1 files changed, 114 insertions, 0 deletions
diff --git a/protocols/Steam/src/steam_crypt.cpp b/protocols/Steam/src/steam_crypt.cpp
new file mode 100644
index 0000000000..7c7fa07312
--- /dev/null
+++ b/protocols/Steam/src/steam_crypt.cpp
@@ -0,0 +1,114 @@
+#include "stdafx.h"
+
+#pragma comment(lib, "crypt32.lib")
+
+int CSteamProto::RsaEncrypt(const char *pszModulus, DWORD &exponent, const char *data, BYTE *encryptedData, DWORD &encryptedSize)
+{
+	DWORD cchModulus = (DWORD)mir_strlen(pszModulus);
+	int result = 0;
+	BYTE *pbBuffer = nullptr;
+	BYTE *pKeyBlob = nullptr;
+	HCRYPTKEY phKey = 0;
+	HCRYPTPROV hCSP = 0;
+
+	// convert hex string to byte array
+	DWORD cbLen = 0, dwSkip = 0, dwFlags = 0;
+	if (!CryptStringToBinaryA(pszModulus, cchModulus, CRYPT_STRING_HEX, nullptr, &cbLen, &dwSkip, &dwFlags))
+	{
+		result = GetLastError();
+		goto exit;
+	}
+
+	// allocate a new buffer.
+	pbBuffer = (BYTE*)malloc(cbLen);
+	if (!CryptStringToBinaryA(pszModulus, cchModulus, CRYPT_STRING_HEX, pbBuffer, &cbLen, &dwSkip, &dwFlags))
+	{
+		result = GetLastError();
+		goto exit;
+	}
+
+	// reverse byte array, because of microsoft
+	for (int i = 0; i < (int)(cbLen / 2); ++i)
+	{
+		BYTE temp = pbBuffer[cbLen - i - 1];
+		pbBuffer[cbLen - i - 1] = pbBuffer[i];
+		pbBuffer[i] = temp;
+	}
+	
+	if (!CryptAcquireContext(&hCSP, nullptr, nullptr, PROV_RSA_AES, CRYPT_SILENT) &&
+		!CryptAcquireContext(&hCSP, nullptr, nullptr, PROV_RSA_AES, CRYPT_SILENT | CRYPT_NEWKEYSET))
+	{
+		result = GetLastError();
+		goto exit;
+	}
+
+	// Move the key into the key container.
+	DWORD cbKeyBlob = sizeof(PUBLICKEYSTRUC) + sizeof(RSAPUBKEY) + cbLen;
+	pKeyBlob = (BYTE*)malloc(cbKeyBlob);
+
+	// Fill in the data.
+	PUBLICKEYSTRUC *pPublicKey = (PUBLICKEYSTRUC*)pKeyBlob;
+	pPublicKey->bType = PUBLICKEYBLOB; 
+	pPublicKey->bVersion = CUR_BLOB_VERSION;  // Always use this value.
+	pPublicKey->reserved = 0;                 // Must be zero.
+	pPublicKey->aiKeyAlg = CALG_RSA_KEYX;     // RSA public-key key exchange. 
+
+	// The next block of data is the RSAPUBKEY structure.
+	RSAPUBKEY *pRsaPubKey = (RSAPUBKEY*)(pKeyBlob + sizeof(PUBLICKEYSTRUC));
+	pRsaPubKey->magic = 0x31415352; // RSA1 // Use public key
+	pRsaPubKey->bitlen = cbLen * 8;  // Number of bits in the modulus.
+	pRsaPubKey->pubexp = exponent; // Exponent.
+
+	// Copy the modulus into the blob. Put the modulus directly after the
+	// RSAPUBKEY structure in the blob.
+	BYTE *pKey = (BYTE*)(((BYTE *)pRsaPubKey) + sizeof(RSAPUBKEY));
+	//pKeyBlob + sizeof(BLOBHEADER)+ sizeof(RSAPUBKEY); 
+	memcpy(pKey, pbBuffer, cbLen);
+
+	// Now import public key	
+	if (!CryptImportKey(hCSP, pKeyBlob, cbKeyBlob, 0, 0, &phKey))
+	{
+		result = GetLastError();
+		goto exit;
+	}
+
+	DWORD dataSize = (DWORD)mir_strlen(data);
+
+	// if data is not allocated just renurn size
+	if (encryptedData == nullptr)
+	{
+		// get length of encrypted data
+		if (!CryptEncrypt(phKey, 0, TRUE, 0, nullptr, &encryptedSize, dataSize))
+			result = GetLastError();
+		goto exit;
+	}
+
+	// encrypt password
+	memcpy(encryptedData, data, dataSize);
+	if (!CryptEncrypt(phKey, 0, TRUE, 0, encryptedData, &dataSize, encryptedSize))
+	{
+		result = GetLastError();
+		goto exit;
+	}
+
+	// reverse byte array again
+	for (int i = 0; i < (int)(encryptedSize / 2); ++i)
+	{
+		BYTE temp = encryptedData[encryptedSize - i - 1];
+		encryptedData[encryptedSize - i - 1] = encryptedData[i];
+		encryptedData[i] = temp;
+	}
+
+exit:
+	if (pKeyBlob)
+		free(pKeyBlob);
+	if (phKey)
+		CryptDestroyKey(phKey);
+	
+	if (pbBuffer)
+		free(pbBuffer);
+	if (hCSP)
+		CryptReleaseContext(hCSP, 0);
+
+	return 0;
+}