Mercurial > hg > nginx-quic
view src/event/quic/ngx_event_quic_protection.c @ 8637:13cb758e6ac0 quic
QUIC: reset stream only once.
author | Roman Arutyunyan <arut@nginx.com> |
---|---|
date | Wed, 22 Sep 2021 14:02:56 +0300 |
parents | d458101b7b81 |
children | 6d1488b62dc5 |
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/* * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> #include <ngx_event_quic_connection.h> /* RFC 5116, 5.1 and RFC 8439, 2.3 for all supported ciphers */ #define NGX_QUIC_IV_LEN 12 /* RFC 9001, 5.4.1. Header Protection Application: 5-byte mask */ #define NGX_QUIC_HP_LEN 5 #define NGX_QUIC_AES_128_KEY_LEN 16 #define NGX_AES_128_GCM_SHA256 0x1301 #define NGX_AES_256_GCM_SHA384 0x1302 #define NGX_CHACHA20_POLY1305_SHA256 0x1303 #ifdef OPENSSL_IS_BORINGSSL #define ngx_quic_cipher_t EVP_AEAD #else #define ngx_quic_cipher_t EVP_CIPHER #endif typedef struct { const ngx_quic_cipher_t *c; const EVP_CIPHER *hp; const EVP_MD *d; } ngx_quic_ciphers_t; typedef struct ngx_quic_secret_s { ngx_str_t secret; ngx_str_t key; ngx_str_t iv; ngx_str_t hp; } ngx_quic_secret_t; typedef struct { ngx_quic_secret_t client; ngx_quic_secret_t server; } ngx_quic_secrets_t; struct ngx_quic_keys_s { ngx_quic_secrets_t secrets[NGX_QUIC_ENCRYPTION_LAST]; ngx_quic_secrets_t next_key; ngx_uint_t cipher; }; static ngx_int_t ngx_hkdf_expand(u_char *out_key, size_t out_len, const EVP_MD *digest, const u_char *prk, size_t prk_len, const u_char *info, size_t info_len); static ngx_int_t ngx_hkdf_extract(u_char *out_key, size_t *out_len, const EVP_MD *digest, const u_char *secret, size_t secret_len, const u_char *salt, size_t salt_len); static uint64_t ngx_quic_parse_pn(u_char **pos, ngx_int_t len, u_char *mask, uint64_t *largest_pn); static void ngx_quic_compute_nonce(u_char *nonce, size_t len, uint64_t pn); static ngx_int_t ngx_quic_ciphers(ngx_uint_t id, ngx_quic_ciphers_t *ciphers, enum ssl_encryption_level_t level); static ngx_int_t ngx_quic_tls_open(const ngx_quic_cipher_t *cipher, ngx_quic_secret_t *s, ngx_str_t *out, u_char *nonce, ngx_str_t *in, ngx_str_t *ad, ngx_log_t *log); static ngx_int_t ngx_quic_tls_seal(const ngx_quic_cipher_t *cipher, ngx_quic_secret_t *s, ngx_str_t *out, u_char *nonce, ngx_str_t *in, ngx_str_t *ad, ngx_log_t *log); static ngx_int_t ngx_quic_tls_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_hkdf_expand(ngx_pool_t *pool, const EVP_MD *digest, ngx_str_t *out, ngx_str_t *label, const uint8_t *prk, size_t prk_len); static ngx_int_t ngx_quic_create_packet(ngx_quic_header_t *pkt, ngx_str_t *res); static ngx_int_t ngx_quic_create_retry_packet(ngx_quic_header_t *pkt, ngx_str_t *res); static ngx_int_t ngx_quic_ciphers(ngx_uint_t id, ngx_quic_ciphers_t *ciphers, enum ssl_encryption_level_t level) { ngx_int_t len; if (level == ssl_encryption_initial) { id = NGX_AES_128_GCM_SHA256; } switch (id) { case NGX_AES_128_GCM_SHA256: #ifdef OPENSSL_IS_BORINGSSL ciphers->c = EVP_aead_aes_128_gcm(); #else ciphers->c = EVP_aes_128_gcm(); #endif ciphers->hp = EVP_aes_128_ctr(); ciphers->d = EVP_sha256(); len = 16; break; case NGX_AES_256_GCM_SHA384: #ifdef OPENSSL_IS_BORINGSSL ciphers->c = EVP_aead_aes_256_gcm(); #else ciphers->c = EVP_aes_256_gcm(); #endif ciphers->hp = EVP_aes_256_ctr(); ciphers->d = EVP_sha384(); len = 32; break; case NGX_CHACHA20_POLY1305_SHA256: #ifdef OPENSSL_IS_BORINGSSL ciphers->c = EVP_aead_chacha20_poly1305(); #else ciphers->c = EVP_chacha20_poly1305(); #endif #ifdef OPENSSL_IS_BORINGSSL ciphers->hp = (const EVP_CIPHER *) EVP_aead_chacha20_poly1305(); #else ciphers->hp = EVP_chacha20(); #endif ciphers->d = EVP_sha256(); len = 32; break; default: return NGX_ERROR; } return len; } ngx_int_t ngx_quic_keys_set_initial_secret(ngx_pool_t *pool, ngx_quic_keys_t *keys, ngx_str_t *secret, uint32_t version) { size_t is_len; uint8_t is[SHA256_DIGEST_LENGTH]; ngx_uint_t i; const EVP_MD *digest; ngx_quic_secret_t *client, *server; static const uint8_t salt[20] = "\x38\x76\x2c\xf7\xf5\x59\x34\xb3\x4d\x17" "\x9a\xe6\xa4\xc8\x0c\xad\xcc\xbb\x7f\x0a"; static const uint8_t salt29[20] = "\xaf\xbf\xec\x28\x99\x93\xd2\x4c\x9e\x97" "\x86\xf1\x9c\x61\x11\xe0\x43\x90\xa8\x99"; client = &keys->secrets[ssl_encryption_initial].client; server = &keys->secrets[ssl_encryption_initial].server; /* * RFC 9001, section 5. Packet Protection * * Initial packets use AEAD_AES_128_GCM. The hash function * for HKDF when deriving initial secrets and keys is SHA-256. */ digest = EVP_sha256(); is_len = SHA256_DIGEST_LENGTH; if (ngx_hkdf_extract(is, &is_len, digest, secret->data, secret->len, (version & 0xff000000) ? salt29 : salt, sizeof(salt)) != NGX_OK) { return NGX_ERROR; } ngx_str_t iss = { .data = is, .len = is_len }; ngx_log_debug0(NGX_LOG_DEBUG_EVENT, pool->log, 0, "quic ngx_quic_set_initial_secret"); #ifdef NGX_QUIC_DEBUG_CRYPTO ngx_log_debug3(NGX_LOG_DEBUG_EVENT, pool->log, 0, "quic salt len:%uz %*xs", sizeof(salt), sizeof(salt), salt); ngx_log_debug3(NGX_LOG_DEBUG_EVENT, pool->log, 0, "quic initial secret len:%uz %*xs", is_len, is_len, is); #endif client->secret.len = SHA256_DIGEST_LENGTH; server->secret.len = SHA256_DIGEST_LENGTH; client->key.len = NGX_QUIC_AES_128_KEY_LEN; server->key.len = NGX_QUIC_AES_128_KEY_LEN; client->hp.len = NGX_QUIC_AES_128_KEY_LEN; server->hp.len = NGX_QUIC_AES_128_KEY_LEN; client->iv.len = NGX_QUIC_IV_LEN; server->iv.len = NGX_QUIC_IV_LEN; struct { ngx_str_t label; ngx_str_t *key; ngx_str_t *prk; } seq[] = { /* labels per RFC 9001, 5.1. Packet Protection Keys */ { ngx_string("tls13 client in"), &client->secret, &iss }, { ngx_string("tls13 quic key"), &client->key, &client->secret }, { ngx_string("tls13 quic iv"), &client->iv, &client->secret }, { ngx_string("tls13 quic hp"), &client->hp, &client->secret }, { ngx_string("tls13 server in"), &server->secret, &iss }, { ngx_string("tls13 quic key"), &server->key, &server->secret }, { ngx_string("tls13 quic iv"), &server->iv, &server->secret }, { ngx_string("tls13 quic hp"), &server->hp, &server->secret }, }; for (i = 0; i < (sizeof(seq) / sizeof(seq[0])); i++) { if (ngx_quic_hkdf_expand(pool, digest, seq[i].key, &seq[i].label, seq[i].prk->data, seq[i].prk->len) != NGX_OK) { return NGX_ERROR; } } return NGX_OK; } static ngx_int_t ngx_quic_hkdf_expand(ngx_pool_t *pool, const EVP_MD *digest, ngx_str_t *out, ngx_str_t *label, const uint8_t *prk, size_t prk_len) { size_t info_len; uint8_t *p; uint8_t info[20]; if (out->data == NULL) { out->data = ngx_pnalloc(pool, out->len); if (out->data == NULL) { return NGX_ERROR; } } info_len = 2 + 1 + label->len + 1; info[0] = 0; info[1] = out->len; info[2] = label->len; p = ngx_cpymem(&info[3], label->data, label->len); *p = '\0'; if (ngx_hkdf_expand(out->data, out->len, digest, prk, prk_len, info, info_len) != NGX_OK) { ngx_ssl_error(NGX_LOG_INFO, pool->log, 0, "ngx_hkdf_expand(%V) failed", label); return NGX_ERROR; } #ifdef NGX_QUIC_DEBUG_CRYPTO ngx_log_debug3(NGX_LOG_DEBUG_EVENT, pool->log, 0, "quic expand %V key len:%uz %xV", label, out->len, out); #endif return NGX_OK; } static ngx_int_t ngx_hkdf_expand(u_char *out_key, size_t out_len, const EVP_MD *digest, const uint8_t *prk, size_t prk_len, const u_char *info, size_t info_len) { #ifdef OPENSSL_IS_BORINGSSL if (HKDF_expand(out_key, out_len, digest, prk, prk_len, info, info_len) == 0) { return NGX_ERROR; } return NGX_OK; #else EVP_PKEY_CTX *pctx; pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, NULL); if (pctx == NULL) { return NGX_ERROR; } if (EVP_PKEY_derive_init(pctx) <= 0) { goto failed; } if (EVP_PKEY_CTX_hkdf_mode(pctx, EVP_PKEY_HKDEF_MODE_EXPAND_ONLY) <= 0) { goto failed; } if (EVP_PKEY_CTX_set_hkdf_md(pctx, digest) <= 0) { goto failed; } if (EVP_PKEY_CTX_set1_hkdf_key(pctx, prk, prk_len) <= 0) { goto failed; } if (EVP_PKEY_CTX_add1_hkdf_info(pctx, info, info_len) <= 0) { goto failed; } if (EVP_PKEY_derive(pctx, out_key, &out_len) <= 0) { goto failed; } EVP_PKEY_CTX_free(pctx); return NGX_OK; failed: EVP_PKEY_CTX_free(pctx); return NGX_ERROR; #endif } static ngx_int_t ngx_hkdf_extract(u_char *out_key, size_t *out_len, const EVP_MD *digest, const u_char *secret, size_t secret_len, const u_char *salt, size_t salt_len) { #ifdef OPENSSL_IS_BORINGSSL if (HKDF_extract(out_key, out_len, digest, secret, secret_len, salt, salt_len) == 0) { return NGX_ERROR; } return NGX_OK; #else EVP_PKEY_CTX *pctx; pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, NULL); if (pctx == NULL) { return NGX_ERROR; } if (EVP_PKEY_derive_init(pctx) <= 0) { goto failed; } if (EVP_PKEY_CTX_hkdf_mode(pctx, EVP_PKEY_HKDEF_MODE_EXTRACT_ONLY) <= 0) { goto failed; } if (EVP_PKEY_CTX_set_hkdf_md(pctx, digest) <= 0) { goto failed; } if (EVP_PKEY_CTX_set1_hkdf_key(pctx, secret, secret_len) <= 0) { goto failed; } if (EVP_PKEY_CTX_set1_hkdf_salt(pctx, salt, salt_len) <= 0) { goto failed; } if (EVP_PKEY_derive(pctx, out_key, out_len) <= 0) { goto failed; } EVP_PKEY_CTX_free(pctx); return NGX_OK; failed: EVP_PKEY_CTX_free(pctx); return NGX_ERROR; #endif } static ngx_int_t ngx_quic_tls_open(const ngx_quic_cipher_t *cipher, ngx_quic_secret_t *s, ngx_str_t *out, u_char *nonce, ngx_str_t *in, ngx_str_t *ad, ngx_log_t *log) { #ifdef OPENSSL_IS_BORINGSSL EVP_AEAD_CTX *ctx; ctx = EVP_AEAD_CTX_new(cipher, s->key.data, s->key.len, EVP_AEAD_DEFAULT_TAG_LENGTH); if (ctx == NULL) { ngx_ssl_error(NGX_LOG_INFO, log, 0, "EVP_AEAD_CTX_new() failed"); return NGX_ERROR; } if (EVP_AEAD_CTX_open(ctx, out->data, &out->len, out->len, nonce, s->iv.len, in->data, in->len, ad->data, ad->len) != 1) { EVP_AEAD_CTX_free(ctx); ngx_ssl_error(NGX_LOG_INFO, log, 0, "EVP_AEAD_CTX_open() failed"); return