eliminated multiple of 16 check for AES

valvor · Jun 8, 2014 · a6cc2e6 · a6cc2e6
1 parent eb44fdf
commit a6cc2e6
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Showing 3 changed files with 7 additions and 14 deletions.
diff --git a/SSU.cpp b/SSU.cpp
@@ -524,7 +524,6 @@ namespace ssu
 		header->time = htobe32 (i2p::util::GetSecondsSinceEpoch ());
 		uint8_t * encrypted = &header->flag;
 		uint16_t encryptedLen = len - (encrypted - buf);
-		encryptedLen = (encryptedLen>>4)<<4; // make sure 16 bytes boundary, TODO: do we really need it? 
 		m_SessionKeyEncryption.Encrypt (encrypted, encryptedLen, encrypted);
 		// assume actual buffer size is 18 (16 + 2) bytes more
 		memcpy (buf + len, header->iv, 16);
@@ -557,7 +556,6 @@ namespace ssu
 		SSUHeader * header = (SSUHeader *)buf;
 		uint8_t * encrypted = &header->flag;
 		uint16_t encryptedLen = len - (encrypted - buf);	
-		encryptedLen = (encryptedLen>>4)<<4; // make sure 16 bytes boundary 
 		if (encryptedLen > 0)
 		{	
 			m_SessionKeyDecryption.SetIV (header->iv);

diff --git a/aes.cpp b/aes.cpp
@@ -197,12 +197,10 @@ namespace crypto
 #endif		
 	}
 
-	bool CBCEncryption::Encrypt (const uint8_t * in, std::size_t len, uint8_t * out)
+	void CBCEncryption::Encrypt (const uint8_t * in, std::size_t len, uint8_t * out)
 	{
-		div_t d = div (len, 16);
-		if (d.rem) return false; // len is not multipple of 16
-		Encrypt (d.quot, (const ChipherBlock *)in, (ChipherBlock *)out); 
-		return true;
+		// len/16
+		Encrypt (len >> 4, (const ChipherBlock *)in, (ChipherBlock *)out); 
 	}
 
 	void CBCEncryption::Encrypt (const uint8_t * in, uint8_t * out)
@@ -260,12 +258,9 @@ namespace crypto
 #endif
 	}
 
-	bool CBCDecryption::Decrypt (const uint8_t * in, std::size_t len, uint8_t * out)
+	void CBCDecryption::Decrypt (const uint8_t * in, std::size_t len, uint8_t * out)
 	{
-		div_t d = div (len, 16);
-		if (d.rem) return false; // len is not multiple of 16
-		Decrypt (d.quot, (const ChipherBlock *)in, (ChipherBlock *)out); 
-		return true;
+		Decrypt (len >> 4, (const ChipherBlock *)in, (ChipherBlock *)out); 
 	}
 
 	void CBCDecryption::Decrypt (const uint8_t * in, uint8_t * out)

diff --git a/aes.h b/aes.h
@@ -109,7 +109,7 @@ namespace crypto
 			void SetIV (const uint8_t * iv) { memcpy (m_LastBlock.buf, iv, 16); }; // 16 bytes
 
 			void Encrypt (int numBlocks, const ChipherBlock * in, ChipherBlock * out);
-			bool Encrypt (const uint8_t * in, std::size_t len, uint8_t * out);
+			void Encrypt (const uint8_t * in, std::size_t len, uint8_t * out);
 			void Encrypt (const uint8_t * in, uint8_t * out); // one block
 
 		private:
@@ -129,7 +129,7 @@ namespace crypto
 			void SetIV (const uint8_t * iv) { memcpy (m_IV.buf, iv, 16); }; // 16 bytes
 
 			void Decrypt (int numBlocks, const ChipherBlock * in, ChipherBlock * out);
-			bool Decrypt (const uint8_t * in, std::size_t len, uint8_t * out);
+			void Decrypt (const uint8_t * in, std::size_t len, uint8_t * out);
 			void Decrypt (const uint8_t * in, uint8_t * out); // one block
 
 		private: