Mercurial > hg > nginx
view src/event/quic/ngx_event_quic_tokens.c @ 8816:7f29db5294bd quic
QUIC: avoid processing 1-RTT with incomplete handshake in OpenSSL.
OpenSSL is known to provide read keys for an encryption level before the
level is active in TLS, following the old BoringSSL API. In BoringSSL,
it was then fixed to defer releasing read keys until QUIC may use them.
author | Sergey Kandaurov <pluknet@nginx.com> |
---|---|
date | Thu, 22 Jul 2021 15:00:37 +0300 |
parents | 2029a30863e2 |
children | 75daac63f798 |
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/* * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> #include <ngx_sha1.h> #include <ngx_event_quic_connection.h> #define NGX_QUIC_MAX_TOKEN_SIZE 64 /* SHA-1(addr)=20 + sizeof(time_t) + retry(1) + odcid.len(1) + odcid */ /* RFC 3602, 2.1 and 2.4 for AES-CBC block size and IV length */ #define NGX_QUIC_AES_256_CBC_IV_LEN 16 #define NGX_QUIC_AES_256_CBC_BLOCK_SIZE 16 static void ngx_quic_address_hash(struct sockaddr *sockaddr, socklen_t socklen, ngx_uint_t no_port, u_char buf[20]); ngx_int_t ngx_quic_new_sr_token(ngx_connection_t *c, ngx_str_t *cid, u_char *secret, u_char *token) { ngx_str_t tmp; tmp.data = secret; tmp.len = NGX_QUIC_SR_KEY_LEN; if (ngx_quic_derive_key(c->log, "sr_token_key", &tmp, cid, token, NGX_QUIC_SR_TOKEN_LEN) != NGX_OK) { return NGX_ERROR; } #if (NGX_DEBUG) ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0, "quic stateless reset token %*xs", (size_t) NGX_QUIC_SR_TOKEN_LEN, token); #endif return NGX_OK; } ngx_int_t ngx_quic_new_token(ngx_connection_t *c, struct sockaddr *sockaddr, socklen_t socklen, u_char *key, ngx_str_t *token, ngx_str_t *odcid, time_t exp, ngx_uint_t is_retry) { int len, iv_len; u_char *p, *iv; EVP_CIPHER_CTX *ctx; const EVP_CIPHER *cipher; u_char in[NGX_QUIC_MAX_TOKEN_SIZE]; ngx_quic_address_hash(sockaddr, socklen, !is_retry, in); p = in + 20; p = ngx_cpymem(p, &exp, sizeof(time_t)); *p++ = is_retry ? 1 : 0; if (odcid) { *p++ = odcid->len; p = ngx_cpymem(p, odcid->data, odcid->len); } else { *p++ = 0; } len = p - in; cipher = EVP_aes_256_cbc(); iv_len = NGX_QUIC_AES_256_CBC_IV_LEN; token->len = iv_len + len + NGX_QUIC_AES_256_CBC_BLOCK_SIZE; token->data = ngx_pnalloc(c->pool, token->len); if (token->data == NULL) { return NGX_ERROR; } ctx = EVP_CIPHER_CTX_new(); if (ctx == NULL) { return NGX_ERROR; } iv = token->data; if (RAND_bytes(iv, iv_len) <= 0 || !EVP_EncryptInit_ex(ctx, cipher, NULL, key, iv)) { EVP_CIPHER_CTX_free(ctx); return NGX_ERROR; } token->len = iv_len; if (EVP_EncryptUpdate(ctx, token->data + token->len, &len, in, len) != 1) { EVP_CIPHER_CTX_free(ctx); return NGX_ERROR; } token->len += len; if (EVP_EncryptFinal_ex(ctx, token->data + token->len, &len) <= 0) { EVP_CIPHER_CTX_free(ctx); return NGX_ERROR; } token->len += len; EVP_CIPHER_CTX_free(ctx); #ifdef NGX_QUIC_DEBUG_PACKETS ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0, "quic