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2a3d0ee9d5
ChaCha20-Poly1305 is an AEAD cipher, and requires a unique nonce input for every encryption operation. RFC 7539 specifies that the nonce value (IV) should be 96 bits (12 bytes). OpenSSL allows a variable nonce length and front pads the nonce with 0 bytes if it is less than 12 bytes. However it also incorrectly allows a nonce to be set of up to 16 bytes. In this case only the last 12 bytes are significant and any additional leading bytes are ignored. It is a requirement of using this cipher that nonce values are unique. Messages encrypted using a reused nonce value are susceptible to serious confidentiality and integrity attacks. If an application changes the default nonce length to be longer than 12 bytes and then makes a change to the leading bytes of the nonce expecting the new value to be a new unique nonce then such an application could inadvertently encrypt messages with a reused nonce. Additionally the ignored bytes in a long nonce are not covered by the integrity guarantee of this cipher. Any application that relies on the integrity of these ignored leading bytes of a long nonce may be further affected. Any OpenSSL internal use of this cipher, including in SSL/TLS, is safe because no such use sets such a long nonce value. However user applications that use this cipher directly and set a non-default nonce length to be longer than 12 bytes may be vulnerable. CVE-2019-1543 Fixes #8345 Reviewed-by: Paul Dale <paul.dale@oracle.com> Reviewed-by: Richard Levitte <levitte@openssl.org> (Merged from https://github.com/openssl/openssl/pull/8406)
633 lines
20 KiB
C
633 lines
20 KiB
C
/*
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* Copyright 2015-2018 The OpenSSL Project Authors. All Rights Reserved.
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*
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* Licensed under the Apache License 2.0 (the "License"). You may not use
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* this file except in compliance with the License. You can obtain a copy
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* in the file LICENSE in the source distribution or at
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* https://www.openssl.org/source/license.html
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*/
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#include <stdio.h>
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#include "internal/cryptlib.h"
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#ifndef OPENSSL_NO_CHACHA
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# include <openssl/evp.h>
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# include <openssl/objects.h>
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# include "internal/evp_int.h"
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# include "evp_locl.h"
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# include "internal/chacha.h"
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typedef struct {
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union {
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double align; /* this ensures even sizeof(EVP_CHACHA_KEY)%8==0 */
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unsigned int d[CHACHA_KEY_SIZE / 4];
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} key;
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unsigned int counter[CHACHA_CTR_SIZE / 4];
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unsigned char buf[CHACHA_BLK_SIZE];
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unsigned int partial_len;
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} EVP_CHACHA_KEY;
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#define data(ctx) ((EVP_CHACHA_KEY *)(ctx)->cipher_data)
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#define CHACHA20_POLY1305_MAX_IVLEN 12
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static int chacha_init_key(EVP_CIPHER_CTX *ctx,
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const unsigned char user_key[CHACHA_KEY_SIZE],
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const unsigned char iv[CHACHA_CTR_SIZE], int enc)
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{
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EVP_CHACHA_KEY *key = data(ctx);
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unsigned int i;
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if (user_key)
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for (i = 0; i < CHACHA_KEY_SIZE; i+=4) {
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key->key.d[i/4] = CHACHA_U8TOU32(user_key+i);
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}
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if (iv)
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for (i = 0; i < CHACHA_CTR_SIZE; i+=4) {
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key->counter[i/4] = CHACHA_U8TOU32(iv+i);
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}
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key->partial_len = 0;
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return 1;
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}
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static int chacha_cipher(EVP_CIPHER_CTX * ctx, unsigned char *out,
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const unsigned char *inp, size_t len)
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{
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EVP_CHACHA_KEY *key = data(ctx);
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unsigned int n, rem, ctr32;
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if ((n = key->partial_len)) {
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while (len && n < CHACHA_BLK_SIZE) {
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*out++ = *inp++ ^ key->buf[n++];
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len--;
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}
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key->partial_len = n;
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if (len == 0)
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return 1;
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if (n == CHACHA_BLK_SIZE) {
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key->partial_len = 0;
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key->counter[0]++;
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if (key->counter[0] == 0)
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key->counter[1]++;
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}
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}
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rem = (unsigned int)(len % CHACHA_BLK_SIZE);
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len -= rem;
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ctr32 = key->counter[0];
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while (len >= CHACHA_BLK_SIZE) {
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size_t blocks = len / CHACHA_BLK_SIZE;
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/*
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* 1<<28 is just a not-so-small yet not-so-large number...
