diff --git a/Makefile.in b/Makefile.in
index 14f5599..d428259 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -50,7 +50,7 @@ MAN8DIR=$(MANDIR)/man8
N2N_LIB=libn2n.a
N2N_OBJS=n2n.o wire.o minilzo.o twofish.o \
edge_utils.o sn_utils.o \
- transform_null.o transform_tf.o transform_aes.o \
+ transform_null.o transform_tf.o transform_aes.o transform_cc20.o \
tuntap_freebsd.o tuntap_netbsd.o tuntap_linux.o \
tuntap_osx.o
LIBS_EDGE+=$(LIBS_EDGE_OPT)
diff --git a/edge_utils.c b/edge_utils.c
index acae39e..9376503 100644
--- a/edge_utils.c
+++ b/edge_utils.c
@@ -138,6 +138,7 @@ static const char* transop_str(enum n2n_transform tr) {
case N2N_TRANSFORM_ID_NULL: return("null");
case N2N_TRANSFORM_ID_TWOFISH: return("twofish");
case N2N_TRANSFORM_ID_AESCBC: return("AES-CBC");
+ case N2N_TRANSFORM_ID_CHACHA20:return("ChaCha20");
default: return("invalid");
};
}
@@ -240,6 +241,11 @@ n2n_edge_t* edge_init(const tuntap_dev *dev, const n2n_edge_conf_t *conf, int *r
case N2N_TRANSFORM_ID_AESCBC:
rc = n2n_transop_aes_cbc_init(&eee->conf, &eee->transop);
break;
+#endif
+#ifdef HAVE_OPENSSL_1_1
+ case N2N_TRANSFORM_ID_CHACHA20:
+ rc = n2n_transop_cc20_init(&eee->conf, &eee->transop);
+ break;
#endif
default:
rc = n2n_transop_null_init(&eee->conf, &eee->transop);
diff --git a/n2n.h b/n2n.h
index dbdb5a3..5c23480 100644
--- a/n2n.h
+++ b/n2n.h
@@ -293,6 +293,9 @@ int n2n_transop_twofish_init(const n2n_edge_conf_t *conf, n2n_trans_op_t *ttt);
#ifdef N2N_HAVE_AES
int n2n_transop_aes_cbc_init(const n2n_edge_conf_t *conf, n2n_trans_op_t *ttt);
#endif
+#ifdef HAVE_OPENSSL_1_1
+int n2n_transop_cc20_init(const n2n_edge_conf_t *conf, n2n_trans_op_t *ttt);
+#endif
/* Log */
void setTraceLevel(int level);
diff --git a/n2n_transforms.h b/n2n_transforms.h
index 1ede8cf..f203257 100644
--- a/n2n_transforms.h
+++ b/n2n_transforms.h
@@ -30,6 +30,7 @@ typedef enum n2n_transform {
N2N_TRANSFORM_ID_NULL = 1,
N2N_TRANSFORM_ID_TWOFISH = 2,
N2N_TRANSFORM_ID_AESCBC = 3,
+ N2N_TRANSFORM_ID_CHACHA20 = 4,
} n2n_transform_t;
struct n2n_trans_op;
diff --git a/tools/benchmark.c b/tools/benchmark.c
index 381f511..9197035 100644
--- a/tools/benchmark.c
+++ b/tools/benchmark.c
@@ -96,6 +96,9 @@ int main(int argc, char * argv[]) {
n2n_trans_op_t transop_null, transop_twofish;
#ifdef N2N_HAVE_AES
n2n_trans_op_t transop_aes_cbc;
+#endif
+#ifdef HAVE_OPENSSL_1_1
+ n2n_trans_op_t transop_cc20;
#endif
n2n_edge_conf_t conf;
@@ -112,6 +115,9 @@ int main(int argc, char * argv[]) {
#ifdef N2N_HAVE_AES
n2n_transop_aes_cbc_init(&conf, &transop_aes_cbc);
#endif
+#ifdef HAVE_OPENSSL_1_1
+ n2n_transop_cc20_init(&conf, &transop_cc20);
+#endif
/* Run the tests */
run_transop_benchmark("transop_null", &transop_null, &conf, pktbuf);
@@ -119,6 +125,9 @@ int main(int argc, char * argv[]) {
#ifdef N2N_HAVE_AES
run_transop_benchmark("transop_aes", &transop_aes_cbc, &conf, pktbuf);
#endif
+#ifdef N2N_HAVE_AES
