From dac1f42ef81ac1119430fd294a6b35b0b8cd6837 Mon Sep 17 00:00:00 2001
From: George Hazan <george.hazan@gmail.com>
Date: Sun, 25 Jan 2015 17:45:10 +0000
Subject: - class KeyStream extracted to the separate module; - xml attributes
 redesigned to produce efficient code; - many small improvements

git-svn-id: http://svn.miranda-ng.org/main/trunk@11905 1316c22d-e87f-b044-9b9b-93d7a3e3ba9c
---
 protocols/WhatsApp/src/WhatsAPI++/KeyStream.cpp | 89 +++++++++++++++++++++++++
 1 file changed, 89 insertions(+)
 create mode 100644 protocols/WhatsApp/src/WhatsAPI++/KeyStream.cpp

(limited to 'protocols/WhatsApp/src/WhatsAPI++/KeyStream.cpp')

diff --git a/protocols/WhatsApp/src/WhatsAPI++/KeyStream.cpp b/protocols/WhatsApp/src/WhatsAPI++/KeyStream.cpp
new file mode 100644
index 0000000000..f4741729a7
--- /dev/null
+++ b/protocols/WhatsApp/src/WhatsAPI++/KeyStream.cpp
@@ -0,0 +1,89 @@
+/*
+ * WALogin.cpp
+ *
+ *  Created on: 26/06/2012
+ *      Author: Antonio
+ */
+
+#include "../common.h" // #TODO Remove Miranda-dependency
+
+#include "WALogin.h"
+#include "ByteArray.h"
+#include "ProtocolTreeNode.h"
+#include "WAException.h"
+
+using namespace Utilities;
+
+KeyStream::KeyStream(unsigned char* _key, unsigned char* _keyMac) :
+	seq(0)
+{
+	memcpy(key, _key, 20);
+	memcpy(keyMac, _keyMac, 20);
+
+	RC4_set_key(&this->rc4, 20, this->key);
+
+	unsigned char drop[768];
+	RC4(&this->rc4, sizeof(drop), drop, drop);
+
+	HMAC_CTX_init(&hmac);
+}
+
+KeyStream::~KeyStream()
+{
+	HMAC_CTX_cleanup(&hmac);
+}
+
+void KeyStream::keyFromPasswordAndNonce(const std::string& pass, const std::vector<unsigned char>& nonce, unsigned char *out)
+{
+	size_t cbSize = nonce.size();
+
+	uint8_t *pNonce = (uint8_t*)_alloca(cbSize + 1);
+	memcpy(pNonce, nonce.data(), cbSize);
+
+	for (int i = 0; i < 4; i++) {
+		pNonce[cbSize] = i + 1;
+		PKCS5_PBKDF2_HMAC_SHA1(pass.data(), (int)pass.size(), pNonce, (int)cbSize+1, 2, 20, out + i*20);
+	}
+}
+
+void KeyStream::decodeMessage(unsigned char* buffer, int macOffset, int offset, const int length)
+{
+	unsigned char digest[20];
+	this->hmacsha1(buffer + offset, length, digest);
+
+	if (memcmp(&buffer[macOffset], digest, 4))
+		throw WAException("invalid MAC", WAException::CORRUPT_STREAM_EX, 0);
+
+	unsigned char* out = (unsigned char*)_alloca(length);
+	RC4(&this->rc4, length, buffer + offset, out);
+	memcpy(buffer + offset, out, length);
+}
+
+void KeyStream::encodeMessage(unsigned char* buffer, int macOffset, int offset, const int length)
+{
+	unsigned char* out = (unsigned char*)_alloca(length);
+	RC4(&this->rc4, length, buffer + offset, out);
+	memcpy(buffer + offset, out, length);
+
+	unsigned char digest[20];
+	this->hmacsha1(buffer + offset, length, digest);
+	memcpy(buffer + macOffset, digest, 4);
+}
+
+void KeyStream::hmacsha1(unsigned char* text, int textLength, unsigned char *out)
+{
+	HMAC_Init(&hmac, this->keyMac, 20, EVP_sha1());
+	HMAC_Update(&hmac, text, textLength);
+
+	unsigned char hmacInt[4];
+	hmacInt[0] = (this->seq >> 24);
+	hmacInt[1] = (this->seq >> 16);
+	hmacInt[2] = (this->seq >> 8);
+	hmacInt[3] = (this->seq);
+	HMAC_Update(&hmac, hmacInt, sizeof(hmacInt));
+
+	unsigned int mdLength;
+	HMAC_Final(&hmac, out, &mdLength);
+
+	this->seq++;
+}
-- 
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