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* Below condition is practically never met, but it has to
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* be checked for code correctness.
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*/
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if (sizeof(size_t)>sizeof(unsigned int) && blocks>(1U<<28))
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blocks = (1U<<28);
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/*
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* As ChaCha20_ctr32 operates on 32-bit counter, caller
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* has to handle overflow. 'if' below detects the
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* overflow, which is then handled by limiting the
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* amount of blocks to the exact overflow point...
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*/
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ctr32 += (unsigned int)blocks;
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if (ctr32 < blocks) {
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blocks -= ctr32;
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ctr32 = 0;
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}
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blocks *= CHACHA_BLK_SIZE;
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ChaCha20_ctr32(out, inp, blocks, key->key.d, key->counter);
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len -= blocks;
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inp += blocks;
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out += blocks;
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key->counter[0] = ctr32;
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if (ctr32 == 0) key->counter[1]++;
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}
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if (rem) {
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memset(key->buf, 0, sizeof(key->buf));
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ChaCha20_ctr32(key->buf, key->buf, CHACHA_BLK_SIZE,
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key->key.d, key->counter);
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for (n = 0; n < rem; n++)
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out[n] = inp[n] ^ key->buf[n];
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key->partial_len = rem;
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}
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return 1;
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}
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static const EVP_CIPHER chacha20 = {
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NID_chacha20,
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1, /* block_size */
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CHACHA_KEY_SIZE, /* key_len */
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CHACHA_CTR_SIZE, /* iv_len, 128-bit counter in the context */
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EVP_CIPH_CUSTOM_IV | EVP_CIPH_ALWAYS_CALL_INIT,
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chacha_init_key,
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chacha_cipher,
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NULL,
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sizeof(EVP_CHACHA_KEY),
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NULL,
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NULL,
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NULL,
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NULL
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};
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const EVP_CIPHER *EVP_chacha20(void)
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{
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return &chacha20;
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}
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# ifndef OPENSSL_NO_POLY1305
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# include "internal/poly1305.h"
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typedef struct {
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EVP_CHACHA_KEY key;
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unsigned int nonce[12/4];
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unsigned char tag[POLY1305_BLOCK_SIZE];
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unsigned char tls_aad[POLY1305_BLOCK_SIZE];
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struct { uint64_t aad, text; } len;
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int aad, mac_inited, tag_len, nonce_len;
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size_t tls_payload_length;
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} EVP_CHACHA_AEAD_CTX;
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# define NO_TLS_PAYLOAD_LENGTH ((size_t)-1)
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# define aead_data(ctx) ((EVP_CHACHA_AEAD_CTX *)(ctx)->cipher_data)
