mirror of
https://github.com/warmcat/libwebsockets.git
synced 2025-03-09 00:00:04 +01:00
c9731c5f17
This is a huge patch that should be a global NOP. For unix type platforms it enables -Wconversion to issue warnings (-> error) for all automatic casts that seem less than ideal but are normally concealed by the toolchain. This is things like passing an int to a size_t argument. Once enabled, I went through all args on my default build (which build most things) and tried to make the removed default cast explicit. With that approach it neither change nor bloat the code, since it compiles to whatever it was doing before, just with the casts made explicit... in a few cases I changed some length args from int to size_t but largely left the causes alone. From now on, new code that is relying on less than ideal casting will complain and nudge me to improve it by warnings.
173 lines
5.2 KiB
C
173 lines
5.2 KiB
C
/*
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* libwebsockets - small server side websockets and web server implementation
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*
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* Copyright (C) 2010 - 2020 Andy Green <andy@warmcat.com>
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to
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* deal in the Software without restriction, including without limitation the
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* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
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* sell copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
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* IN THE SOFTWARE.
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*/
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#include "private-lib-core.h"
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#include "private-lib-jose-jwe.h"
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/*
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* NOTICE this is AESGCM content encryption, it's not AES GCM key wrapping
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*
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*
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* This section defines the specifics of performing authenticated
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* encryption with AES in Galois/Counter Mode (GCM) ([AES] and
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* [NIST.800-38D]).
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*
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* The CEK is used as the encryption key.
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*
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* Use of an IV of size 96 bits is REQUIRED with this algorithm.
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*
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* The requested size of the Authentication Tag output MUST be 128 bits,
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* regardless of the key size.
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*
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* For decrypt: decrypt the KEK, then decrypt the payload
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*
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* For encrypt: encrypt the payload, then encrypt the KEK
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*/
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/*
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* encrypting... enc_cek is unencrypted
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*/
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int
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lws_jwe_encrypt_gcm(struct lws_jwe *jwe,
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uint8_t *enc_cek, uint8_t *aad, int aad_len)
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{
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struct lws_gencrypto_keyelem el;
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struct lws_genaes_ctx aesctx;
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size_t ivs = LWS_AESGCM_IV;
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int n;
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/* Some sanity checks on what came in */
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/* MUST be 128-bit for all sizes */
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if (jwe->jws.map.len[LJWE_ATAG] != LWS_AESGCM_TAG) {
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lwsl_notice("%s: AESGCM tag size must be 128b, got %d\n",
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__func__, jwe->jws.map.len[LJWE_ATAG]);
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return -1;
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}
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if (jwe->jws.map.len[LJWE_IV] != LWS_AESGCM_IV) { /* MUST be 96-bit */
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lwsl_notice("%s: AESGCM IV must be 128b, got %d\n", __func__,
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jwe->jws.map.len[LJWE_IV]);
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return -1;
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}
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/* EKEY is directly the CEK KEY */
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el.buf = enc_cek;
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el.len = jwe->jose.enc_alg->keybits_fixed / 8;
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if (lws_genaes_create(&aesctx, LWS_GAESO_ENC, LWS_GAESM_GCM,
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&el, LWS_GAESP_NO_PADDING, NULL)) {
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lwsl_err("%s: lws_genaes_create failed\n", __func__);
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return -1;
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}
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/* aad */
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n = lws_genaes_crypt(&aesctx, aad, (unsigned int)aad_len, NULL,
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(uint8_t *)jwe->jws.map.buf[LJWE_IV],
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(uint8_t *)jwe->jws.map.buf[LJWE_ATAG], &ivs,
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LWS_AESGCM_TAG);
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if (n) {
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lwsl_err("%s: lws_genaes_crypt aad failed\n", __func__);
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return -1;
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}
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/* payload */
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n = lws_genaes_crypt(&aesctx, (uint8_t *)jwe->jws.map.buf[LJWE_CTXT],
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jwe->jws.map.len[LJWE_CTXT],
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(uint8_t *)jwe->jws.map.buf[LJWE_CTXT],
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(uint8_t *)jwe->jws.map.buf[LJWE_IV],
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NULL, &ivs,
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LWS_AESGCM_TAG);
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n |= lws_genaes_destroy(&aesctx, (uint8_t *)jwe->jws.map.buf[LJWE_ATAG],
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LWS_AESGCM_TAG);
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if (n) {
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lwsl_err("%s: lws_genaes_crypt failed\n", __func__);
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return -1;
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}
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return (int)jwe->jws.map.len[LJWE_CTXT];
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}
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int
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lws_jwe_auth_and_decrypt_gcm(struct lws_jwe *jwe,
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uint8_t *enc_cek, uint8_t *aad, int aad_len)
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{
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struct lws_gencrypto_keyelem el;
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struct lws_genaes_ctx aesctx;
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size_t ivs = LWS_AESGCM_IV;
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uint8_t tag[LWS_AESGCM_TAG];
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int n;
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/* Some sanity checks on what came in */
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/* Tag MUST be 128-bit for all sizes */
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if (jwe->jws.map.len[LJWE_ATAG] != LWS_AESGCM_TAG) {
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lwsl_notice("%s: AESGCM tag size must be 128b, got %d\n",
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__func__, jwe->jws.map.len[LJWE_ATAG]);
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return -1;
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}
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if (jwe->jws.map.len[LJWE_IV] != LWS_AESGCM_IV) { /* MUST be 96-bit */
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lwsl_notice("%s: AESGCM IV must be 128b, got %d\n", __func__,
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jwe->jws.map.len[LJWE_IV]);
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return -1;
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}
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/* EKEY is directly the CEK KEY */
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el.buf = enc_cek;
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el.len = jwe->jose.enc_alg->keybits_fixed / 8;
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if (lws_genaes_create(&aesctx, LWS_GAESO_DEC, LWS_GAESM_GCM,
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&el, LWS_GAESP_NO_PADDING, NULL)) {
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lwsl_err("%s: lws_genaes_create failed\n", __func__);
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return -1;
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}
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n = lws_genaes_crypt(&aesctx, aad, (unsigned int)aad_len,
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NULL,
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(uint8_t *)jwe->jws.map.buf[LJWE_IV],
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(uint8_t *)jwe->jws.map.buf[LJWE_ATAG], &ivs, 16);
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if (n) {
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lwsl_err("%s: lws_genaes_crypt aad failed\n", __func__);
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return -1;
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}
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n = lws_genaes_crypt(&aesctx, (uint8_t *)jwe->jws.map.buf[LJWE_CTXT],
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jwe->jws.map.len[LJWE_CTXT],
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(uint8_t *)jwe->jws.map.buf[LJWE_CTXT],
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(uint8_t *)jwe->jws.map.buf[LJWE_IV],
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(uint8_t *)jwe->jws.map.buf[LJWE_ATAG], &ivs, 16);
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n |= lws_genaes_destroy(&aesctx, tag, sizeof(tag));
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if (n) {
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lwsl_err("%s: lws_genaes_crypt failed\n", __func__);
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return -1;
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}
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return (int)jwe->jws.map.len[LJWE_CTXT];
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}
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