NGX_ERROR; } EVP_AEAD_CTX_free(ctx); #else int len; u_char *tag; EVP_CIPHER_CTX *ctx; 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_DecryptInit_ex(ctx, cipher, NULL, NULL, NULL) != 1) { EVP_CIPHER_CTX_free(ctx); ngx_ssl_error(NGX_LOG_INFO, log, 0, "EVP_DecryptInit_ex() failed"); return NGX_ERROR; } if (EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_GCM_SET_IVLEN, s->iv.len, NULL) == 0) { EVP_CIPHER_CTX_free(ctx); ngx_ssl_error(NGX_LOG_INFO, log, 0, "EVP_CIPHER_CTX_ctrl(EVP_CTRL_GCM_SET_IVLEN) failed"); return NGX_ERROR; } if (EVP_DecryptInit_ex(ctx, NULL, NULL, s->key.data, nonce) != 1) { EVP_CIPHER_CTX_free(ctx); ngx_ssl_error(NGX_LOG_INFO, log, 0, "EVP_DecryptInit_ex() failed"); return NGX_ERROR; } if (EVP_DecryptUpdate(ctx, NULL, &len, ad->data, ad->len) != 1) { EVP_CIPHER_CTX_free(ctx); ngx_ssl_error(NGX_LOG_INFO, log, 0, "EVP_DecryptUpdate() failed"); return NGX_ERROR; } if (EVP_DecryptUpdate(ctx, out->data, &len, in->data, in->len - EVP_GCM_TLS_TAG_LEN) != 1) { EVP_CIPHER_CTX_free(ctx); ngx_ssl_error(NGX_LOG_INFO, log, 0, "EVP_DecryptUpdate() failed"); return NGX_ERROR; } out->len = len; tag = in->data + in->len - EVP_GCM_TLS_TAG_LEN; if (EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_GCM_SET_TAG, EVP_GCM_TLS_TAG_LEN, tag) == 0) { EVP_CIPHER_CTX_free(ctx); ngx_ssl_error(NGX_LOG_INFO, log, 0, "EVP_CIPHER_CTX_ctrl(EVP_CTRL_GCM_SET_TAG) failed"); return NGX_ERROR; } if (EVP_DecryptFinal_ex(ctx, out->data + len, &len) <= 0) { EVP_CIPHER_CTX_free(ctx); ngx_ssl_error(NGX_LOG_INFO, log, 0, "EVP_DecryptFinal_ex failed"); return NGX_ERROR; } out->len += len; EVP_CIPHER_CTX_free(ctx); #endif return NGX_OK; } static ngx_int_t ngx_quic_tls_seal(const ngx_quic_cipher_t *cipher, ngx_quic_secret_t *s, ngx_str_t *out, u_char *nonce, ngx_str_t *in, ngx_str_t *ad, ngx_log_t *log) { #ifdef OPENSSL_IS_BORINGSSL EVP_AEAD_CTX *ctx; ctx = EVP_AEAD_CTX_new(cipher, s->key.data, s->key.len, EVP_AEAD_DEFAULT_TAG_LENGTH); if (ctx == NULL) { ngx_ssl_error(NGX_LOG_INFO, log, 0, "EVP_AEAD_CTX_new() failed"); return NGX_ERROR; } if (EVP_AEAD_CTX_seal(ctx, out->data, &out->len, out->len, nonce, s->iv.len, in->data, in->len, ad->data, ad->len) != 1) { EVP_AEAD_CTX_free(ctx); ngx_ssl_error(NGX_LOG_INFO, log, 0, "EVP_AEAD_CTX_seal() failed"); return NGX_ERROR; } EVP_AEAD_CTX_free(ctx); #else int len; EVP_CIPHER_CTX *ctx; 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, NULL, NULL) != 1) { EVP_CIPHER_CTX_free(ctx); ngx_ssl_error(NGX_LOG_INFO, log, 0, "EVP_EncryptInit_ex() failed"); return NGX_ERROR; } if (EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_GCM_SET_IVLEN, s->iv.len, NULL) == 0) { EVP_CIPHER_CTX_free(ctx); ngx_ssl_error(NGX_LOG_INFO, log, 0, "EVP_CIPHER_CTX_ctrl(EVP_CTRL_GCM_SET_IVLEN) failed"); return NGX_ERROR; } if (EVP_EncryptInit_ex(ctx, NULL, NULL, s->key.data, nonce) != 1) { EVP_CIPHER_CTX_free(ctx); ngx_ssl_error(NGX_LOG_INFO, log, 0, "EVP_EncryptInit_ex() failed"); return NGX_ERROR; } if (EVP_EncryptUpdate(ctx, NULL, &len, ad->data, ad->len) != 1) { EVP_CIPHER_CTX_free(ctx); ngx_ssl_error(NGX_LOG_INFO, log, 0, "EVP_EncryptUpdate() failed"); return NGX_ERROR; } if (EVP_EncryptUpdate(ctx, out->data, &len, in->data, in->len) != 