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# define POLY1305_ctx(actx) ((POLY1305 *)(actx + 1))
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static int chacha20_poly1305_init_key(EVP_CIPHER_CTX *ctx,
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const unsigned char *inkey,
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const unsigned char *iv, int enc)
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{
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EVP_CHACHA_AEAD_CTX *actx = aead_data(ctx);
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if (!inkey && !iv)
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return 1;
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actx->len.aad = 0;
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actx->len.text = 0;
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actx->aad = 0;
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actx->mac_inited = 0;
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actx->tls_payload_length = NO_TLS_PAYLOAD_LENGTH;
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if (iv != NULL) {
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unsigned char temp[CHACHA_CTR_SIZE] = { 0 };
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/* pad on the left */
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if (actx->nonce_len <= CHACHA_CTR_SIZE)
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memcpy(temp + CHACHA_CTR_SIZE - actx->nonce_len, iv,
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actx->nonce_len);
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chacha_init_key(ctx, inkey, temp, enc);
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actx->nonce[0] = actx->key.counter[1];
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actx->nonce[1] = actx->key.counter[2];
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actx->nonce[2] = actx->key.counter[3];
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} else {
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chacha_init_key(ctx, inkey, NULL, enc);
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}
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return 1;
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}
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# if !defined(OPENSSL_SMALL_FOOTPRINT)
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# if defined(POLY1305_ASM) && (defined(__x86_64) || defined(__x86_64__) || \
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defined(_M_AMD64) || defined(_M_X64))
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# define XOR128_HELPERS
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void *xor128_encrypt_n_pad(void *out, const void *inp, void *otp, size_t len);
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void *xor128_decrypt_n_pad(void *out, const void *inp, void *otp, size_t len);
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static const unsigned char zero[4 * CHACHA_BLK_SIZE] = { 0 };
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# else
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static const unsigned char zero[2 * CHACHA_BLK_SIZE] = { 0 };
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# endif
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static int chacha20_poly1305_tls_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
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const unsigned char *in, size_t len)
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{
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EVP_CHACHA_AEAD_CTX *actx = aead_data(ctx);
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size_t tail, tohash_len, buf_len, plen = actx->tls_payload_length;
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unsigned char *buf, *tohash, *ctr, storage[sizeof(zero) + 32];
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if (len != plen + POLY1305_BLOCK_SIZE)
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return -1;
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buf = storage + ((0 - (size_t)storage) & 15); /* align */
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ctr = buf + CHACHA_BLK_SIZE;
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tohash = buf + CHACHA_BLK_SIZE - POLY1305_BLOCK_SIZE;
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# ifdef XOR128_HELPERS
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if (plen <= 3 * CHACHA_BLK_SIZE) {
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actx->key.counter[0] = 0;
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buf_len = (plen + 2 * CHACHA_BLK_SIZE - 1) & (0 - CHACHA_BLK_SIZE);
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ChaCha20_ctr32(buf, zero, buf_len, actx->key.key.d,
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actx->key.counter);
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Poly1305_Init(POLY1305_ctx(actx), buf);
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actx->key.partial_len = 0;
