From 999ae6be3243c7b4a815247199447b53c39a3d65 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Mon, 6 May 2024 03:26:58 +0200 Subject: Adding upstream version 1:7.9p1. Signed-off-by: Daniel Baumann --- cipher-ctr.c | 146 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 146 insertions(+) create mode 100644 cipher-ctr.c (limited to 'cipher-ctr.c') diff --git a/cipher-ctr.c b/cipher-ctr.c new file mode 100644 index 0000000..32771f2 --- /dev/null +++ b/cipher-ctr.c @@ -0,0 +1,146 @@ +/* $OpenBSD: cipher-ctr.c,v 1.11 2010/10/01 23:05:32 djm Exp $ */ +/* + * Copyright (c) 2003 Markus Friedl + * + * 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 "includes.h" + +#if defined(WITH_OPENSSL) && !defined(OPENSSL_HAVE_EVPCTR) +#include + +#include +#include + +#include + +#include "xmalloc.h" +#include "log.h" + +/* compatibility with old or broken OpenSSL versions */ +#include "openbsd-compat/openssl-compat.h" + +#ifndef USE_BUILTIN_RIJNDAEL +#include +#endif + +struct ssh_aes_ctr_ctx +{ + AES_KEY aes_ctx; + u_char aes_counter[AES_BLOCK_SIZE]; +}; + +/* + * increment counter 'ctr', + * the counter is of size 'len' bytes and stored in network-byte-order. + * (LSB at ctr[len-1], MSB at ctr[0]) + */ +static void +ssh_ctr_inc(u_char *ctr, size_t len) +{ + int i; + + for (i = len - 1; i >= 0; i--) + if (++ctr[i]) /* continue on overflow */ + return; +} + +static int +ssh_aes_ctr(EVP_CIPHER_CTX *ctx, u_char *dest, const u_char *src, + LIBCRYPTO_EVP_INL_TYPE len) +{ + struct ssh_aes_ctr_ctx *c; + size_t n = 0; + u_char buf[AES_BLOCK_SIZE]; + + if (len == 0) + return (1); + if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) + return (0); + + while ((len--) > 0) { + if (n == 0) { + AES_encrypt(c->aes_counter, buf, &c->aes_ctx); + ssh_ctr_inc(c->aes_counter, AES_BLOCK_SIZE); + } + *(dest++) = *(src++) ^ buf[n]; + n = (n + 1) % AES_BLOCK_SIZE; + } + return (1); +} + +static int +ssh_aes_ctr_init(EVP_CIPHER_CTX *ctx, const u_char *key, const u_char *iv, + int enc) +{ + struct ssh_aes_ctr_ctx *c; + + if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) { + c = xmalloc(sizeof(*c)); + EVP_CIPHER_CTX_set_app_data(ctx, c); + } + if (key != NULL) + AES_set_encrypt_key(key, EVP_CIPHER_CTX_key_length(ctx) * 8, + &c->aes_ctx); + if (iv != NULL) + memcpy(c->aes_counter, iv, AES_BLOCK_SIZE); + return (1); +} + +static int +ssh_aes_ctr_cleanup(EVP_CIPHER_CTX *ctx) +{ + struct ssh_aes_ctr_ctx *c; + + if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) != NULL) { + memset(c, 0, sizeof(*c)); + free(c); + EVP_CIPHER_CTX_set_app_data(ctx, NULL); + } + return (1); +} + +void +ssh_aes_ctr_iv(EVP_CIPHER_CTX *evp, int doset, u_char * iv, size_t len) +{ + struct ssh_aes_ctr_ctx *c; + + if ((c = EVP_CIPHER_CTX_get_app_data(evp)) == NULL) + fatal("ssh_aes_ctr_iv: no context"); + if (doset) + memcpy(c->aes_counter, iv, len); + else + memcpy(iv, c->aes_counter, len); +} + +const EVP_CIPHER * +evp_aes_128_ctr(void) +{ + static EVP_CIPHER aes_ctr; + + memset(&aes_ctr, 0, sizeof(EVP_CIPHER)); + aes_ctr.nid = NID_undef; + aes_ctr.block_size = AES_BLOCK_SIZE; + aes_ctr.iv_len = AES_BLOCK_SIZE; + aes_ctr.key_len = 16; + aes_ctr.init = ssh_aes_ctr_init; + aes_ctr.cleanup = ssh_aes_ctr_cleanup; + aes_ctr.do_cipher = ssh_aes_ctr; +#ifndef SSH_OLD_EVP + aes_ctr.flags = EVP_CIPH_CBC_MODE | EVP_CIPH_VARIABLE_LENGTH | + EVP_CIPH_ALWAYS_CALL_INIT | EVP_CIPH_CUSTOM_IV; +#endif + return (&aes_ctr); +} + +#endif /* defined(WITH_OPENSSL) && !defined(OPENSSL_HAVE_EVPCTR) */ -- cgit v1.2.3