1) { EVP_CIPHER_CTX_free(ctx); ngx_ssl_error(NGX_LOG_INFO, log, 0, "EVP_EncryptUpdate() failed"); return NGX_ERROR; } out->len = len; if (EVP_EncryptFinal_ex(ctx, out->data + out->len, &len) <= 0) { EVP_CIPHER_CTX_free(ctx); ngx_ssl_error(NGX_LOG_INFO, log, 0, "EVP_EncryptFinal_ex failed"); return NGX_ERROR; } out->len += len; if (EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_GCM_GET_TAG, EVP_GCM_TLS_TAG_LEN, out->data + in->len) == 0) { EVP_CIPHER_CTX_free(ctx); ngx_ssl_error(NGX_LOG_INFO, log, 0, "EVP_CIPHER_CTX_ctrl(EVP_CTRL_GCM_GET_TAG) failed"); return NGX_ERROR; } EVP_CIPHER_CTX_free(ctx); out->len += EVP_GCM_TLS_TAG_LEN; #endif return NGX_OK; } static ngx_int_t ngx_quic_tls_hp(ngx_log_t *log, const EVP_CIPHER *cipher, ngx_quic_secret_t *s, u_char *out, u_char *in) { 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); return NGX_OK; } #endif ctx = EVP_CIPHER_CTX_new(); if (ctx == NULL) { return NGX_ERROR; } if (EVP_EncryptInit_ex(ctx, cipher, NULL, s->hp.data, in) != 1) { ngx_ssl_error(NGX_LOG_INFO, log, 0, "EVP_EncryptInit_ex() failed"); goto failed; } if (!EVP_EncryptUpdate(ctx, out, &outlen, zero, NGX_QUIC_HP_LEN)) { ngx_ssl_error(NGX_LOG_INFO, log, 0, "EVP_EncryptUpdate() failed"); goto failed; } 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; } EVP_CIPHER_CTX_free(ctx); return NGX_OK; failed: EVP_CIPHER_CTX_free(ctx); return NGX_ERROR; } int ngx_quic_keys_set_encryption_secret(ngx_pool_t *pool, ngx_uint_t is_write, ngx_quic_keys_t *keys, enum ssl_encryption_level_t level, const SSL_CIPHER *cipher, const uint8_t *secret, size_t secret_len) { ngx_int_t key_len; ngx_uint_t i; ngx_quic_secret_t *peer_secret; ngx_quic_ciphers_t ciphers; peer_secret = is_write ? &keys->secrets[level].server : &keys->secrets[level].client; keys->cipher = SSL_CIPHER_get_protocol_id(cipher); key_len = ngx_quic_ciphers(keys->cipher, &ciphers, level); if (key_len == NGX_ERROR) { ngx_ssl_error(NGX_LOG_INFO, pool->log, 0, "unexpected cipher"); return 0; } if (level == ssl_encryption_initial) { return 0; } peer_secret->secret.data = ngx_pnalloc(pool, secret_len); if (peer_secret->secret.data == NULL) { return NGX_ERROR; } peer_secret->secret.len = secret_len; ngx_memcpy(peer_secret->secret.data, secret, secret_len); peer_secret->key.len = key_len; peer_secret->iv.len = NGX_QUIC_IV_LEN; peer_secret->hp.len = key_len; struct { ngx_str_t label; ngx_str_t *key; const uint8_t *secret; } seq[] = { { ngx_string("tls13 quic key"), &peer_secret->key, secret }, { ngx_string("tls13 quic iv"), &peer_secret->iv, secret }, { ngx_string("tls13 quic hp"), &peer_secret->hp, secret }, }; for (i = 0; i < (sizeof(seq) / sizeof(seq[0])); i++) { if (ngx_quic_hkdf_expand(pool, ciphers.d, seq[i].key, &seq[i].label, seq[i].secret, secret_len) != NGX_OK) { return 0; } } return 1; } ngx_quic_keys_t * ngx_quic_keys_new(ngx_pool_t *pool) { return ngx_pcalloc(pool, sizeof(ngx_quic_keys_t)); } ngx_uint_t ngx_quic_keys_available(ngx_quic_keys_t *keys, enum ssl_encryption_level_t level) { return keys->secrets[level].client.key.len != 0; } void ngx_quic_keys_discard(ngx_quic_keys_t *keys, enum ssl_encryption_level_t level) { keys->secrets[level].client.key.len = 0; } void