X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=crypt.c;h=06ae6265010a946bd51a1e64b1c620f0e4c89fc3;hp=5445138d53f6589ebce6645b027531f02b74c860;hb=698178774b857a8959fe70e360ae6ff755eacf8e;hpb=74145aabe851ba5b7eff47b650f401f49b5c740d

diff --git a/crypt.c b/crypt.c
index 5445138d..06ae6265 100644
--- a/crypt.c
+++ b/crypt.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2005-2013 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2005 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"
@@ -260,18 +261,35 @@ int pub_encrypt(struct asymmetric_key *pub, unsigned char *inbuf,
 }
 
 struct stream_cipher {
-	RC4_KEY key;
+	bool use_aes;
+	union {
+		RC4_KEY rc4_key;
+		EVP_CIPHER_CTX *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)
 {
 	struct stream_cipher *sc = para_malloc(sizeof(*sc));
-	RC4_set_key(&sc->key, len, data);
+
+	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);
+	sc->context.aes = EVP_CIPHER_CTX_new();
+	EVP_EncryptInit_ex(sc->context.aes, EVP_aes_128_ctr(), NULL, data,
+		data + AES_CRT128_BLOCK_SIZE);
 	return sc;
 }
 
 void sc_free(struct stream_cipher *sc)
 {
+	if (!sc)
+		return;
+	EVP_CIPHER_CTX_free(sc->context.aes);
 	free(sc);
 }
 
@@ -282,10 +300,9 @@ 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);
@@ -306,6 +323,32 @@ void sc_crypt(struct stream_cipher *sc, struct iovec *src, struct iovec *dst)
 	((char *)dst->iov_base)[len] = '\0';
 }
 
+static void aes_ctr128_crypt(EVP_CIPHER_CTX *ctx, struct iovec *src,
+		struct iovec *dst)
+{
+	int ret, inlen = src->iov_len, outlen, tmplen;
+
+	*dst = (typeof(*dst)) {
+		/* Add one for the terminating zero byte. */
+		.iov_base = para_malloc(inlen + 1),
+		.iov_len = inlen
+	};
+	ret = EVP_EncryptUpdate(ctx, dst->iov_base, &outlen, src->iov_base, inlen);
+	assert(ret != 0);
+	ret = EVP_EncryptFinal_ex(ctx, dst->iov_base + outlen, &tmplen);
+	assert(ret != 0);
+	outlen += tmplen;
+	((char *)dst->iov_base)[outlen] = '\0';
+	dst->iov_len = outlen;
+}
+
+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;