X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=crypt.c;h=1678977a4502a008a695843b5e56a0e9a4bc6a79;hp=b8577dfc5ab164a5f0b382273aab1c8083a05ef1;hb=3a6b996d8b39fdc067df352d1eee757ef2a8f49b;hpb=282a5e463090205ef8a12f50a9ecf6498b860e88

diff --git a/crypt.c b/crypt.c
index b8577dfc..1678977a 100644
--- a/crypt.c
+++ b/crypt.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2005-2013 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2005-2014 Andre Noll <maan@tuebingen.mpg.de>
  *
  * Licensed under the GPL v2. For licencing details see COPYING.
  */
@@ -15,6 +15,7 @@
 #include <openssl/pem.h>
 #include <openssl/sha.h>
 #include <openssl/bn.h>
+#include <openssl/aes.h>
 
 #include "para.h"
 #include "error.h"
@@ -147,8 +148,7 @@ static int read_rsa_bignums(const unsigned char *blob, int blen, RSA **result)
 	*result = rsa;
 	return 1;
 fail:
-	if (rsa)
-		RSA_free(rsa);
+	RSA_free(rsa);
 	return ret;
 }
 
@@ -260,14 +260,40 @@ int pub_encrypt(struct asymmetric_key *pub, unsigned char *inbuf,
 	return ret < 0? -E_ENCRYPT : ret;
 }
 
+struct aes_ctr_128_context {
+	AES_KEY key;
+	unsigned char ivec[AES_CRT128_BLOCK_SIZE];
+	unsigned char ecount[AES_CRT128_BLOCK_SIZE];
+	unsigned int num;
+};
+
 struct stream_cipher {
-	RC4_KEY key;
+	bool use_aes;
+	union {
+		RC4_KEY rc4_key;
+		struct aes_ctr_128_context aes;
+	} context;
 };
 
-struct stream_cipher *sc_new(const unsigned char *data, int len)
+struct stream_cipher *sc_new(const unsigned char *data, int len,
+		bool use_aes)
 {
+	int ret;
 	struct stream_cipher *sc = para_malloc(sizeof(*sc));
-	RC4_set_key(&sc->key, len, data);
+	struct aes_ctr_128_context *aes;
+
+	sc->use_aes = use_aes;
+	if (!use_aes) {
+		RC4_set_key(&sc->context.rc4_key, len, data);
+		return sc;
+	}
+	assert(len >= 2 * AES_CRT128_BLOCK_SIZE);
+	aes = &sc->context.aes;
+	ret = AES_set_encrypt_key(data, AES_CRT128_BLOCK_SIZE * 8 /* bits */,
+		&aes->key);
+	assert(ret == 0);
+	memcpy(aes->ivec, data + AES_CRT128_BLOCK_SIZE, AES_CRT128_BLOCK_SIZE);
+	aes->num = 0;
 	return sc;
 }
 
@@ -283,10 +309,9 @@ void sc_free(struct stream_cipher *sc)
  */
 #define RC4_ALIGN 8
 
-void sc_crypt(struct stream_cipher *sc, struct iovec *src, struct iovec *dst)
+static void rc4_crypt(RC4_KEY *key, struct iovec *src, struct iovec *dst)
 {
 	size_t len = src->iov_len, l1, l2;
-	RC4_KEY *key = &sc->key;
 
 	assert(len > 0);
 	assert(len < ((typeof(src->iov_len))-1) / 2);
@@ -307,6 +332,28 @@ void sc_crypt(struct stream_cipher *sc, struct iovec *src, struct iovec *dst)
 	((char *)dst->iov_base)[len] = '\0';
 }
 
+static void aes_ctr128_crypt(struct aes_ctr_128_context *aes, struct iovec *src,
+		struct iovec *dst)
+{
+	size_t len = src->iov_len;
+
+	*dst = (typeof(*dst)) {
+		/* Add one for the terminating zero byte. */
+		.iov_base = para_malloc(len + 1),
+		.iov_len = len
+	};
+	AES_ctr128_encrypt(src->iov_base, dst->iov_base, len,
+		&aes->key, aes->ivec, aes->ecount, &aes->num);
+	((char *)dst->iov_base)[len] = '\0';
+}
+
+void sc_crypt(struct stream_cipher *sc, struct iovec *src, struct iovec *dst)
+{
+	if (sc->use_aes)
+		return aes_ctr128_crypt(&sc->context.aes, src, dst);
+	return rc4_crypt(&sc->context.rc4_key, src, dst);
+}
+
 void hash_function(const char *data, unsigned long len, unsigned char *hash)
 {
 	SHA_CTX c;