diff --git a/puer.c b/puer.c
index 5b1845a..15b576c 100644
--- a/puer.c
+++ b/puer.c
@@ -305,6 +305,9 @@ void kdf(unsigned char key[16], unsigned char salt[32], unsigned char passphrase
 
 	// Use first 128 bits of final hash as the key
 	memcpy(key, final_hash, 16);
+
+	// Empty the buffer
+	explicit_bzero(workbuf, sizeof(workbuf));
 }
 
 // 16 bit authentication tag
@@ -378,9 +381,6 @@ void ccm_xor_block(unsigned char block[16], uint32_t key[4], uint32_t messageind
 	}
 }
 
-// IMPORTANT: The underlying message[] must be addressable until the index
-// ceil(length / 16)*16, but the length only reflects the actual message
-// length
 void ccm_encrypt(unsigned char key[16], uint32_t messageindex, unsigned char message[], uint32_t length, unsigned char mac[16]) {
 	uint32_t key_words[4];
 	block2words(key_words, key);
@@ -391,14 +391,22 @@ void ccm_encrypt(unsigned char key[16], uint32_t messageindex, unsigned char mes
 	// Encrypt
 	// MAC is xored with first block of keystream
 	ccm_xor_block(mac, key_words, messageindex, 0);
-	// Xor the message
-	for (uint32_t index = 0; index < length; index += 16) {
+
+	// Xor full blocks
+	size_t index = 0;
+	for (; index + 16 <= length; index += 16) {
 		// Message blocks are numbered from index 1 onwards
 		ccm_xor_block(&message[index], key_words, messageindex, index + 1);
 	}
+	// Xor partial block, if any
+	if (index < length) {
+		unsigned char fullblock[16];
+		memcpy(fullblock, &message[index], length - index);
+		ccm_xor_block(fullblock, key_words, messageindex, index + 1);
+		memcpy(&message[index], fullblock, length - index);
+	}
 }
 
-// Same requirements for message[] hold as with ccm_encrypt
 bool ccm_decrypt(unsigned char key[16], uint32_t messageindex, unsigned char message[], uint32_t length, unsigned char mac[16]) {
 	uint32_t key_words[4];
 	block2words(key_words, key);
@@ -406,11 +414,20 @@ bool ccm_decrypt(unsigned char key[16], uint32_t messageindex, unsigned char mes
 	// Decrypt
 	// MAC is xored with first block of keystream
 	ccm_xor_block(mac, key_words, messageindex, 0);
-	// Xor the message
-	for (uint32_t index = 0; index < length; index += 16) {
+
+	// Xor full blocks
+	size_t index = 0;
+	for (; index + 16 <= length; index += 16) {
 		// Message blocks are numbered from index 1 onwards
 		ccm_xor_block(&message[index], key_words, messageindex, index + 1);
 	}
+	// Xor partial block, if any
+	if (index < length) {
+		unsigned char fullblock[16];
+		memcpy(fullblock, &message[index], length - index);
+		ccm_xor_block(fullblock, key_words, messageindex, index + 1);
+		memcpy(&message[index], fullblock, length - index);
+	}
 
 	// Compute the expected authentication tag
 	unsigned char computed_mac[16];
@@ -526,8 +543,14 @@ int main(void) {
 	printf("\n\n");
 
 	char *message = "Syökää parsaa ja palvokaa saatanaa";
-	unsigned char buf[64] = {69};
+	unsigned char buf[64];
+	memset(buf, 0xab, sizeof(buf));
 	strcpy((char*)buf, message);
+	for (size_t i = 0; i < sizeof(buf); i++) {
+		printf("%02hhx ", buf[i]);
+		if (i % 16 == 15) printf("\n");
+	}
+	printf("\n");
 
 	ccm_encrypt(key, 25, buf, strlen(message), &buf[48]);
 	for (size_t i = 0; i < sizeof(buf); i++) {