diff --git a/src/qca_default.cpp b/src/qca_default.cpp
--- a/src/qca_default.cpp
+++ b/src/qca_default.cpp
@@ -184,9 +184,9 @@
 
     md5_state_t()
     {
-        memset(count, 0, 2 * sizeof(md5_word_t));
-        memset(abcd, 0, 4 * sizeof(md5_word_t));
-        memset(buf, 0, 64 * sizeof(md5_byte_t));
+        memset(count, 0, sizeof(count));
+        memset(abcd, 0, sizeof(abcd));
+        memset(buf, 0, sizeof(buf));
     }
 
     md5_state_t(const md5_state_t &from)
@@ -196,7 +196,9 @@
 
     md5_state_t & operator=(const md5_state_t &from)
     {
-        *this = from;
+        memcpy(count, from.count, sizeof(count));
+        memcpy(abcd, from.abcd, sizeof(abcd));
+        memcpy(buf, from.buf, sizeof(buf));
         return *this;
     }
 };
@@ -585,9 +587,9 @@
 
 	SHA1_CONTEXT()
 	{
-		memset(state, 0, 5 * sizeof(quint32));
-		memset(count, 0, 2 * sizeof(quint32));
-		memset(buffer, 0, 64 * sizeof(unsigned char));
+		memset(state, 0, sizeof(state));
+		memset(count, 0, sizeof(count));
+		memset(buffer, 0, sizeof(buffer));
 	}
 
 	SHA1_CONTEXT(const SHA1_CONTEXT &from)
@@ -597,7 +599,9 @@
 
 	SHA1_CONTEXT & operator=(const SHA1_CONTEXT &from)
 	{
-		*this = from;
+		memcpy(state, from.state, sizeof(state));
+		memcpy(count, from.count, sizeof(count));
+		memcpy(buffer, from.buffer, sizeof(buffer));
 		return *this;
 	}
 };