---
 crypto/evp/e_aes.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/crypto/evp/e_aes.c
+++ b/crypto/evp/e_aes.c
@@ -2742,6 +2742,9 @@ static int aes_cbc_cipher(EVP_CIPHER_CTX
 {
     EVP_AES_KEY *dat = EVP_C_DATA(EVP_AES_KEY,ctx);
 
+    if (!len)
+        return 1;
+
     if (dat->stream.cbc)
         (*dat->stream.cbc) (in, out, len, &dat->ks,
                             EVP_CIPHER_CTX_iv_noconst(ctx),