new token len:%uz %xV", token->len, token); #endif return NGX_OK; } static void ngx_quic_address_hash(struct sockaddr *sockaddr, socklen_t socklen, ngx_uint_t no_port, u_char buf[20]) { size_t len; u_char *data; ngx_sha1_t sha1; struct sockaddr_in *sin; #if (NGX_HAVE_INET6) struct sockaddr_in6 *sin6; #endif len = (size_t) socklen; data = (u_char *) sockaddr; if (no_port) { switch (sockaddr->sa_family) { #if (NGX_HAVE_INET6) case AF_INET6: sin6 = (struct sockaddr_in6 *) sockaddr; len = sizeof(struct in6_addr); data = sin6->sin6_addr.s6_addr; break; #endif case AF_INET: sin = (struct sockaddr_in *) sockaddr; len = sizeof(in_addr_t); data = (u_char *) &sin->sin_addr; break; } } ngx_sha1_init(&sha1); ngx_sha1_update(&sha1, data, len); ngx_sha1_final(buf, &sha1); } ngx_int_t ngx_quic_validate_token(ngx_connection_t *c, u_char *key, ngx_quic_header_t *pkt) { int len, tlen, iv_len; u_char *iv, *p; time_t now, exp; size_t total; ngx_str_t odcid; EVP_CIPHER_CTX *ctx; const EVP_CIPHER *cipher; u_char addr_hash[20]; u_char tdec[NGX_QUIC_MAX_TOKEN_SIZE]; /* Retry token or NEW_TOKEN in a previous connection */ cipher = EVP_aes_256_cbc(); iv = pkt->token.data; iv_len = NGX_QUIC_AES_256_CBC_IV_LEN; /* sanity checks */ if (pkt->token.len < (size_t) iv_len + NGX_QUIC_AES_256_CBC_BLOCK_SIZE) { goto garbage; } if (pkt->token.len > (size_t) iv_len + NGX_QUIC_MAX_TOKEN_SIZE) { goto garbage; } ctx = EVP_CIPHER_CTX_new(); if (ctx == NULL) { return NGX_ERROR; } if (!EVP_DecryptInit_ex(ctx, cipher, NULL, key, iv)) { EVP_CIPHER_CTX_free(ctx); return NGX_ERROR; } p = pkt->token.data + iv_len; len = pkt->token.len - iv_len; if (EVP_DecryptUpdate(ctx, tdec, &len, p, len) != 1) { EVP_CIPHER_CTX_free(ctx); goto garbage; } total = len; if (EVP_DecryptFinal_ex(ctx, tdec + len, &tlen) <= 0) { EVP_CIPHER_CTX_free(ctx); goto garbage; } total += tlen; EVP_CIPHER_CTX_free(ctx); if (total < (20 + sizeof(time_t) + 2)) { goto garbage; } p = tdec + 20; ngx_memcpy(&exp, p, sizeof(time_t)); p += sizeof(time_t); pkt->retried = (*p++ == 1); ngx_quic_address_hash(c->sockaddr, c->socklen, !pkt->retried, addr_hash); if (ngx_memcmp(tdec, addr_hash, 20) != 0) { goto bad_token; } odcid.len = *p++; if (odcid.len) { if (odcid.len > NGX_QUIC_MAX_CID_LEN) { goto bad_token; } if ((size_t)(tdec + total - p) < odcid.len) { goto bad_token; } odcid.data = p; p += odcid.len; } now = ngx_time(); if (now > exp) { ngx_log_error(NGX_LOG_INFO, c->log, 0, "quic expired token"); return NGX_DECLINED; } if (odcid.len) { pkt->odcid.len = odcid.len; pkt->odcid.data = ngx_pstrdup(c->pool, &odcid); if (pkt->odcid.data == NULL) { return NGX_ERROR; } } else { pkt->odcid = pkt->dcid; } pkt->validated = 1; return NGX_OK; garbage: ngx_log_error(NGX_LOG_INFO, c->log, 0, "quic garbage token"); return NGX_ABORT; bad_token: ngx_log_error(NGX_LOG_INFO, c->log, 0, "quic invalid token"); return NGX_DECLINED; }