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memcpy(tohash, actx->tls_aad, POLY1305_BLOCK_SIZE);
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tohash_len = POLY1305_BLOCK_SIZE;
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actx->len.aad = EVP_AEAD_TLS1_AAD_LEN;
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actx->len.text = plen;
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if (plen) {
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if (ctx->encrypt)
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ctr = xor128_encrypt_n_pad(out, in, ctr, plen);
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else
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ctr = xor128_decrypt_n_pad(out, in, ctr, plen);
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in += plen;
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out += plen;
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tohash_len = (size_t)(ctr - tohash);
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}
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}
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# else
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if (plen <= CHACHA_BLK_SIZE) {
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size_t i;
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actx->key.counter[0] = 0;
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ChaCha20_ctr32(buf, zero, (buf_len = 2 * CHACHA_BLK_SIZE),
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actx->key.key.d, actx->key.counter);
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Poly1305_Init(POLY1305_ctx(actx), buf);
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actx->key.partial_len = 0;
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memcpy(tohash, actx->tls_aad, POLY1305_BLOCK_SIZE);
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tohash_len = POLY1305_BLOCK_SIZE;
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actx->len.aad = EVP_AEAD_TLS1_AAD_LEN;
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actx->len.text = plen;
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if (ctx->encrypt) {
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for (i = 0; i < plen; i++) {
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out[i] = ctr[i] ^= in[i];
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}
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} else {
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for (i = 0; i < plen; i++) {
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unsigned char c = in[i];
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out[i] = ctr[i] ^ c;
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ctr[i] = c;
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}
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}
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in += i;
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out += i;
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tail = (0 - i) & (POLY1305_BLOCK_SIZE - 1);
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memset(ctr + i, 0, tail);
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ctr += i + tail;
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tohash_len += i + tail;
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}
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# endif
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else {
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actx->key.counter[0] = 0;
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ChaCha20_ctr32(buf, zero, (buf_len = CHACHA_BLK_SIZE),
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actx->key.key.d, actx->key.counter);
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Poly1305_Init(POLY1305_ctx(actx), buf);
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actx->key.counter[0] = 1;
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actx->key.partial_len = 0;
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Poly1305_Update(POLY1305_ctx(actx), actx->tls_aad, POLY1305_BLOCK_SIZE);
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tohash = ctr;
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tohash_len = 0;
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actx->len.aad = EVP_AEAD_TLS1_AAD_LEN;
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actx->len.text = plen;
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if (ctx->encrypt) {
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ChaCha20_ctr32(out, in, plen, actx->key.key.d, actx->key.counter);
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Poly1305_Update(POLY1305_ctx(actx), out, plen);
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} else {
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Poly1305_Update(POLY1305_ctx(actx), in, plen);
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ChaCha20_ctr32(out, in, plen, actx->key.key.d, actx->key.counter);
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}
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in += plen;
