// SslContext.cpp

// Implements the cSslContext class that holds everything a single SSL context needs to function

#include "Globals.h"
#include "SslContext.h"
#include "EntropyContext.h"
#include "CtrDrbgContext.h"





cSslContext::cSslContext(void) :
	m_IsValid(false),
	m_HasHandshaken(false)
{
}





cSslContext::~cSslContext()
{
	if (m_IsValid)
	{
		ssl_free(&m_Ssl);
	}
}





int cSslContext::Initialize(bool a_IsClient, const SharedPtr<cCtrDrbgContext> & a_CtrDrbg)
{
	// Check double-initialization:
	if (m_IsValid)
	{
		LOGWARNING("SSL: Double initialization is not supported.");
		return POLARSSL_ERR_SSL_MALLOC_FAILED;  // There is no return value well-suited for this, reuse this one.
	}
	
	// Set the CtrDrbg context, create a new one if needed:
	m_CtrDrbg = a_CtrDrbg;
	if (m_CtrDrbg.get() == NULL)
	{
		m_CtrDrbg.reset(new cCtrDrbgContext);
		m_CtrDrbg->Initialize("MCServer", 8);
	}
	
	// Initialize PolarSSL's structures:
	memset(&m_Ssl, 0, sizeof(m_Ssl));
	int res = ssl_init(&m_Ssl);
	if (res != 0)
	{
		return res;
	}
	ssl_set_endpoint(&m_Ssl, a_IsClient ? SSL_IS_CLIENT : SSL_IS_SERVER);
	ssl_set_authmode(&m_Ssl, SSL_VERIFY_OPTIONAL);
	ssl_set_rng(&m_Ssl, ctr_drbg_random, &m_CtrDrbg->m_CtrDrbg);
	ssl_set_bio(&m_Ssl, ReceiveEncrypted, this, SendEncrypted, this);
	
	#ifdef _DEBUG
		ssl_set_dbg(&m_Ssl, &SSLDebugMessage, this);
	#endif
	
	m_IsValid = true;
	return 0;
}





void cSslContext::SetCACerts(const cX509CertPtr & a_CACert, const AString & a_ExpectedPeerName)
{
	// Store the data in our internal buffers, to avoid losing the pointers later on
	// PolarSSL will need these after this call returns, and the caller may move / delete the data before that:
	m_ExpectedPeerName = a_ExpectedPeerName;
	m_CACerts = a_CACert;
	
	// Set the trusted CA root cert store:
	ssl_set_authmode(&m_Ssl, SSL_VERIFY_REQUIRED);
	ssl_set_ca_chain(&m_Ssl, m_CACerts->GetInternal(), NULL, m_ExpectedPeerName.empty() ? NULL : m_ExpectedPeerName.c_str());
}





int cSslContext::WritePlain(const void * a_Data, size_t a_NumBytes)
{
	ASSERT(m_IsValid);  // Need to call Initialize() first
	if (!m_HasHandshaken)
	{
		int res = Handshake();
		if (res != 0)
		{
			return res;
		}
	}
	
	return ssl_write(&m_Ssl, (const unsigned char *)a_Data, a_NumBytes);
}





int cSslContext::ReadPlain(void * a_Data, size_t a_MaxBytes)
{
	ASSERT(m_IsValid);  // Need to call Initialize() first
	if (!m_HasHandshaken)
	{
		int res = Handshake();
		if (res != 0)
		{
			return res;
		}
	}
	
	return ssl_read(&m_Ssl, (unsigned char *)a_Data, a_MaxBytes);
}





int cSslContext::Handshake(void)
{
	ASSERT(m_IsValid);  // Need to call Initialize() first
	ASSERT(!m_HasHandshaken);  // Must not call twice
	
	int res = ssl_handshake(&m_Ssl);
	if (res == 0)
	{
		m_HasHandshaken = true;
	}
	return res;
}





int cSslContext::NotifyClose(void)
{
	return ssl_close_notify(&m_Ssl);
}





#ifdef _DEBUG
	void cSslContext::SSLDebugMessage(void * a_UserParam, int a_Level, const char * a_Text)
	{
		if (a_Level > 3)
		{
			// Don't want the trace messages
			return;
		}
		
		// Remove the terminating LF:
		size_t len = strlen(a_Text) - 1;
		while ((len > 0) && (a_Text[len] <= 32))
		{
			len--;
		}
		AString Text(a_Text, len + 1);
		
		LOGD("SSL (%d): %s", a_Level, Text.c_str());
	}
#endif  // _DEBUG