check in v3.8.0 source

crypto/evp/e_chacha.c

@@ -0,0 +1,78 @@
+/* $OpenBSD: e_chacha.c,v 1.10 2022/11/26 16:08:52 tb Exp $ */
+/*
+ * Copyright (c) 2014 Joel Sing <jsing@openbsd.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.
+ */
+
+#include <openssl/opensslconf.h>
+
+#ifndef OPENSSL_NO_CHACHA
+
+#include <openssl/chacha.h>
+#include <openssl/evp.h>
+#include <openssl/objects.h>
+
+#include "evp_local.h"
+
+static int
+chacha_init(EVP_CIPHER_CTX *ctx, const unsigned char *key,
+    const unsigned char *openssl_iv, int enc)
+{
+	if (key != NULL)
+		ChaCha_set_key((ChaCha_ctx *)ctx->cipher_data, key,
+		    EVP_CIPHER_CTX_key_length(ctx) * 8);
+	if (openssl_iv != NULL) {
+		const unsigned char *iv = openssl_iv + 8;
+		const unsigned char *counter = openssl_iv;
+
+		ChaCha_set_iv((ChaCha_ctx *)ctx->cipher_data, iv, counter);
+	}
+	return 1;
+}
+
+static int
+chacha_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out, const unsigned char *in,
+    size_t len)
+{
+	ChaCha((ChaCha_ctx *)ctx->cipher_data, out, in, len);
+	return 1;
+}
+
+static const EVP_CIPHER chacha20_cipher = {
+	.nid = NID_chacha20,
+	.block_size = 1,
+	.key_len = 32,
+	/* 
+	 * The 128 bit EVP IV is split for ChaCha into four 32 bit pieces:
+	 * 			counter[0]	counter[1]	iv[0]	iv[1]
+	 * OpenSSL exposes these as:
+	 * 	openssl_iv =	counter[0]	iv[0]		iv[1]	iv[2]
+	 * Due to the cipher internal state's symmetry, these are functionally
+	 * equivalent.
+	 */
+	.iv_len = 16,
+	.flags = EVP_CIPH_STREAM_CIPHER | EVP_CIPH_ALWAYS_CALL_INIT |
+	    EVP_CIPH_CUSTOM_IV,
+	.init = chacha_init,
+	.do_cipher = chacha_cipher,
+	.ctx_size = sizeof(ChaCha_ctx)
+};
+
+const EVP_CIPHER *
+EVP_chacha20(void)
+{
+	return (&chacha20_cipher);
+}
+
+#endif