endl;
std::cout << std::endl;
return v;
}
string convert_cryptopp_integer_str(Integer n){
std::vector<byte> resarr2 = convert_cryptopp_integer(n);
string res(resarr2.begin(), resarr2.end());
return res;
}
std::string encrypt_rsa(std::string message, CryptoPP::RSA::PublicKey key)
{
try{
/* This was the previous code I couldn't get working without the -static
flag
cout << " In encrypt rsa string " << endl;
std::string str(message.begin(), message.end());
message = b64encode(str);
CryptoPP::AutoSeededRandomPool rng;
//CryptoPP::RSAES_OAEP_SHA_Encryptor encryptor(key);
CryptoPP::RSAES_PKCS1v15_Encryptor encryptor(key);
std::string ciphertext;
CryptoPP::StringSource(message, true, new CryptoPP::PK_EncryptorFilter(rng,
encryptor, new CryptoPP::StringSink(ciphertext)));
return ciphertext;
*/
std::string str(message.begin(), message.end());
string message = b64encode(str);
cout << " Got message of length" << message.length() << endl;
//convert the message to b64
string ts="\0"s;
ts += "\2"s;
//Add the 00 02 start header
int target_length = key.GetModulus().ByteCount();
int msglength = message.length();
int padding_length = target_length - msglength - 3;
//calculate the padding length for PKCS1 v1.5
SecByteBlock rand(padding_length);
OS_GenerateRandomBlock(true, rand, padding_length);
string rands;
HexEncoder hex(new StringSink(rands));
hex.Put(rand, rand.size());
hex.MessageEnd();
std::regex reg("\0");
rands = std::regex_replace(rands,reg,"a");
rands.erase(padding_length);
//generate random padding, replace any NULLs with "a"
if(message.size()<key.GetModulus().ByteCount()){
ts += rands;
//add the padding to the message
ts += "\0"s;
//NULL terminate the padding
ts = ts + message;
//add the payload
}
const char* msg_c = ts.c_str();
Integer m((const byte*)ts.data(), ts.size());
//convert it to Integer
Integer c = key.ApplyFunction(m);
//encrypt it
size_t ensize = c.MinEncodedSize();
//get the size
std::vector<byte> resarr2 = convert_cryptopp_integer(c);
string res(resarr2.begin(), resarr2.end());
//This works
//string res = convert_cryptopp_integer_str(c);
//This line above doesn't work is it memory issue of the vector<byte> going
out of scope??
return res;
}
catch(Exception e)
{
std::cout << "error encrypting RSA " << e.what();
return "";
}
}
On Tuesday, April 25, 2023 at 4:47:38 PM UTC-4 Dwight Kulkarni wrote:
> Hi all:
>
> ldd ./server compiled without the -static flag shows following .so
> dependencies.
>
> Since the -static flag will add the same libraries as .a form, it will
> compile a slightly different version. I am trying to think why the
> encryption would produce two different results, maybe something like big
> endian or little endian treatment in a particular function ? Maybe
> difference in the random generator ? Maybe byte size differences due to
> typedef ?
>
> linux-vdso.so.1 (0x00007ffc5e0d7000)
> libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6
> (0x00007f8712987000)
> libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f87125e9000)
> libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007f87123d1000)
> libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0
> (0x00007f87121b2000)
> libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f8711dc1000)
> /lib64/ld-linux-x86-64.so.2 (0x00007f87131e2000)
>
> On Tuesday, April 25, 2023 at 2:47:34 PM UTC-4 Dwight Kulkarni wrote:
>
>> Further info:
>>
>> *without -static*, this is the output from the remote server:
>>
>> broker got data of size 512
>> Broker handler thread started... 512
>> first two bytes are 128 and 198 and 154
>> *clear text begins with 68 180 -------------->> this should be 00 02*
>> Either no 00 02 beginning block or no 00 separator byte found in proper
>> range
>> Decryption failed
>> Exception occurred: 'NoneType' object has no attribute 'decode'
>>
>>
>> with -static flag, this is the output from the remote server:
>>
>> broker got data of size 512
>> Broker handler thread started... 512
>> first two bytes are 51 and 252 and 242
>> *clear text begins with 0 2 -------------> this is the correct value*
>> Got base64 bytes
>>
>> b'eyJtZXNzYWdlIjoiMSIsInRybiI6MzM0NjQ1NjksInNlc3Npb24iOiJzc2Vzc2lvbiIsInBhc3Njb2RlIjoic3Bhc3Njb2RlIiwiZGF0ZXRpbWUiOiIwNC8yNS8yMDIzIDE4OjE1OjA0LjEwOCIsInNlcmlhbCI6InNzZXJpYWwiLCJjYW1lcmFfcG9ydCI6NTAwMCwia2V5IjoiTURObE1XWTBOMlUyTnpFNE1HTXdaak5pWkRZeE1UZ3haVGcyT0dFd05XST0iLCJpdiI6Ik9ETmtZMk0zTVdJek5UUmtaVFUyTUROak1HVTRaakptWlRNME5UQmhZMk09IiwidCI6Mn0='
>> initializing the lock...
>>
>> On Tuesday, April 25, 2023 at 2:33:23 PM UTC-4 Dwight Kulkarni wrote:
>>
>>> Hi all,
>>>
>>> I have my RSA encrypt function as below.
>>>
>>> I compile my program with the following:
>>>
>>> g++ -g -c -static -pthread -I../
>>> -I/data/prj/external-libs/include/cryptopp/
>>> ../src/threading/server.cpp
>>>
>>> g++ -g ../lbin/*.o -static -pthread -o server
>>> -L/data/prj/external-libs/lib/
>>> -l:libcryptopp.a
>>>
>>> Here is what is strange.
>>>
>>> If I include the -static flag, when I run the encrypt_rsa command below
>>> on the remote server it correctly decrypts.
>>>
>>> If I remove the -static flag, on the remove server it doesn't get the
>>> proper message. However, the message that locally encrypted and decrypted
>>> still works.
>>>
>>> It doesn't throw any error, encryption completes, but when the server
>>> receives it, it doesn't decrypt properly.
>>>
>>> During compilation of the .a library from makefile it did not have a
>>> -static flag.
>>>
>>>
>>>
>>>
>>> std::string encrypt_rsa(std::string message, CryptoPP::RSA::PublicKey
>>> key)
>>> {
>>>
>>> try{
>>> cout << " In encrypt rsa string " << endl;
>>> message = b64encode(message);
>>> CryptoPP::AutoSeededRandomPool rng;
>>>
>>> //CryptoPP::RSAES_OAEP_SHA_Encryptor encryptor(key);
>>> CryptoPP::RSAES_PKCS1v15_Encryptor encryptor(key);
>>> std::string ciphertext;
>>> CryptoPP::StringSource(message, true, new CryptoPP::PK_EncryptorFilter(
>>> rng, encryptor, new CryptoPP::StringSink(ciphertext)));
>>> return ciphertext;
>>>
>>> }
>>> catch(...)
>>> {
>>> std::cout << "error encrypting RSA";
>>> return "";
>>> }
>>> }
>>>
>>
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