lws-genaes.h

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/*
 * libwebsockets - small server side websockets and web server implementation
 *
 * Copyright (C) 2010 - 2020 Andy Green <andy@warmcat.com>
 *
 * 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.
 */

 
#if defined(LWS_WITH_MBEDTLS)
#include <mbedtls/aes.h>
#include <mbedtls/gcm.h>
#endif
 
enum enum_aes_modes {
        LWS_GAESM_CBC,
        LWS_GAESM_CFB128,
        LWS_GAESM_CFB8,
        LWS_GAESM_CTR,
        LWS_GAESM_ECB,
        LWS_GAESM_OFB,
        LWS_GAESM_XTS,             /* care... requires double-length key */
        LWS_GAESM_GCM,
        LWS_GAESM_KW,
};
 
enum enum_aes_operation {
        LWS_GAESO_ENC,
        LWS_GAESO_DEC
};
 
enum enum_aes_padding {
        LWS_GAESP_NO_PADDING,
        LWS_GAESP_WITH_PADDING
};
 
/* include/libwebsockets/lws-jwk.h must be included before this */
 
#define LWS_AES_BLOCKSIZE 128
#define LWS_AES_CBC_BLOCKLEN 16
 
struct lws_genaes_ctx {
#if defined(LWS_WITH_MBEDTLS)
        union {
                mbedtls_aes_context ctx;
#if defined(MBEDTLS_CIPHER_MODE_XTS)
                mbedtls_aes_xts_context ctx_xts;
#endif
                mbedtls_gcm_context ctx_gcm;
        } u;
#else
        EVP_CIPHER_CTX *ctx;
        const EVP_CIPHER *cipher;
        ENGINE *engine;
        char init;
#endif
        unsigned char tag[16];
        struct lws_gencrypto_keyelem *k;
        enum enum_aes_operation op;
        enum enum_aes_modes mode;
        enum enum_aes_padding padding;
        int taglen;
        char underway;
};

LWS_VISIBLE LWS_EXTERN int
lws_genaes_create(struct lws_genaes_ctx *ctx, enum enum_aes_operation op,
                  enum enum_aes_modes mode, struct lws_gencrypto_keyelem *el,
                  enum enum_aes_padding padding, void *engine);

LWS_VISIBLE LWS_EXTERN int
lws_genaes_destroy(struct lws_genaes_ctx *ctx, unsigned char *tag, size_t tlen);

LWS_VISIBLE LWS_EXTERN int
lws_genaes_crypt(struct lws_genaes_ctx *ctx, const uint8_t *in, size_t len,
                 uint8_t *out,
                 uint8_t *iv_or_nonce_ctr_or_data_unit_16,
                 uint8_t *stream_block_16,
                 size_t *nc_or_iv_off, int taglen);