diff --git a/lib/cipher_funcs.c b/lib/cipher_funcs.c
index 560471e5..0a0ce3b5 100644
--- a/lib/cipher_funcs.c
+++ b/lib/cipher_funcs.c
@@ -249,8 +249,8 @@ rij_decrypt(unsigned char *in, size_t in_len,
     /* Remove the first block since it contains the salt (it was consumed
      * by the rijndael_init() function above).
     */
-    in_len -= 16;
-    memmove(in, in+16, in_len);
+    in_len -= RIJNDAEL_BLOCKSIZE;
+    memmove(in, in+RIJNDAEL_BLOCKSIZE, in_len);
 
     block_decrypt(&ctx, in, in_len, out, ctx.iv);
 
diff --git a/lib/fko_encryption.c b/lib/fko_encryption.c
index 5f1788a0..af43a870 100644
--- a/lib/fko_encryption.c
+++ b/lib/fko_encryption.c
@@ -139,6 +139,15 @@ _rijndael_decrypt(fko_ctx_t ctx, const char *dec_key, int encryption_mode)
 
     cipher_len = b64_decode(ctx->encrypted_msg, cipher);
 
+    /* Since we're using AES, make sure the incoming data is a multiple of
+     * the blocksize
+    */
+    if((cipher_len % RIJNDAEL_BLOCKSIZE) != 0)
+    {
+        free(cipher);
+        return(FKO_ERROR_INVALID_DATA);
+    }
+
     /* Create a bucket for the plaintext data and decrypt the message
      * data into it.
     */