+ run_transop_benchmark("transop_cc20", &transop_cc20, &conf, pktbuf);
+#endif
/* Cleanup */
transop_null.deinit(&transop_null);
@@ -126,6 +135,9 @@ int main(int argc, char * argv[]) {
#ifdef N2N_HAVE_AES
transop_aes_cbc.deinit(&transop_aes_cbc);
#endif
+#ifdef HAVE_OPENSSL_1_1
+ transop_cc20.deinit(&transop_cc20);
+#endif
return 0;
}
diff --git a/transform_cc20.c b/transform_cc20.c
new file mode 100644
index 0000000..d6e2ee1
--- /dev/null
+++ b/transform_cc20.c
@@ -0,0 +1,293 @@
+/**
+ * (C) 2007-20 - ntop.org and contributors
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not see see
+ *
+ */
+
+#include "n2n.h"
+#include "n2n_transforms.h"
+
+#ifdef HAVE_OPENSSL_1_1
+
+#include
+#include
+#include
+
+#define N2N_CC20_TRANSFORM_VERSION 1 /* version of the transform encoding */
+#define N2N_CC20_IVEC_SIZE 16
+
+#define CC20_KEY_BYTES (256/8)
+
+/* ChaCha20 plaintext preamble */
+#define TRANSOP_CC20_VER_SIZE 1 /* Support minor variants in encoding in one module. */
+#define TRANSOP_CC20_PREAMBLE_SIZE (TRANSOP_CC20_VER_SIZE + N2N_CC20_IVEC_SIZE)
+
+typedef unsigned char n2n_cc20_ivec_t[N2N_CC20_IVEC_SIZE];
+
+typedef struct transop_cc20 {
+ EVP_CIPHER_CTX *enc_ctx; /* openssl's reusable evp_* encryption context */
+ EVP_CIPHER_CTX *dec_ctx; /* openssl's reusable evp_* decryption context */
+ const EVP_CIPHER *cipher; /* cipher to use: EVP_chacha20() */
+ uint8_t key[32]; /* the pure key data for payload encryption & decryption */
+} transop_cc20_t;
+
+/* ****************************************************** */
+
+static int transop_deinit_cc20(n2n_trans_op_t *arg) {
+ transop_cc20_t *priv = (transop_cc20_t *)arg->priv;
+
+ EVP_CIPHER_CTX_free(priv->enc_ctx);
+ EVP_CIPHER_CTX_free(priv->dec_ctx);
+
+ if(priv)
+ free(priv);
+
+ return 0;
+}
+
+/* ****************************************************** */
+
+/* get any erorr message out of openssl
+ taken from https://en.wikibooks.org/wiki/OpenSSL/Error_handling */
+char *openssl_err_as_string (void) {
+ BIO *bio = BIO_new (BIO_s_mem ());
+ ERR_print_errors (bio);
+ char *buf = NULL;
+ size_t len = BIO_get_mem_data (bio, &buf);
+ char *ret = (char *) calloc (1, 1 + len);
+
+ if(ret)
+ memcpy (ret, buf, len);
+
+ BIO_free (bio);
+ return ret;
+}
+
+/* ****************************************************** */
+
+static void set_cc20_iv(transop_cc20_t *priv, n2n_cc20_ivec_t ivec) {
+ // keep in mind the following condition: N2N_CC20_IVEC_SIZE % sizeof(rand_value) == 0 !
+ uint32_t rand_value;
+ for (uint8_t i = 0; i < N2N_CC20_IVEC_SIZE; i += sizeof(rand_value)) {
+ rand_value = rand(); // CONCERN: rand() is not consideren cryptographicly secure, REPLACE later
+ memcpy(ivec + i, &rand_value, sizeof(rand_value));
+ }
+}
+
+/* ****************************************************** */
+
+/** The ChaCha20 packet format consists of:
+ *
+ * - a 8-bit cc20 encoding version in clear text
+ * - a 128-bit random IV
+ * - encrypted payload.
