Deprecate encrypted BLOB checksum

The MD5 checksum was calculated on unencrypted data. This offered a
possibility for a dictionary attack.

Signed-off-by: Simon Rozman <simon@rozman.si>
This commit is contained in:
2020-05-13 08:26:07 +02:00
parent 7897d0716c
commit a6bdb42ece
3 changed files with 33 additions and 11 deletions

View File

@@ -327,7 +327,8 @@ namespace eap
enum class enc_alg_t {
unknown = -1, ///< Unknown encryption
none = 0, ///< Unencrypted
native, ///< native module encryption
native, ///< native module encryption (version 2)
native_v1, ///< native module encryption (version 1, deprecated)
kph, ///< KPH encryption
};

View File

@@ -364,6 +364,7 @@ namespace eap
///
/// \returns Encrypted data with 16B MD5 hash appended
///
[[deprecated("Unencrypted hash allows dictionary attacks")]]
std::vector<unsigned char> encrypt_md5(_In_ HCRYPTPROV hProv, _In_bytecount_(size) const void *data, _In_ size_t size) const;
@@ -376,6 +377,7 @@ namespace eap
/// \returns Encrypted data with 16B MD5 hash appended
///
template<class _Elem, class _Traits, class _Ax>
[[deprecated("Unencrypted hash allows dictionary attacks")]]
std::vector<unsigned char> encrypt_md5(_In_ HCRYPTPROV hProv, _In_ const std::basic_string<_Elem, _Traits, _Ax> &val) const
{
return encrypt_md5(hProv, val.c_str(), val.length()*sizeof(_Elem));
@@ -391,6 +393,7 @@ namespace eap
/// \returns Encrypted data with 16B MD5 hash appended
///
template<class _Traits, class _Ax>
[[deprecated("Unencrypted hash allows dictionary attacks")]]
std::vector<unsigned char> encrypt_md5(_In_ HCRYPTPROV hProv, _In_ const std::basic_string<wchar_t, _Traits, _Ax> &val) const
{
winstd::sanitizing_string val_utf8;
@@ -451,7 +454,7 @@ namespace eap
template<class _Elem, class _Traits, class _Ax>
std::basic_string<_Elem, _Traits, _Ax> decrypt_str(_In_ HCRYPTPROV hProv, _In_bytecount_(size) const void *data, _In_ size_t size, _In_opt_ HCRYPTHASH hHash = NULL) const
{
std::vector<_Elem, sanitizing_allocator<_Elem> > buf(std::move(decrypt(hProv, data, size, hHash)));
std::vector<_Elem, sanitizing_allocator<_Elem> > buf(std::move(decrypt<_Elem, sanitizing_allocator<_Elem> >(hProv, data, size, hHash)));
return std::basic_string<_Elem, _Traits, _Ax>(buf.data(), buf.size());
}
@@ -469,7 +472,7 @@ namespace eap
template<class _Traits, class _Ax>
std::basic_string<wchar_t, _Traits, _Ax> decrypt_str(_In_ HCRYPTPROV hProv, _In_bytecount_(size) const void *data, _In_ size_t size, _In_opt_ HCRYPTHASH hHash = NULL) const
{
winstd::sanitizing_string buf(std::move(decrypt_str(hProv, data, size, hHash)));
winstd::sanitizing_string buf(std::move(decrypt_str<char, std::char_traits<char>, sanitizing_allocator<char> >(hProv, data, size, hHash)));
std::basic_string<wchar_t, _Traits, _Ax> dec;
MultiByteToWideChar(CP_UTF8, 0, buf, dec);
return dec;
@@ -486,6 +489,7 @@ namespace eap
/// \returns Decrypted data
///
template<class _Ty, class _Ax>
[[deprecated("Unencrypted hash allows dictionary attacks")]]
std::vector<_Ty, _Ax> decrypt_md5(_In_ HCRYPTPROV hProv, _In_bytecount_(size) const void *data, _In_ size_t size) const
{
// Create hash.
@@ -522,6 +526,7 @@ namespace eap
/// \returns Decrypted string
///
template<class _Elem, class _Traits, class _Ax>
[[deprecated("Unencrypted hash allows dictionary attacks")]]
std::basic_string<_Elem, _Traits, _Ax> decrypt_str_md5(_In_ HCRYPTPROV hProv, _In_bytecount_(size) const void *data, _In_ size_t size) const
{
std::vector<_Elem, sanitizing_allocator<_Elem> > buf(std::move(decrypt_md5<_Elem, sanitizing_allocator<_Elem> >(hProv, data, size)));
@@ -539,6 +544,7 @@ namespace eap
/// \returns Decrypted string
///
template<class _Traits, class _Ax>
[[deprecated("Unencrypted hash allows dictionary attacks")]]
std::basic_string<wchar_t, _Traits, _Ax> decrypt_str_md5(_In_ HCRYPTPROV hProv, _In_bytecount_(size) const void *data, _In_ size_t size) const
{
winstd::sanitizing_string buf(std::move(decrypt_str_md5<char, std::char_traits<char>, sanitizing_allocator<char> >(hProv, data, size)));
@@ -573,7 +579,7 @@ namespace eap
throw winstd::win_runtime_error(__FUNCTION__ " CryptAcquireContext failed.");
// Decrypt data.
return std::move(decrypt_md5<unsigned char, winstd::sanitizing_allocator<unsigned char> >(cp, pDataIn, dwDataInSize));
return std::move(decrypt<unsigned char, winstd::sanitizing_allocator<unsigned char> >(cp, pDataIn, dwDataInSize));
#else
return sanitizing_blob(pDataIn, pDataIn + dwDataInSize);
#endif
@@ -602,7 +608,7 @@ namespace eap
throw winstd::win_runtime_error(__FUNCTION__ " CryptAcquireContext failed.");
// Decrypt data.
std::vector<unsigned char, winstd::sanitizing_allocator<unsigned char> > data(std::move(decrypt_md5<unsigned char, winstd::sanitizing_allocator<unsigned char> >(cp, pDataIn, dwDataInSize)));
std::vector<unsigned char, winstd::sanitizing_allocator<unsigned char> > data(std::move(decrypt<unsigned char, winstd::sanitizing_allocator<unsigned char> >(cp, pDataIn, dwDataInSize)));
cursor_in cursor = { data.data(), data.data() + data.size() };
#else
@@ -637,7 +643,7 @@ namespace eap
throw winstd::win_runtime_error(__FUNCTION__ " CryptAcquireContext failed.");
// Encrypt BLOB.
std::vector<unsigned char> data_enc(std::move(encrypt_md5(cp, data.data(), data.size())));
std::vector<unsigned char> data_enc(std::move(encrypt(cp, data.data(), data.size())));
// Copy encrypted BLOB to output.
*pdwDataOutSize = (DWORD)data_enc.size();
@@ -685,7 +691,7 @@ namespace eap
throw winstd::win_runtime_error(__FUNCTION__ " CryptAcquireContext failed.");
// Encrypt BLOB.
std::vector<unsigned char> data_enc(std::move(encrypt_md5(cp, data.data(), data.size())));
std::vector<unsigned char> data_enc(std::move(encrypt(cp, data.data(), data.size())));
// Copy encrypted BLOB to output.
*pdwDataOutSize = (DWORD)data_enc.size();