Adding upstream version 1:9.2p1.upstream/1%9.2p1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 139 insertions, 0 deletions

diff --git a/cipher-chachapoly.c b/cipher-chachapoly.c
new file mode 100644
index 0000000..716f8d4
--- /dev/null
+++ b/cipher-chachapoly.c
@@ -0,0 +1,139 @@
+/*
+ * Copyright (c) 2013 Damien Miller <djm@mindrot.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/* $OpenBSD: cipher-chachapoly.c,v 1.9 2020/04/03 04:27:03 djm Exp $ */
+
+#include "includes.h"
+#ifdef WITH_OPENSSL
+#include "openbsd-compat/openssl-compat.h"
+#endif
+
+#if !defined(HAVE_EVP_CHACHA20) || defined(HAVE_BROKEN_CHACHA20)
+
+#include <sys/types.h>
+#include <stdarg.h> /* needed for log.h */
+#include <string.h>
+#include <stdio.h>  /* needed for misc.h */
+
+#include "log.h"
+#include "sshbuf.h"
+#include "ssherr.h"
+#include "cipher-chachapoly.h"
+
+struct chachapoly_ctx {
+	struct chacha_ctx main_ctx, header_ctx;
+};
+
+struct chachapoly_ctx *
+chachapoly_new(const u_char *key, u_int keylen)
+{
+	struct chachapoly_ctx *ctx;
+
+	if (keylen != (32 + 32)) /* 2 x 256 bit keys */
+		return NULL;
+	if ((ctx = calloc(1, sizeof(*ctx))) == NULL)
+		return NULL;
+	chacha_keysetup(&ctx->main_ctx, key, 256);
+	chacha_keysetup(&ctx->header_ctx, key + 32, 256);
+	return ctx;
+}
+
+void
+chachapoly_free(struct chachapoly_ctx *cpctx)
+{
+	freezero(cpctx, sizeof(*cpctx));
+}
+
+/*
+ * chachapoly_crypt() operates as following:
+ * En/decrypt with header key 'aadlen' bytes from 'src', storing result
+ * to 'dest'. The ciphertext here is treated as additional authenticated
+ * data for MAC calculation.
+ * En/decrypt 'len' bytes at offset 'aadlen' from 'src' to 'dest'. Use
+ * POLY1305_TAGLEN bytes at offset 'len'+'aadlen' as the authentication
+ * tag. This tag is written on encryption and verified on decryption.
+ */
+int
+chachapoly_crypt(struct chachapoly_ctx *ctx, u_int seqnr, u_char *dest,
+    const u_char *src, u_int len, u_int aadlen, u_int authlen, int do_encrypt)
+{
+	u_char seqbuf[8];
+	const u_char one[8] = { 1, 0, 0, 0, 0, 0, 0, 0 }; /* NB little-endian */
+	u_char expected_tag[POLY1305_TAGLEN], poly_key[POLY1305_KEYLEN];
+	int r = SSH_ERR_INTERNAL_ERROR;
+
+	/*
+	 * Run ChaCha20 once to generate the Poly1305 key. The IV is the
+	 * packet sequence number.
+	 */
+	memset(poly_key, 0, sizeof(poly_key));
+	POKE_U64(seqbuf, seqnr);
+	chacha_ivsetup(&ctx->main_ctx, seqbuf, NULL);
+	chacha_encrypt_bytes(&ctx->main_ctx,
+	    poly_key, poly_key, sizeof(poly_key));
+
+	/* If decrypting, check tag before anything else */
+	if (!do_encrypt) {
+		const u_char *tag = src + aadlen + len;
+
+		poly1305_auth(expected_tag, src, aadlen + len, poly_key);
+		if (timingsafe_bcmp(expected_tag, tag, POLY1305_TAGLEN) != 0) {
+			r = SSH_ERR_MAC_INVALID;
+			goto out;
+		}
+	}
+
+	/* Crypt additional data */
+	if (aadlen) {
+		chacha_ivsetup(&ctx->header_ctx, seqbuf, NULL);
+		chacha_encrypt_bytes(&ctx->header_ctx, src, dest, aadlen);
+	}
+
+	/* Set Chacha's block counter to 1 */
+	chacha_ivsetup(&ctx->main_ctx, seqbuf, one);
+	chacha_encrypt_bytes(&ctx->main_ctx, src + aadlen,
+	    dest + aadlen, len);
+
+	/* If encrypting, calculate and append tag */
+	if (do_encrypt) {
+		poly1305_auth(dest + aadlen + len, dest, aadlen + len,
+		    poly_key);
+	}
+	r = 0;
+ out:
+	explicit_bzero(expected_tag, sizeof(expected_tag));
+	explicit_bzero(seqbuf, sizeof(seqbuf));
+	explicit_bzero(poly_key, sizeof(poly_key));
+	return r;
+}
+
+/* Decrypt and extract the encrypted packet length */
+int
+chachapoly_get_length(struct chachapoly_ctx *ctx,
+    u_int *plenp, u_int seqnr, const u_char *cp, u_int len)
+{
+	u_char buf[4], seqbuf[8];
+
+	if (len < 4)
+		return SSH_ERR_MESSAGE_INCOMPLETE;
+	POKE_U64(seqbuf, seqnr);
+	chacha_ivsetup(&ctx->header_ctx, seqbuf, NULL);
+	chacha_encrypt_bytes(&ctx->header_ctx, cp, buf, 4);
+	*plenp = PEEK_U32(buf);
+	return 0;
+}
+
+#endif /* !defined(HAVE_EVP_CHACHA20) || defined(HAVE_BROKEN_CHACHA20) */