+ *
+ * [V|IIII|DDDDDDDDDDDDDDDDDDDDD]
+ * |<---- encrypted ---->|
+ */
+static int transop_encode_cc20(n2n_trans_op_t * arg,
+ uint8_t * outbuf,
+ size_t out_len,
+ const uint8_t * inbuf,
+ size_t in_len,
+ const uint8_t * peer_mac) {
+ int len=-1;
+ transop_cc20_t * priv = (transop_cc20_t *)arg->priv;
+ uint8_t assembly[N2N_PKT_BUF_SIZE] = {0};
+
+ if(in_len <= N2N_PKT_BUF_SIZE) {
+ if((in_len + TRANSOP_CC20_PREAMBLE_SIZE) <= out_len) {
+ size_t idx=0;
+ n2n_cc20_ivec_t enc_ivec = {0};
+
+ traceEvent(TRACE_DEBUG, "encode_cc20 %lu", in_len);
+
+ /* Encode the ChaCha20 format version. */
+ encode_uint8(outbuf, &idx, N2N_CC20_TRANSFORM_VERSION);
+
+ /* Generate and encode the IV. */
+ set_cc20_iv(priv, enc_ivec);
+ encode_buf(outbuf, &idx, &enc_ivec, N2N_CC20_IVEC_SIZE);
+
+ /* Encrypt the assembly contents and write the ciphertext after the iv. */
+ /* len is set to the length of the cipher plain text to be encrpyted
+ which is (in this case) identical to original packet lentgh */
+ len = in_len;
+
+ /* The assembly buffer is a source for encrypting data.
+ * The whole contents of assembly are encrypted. */
+ memcpy(assembly, inbuf, in_len);
+
+ EVP_CIPHER_CTX *ctx = priv->enc_ctx;
+ int evp_len;
+ int evp_ciphertext_len;
+
+ if(1 == EVP_EncryptInit_ex(ctx, priv->cipher, NULL, priv->key, enc_ivec)) {
+ if(1 == EVP_CIPHER_CTX_set_padding(ctx, 0)) {
+ if(1 == EVP_EncryptUpdate(ctx, outbuf + TRANSOP_CC20_PREAMBLE_SIZE, &evp_len, assembly, len)) {
+ evp_ciphertext_len = evp_len;
+ if(1 == EVP_EncryptFinal_ex(ctx, outbuf + TRANSOP_CC20_PREAMBLE_SIZE + evp_len, &evp_len)) {
+ evp_ciphertext_len += evp_len;
+
+ if(evp_ciphertext_len != len)
+ traceEvent(TRACE_ERROR, "encode_cc20 openssl encryption: encrypted %u bytes where %u were expected.\n",
+ evp_ciphertext_len, len);
+ } else
+ traceEvent(TRACE_ERROR, "encode_cc20 openssl final encryption: %s\n", openssl_err_as_string());
+ } else
+ traceEvent(TRACE_ERROR, "encode_cc20 openssl encrpytion: %s\n", openssl_err_as_string());
+ } else
+ traceEvent(TRACE_ERROR, "encode_cc20 openssl padding setup: %s\n", openssl_err_as_string());
+ } else
+ traceEvent(TRACE_ERROR, "encode_cc20 openssl init: %s\n", openssl_err_as_string());
+
+ EVP_CIPHER_CTX_reset(ctx);
+
+ len += TRANSOP_CC20_PREAMBLE_SIZE; /* size of data carried in UDP. */
+ } else
+ traceEvent(TRACE_ERROR, "encode_cc20 outbuf too small.");
+ } else
+ traceEvent(TRACE_ERROR, "encode_cc20 inbuf too big to encrypt.");
+
+ return len;
+}
+
+/* ****************************************************** */
+
+/* See transop_encode_cc20 for packet format */
+static int transop_decode_cc20(n2n_trans_op_t * arg,
+ uint8_t * outbuf,
+ size_t out_len,
+ const uint8_t * inbuf,
+ size_t in_len,
+ const uint8_t * peer_mac) {
+ int len=0;
+ transop_cc20_t * priv = (transop_cc20_t *)arg->priv;
+ uint8_t assembly[N2N_PKT_BUF_SIZE];
+
+ if(((in_len - TRANSOP_CC20_PREAMBLE_SIZE) <= N2N_PKT_BUF_SIZE) /* Cipher text fits in assembly */
+ && (in_len >= TRANSOP_CC20_PREAMBLE_SIZE) /* Has at least version, iv */
+ )
+ {
+ size_t rem=in_len;
+ size_t idx=0;
+ uint8_t cc20_enc_ver=0;
+ n2n_cc20_ivec_t dec_ivec = {0};
+
+ /* Get the encoding version to make sure it is supported */
+ decode_uint8(&cc20_enc_ver, inbuf, &rem, &idx );
+
+ if(N2N_CC20_TRANSFORM_VERSION == cc20_enc_ver) {
+ /* Get the IV */
+ decode_buf((uint8_t *)&dec_ivec, N2N_CC20_IVEC_SIZE, inbuf, &rem, &idx);
+
