From 90e2fe2709fa0badeb6a87e000467da16eb25391 Mon Sep 17 00:00:00 2001
From: Jeremy Allison <jra@samba.org>
Date: Fri, 1 Sep 2017 11:44:21 -0700
Subject: [PATCH] lib: crypto: Add the ability to call AES implementations from
 libnettle.

libnettle implements the AESNI Intel instruction set, so should be
faster than our internal implementation if available on x86_64.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=13008

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Jeremy Allison <jra@samba.org>
---
 lib/crypto/aes.h             | 57 ++++++++++++++++++++++++++++++++++++++++++++
 lib/crypto/wscript_build     |  2 ++
 lib/crypto/wscript_configure |  2 ++
 3 files changed, 61 insertions(+)

diff --git a/lib/crypto/aes.h b/lib/crypto/aes.h
index 48ea764d514..a3b98bc15c9 100644
--- a/lib/crypto/aes.h
+++ b/lib/crypto/aes.h
@@ -36,6 +36,56 @@
 #ifndef LIB_CRYPTO_AES_H
 #define LIB_CRYPTO_AES_H 1
 
+#if CRYPTO_AES_USE_NETTLE
+#include <nettle/aes.h>
+#include <nettle/memxor.h>
+
+/*
+ * Defining these as 1 means use the Samba implementations in
+ * lib/crypto/aes.c
+ */
+
+#define SAMBA_AES_CBC_ENCRYPT 1
+#define SAMBA_AES_CFB8_ENCRYPT 1
+
+typedef struct aes_ctx AES_KEY;
+
+/*
+ * Symbol renaming to call libnettle functions - not Samba implementations
+ * in lib/crypto/aes.c
+ */
+
+#define AES_set_encrypt_key(userkey, bits, key) \
+	aes_set_encrypt_key(key, bits/8, userkey)
+#define AES_set_decrypt_key(userkey, bits, key) aes_set_decrypt_key(key, bits/8, userkey)
+#define AES_encrypt(src, dst, key) aes_encrypt(key, AES_BLOCK_SIZE, dst, src)
+#define AES_decrypt(src, dst, key) aes_decrypt(key, AES_BLOCK_SIZE, dst, src)
+#define aes_block_xor(in1, in2, out) memxor3(out, in1, in2, AES_BLOCK_SIZE)
+
+/*
+ * Symbol renaming to call Samba implementations in
+ * lib/crypto/aes.c
+ */
+
+#define AES_cbc_encrypt samba_AES_cbc_encrypt
+#define AES_cfb8_encrypt samba_AES_cfb8_encrypt
+
+#define AES_ENCRYPT 1
+#define AES_DECRYPT 0
+
+void AES_cbc_encrypt(const unsigned char *, unsigned char *,
+		     const unsigned long, const AES_KEY *,
+		     unsigned char *, int);
+
+void AES_cfb8_encrypt(const unsigned char *in, unsigned char *out,
+		      unsigned long size, const AES_KEY *key,
+		      unsigned char *iv, int forward_encrypt);
+
+#define aes_cfb8_encrypt(in, out, size, key, iv, forward_encrypt) \
+	AES_cfb8_encrypt(in, out, size, key, iv, forward_encrypt)
+
+#else /* CRYPTO_AES_USE_NETTLE */
+
 #define SAMBA_RIJNDAEL 1
 #define SAMBA_AES_CBC_ENCRYPT 1
 #define SAMBA_AES_CFB8_ENCRYPT 1
@@ -119,6 +169,13 @@ static inline void aes_block_xor(const uint8_t in1[AES_BLOCK_SIZE],
 }
 #endif /* SAMBA_AES_BLOCK_XOR */
 
+#endif /* CRYPTO_AES_USE_NETTLE */
+
+/*
+ * These next inline functions are not included in libnettle,
+ * so are needed for both Samba and libnettle choices.
+ */
+
 static inline void aes_block_lshift(const uint8_t in[AES_BLOCK_SIZE],
 				    uint8_t out[AES_BLOCK_SIZE])
 {
diff --git a/lib/crypto/wscript_build b/lib/crypto/wscript_build
index d1f152ebcf1..38a6b616b69 100644
--- a/lib/crypto/wscript_build
+++ b/lib/crypto/wscript_build
@@ -10,6 +10,8 @@ elif bld.CONFIG_SET('HAVE_SYS_MD5_H') and bld.CONFIG_SET('HAVE_LIBMD'):
 	extra_deps += ' md'
 elif not bld.CONFIG_SET('HAVE_SYS_MD5_H') and not bld.CONFIG_SET('HAVE_COMMONCRYPTO_COMMONDIGEST_H'):
 	extra_source += ' md5.c'
+if bld.CONFIG_SET('CRYPTO_AES_USE_NETTLE'):
+	extra_deps += ' nettle'
 
 bld.SAMBA_SUBSYSTEM('LIBCRYPTO',
         source='''crc32.c hmacmd5.c md4.c arcfour.c sha256.c sha512.c hmacsha256.c
diff --git a/lib/crypto/wscript_configure b/lib/crypto/wscript_configure
index 130acec4381..3268b50bd15 100644
--- a/lib/crypto/wscript_configure
+++ b/lib/crypto/wscript_configure
@@ -13,3 +13,5 @@ if conf.CHECK_FUNCS('SHA256_Update'):
 	conf.DEFINE('SHA256_RENAME_NEEDED', 1)
 if conf.CHECK_FUNCS('SHA512_Update'):
 	conf.DEFINE('SHA512_RENAME_NEEDED', 1)
+if conf.CHECK_FUNCS_IN('aes_set_encrypt_key', 'nettle', headers='nettle/aes.h'):
+	conf.DEFINE('CRYPTO_AES_USE_NETTLE', 1)
-- 
2.14.1.581.gf28d330327-goog