diff options
Diffstat (limited to 'src/event/quic/ngx_event_quic_protection.c')
| -rw-r--r-- | src/event/quic/ngx_event_quic_protection.c | 1207 |
1 files changed, 1207 insertions, 0 deletions
diff --git a/src/event/quic/ngx_event_quic_protection.c b/src/event/quic/ngx_event_quic_protection.c new file mode 100644 index 000000000..12dd233b8 --- /dev/null +++ b/src/event/quic/ngx_event_quic_protection.c @@ -0,0 +1,1207 @@ + +/* + * Copyright (C) Nginx, Inc. + */ + + +#include <ngx_config.h> +#include <ngx_core.h> +#include <ngx_event.h> +#include <ngx_event_quic_transport.h> +#include <ngx_event_quic_protection.h> + + +#define NGX_QUIC_IV_LEN 12 + +#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; + const EVP_CIPHER *cipher; + 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; + + /* AEAD_AES_128_GCM prior to handshake, quic-tls-23#section-5.3 */ + + cipher = EVP_aes_128_gcm(); + 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 + + /* draft-ietf-quic-tls-23#section-5.2 */ + client->secret.len = SHA256_DIGEST_LENGTH; + server->secret.len = SHA256_DIGEST_LENGTH; + + client->key.len = EVP_CIPHER_key_length(cipher); + server->key.len = EVP_CIPHER_key_length(cipher); + + client->hp.len = EVP_CIPHER_key_length(cipher); + server->hp.len = EVP_CIPHER_key_length(cipher); + + client->iv.len = EVP_CIPHER_iv_length(cipher); + server->iv.len = EVP_CIPHER_iv_length(cipher); + + struct { + ngx_str_t label; + ngx_str_t *key; + ngx_str_t *prk; + } seq[] = { + + /* draft-ietf-quic-tls-23#section-5.2 */ + { 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, + }, + { + /* AEAD_AES_128_GCM prior to handshake, quic-tls-23#section-5.4.1 */ + ngx_string("tls13 quic hp"), + &client->hp, + &client->secret, + }, + { ngx_string("tls13 server in"), &server->secret, &iss }, + { + /* AEAD_AES_128_GCM prior to handshake, quic-tls-23#section-5.3 */ + ngx_string("tls13 quic key"), + &server->key, + &server->secret, + }, + { + ngx_string("tls13 quic iv"), + &server->iv, + &server->secret, + }, + { + /* AEAD_AES_128_GCM prior to handshake, quic-tls-23#section-5.4.1 */ + 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[5] = {0}; + +#ifdef OPENSSL_IS_BORINGSSL + uint32_t counter; + + ngx_memcpy(&counter, in, sizeof(uint32_t)); + + if (cipher == (const EVP_CIPHER *) EVP_aead_chacha20_poly1305()) { + CRYPTO_chacha_20(out, zero, 5, s->hp.data, &in[4], counter); + 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, 5)) { + ngx_ssl_error(NGX_LOG_INFO, log, 0, "EVP_EncryptUpdate() failed"); + goto failed; + } + + if (!EVP_EncryptFinal_ex(ctx, out + 5, &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 = current->client.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 = current->server.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[12], mask[16]; + + 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; + } + + /* quic-tls: 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[12] = + "\x46\x15\x99\xd3\x5d\x63\x2b\xf2\x23\x98\x25\xbb"; + static u_char nonce29[12] = + "\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 = sizeof(nonce); + + 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 mask[16], nonce[12]; + + 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; + + /* draft-ietf-quic-tls-23#section-5.4.2: + * the Packet Number field is assumed to be 4 bytes long + * draft-ietf-quic-tls-23#section-5.4.[34]: + * AES-Based and ChaCha20-Based header protections 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) { + /* + * 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)) { + /* + * 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; +} + |