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out += plen;
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tail = (0 - plen) & (POLY1305_BLOCK_SIZE - 1);
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Poly1305_Update(POLY1305_ctx(actx), zero, tail);
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}
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{
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const union {
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long one;
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char little;
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} is_endian = { 1 };
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if (is_endian.little) {
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memcpy(ctr, (unsigned char *)&actx->len, POLY1305_BLOCK_SIZE);
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} else {
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ctr[0] = (unsigned char)(actx->len.aad);
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ctr[1] = (unsigned char)(actx->len.aad>>8);
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ctr[2] = (unsigned char)(actx->len.aad>>16);
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ctr[3] = (unsigned char)(actx->len.aad>>24);
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ctr[4] = (unsigned char)(actx->len.aad>>32);
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ctr[5] = (unsigned char)(actx->len.aad>>40);
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ctr[6] = (unsigned char)(actx->len.aad>>48);
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ctr[7] = (unsigned char)(actx->len.aad>>56);
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ctr[8] = (unsigned char)(actx->len.text);
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ctr[9] = (unsigned char)(actx->len.text>>8);
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ctr[10] = (unsigned char)(actx->len.text>>16);
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ctr[11] = (unsigned char)(actx->len.text>>24);
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ctr[12] = (unsigned char)(actx->len.text>>32);
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ctr[13] = (unsigned char)(actx->len.text>>40);
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ctr[14] = (unsigned char)(actx->len.text>>48);
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ctr[15] = (unsigned char)(actx->len.text>>56);
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}
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tohash_len += POLY1305_BLOCK_SIZE;
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}
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Poly1305_Update(POLY1305_ctx(actx), tohash, tohash_len);
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OPENSSL_cleanse(buf, buf_len);
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Poly1305_Final(POLY1305_ctx(actx), ctx->encrypt ? actx->tag
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: tohash);
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actx->tls_payload_length = NO_TLS_PAYLOAD_LENGTH;
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if (ctx->encrypt) {
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memcpy(out, actx->tag, POLY1305_BLOCK_SIZE);
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} else {
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if (CRYPTO_memcmp(tohash, in, POLY1305_BLOCK_SIZE)) {
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memset(out - (len - POLY1305_BLOCK_SIZE), 0,
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len - POLY1305_BLOCK_SIZE);
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return -1;
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}
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}
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return len;
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}
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# else
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static const unsigned char zero[CHACHA_BLK_SIZE] = { 0 };
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# endif
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static int chacha20_poly1305_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
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const unsigned char *in, size_t len)
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{
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EVP_CHACHA_AEAD_CTX *actx = aead_data(ctx);
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size_t rem, plen = actx->tls_payload_length;
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if (!actx->mac_inited) {
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# if !defined(OPENSSL_SMALL_FOOTPRINT)
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if (plen != NO_TLS_PAYLOAD_LENGTH && out != NULL)
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return chacha20_poly1305_tls_cipher(ctx, out, in, len);
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# endif
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actx->key.counter[0] = 0;
