lws-genaes.h

/*
 * libwebsockets - small server side websockets and web server implementation
 *
 * Copyright (C) 2010 - 2018 Andy Green <andy@warmcat.com>
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation:
 *  version 2.1 of the License.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 *  MA  02110-1301  USA
 *
 * included from libwebsockets.h
 */
 
 
#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
 
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);