ngx_quic_keys_switch(ngx_connection_t *c, ngx_quic_keys_t *keys) { ngx_quic_secrets_t *current, *next, tmp; current = &keys->secrets[ssl_encryption_application]; next = &keys->next_key; tmp = *current; *current = *next; *next = tmp; } ngx_int_t ngx_quic_keys_update(ngx_connection_t *c, ngx_quic_keys_t *keys) { ngx_uint_t i; ngx_quic_ciphers_t ciphers; ngx_quic_secrets_t *current, *next; current = &keys->secrets[ssl_encryption_application]; next = &keys->next_key; ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, 0, "quic key update"); if (ngx_quic_ciphers(keys->cipher, &ciphers, ssl_encryption_application) == NGX_ERROR) { return NGX_ERROR; } next->client.secret.len = current->client.secret.len; next->client.key.len = current->client.key.len; next->client.iv.len = NGX_QUIC_IV_LEN; next->client.hp = current->client.hp; 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; struct { ngx_str_t label; ngx_str_t *key; ngx_str_t *secret; } seq[] = { { ngx_string("tls13 quic ku"), &next->client.secret, ¤t->client.secret, }, { ngx_string("tls13 quic key"), &next->client.key, &next->client.secret, }, { ngx_string("tls13 quic iv"), &next->client.iv, &next->client.secret, }, { ngx_string("tls13 quic ku"), &next->server.secret, ¤t->server.secret, }, { ngx_string("tls13 quic key"), &next->server.key, &next->server.secret, }, { ngx_string("tls13 quic iv"), &next->server.iv, &next->server.secret, }, }; for (i = 0; i < (sizeof(seq) / sizeof(seq[0])); i++) { if (ngx_quic_hkdf_expand(c->pool, ciphers.d, seq[i].key, &seq[i].label, seq[i].secret->data, seq[i].secret->len) != NGX_OK) { return NGX_ERROR; } } return NGX_OK; } static ngx_int_t ngx_quic_create_packet(ngx_quic_header_t *pkt, ngx_str_t *res) { u_char *pnp, *sample; ngx_str_t ad, out; ngx_uint_t i; ngx_quic_secret_t *secret; ngx_quic_ciphers_t ciphers; u_char nonce[NGX_QUIC_IV_LEN], mask[NGX_QUIC_HP_LEN]; out.len = pkt->payload.len + EVP_GCM_TLS_TAG_LEN; ad.data = res->data; ad.len = ngx_quic_create_header(pkt, ad.data, out.len, &pnp); out.data = res->data + ad.len; #ifdef NGX_QUIC_DEBUG_CRYPTO ngx_log_debug2(NGX_LOG_DEBUG_EVENT, pkt->log, 0, "quic ad len:%uz %xV", ad.len, &ad); #endif if (ngx_quic_ciphers(pkt->keys->cipher, &ciphers, pkt->level) == NGX_ERROR) { return NGX_ERROR; } secret = &pkt->keys->secrets[pkt->level].server; ngx_memcpy(nonce, secret->iv.data, secret->iv.len); ngx_quic_compute_nonce(nonce, sizeof(nonce), pkt->number); if (ngx_quic_tls_seal(ciphers.c, secret, &out, nonce, &pkt->payload, &ad, pkt->log) != NGX_OK) { return NGX_ERROR; } sample = &out.data[4 - pkt->num_len]; if (ngx_quic_tls_hp(pkt->log, ciphers.hp, secret, mask, sample) != NGX_OK) { return NGX_ERROR; } /* RFC 9001, 5.4.1. Header Protection Application */ ad.data[0] ^= mask[0] & ngx_quic_pkt_hp_mask(pkt->flags); for (i = 0; i < pkt->num_len; i++) { pnp[i] ^= mask[i + 1]; } res->len = ad.len + out.len; return NGX_OK; } static ngx_int_t ngx_quic_create_retry_packet(ngx_quic_header_t *pkt, ngx_str_t *res) { u_char *start; ngx_str_t ad, itag; ngx_quic_secret_t secret; ngx_quic_ciphers_t ciphers; /* 5.8. Retry Packet Integrity */ static u_char key[16] = "\xbe\x0c\x69\x0b\x9f\x66\x57\x5a\x1d\x76\x6b\x54\xe3\x68\xc8\x4e"; static