diff --git a/lib/des/aes.c b/lib/des/aes.c
index 2f6c8fcf9..6195bd5f3 100644
--- a/lib/des/aes.c
+++ b/lib/des/aes.c
@@ -43,6 +43,8 @@ RCSID("$Id$");
 #include <ktypes.h>
 #endif
 
+#include <string.h>
+
 #include "rijndael-alg-fst.h"
 #include "aes.h"
 
@@ -75,3 +77,50 @@ AES_decrypt(const unsigned char *in, unsigned char *out, const AES_KEY *key)
 {
     rijndaelDecrypt(key->key, key->rounds, in, out);
 }
+
+void
+AES_cbc_encrypt(const unsigned char *in, unsigned char *out,
+		unsigned long size, const AES_KEY *key,
+		unsigned char *iv, int encrypt)
+{
+    char tmp[AES_BLOCK_SIZE];
+    int i;
+
+    if (encrypt) {
+	while (size >= AES_BLOCK_SIZE) {
+	    for (i = 0; i < AES_BLOCK_SIZE; i++)
+		tmp[i] = in[i] ^ iv[i];
+	    AES_encrypt(tmp, out, key);
+	    memcpy(iv, out, AES_BLOCK_SIZE);
+	    size -= AES_BLOCK_SIZE;
+	    in += AES_BLOCK_SIZE;
+	    out += AES_BLOCK_SIZE;
+	}
+	if (size) {
+	    for (i = 0; i < size; i++)
+		tmp[i] = in[i] ^ iv[i];
+	    for (i = size; i < AES_BLOCK_SIZE; i++)
+		tmp[i] = iv[i];
+	    AES_encrypt(tmp, out, key);
+	    memcpy(iv, out, AES_BLOCK_SIZE);
+	}
+    } else {
+	while (size >= AES_BLOCK_SIZE) {
+	    memcpy(tmp, in, AES_BLOCK_SIZE);
+	    AES_decrypt(tmp, out, key);
+	    for (i = 0; i < AES_BLOCK_SIZE; i++)
+		out[i] ^= iv[i];
+	    memcpy(iv, tmp, AES_BLOCK_SIZE);
+	    size -= AES_BLOCK_SIZE;
+	    in += AES_BLOCK_SIZE;
+	    out += AES_BLOCK_SIZE;
+	}
+	if (size) {
+	    memcpy(tmp, in, AES_BLOCK_SIZE);
+	    AES_decrypt(tmp, out, key);
+	    for (i = 0; i < size; i++)
+		out[i] ^= iv[i];
+	    memcpy(iv, tmp, AES_BLOCK_SIZE);
+	}
+    }
+}
diff --git a/lib/des/aes.h b/lib/des/aes.h
index e4c890a38..3ab264d34 100644
--- a/lib/des/aes.h
+++ b/lib/des/aes.h
@@ -52,3 +52,7 @@ int AES_set_decrypt_key(const unsigned char *, const int, AES_KEY *);
 
 void AES_encrypt(const unsigned char *, unsigned char *, const AES_KEY *);
 void AES_decrypt(const unsigned char *, unsigned char *, const AES_KEY *);
+
+void AES_cbc_encrypt(const unsigned char *, unsigned char *,
+		     const unsigned long, const AES_KEY *,
+		     unsigned char *, int);