QUIC: reusing crypto contexts for header protection.

This commit is contained in:
Sergey Kandaurov 2023-10-20 18:05:07 +04:00
parent 52d50714eb
commit 4f60ee789e
2 changed files with 75 additions and 28 deletions

View File

@ -32,8 +32,12 @@ static ngx_int_t ngx_quic_crypto_open(ngx_quic_secret_t *s, ngx_str_t *out,
static ngx_int_t ngx_quic_crypto_common(ngx_quic_secret_t *s, ngx_str_t *out,
u_char *nonce, ngx_str_t *in, ngx_str_t *ad, ngx_log_t *log);
#endif
static ngx_int_t ngx_quic_crypto_hp(ngx_log_t *log, const EVP_CIPHER *cipher,
ngx_quic_secret_t *s, u_char *out, u_char *in);
static ngx_int_t ngx_quic_crypto_hp_init(const EVP_CIPHER *cipher,
ngx_quic_secret_t *s, ngx_log_t *log);
static ngx_int_t ngx_quic_crypto_hp(ngx_quic_secret_t *s,
u_char *out, u_char *in, ngx_log_t *log);
static void ngx_quic_crypto_hp_cleanup(ngx_quic_secret_t *s);
static ngx_int_t ngx_quic_create_packet(ngx_quic_header_t *pkt,
ngx_str_t *res);
@ -196,6 +200,14 @@ ngx_quic_keys_set_initial_secret(ngx_quic_keys_t *keys, ngx_str_t *secret,
goto failed;
}
if (ngx_quic_crypto_hp_init(ciphers.hp, client, log) == NGX_ERROR) {
goto failed;
}
if (ngx_quic_crypto_hp_init(ciphers.hp, server, log) == NGX_ERROR) {
goto failed;
}
return NGX_OK;
failed:
@ -556,53 +568,82 @@ ngx_quic_crypto_cleanup(ngx_quic_secret_t *s)
static ngx_int_t
ngx_quic_crypto_hp(ngx_log_t *log, const EVP_CIPHER *cipher,
ngx_quic_secret_t *s, u_char *out, u_char *in)
ngx_quic_crypto_hp_init(const EVP_CIPHER *cipher, ngx_quic_secret_t *s,
ngx_log_t *log)
{
int outlen;
EVP_CIPHER_CTX *ctx;
u_char zero[NGX_QUIC_HP_LEN] = {0};
#ifdef OPENSSL_IS_BORINGSSL
uint32_t cnt;
ngx_memcpy(&cnt, in, sizeof(uint32_t));
if (cipher == (const EVP_CIPHER *) EVP_aead_chacha20_poly1305()) {
CRYPTO_chacha_20(out, zero, NGX_QUIC_HP_LEN, s->hp.data, &in[4], cnt);
if (cipher == (EVP_CIPHER *) EVP_aead_chacha20_poly1305()) {
/* no EVP interface */
s->hp_ctx = NULL;
return NGX_OK;
}
#endif
ctx = EVP_CIPHER_CTX_new();
if (ctx == NULL) {
ngx_ssl_error(NGX_LOG_INFO, log, 0, "EVP_CIPHER_CTX_new() failed");
return NGX_ERROR;
}
if (EVP_EncryptInit_ex(ctx, cipher, NULL, s->hp.data, in) != 1) {
if (EVP_EncryptInit_ex(ctx, cipher, NULL, s->hp.data, NULL) != 1) {
EVP_CIPHER_CTX_free(ctx);
ngx_ssl_error(NGX_LOG_INFO, log, 0, "EVP_EncryptInit_ex() failed");
goto failed;
return NGX_ERROR;
}
s->hp_ctx = ctx;
return NGX_OK;
}
static ngx_int_t
ngx_quic_crypto_hp(ngx_quic_secret_t *s, u_char *out, u_char *in,
ngx_log_t *log)
{
int outlen;
EVP_CIPHER_CTX *ctx;
u_char zero[NGX_QUIC_HP_LEN] = {0};
ctx = s->hp_ctx;
#ifdef OPENSSL_IS_BORINGSSL