u_char key29[16] = "\xcc\xce\x18\x7e\xd0\x9a\x09\xd0\x57\x28\x15\x5a\x6c\xb9\x6b\xe1"; static u_char nonce[NGX_QUIC_IV_LEN] = "\x46\x15\x99\xd3\x5d\x63\x2b\xf2\x23\x98\x25\xbb"; static u_char nonce29[NGX_QUIC_IV_LEN] = "\xe5\x49\x30\xf9\x7f\x21\x36\xf0\x53\x0a\x8c\x1c"; static ngx_str_t in = ngx_string(""); ad.data = res->data; ad.len = ngx_quic_create_retry_itag(pkt, ad.data, &start); itag.data = ad.data + ad.len; itag.len = EVP_GCM_TLS_TAG_LEN; #ifdef NGX_QUIC_DEBUG_CRYPTO ngx_log_debug2(NGX_LOG_DEBUG_EVENT, pkt->log, 0, "quic retry itag len:%uz %xV", ad.len, &ad); #endif if (ngx_quic_ciphers(0, &ciphers, pkt->level) == NGX_ERROR) { return NGX_ERROR; } secret.key.len = sizeof(key); secret.key.data = (pkt->version & 0xff000000) ? key29 : key; secret.iv.len = NGX_QUIC_IV_LEN; if (ngx_quic_tls_seal(ciphers.c, &secret, &itag, (pkt->version & 0xff000000) ? nonce29 : nonce, &in, &ad, pkt->log) != NGX_OK) { return NGX_ERROR; } res->len = itag.data + itag.len - start; res->data = start; return NGX_OK; } ngx_int_t ngx_quic_derive_key(ngx_log_t *log, const char *label, ngx_str_t *secret, ngx_str_t *salt, u_char *out, size_t len) { size_t is_len, info_len; uint8_t *p; const EVP_MD *digest; uint8_t is[SHA256_DIGEST_LENGTH]; uint8_t info[20]; digest = EVP_sha256(); is_len = SHA256_DIGEST_LENGTH; if (ngx_hkdf_extract(is, &is_len, digest, secret->data, secret->len, salt->data, salt->len) != NGX_OK) { ngx_ssl_error(NGX_LOG_INFO, log, 0, "ngx_hkdf_extract(%s) failed", label); return NGX_ERROR; } info[0] = 0; info[1] = len; info[2] = ngx_strlen(label); info_len = 2 + 1 + info[2] + 1; if (info_len >= 20) { ngx_log_error(NGX_LOG_INFO, log, 0, "ngx_quic_create_key label \"%s\" too long", label); return NGX_ERROR; } p = ngx_cpymem(&info[3], label, info[2]); *p = '\0'; if (ngx_hkdf_expand(out, len, digest, is, is_len, info, info_len) != NGX_OK) { ngx_ssl_error(NGX_LOG_INFO, log, 0, "ngx_hkdf_expand(%s) failed", label); return NGX_ERROR; } return NGX_OK; } static uint64_t ngx_quic_parse_pn(u_char **pos, ngx_int_t len, u_char *mask, uint64_t *largest_pn) { u_char *p; uint64_t truncated_pn, expected_pn, candidate_pn; uint64_t pn_nbits, pn_win, pn_hwin, pn_mask; pn_nbits = ngx_min(len * 8, 62); p = *pos; truncated_pn = *p++ ^ *mask++; while (--len) { truncated_pn = (truncated_pn << 8) + (*p++ ^ *mask++); } *pos = p; expected_pn = *largest_pn + 1; pn_win = 1ULL << pn_nbits; pn_hwin = pn_win / 2; pn_mask = pn_win - 1; candidate_pn = (expected_pn & ~pn_mask) | truncated_pn; if ((int64_t) candidate_pn <= (int64_t) (expected_pn - pn_hwin) && candidate_pn < (1ULL << 62) - pn_win) { candidate_pn += pn_win; } else if (candidate_pn > expected_pn + pn_hwin && candidate_pn >= pn_win) { candidate_pn -= pn_win; } *largest_pn = ngx_max((int64_t) *largest_pn, (int64_t) candidate_pn); return candidate_pn; } static void ngx_quic_compute_nonce(u_char *nonce, size_t len, uint64_t pn) { nonce[len - 4] ^= (pn & 0xff000000) >> 24; nonce[len - 3] ^= (pn & 0x00ff0000) >> 16; nonce[len - 2] ^= (pn & 0x0000ff00) >> 8; nonce[len - 1] ^= (pn & 0x000000ff); } ngx_int_t ngx_quic_encrypt(ngx_quic_header_t *pkt, ngx_str_t *res) { if (ngx_quic_pkt_retry(pkt->flags)) { return ngx_quic_create_retry_packet(pkt, res); } return