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ChaCha20_ctr32(actx->key.buf, zero, CHACHA_BLK_SIZE,
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actx->key.key.d, actx->key.counter);
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Poly1305_Init(POLY1305_ctx(actx), actx->key.buf);
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actx->key.counter[0] = 1;
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actx->key.partial_len = 0;
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actx->len.aad = actx->len.text = 0;
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actx->mac_inited = 1;
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if (plen != NO_TLS_PAYLOAD_LENGTH) {
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Poly1305_Update(POLY1305_ctx(actx), actx->tls_aad,
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EVP_AEAD_TLS1_AAD_LEN);
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actx->len.aad = EVP_AEAD_TLS1_AAD_LEN;
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actx->aad = 1;
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}
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}
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if (in) { /* aad or text */
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if (out == NULL) { /* aad */
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Poly1305_Update(POLY1305_ctx(actx), in, len);
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actx->len.aad += len;
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actx->aad = 1;
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return len;
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} else { /* plain- or ciphertext */
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if (actx->aad) { /* wrap up aad */
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if ((rem = (size_t)actx->len.aad % POLY1305_BLOCK_SIZE))
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Poly1305_Update(POLY1305_ctx(actx), zero,
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POLY1305_BLOCK_SIZE - rem);
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actx->aad = 0;
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}
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actx->tls_payload_length = NO_TLS_PAYLOAD_LENGTH;
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if (plen == NO_TLS_PAYLOAD_LENGTH)
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plen = len;
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else if (len != plen + POLY1305_BLOCK_SIZE)
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return -1;
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if (ctx->encrypt) { /* plaintext */
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chacha_cipher(ctx, out, in, plen);
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Poly1305_Update(POLY1305_ctx(actx), out, plen);
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in += plen;
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out += plen;
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actx->len.text += plen;
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} else { /* ciphertext */
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Poly1305_Update(POLY1305_ctx(actx), in, plen);
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chacha_cipher(ctx, out, in, plen);
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in += plen;
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out += plen;
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actx->len.text += plen;
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}
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}
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}
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if (in == NULL /* explicit final */
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|| plen != len) { /* or tls mode */
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const union {
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long one;
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char little;
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} is_endian = { 1 };
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unsigned char temp[POLY1305_BLOCK_SIZE];
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if (actx->aad) { /* wrap up aad */
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if ((rem = (size_t)actx->len.aad % POLY1305_BLOCK_SIZE))
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Poly1305_Update(POLY1305_ctx(actx), zero,
|
|
POLY1305_BLOCK_SIZE - rem);
|
|
actx->aad = 0;
|
|
}
|
|
|
|
if ((rem = (size_t)actx->len.text % POLY1305_BLOCK_SIZE))
|
|
Poly1305_Update(POLY1305_ctx(actx), zero,
|
|
POLY1305_BLOCK_SIZE - rem);
|
|
|
|
if (is_endian.little) {
|
|
Poly1305_Update(POLY1305_ctx(actx),
|
|
(unsigned char *)&actx->len, POLY1305_BLOCK_SIZE);
|
|
} else {
|
|
temp[0] = (unsigned char)(actx->len.aad);
|
|
temp[1] = (unsigned char)(actx->len.aad>>8);
|
|
temp[2] = (unsigned char)(actx->len.aad>>16);
|
|
temp[3] = (unsigned char)(actx->len.aad>>24);
