X-Git-Url: https://www.bearssl.org/gitweb//home/git/?p=BearSSL;a=blobdiff_plain;f=src%2Fssl%2Fssl_rec_chapol.c;fp=src%2Fssl%2Fssl_rec_chapol.c;h=73b3c78554734f732f19946baf0f2d137c035dbc;hp=0000000000000000000000000000000000000000;hb=b42bd5972f935ffc32019acac6f8a07ae08ae9c2;hpb=9e71c0673a9f46f82e43125919619f296698292e

diff --git a/src/ssl/ssl_rec_chapol.c b/src/ssl/ssl_rec_chapol.c
new file mode 100644
index 0000000..73b3c78
--- /dev/null
+++ b/src/ssl/ssl_rec_chapol.c
@@ -0,0 +1,177 @@
+/*
+ * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining 
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be 
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include "inner.h"
+
+static void
+gen_chapol_init(br_sslrec_chapol_context *cc,
+	br_chacha20_run ichacha, br_poly1305_run ipoly,
+	const void *key, const void *iv)
+{
+	cc->seq = 0;
+	cc->ichacha = ichacha;
+	cc->ipoly = ipoly;
+	memcpy(cc->key, key, sizeof cc->key);
+	memcpy(cc->iv, iv, sizeof cc->iv);
+}
+
+static void
+gen_chapol_process(br_sslrec_chapol_context *cc,
+	int record_type, unsigned version, void *data, size_t len,
+	void *tag, int encrypt)
+{
+	unsigned char header[13];
+	unsigned char nonce[12];
+	uint64_t seq;
+	size_t u;
+
+	seq = cc->seq ++;
+	br_enc64be(header, seq);
+	header[8] = (unsigned char)record_type;
+	br_enc16be(header + 9, version);
+	br_enc16be(header + 11, len);
+	memcpy(nonce, cc->iv, 12);
+	for (u = 0; u < 8; u ++) {
+		nonce[11 - u] ^= (unsigned char)seq;
+		seq >>= 8;
+	}
+	cc->ipoly(cc->key, nonce, data, len, header, sizeof header,
+		tag, cc->ichacha, encrypt);
+}
+
+static void
+in_chapol_init(br_sslrec_chapol_context *cc,
+	br_chacha20_run ichacha, br_poly1305_run ipoly,
+	const void *key, const void *iv)
+{
+	cc->vtable.in = &br_sslrec_in_chapol_vtable;
+	gen_chapol_init(cc, ichacha, ipoly, key, iv);
+}
+
+static int
+chapol_check_length(const br_sslrec_chapol_context *cc, size_t rlen)
+{
+	/*
+	 * Overhead is just the authentication tag (16 bytes).
+	 */
+	(void)cc;
+	return rlen >= 16 && rlen <= (16384 + 16);
+}
+
+static unsigned char *
+chapol_decrypt(br_sslrec_chapol_context *cc,
+	int record_type, unsigned version, void *data, size_t *data_len)
+{
+	unsigned char *buf;
+	size_t u, len;
+	unsigned char tag[16];
+	unsigned bad;
+
+	buf = data;
+	len = *data_len - 16;
+	gen_chapol_process(cc, record_type, version, buf, len, tag, 0);
+	bad = 0;
+	for (u = 0; u < 16; u ++) {
+		bad |= tag[u] ^ buf[len + u];
+	}
+	if (bad) {
+		return NULL;
+	}
+	*data_len = len;
+	return buf;
+}
+
+/* see bearssl_ssl.h */
+const br_sslrec_in_chapol_class br_sslrec_in_chapol_vtable = {
+	{
+		sizeof(br_sslrec_chapol_context),
+		(int (*)(const br_sslrec_in_class *const *, size_t))
+			&chapol_check_length,
+		(unsigned char *(*)(const br_sslrec_in_class **,
+			int, unsigned, void *, size_t *))
+			&chapol_decrypt
+	},
+	(void (*)(const br_sslrec_in_chapol_class **,
+		br_chacha20_run, br_poly1305_run,
+		const void *, const void *))
+		&in_chapol_init
+};
+
+static void
+out_chapol_init(br_sslrec_chapol_context *cc,
+	br_chacha20_run ichacha, br_poly1305_run ipoly,
+	const void *key, const void *iv)
+{
+	cc->vtable.out = &br_sslrec_out_chapol_vtable;
+	gen_chapol_init(cc, ichacha, ipoly, key, iv);
+}
+
+static void
+chapol_max_plaintext(const br_sslrec_chapol_context *cc,
+	size_t *start, size_t *end)
+{
+	size_t len;
+
+	(void)cc;
+	len = *end - *start - 16;
+	if (len > 16384) {
+		len = 16384;
+	}
+	*end = *start + len;
+}
+
+static unsigned char *
+chapol_encrypt(br_sslrec_chapol_context *cc,
+	int record_type, unsigned version, void *data, size_t *data_len)
+{
+	unsigned char *buf;
+	size_t len;
+
+	buf = data;
+	len = *data_len;
+	gen_chapol_process(cc, record_type, version, buf, len, buf + len, 1);
+	buf -= 5;
+	buf[0] = (unsigned char)record_type;
+	br_enc16be(buf + 1, version);
+	br_enc16be(buf + 3, len + 16);
+	*data_len = len + 21;
+	return buf;
+}
+
+/* see bearssl_ssl.h */
+const br_sslrec_out_chapol_class br_sslrec_out_chapol_vtable = {
+	{
+		sizeof(br_sslrec_chapol_context),
+		(void (*)(const br_sslrec_out_class *const *,
+			size_t *, size_t *))
+			&chapol_max_plaintext,
+		(unsigned char *(*)(const br_sslrec_out_class **,
+			int, unsigned, void *, size_t *))
+			&chapol_encrypt
+	},
+	(void (*)(const br_sslrec_out_chapol_class **,
+		br_chacha20_run, br_poly1305_run,
+		const void *, const void *))
+		&out_chapol_init
+};