uint32_t cnt;
if (ctx == NULL) {
ngx_memcpy(&cnt, in, sizeof(uint32_t));
CRYPTO_chacha_20(out, zero, NGX_QUIC_HP_LEN, s->hp.data, &in[4], cnt);
return NGX_OK;
}
#endif
if (EVP_EncryptInit_ex(ctx, NULL, NULL, NULL, in) != 1) {
ngx_ssl_error(NGX_LOG_INFO, log, 0, "EVP_EncryptInit_ex() failed");
return NGX_ERROR;
}
if (!EVP_EncryptUpdate(ctx, out, &outlen, zero, NGX_QUIC_HP_LEN)) {
ngx_ssl_error(NGX_LOG_INFO, log, 0, "EVP_EncryptUpdate() failed");
goto failed;
return NGX_ERROR;
}
if (!EVP_EncryptFinal_ex(ctx, out + NGX_QUIC_HP_LEN, &outlen)) {
ngx_ssl_error(NGX_LOG_INFO, log, 0, "EVP_EncryptFinal_Ex() failed");
goto failed;
return NGX_ERROR;
}
EVP_CIPHER_CTX_free(ctx);
return NGX_OK;
}
failed:
EVP_CIPHER_CTX_free(ctx);
return NGX_ERROR;
static void
ngx_quic_crypto_hp_cleanup(ngx_quic_secret_t *s)
{
if (s->hp_ctx) {
EVP_CIPHER_CTX_free(s->hp_ctx);
s->hp_ctx = NULL;
}
}
@ -663,6 +704,10 @@ ngx_quic_keys_set_encryption_secret(ngx_log_t *log, ngx_uint_t is_write,
return NGX_ERROR;
}
if (ngx_quic_crypto_hp_init(ciphers.hp, peer_secret, log) == NGX_ERROR) {
return NGX_ERROR;
}
return NGX_OK;
}
@ -690,6 +735,9 @@ ngx_quic_keys_discard(ngx_quic_keys_t *keys,
ngx_quic_crypto_cleanup(client);
ngx_quic_crypto_cleanup(server);
ngx_quic_crypto_hp_cleanup(client);
ngx_quic_crypto_hp_cleanup(server);
}
@ -742,11 +790,13 @@ ngx_quic_keys_update(ngx_event_t *ev)
next->client.key.len = current->client.key.len;
next->client.iv.len = NGX_QUIC_IV_LEN;
next->client.hp = current->client.hp;
next->client.hp_ctx = current->client.hp_ctx;
next->server.secret.len = current->server.secret.len;
next->server.key.len = current->server.key.len;
next->server.iv.len = NGX_QUIC_IV_LEN;
next->server.hp = current->server.hp;
next->server.hp_ctx = current->server.hp_ctx;
ngx_quic_hkdf_set(&seq[0], "tls13 quic ku",
&next->client.secret, &current->client.secret);
@ -840,9 +890,7 @@ ngx_quic_create_packet(ngx_quic_header_t *pkt, ngx_str_t *res)
}
sample = &out.data[4 - pkt->num_len];
if (ngx_quic_crypto_hp(pkt->log, ciphers.hp, secret, mask, sample)
!= NGX_OK)
{
if (ngx_quic_crypto_hp(secret, mask, sample, pkt->log) != NGX_OK) {
return NGX_ERROR;
}
@ -1070,9 +1118,7 @@ ngx_quic_decrypt(ngx_quic_header_t *pkt, uint64_t *largest_pn)
/* header protection */
if (ngx_quic_crypto_hp(pkt->log, ciphers.hp, secret, mask, sample)
!= NGX_OK)
{
if (ngx_quic_crypto_hp(secret, mask, sample, pkt->log) != NGX_OK) {
return NGX_DECLINED;
}

View File

@ -51,6 +51,7 @@ typedef struct {
ngx_quic_iv_t iv;
ngx_quic_md_t hp;
ngx_quic_crypto_ctx_t *ctx;
EVP_CIPHER_CTX *hp_ctx;
} ngx_quic_secret_t;