Fix MD5 checksum for empty buffers

botder · botder · commit 4b15cc360484 · 2021-08-03T20:50:19.000+02:00
diff --git a/Shared/sdk/CChecksum.h b/Shared/sdk/CChecksum.h
@@ -66,7 +66,10 @@ class CChecksum
     {
         CChecksum result;
         result.ulCRC = CRCGenerator::GetCRCFromBuffer(cpBuffer, ulLength);
-        CMD5Hasher().Calculate(cpBuffer, ulLength, result.md5);
+
+        if (result.ulCRC != 0)
+            CMD5Hasher().Calculate(cpBuffer, ulLength, result.md5);
+        
         return result;
     }
 
diff --git a/Shared/sdk/SharedUtil.Hash.hpp b/Shared/sdk/SharedUtil.Hash.hpp
@@ -145,6 +145,9 @@ namespace SharedUtil
 
     void CMD5Hasher::Update(unsigned char* input, unsigned int input_length)
     {
+        if (input_length == 0)
+            return;
+        
         // CRYPT_START
         unsigned int input_index, buffer_index;
         unsigned int buffer_space;            // how much space is left in buffer

Original file line number	Diff line number	Diff line change
`@@ -66,7 +66,10 @@ class CChecksum`
`66`	`66`	`{`
`67`	`67`	`CChecksum result;`
`68`	`68`	`result.ulCRC = CRCGenerator::GetCRCFromBuffer(cpBuffer, ulLength);`
`69`		`- CMD5Hasher().Calculate(cpBuffer, ulLength, result.md5);`
	`69`	`+`
	`70`	`+ if (result.ulCRC != 0)`
	`71`	`+ CMD5Hasher().Calculate(cpBuffer, ulLength, result.md5);`
	`72`	`+`
`70`	`73`	`return result;`
`71`	`74`	`}`
`72`	`75`
Original file line number	Diff line number	Diff line change
`@@ -145,6 +145,9 @@ namespace SharedUtil`
`145`	`145`
`146`	`146`	`void CMD5Hasher::Update(unsigned char* input, unsigned int input_length)`
`147`	`147`	`{`
	`148`	`+ if (input_length == 0)`
	`149`	`+ return;`
	`150`	`+`
`148`	`151`	`// CRYPT_START`
`149`	`152`	`unsigned int input_index, buffer_index;`
`150`	`153`	`unsigned int buffer_space; // how much space is left in buffer`