// 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)
{
memset(&m_Ssl, 0, sizeof(m_Ssl));
}
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_BAD_INPUT_DATA; // 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, a_IsClient ? SSL_VERIFY_OPTIONAL : SSL_VERIFY_NONE); // Clients ask for server's cert but don't verify strictly; servers don't ask clients for certs by default
ssl_set_rng(&m_Ssl, ctr_drbg_random, &m_CtrDrbg->m_CtrDrbg);
ssl_set_bio(&m_Ssl, ReceiveEncrypted, this, SendEncrypted, this);
#ifdef _DEBUG
/*
// These functions allow us to debug SSL and certificate problems, but produce way too much output,
// so they're disabled until someone needs them
ssl_set_dbg(&m_Ssl, &SSLDebugMessage, this);
ssl_set_verify(&m_Ssl, &SSLVerifyCert, this);
*/
/*
// Set ciphersuite to the easiest one to decode, so that the connection can be wireshark-decoded:
static const int CipherSuites[] =
{
TLS_RSA_WITH_RC4_128_MD5,
TLS_RSA_WITH_RC4_128_SHA,
TLS_RSA_WITH_AES_128_CBC_SHA,
0, // Must be 0-terminated!
};
ssl_set_ciphersuites(&m_Ssl, CipherSuites);
*/
#endif
m_IsValid = true;
return 0;
}
void cSslContext::SetOwnCert(const cX509CertPtr & a_OwnCert, const cRsaPrivateKeyPtr & a_OwnCertPrivKey)
{
ASSERT(m_IsValid); // Call Initialize() first
// Check that both the cert and the key is valid:
if ((a_OwnCert.get() == NULL) || (a_OwnCertPrivKey.get() == NULL))
{
LOGWARNING("SSL: Own certificate is not valid, skipping the set.");
return;
}
// Make sure we have the cert stored for later, PolarSSL only uses the cert later on
m_OwnCert = a_OwnCert;
m_OwnCertPrivKey = a_OwnCertPrivKey;
// Set into the context:
ssl_set_own_cert_rsa(&m_Ssl, m_OwnCert->GetInternal(), m_OwnCertPrivKey->GetInternal());
}
void cSslContext::SetOwnCert(const cX509CertPtr & a_OwnCert, const cCryptoKeyPtr & a_OwnCertPrivKey)
{
ASSERT(m_IsValid); // Call Initialize() first
// Check that both the cert and the key is valid:
if ((a_OwnCert.get() == NULL) || (a_OwnCertPrivKey.get() == NULL))
{
LOGWARNING("SSL: Own certificate is not valid, skipping the set.");
return;
}
// Make sure we have the cert stored for later, PolarSSL only uses the cert later on
m_OwnCert = a_OwnCert;
m_OwnCertPrivKey2 = a_OwnCertPrivKey;
// Set into the context:
ssl_set_own_cert(&m_Ssl, m_OwnCert->GetInternal(), m_OwnCertPrivKey2->GetInternal());
}
void cSslContext::SetCACerts(const cX509CertPtr & a_CACert, const AString & a_ExpectedPeerName)
{
ASSERT(m_IsValid); // Call Initialize() first
// 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());
}
int cSslContext::SSLVerifyCert(void * a_This, x509_crt * a_Crt, int a_Depth, int * a_Flags)
{
char buf[1024];
UNUSED(a_This);
LOG("Verify requested for (Depth %d):", a_Depth);
x509_crt_info(buf, sizeof(buf) - 1, "", a_Crt);
LOG("%s", buf);
int Flags = *a_Flags;
if ((Flags & BADCERT_EXPIRED) != 0)
{
LOG(" ! server certificate has expired");
}
if ((Flags & BADCERT_REVOKED) != 0)
{
LOG(" ! server certificate has been revoked");
}
if ((Flags & BADCERT_CN_MISMATCH) != 0)
{
LOG(" ! CN mismatch");
}
if ((Flags & BADCERT_NOT_TRUSTED) != 0)
{
LOG(" ! self-signed or not signed by a trusted CA");
}
if ((Flags & BADCRL_NOT_TRUSTED) != 0)
{
LOG(" ! CRL not trusted");
}
if ((Flags & BADCRL_EXPIRED) != 0)
{
LOG(" ! CRL expired");
}
if ((Flags & BADCERT_OTHER) != 0)
{
LOG(" ! other (unknown) flag");
}
if (Flags == 0)
{
LOG(" This certificate has no flags");
}
return 0;
}
#endif // _DEBUG