|
|
temp[4] = (unsigned char)(actx->len.aad>>32);
|
|
temp[5] = (unsigned char)(actx->len.aad>>40);
|
|
temp[6] = (unsigned char)(actx->len.aad>>48);
|
|
temp[7] = (unsigned char)(actx->len.aad>>56);
|
|
|
|
temp[8] = (unsigned char)(actx->len.text);
|
|
temp[9] = (unsigned char)(actx->len.text>>8);
|
|
temp[10] = (unsigned char)(actx->len.text>>16);
|
|
temp[11] = (unsigned char)(actx->len.text>>24);
|
|
temp[12] = (unsigned char)(actx->len.text>>32);
|
|
temp[13] = (unsigned char)(actx->len.text>>40);
|
|
temp[14] = (unsigned char)(actx->len.text>>48);
|
|
temp[15] = (unsigned char)(actx->len.text>>56);
|
|
|
|
Poly1305_Update(POLY1305_ctx(actx), temp, POLY1305_BLOCK_SIZE);
|
|
}
|
|
Poly1305_Final(POLY1305_ctx(actx), ctx->encrypt ? actx->tag
|
|
: temp);
|
|
actx->mac_inited = 0;
|
|
|
|
if (in != NULL && len != plen) { /* tls mode */
|
|
if (ctx->encrypt) {
|
|
memcpy(out, actx->tag, POLY1305_BLOCK_SIZE);
|
|
} else {
|
|
if (CRYPTO_memcmp(temp, in, POLY1305_BLOCK_SIZE)) {
|
|
memset(out - plen, 0, plen);
|
|
return -1;
|
|
}
|
|
}
|
|
}
|
|
else if (!ctx->encrypt) {
|
|
if (CRYPTO_memcmp(temp, actx->tag, actx->tag_len))
|
|
return -1;
|
|
}
|
|
}
|
|
return len;
|
|
}
|
|
|
|
static int chacha20_poly1305_cleanup(EVP_CIPHER_CTX *ctx)
|
|
{
|
|
EVP_CHACHA_AEAD_CTX *actx = aead_data(ctx);
|
|
if (actx)
|
|
OPENSSL_cleanse(ctx->cipher_data, sizeof(*actx) + Poly1305_ctx_size());
|
|
return 1;
|
|
}
|
|
|
|
static int chacha20_poly1305_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg,
|
|
void *ptr)
|
|
{
|
|
EVP_CHACHA_AEAD_CTX *actx = aead_data(ctx);
|
|
|
|
switch(type) {
|
|
case EVP_CTRL_INIT:
|
|
if (actx == NULL)
|
|
actx = ctx->cipher_data
|
|
= OPENSSL_zalloc(sizeof(*actx) + Poly1305_ctx_size());
|
|
if (actx == NULL) {
|
|
EVPerr(EVP_F_CHACHA20_POLY1305_CTRL, EVP_R_INITIALIZATION_ERROR);
|
|
return 0;
|
|
}
|
|
actx->len.aad = 0;
|
|
actx->len.text = 0;
|
|
actx->aad = 0;
|
|
actx->mac_inited = 0;
|
|
actx->tag_len = 0;
|
|
actx->nonce_len = 12;
|
|
actx->tls_payload_length = NO_TLS_PAYLOAD_LENGTH;
|
|
memset(actx->tls_aad, 0, POLY1305_BLOCK_SIZE);
|
|
return 1;
|
|
|
|
case EVP_CTRL_COPY:
|
|
if (actx) {
|
|
EVP_CIPHER_CTX *dst = (EVP_CIPHER_CTX *)ptr;
|
|
|
|
dst->cipher_data =
|
|
OPENSSL_memdup(actx, sizeof(*actx) + Poly1305_ctx_size());
|
|
if (dst->cipher_data == NULL) {
|
|
EVPerr(EVP_F_CHACHA20_POLY1305_CTRL, EVP_R_COPY_ERROR);
|
|
return 0;
|
|
}
|
|
}
|
|
return 1;
|
|
|
|
case EVP_CTRL_AEAD_SET_IVLEN:
|
|
if (arg <= 0 || arg > CHACHA20_POLY1305_MAX_IVLEN)
|
|
return 0;
|
|
actx->nonce_len = arg;
|
|
return 1;
|
|
|
|
case EVP_CTRL_AEAD_SET_IV_FIXED:
|
|
if (arg != 12)
|
|
return 0;
|
|
actx->nonce[0] = actx->key.counter[1]
|
|
= CHACHA_U8TOU32((unsigned char *)ptr);
|
|
actx->nonce[1] = actx->key.counter[2]
|
|
= CHACHA_U8TOU32((unsigned char *)ptr+4);
|
|
actx->nonce[2] = actx->key.counter[3]
|
|
= CHACHA_U8TOU32((unsigned char *)ptr+8);
|
|
return 1;
|
|
|
|
case EVP_CTRL_AEAD_SET_TAG:
|
|
if (arg <= 0 || arg > POLY1305_BLOCK_SIZE)
|
|
return 0;
|
|
if (ptr != NULL) {
|
|
memcpy(actx->tag, ptr, arg);
|
|
actx->tag_len = arg;
|
|
}
|
|
return 1;
|
|
|
|
case EVP_CTRL_AEAD_GET_TAG:
|
|
if (arg <= 0 || arg > POLY1305_BLOCK_SIZE || !ctx->encrypt)
|
|
return 0;
|
|
memcpy(ptr, actx->tag, arg);
|
|
return 1;
|
|
|
|
case EVP_CTRL_AEAD_TLS1_AAD:
|
|
if (arg != EVP_AEAD_TLS1_AAD_LEN)
|
|
return 0;
|
|
{
|
|
unsigned int len;
|
|
unsigned char *aad = ptr;
|
|
|
|
memcpy(actx->tls_aad, ptr, EVP_AEAD_TLS1_AAD_LEN);
|
|
len = aad[EVP_AEAD_TLS1_AAD_LEN - 2] << 8 |
|
|
aad[EVP_AEAD_TLS1_AAD_LEN - 1];
|
|
aad = actx->tls_aad;
|
|
if (!ctx->encrypt) {
|
|
if (len < POLY1305_BLOCK_SIZE)
|
|
return 0;
|
|
len -= POLY1305_BLOCK_SIZE; /* discount attached tag */
|
|
aad[EVP_AEAD_TLS1_AAD_LEN - 2] = (unsigned char)(len >> 8);
|
|
aad[EVP_AEAD_TLS1_AAD_LEN - 1] = (unsigned char)len;
|
|
}
|
|
actx->tls_payload_length = len;
|
|
|
|
/*
|
|
* merge record sequence number as per RFC7905
|
|
*/
|
|
actx->key.counter[1] = actx->nonce[0];
|
|
actx->key.counter[2] = actx->nonce[1] ^ CHACHA_U8TOU32(aad);
|
|
actx->key.counter[3] = actx->nonce[2] ^ CHACHA_U8TOU32(aad+4);
|
|
actx->mac_inited = 0;
|
|
|
|
return POLY1305_BLOCK_SIZE; /* tag length */
|
|
}
|
|
|
|
case EVP_CTRL_AEAD_SET_MAC_KEY:
|
|
/* no-op */
|
|
return 1;
|
|
|
|
default:
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
static EVP_CIPHER chacha20_poly1305 = {
|
|
NID_chacha20_poly1305,
|
|
1, /* block_size */
|
|
CHACHA_KEY_SIZE, /* key_len */
|
|
12, /* iv_len, 96-bit nonce in the context */
|
|
EVP_CIPH_FLAG_AEAD_CIPHER | EVP_CIPH_CUSTOM_IV |
|
|
EVP_CIPH_ALWAYS_CALL_INIT | EVP_CIPH_CTRL_INIT |
|
|
EVP_CIPH_CUSTOM_COPY | EVP_CIPH_FLAG_CUSTOM_CIPHER,
|
|
chacha20_poly1305_init_key,
|
|
chacha20_poly1305_cipher,
|
|
chacha20_poly1305_cleanup,
|
|
0, /* 0 moves context-specific structure allocation to ctrl */
|
|
NULL, /* set_asn1_parameters */
|
|
NULL, /* get_asn1_parameters */
|
|
chacha20_poly1305_ctrl,
|
|
NULL /* app_data */
|
|
};
|
|
|
|
const EVP_CIPHER *EVP_chacha20_poly1305(void)
|
|
{
|
|
return(&chacha20_poly1305);
|
|
}
|
|
# endif
|
|
#endif
|