+ traceEvent(TRACE_DEBUG, "decode_cc20 %lu", in_len);
+ len = (in_len - TRANSOP_CC20_PREAMBLE_SIZE);
+
+ EVP_CIPHER_CTX *ctx = priv->dec_ctx;
+ int evp_len;
+ int evp_plaintext_len;
+
+ if(1 == EVP_DecryptInit_ex(ctx, priv->cipher, NULL, priv->key, dec_ivec)) {
+ if(1 == EVP_CIPHER_CTX_set_padding(ctx, 0)) {
+ if(1 == EVP_DecryptUpdate(ctx, assembly, &evp_len, inbuf + TRANSOP_CC20_PREAMBLE_SIZE, len)) {
+ evp_plaintext_len = evp_len;
+ if(1 == EVP_DecryptFinal_ex(ctx, assembly + evp_len, &evp_len)) {
+ evp_plaintext_len += evp_len;
+
+ if(evp_plaintext_len != len)
+ traceEvent(TRACE_ERROR, "decode_cc20 openssl decryption: decrypted %u bytes where %u were expected.\n",
+ evp_plaintext_len, len);
+ } else
+ traceEvent(TRACE_ERROR, "decode_cc20 openssl final decryption: %s\n", openssl_err_as_string());
+ } else
+ traceEvent(TRACE_ERROR, "decode_cc20 openssl decrpytion: %s\n", openssl_err_as_string());
+ } else
+ traceEvent(TRACE_ERROR, "decode_cc20 openssl padding setup: %s\n", openssl_err_as_string());
+ } else
+ traceEvent(TRACE_ERROR, "decode_cc20 openssl init: %s\n", openssl_err_as_string());
+
+ EVP_CIPHER_CTX_reset(ctx);
+
+ memcpy(outbuf, assembly, len);
+ } else
+ traceEvent(TRACE_ERROR, "decode_cc20 unsupported ChaCha20 version %u.", cc20_enc_ver);
+ } else
+ traceEvent(TRACE_ERROR, "decode_cc20 inbuf wrong size (%ul) to decrypt.", in_len);
+
+ return len;
+}
+
+/* ****************************************************** */
+
+static int setup_cc20_key(transop_cc20_t *priv, const uint8_t *key, ssize_t key_size) {
+ uint8_t key_mat_buf[SHA256_DIGEST_LENGTH];
+
+ priv->cipher = EVP_chacha20();
+
+ /* Clear out any old possibly longer key matter. */
+ memset(&(priv->key), 0, sizeof(priv->key) );
+ /* The input key always gets hashed to make a more unpredictable and more complete use of the key space */
+ SHA256(key, key_size, key_mat_buf);
+ memcpy (priv->key, key_mat_buf, SHA256_DIGEST_LENGTH);
+
+ traceEvent(TRACE_DEBUG, "ChaCha20 key setup completed\n");
+
+ return(0);
+}
+
+/* ****************************************************** */
+
+static void transop_tick_cc20(n2n_trans_op_t * arg, time_t now) { ; }
+
+/* ****************************************************** */
+
+/* ChaCha20 initialization function */
+int n2n_transop_cc20_init(const n2n_edge_conf_t *conf, n2n_trans_op_t *ttt) {
+ transop_cc20_t *priv;
+ const u_char *encrypt_key = (const u_char *)conf->encrypt_key;
+ size_t encrypt_key_len = strlen(conf->encrypt_key);
+
+ memset(ttt, 0, sizeof(*ttt));
+ ttt->transform_id = N2N_TRANSFORM_ID_CHACHA20;
+
+ ttt->tick = transop_tick_cc20;
+ ttt->deinit = transop_deinit_cc20;
+ ttt->fwd = transop_encode_cc20;
+ ttt->rev = transop_decode_cc20;
+
+ priv = (transop_cc20_t*) calloc(1, sizeof(transop_cc20_t));
+ if(!priv) {
+ traceEvent(TRACE_ERROR, "cannot allocate transop_cc20_t memory");
+ return(-1);
+ }
+ ttt->priv = priv;
+
+ /* Setup openssl's reusable evp_* contexts for encryption and decryption*/
+ if(!(priv->enc_ctx = EVP_CIPHER_CTX_new())) {
+ traceEvent(TRACE_ERROR, "openssl's evp_* encryption context creation: %s\n", openssl_err_as_string());
+ return(-1);
+ }
+
+ if(!(priv->dec_ctx = EVP_CIPHER_CTX_new())) {
+ traceEvent(TRACE_ERROR, "openssl's evp_* decryption context creation: %s\n", openssl_err_as_string());
+ return(-1);
+ }
+
+ /* Setup the cipher and key */
+ return(setup_cc20_key(priv, encrypt_key, encrypt_key_len));
+}
+
+#endif /* HAVE_OPENSSL_1_1 */