ngx_quic_create_packet(pkt, res); } ngx_int_t ngx_quic_decrypt(ngx_quic_header_t *pkt, uint64_t *largest_pn) { u_char *p, *sample; size_t len; uint64_t pn, lpn; ngx_int_t pnl, rc, key_phase; ngx_str_t in, ad; ngx_quic_secret_t *secret; ngx_quic_ciphers_t ciphers; uint8_t nonce[NGX_QUIC_IV_LEN], mask[NGX_QUIC_HP_LEN]; if (ngx_quic_ciphers(pkt->keys->cipher, &ciphers, pkt->level) == NGX_ERROR) { return NGX_ERROR; } secret = &pkt->keys->secrets[pkt->level].client; p = pkt->raw->pos; len = pkt->data + pkt->len - p; /* * RFC 9001, 5.4.2. Header Protection Sample * 5.4.3. AES-Based Header Protection * 5.4.4. ChaCha20-Based Header Protection * * the Packet Number field is assumed to be 4 bytes long * AES and ChaCha20 algorithms sample 16 bytes */ if (len < EVP_GCM_TLS_TAG_LEN + 4) { return NGX_DECLINED; } sample = p + 4; /* header protection */ if (ngx_quic_tls_hp(pkt->log, ciphers.hp, secret, mask, sample) != NGX_OK) { return NGX_DECLINED; } pkt->flags ^= mask[0] & ngx_quic_pkt_hp_mask(pkt->flags); if (ngx_quic_short_pkt(pkt->flags)) { key_phase = (pkt->flags & NGX_QUIC_PKT_KPHASE) != 0; if (key_phase != pkt->key_phase) { secret = &pkt->keys->next_key.client; pkt->key_update = 1; } } lpn = *largest_pn; pnl = (pkt->flags & 0x03) + 1; pn = ngx_quic_parse_pn(&p, pnl, &mask[1], &lpn); pkt->pn = pn; ngx_log_debug1(NGX_LOG_DEBUG_EVENT, pkt->log, 0, "quic packet rx clearflags:%xd", pkt->flags); ngx_log_debug2(NGX_LOG_DEBUG_EVENT, pkt->log, 0, "quic packet rx number:%uL len:%xi", pn, pnl); /* packet protection */ in.data = p; in.len = len - pnl; ad.len = p - pkt->data; ad.data = pkt->plaintext; ngx_memcpy(ad.data, pkt->data, ad.len); ad.data[0] = pkt->flags; do { ad.data[ad.len - pnl] = pn >> (8 * (pnl - 1)) % 256; } while (--pnl); ngx_memcpy(nonce, secret->iv.data, secret->iv.len); ngx_quic_compute_nonce(nonce, sizeof(nonce), pn); #ifdef NGX_QUIC_DEBUG_CRYPTO ngx_log_debug2(NGX_LOG_DEBUG_EVENT, pkt->log, 0, "quic ad len:%uz %xV", ad.len, &ad); #endif pkt->payload.len = in.len - EVP_GCM_TLS_TAG_LEN; pkt->payload.data = pkt->plaintext + ad.len; rc = ngx_quic_tls_open(ciphers.c, secret, &pkt->payload, nonce, &in, &ad, pkt->log); if (rc != NGX_OK) { return NGX_DECLINED; } if (pkt->payload.len == 0) { /* * RFC 9000, 12.4. Frames and Frame Types * * An endpoint MUST treat receipt of a packet containing no * frames as a connection error of type PROTOCOL_VIOLATION. */ ngx_log_error(NGX_LOG_INFO, pkt->log, 0, "quic zero-length packet"); pkt->error = NGX_QUIC_ERR_PROTOCOL_VIOLATION; return NGX_ERROR; } if (pkt->flags & ngx_quic_pkt_rb_mask(pkt->flags)) { /* * RFC 9000, Reserved Bits * * An endpoint MUST treat receipt of a packet that has * a non-zero value for these bits, after removing both * packet and header protection, as a connection error * of type PROTOCOL_VIOLATION. */ ngx_log_error(NGX_LOG_INFO, pkt->log, 0, "quic reserved bit set in packet"); pkt->error = NGX_QUIC_ERR_PROTOCOL_VIOLATION; return NGX_ERROR; } #if defined(NGX_QUIC_DEBUG_CRYPTO) && defined(NGX_QUIC_DEBUG_PACKETS) ngx_log_debug2(NGX_LOG_DEBUG_EVENT, pkt->log, 0, "quic packet payload len:%uz %xV", pkt->payload.len, &pkt->payload); #endif *largest_pn = lpn; return NGX_OK; }