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comparison src/event/quic/ngx_event_quic_tokens.c @ 8752:e19723c40d28 quic

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QUIC: separate files for tokens related processing.
author Vladimir Homutov <vl@nginx.com>
date Tue, 13 Apr 2021 14:41:52 +0300
parents
children b4e6b7049984
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8751:bc910a5ec737 8752:e19723c40d28
1
2 /*
3 * Copyright (C) Nginx, Inc.
4 */
5
6
7 #include <ngx_config.h>
8 #include <ngx_core.h>
9 #include <ngx_event.h>
10 #include <ngx_sha1.h>
11 #include <ngx_event_quic_protection.h>
12
13
14 #define NGX_QUIC_MAX_TOKEN_SIZE 64
15 /* SHA-1(addr)=20 + sizeof(time_t) + retry(1) + odcid.len(1) + odcid */
16
17
18 static void ngx_quic_address_hash(ngx_connection_t *c, ngx_uint_t no_port,
19 u_char buf[20]);
20
21
22 ngx_int_t
23 ngx_quic_new_sr_token(ngx_connection_t *c, ngx_str_t *cid, u_char *secret,
24 u_char *token)
25 {
26 ngx_str_t tmp;
27
28 tmp.data = secret;
29 tmp.len = NGX_QUIC_SR_KEY_LEN;
30
31 if (ngx_quic_derive_key(c->log, "sr_token_key", &tmp, cid, token,
32 NGX_QUIC_SR_TOKEN_LEN)
33 != NGX_OK)
34 {
35 return NGX_ERROR;
36 }
37
38 #if (NGX_DEBUG)
39 ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0,
40 "quic stateless reset token %*xs",
41 (size_t) NGX_QUIC_SR_TOKEN_LEN, token);
42 #endif
43
44 return NGX_OK;
45 }
46
47
48 ngx_int_t
49 ngx_quic_new_token(ngx_connection_t *c, u_char *key, ngx_str_t *token,
50 ngx_str_t *odcid, time_t exp, ngx_uint_t is_retry)
51 {
52 int len, iv_len;
53 u_char *p, *iv;
54 EVP_CIPHER_CTX *ctx;
55 const EVP_CIPHER *cipher;
56
57 u_char in[NGX_QUIC_MAX_TOKEN_SIZE];
58
59 ngx_quic_address_hash(c, !is_retry, in);
60
61 p = in + 20;
62
63 p = ngx_cpymem(p, &exp, sizeof(time_t));
64
65 *p++ = is_retry ? 1 : 0;
66
67 if (odcid) {
68 *p++ = odcid->len;
69 p = ngx_cpymem(p, odcid->data, odcid->len);
70
71 } else {
72 *p++ = 0;
73 }
74
75 len = p - in;
76
77 cipher = EVP_aes_256_cbc();
78 iv_len = EVP_CIPHER_iv_length(cipher);
79
80 token->len = iv_len + len + EVP_CIPHER_block_size(cipher);
81 token->data = ngx_pnalloc(c->pool, token->len);
82 if (token->data == NULL) {
83 return NGX_ERROR;
84 }
85
86 ctx = EVP_CIPHER_CTX_new();
87 if (ctx == NULL) {
88 return NGX_ERROR;
89 }
90
91 iv = token->data;
92
93 if (RAND_bytes(iv, iv_len) <= 0
94 || !EVP_EncryptInit_ex(ctx, cipher, NULL, key, iv))
95 {
96 EVP_CIPHER_CTX_free(ctx);
97 return NGX_ERROR;
98 }
99
100 token->len = iv_len;
101
102 if (EVP_EncryptUpdate(ctx, token->data + token->len, &len, in, len) != 1) {
103 EVP_CIPHER_CTX_free(ctx);
104 return NGX_ERROR;
105 }
106
107 token->len += len;
108
109 if (EVP_EncryptFinal_ex(ctx, token->data + token->len, &len) <= 0) {
110 EVP_CIPHER_CTX_free(ctx);
111 return NGX_ERROR;
112 }
113
114 token->len += len;
115
116 EVP_CIPHER_CTX_free(ctx);
117
118 #ifdef NGX_QUIC_DEBUG_PACKETS
119 ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0,
120 "quic new token len:%uz %xV", token->len, token);
121 #endif
122
123 return NGX_OK;
124 }
125
126
127 static void
128 ngx_quic_address_hash(ngx_connection_t *c, ngx_uint_t no_port, u_char buf[20])
129 {
130 size_t len;
131 u_char *data;
132 ngx_sha1_t sha1;
133 struct sockaddr_in *sin;
134 #if (NGX_HAVE_INET6)
135 struct sockaddr_in6 *sin6;
136 #endif
137
138 len = (size_t) c->socklen;
139 data = (u_char *) c->sockaddr;
140
141 if (no_port) {
142 switch (c->sockaddr->sa_family) {
143
144 #if (NGX_HAVE_INET6)
145 case AF_INET6:
146 sin6 = (struct sockaddr_in6 *) c->sockaddr;
147
148 len = sizeof(struct in6_addr);
149 data = sin6->sin6_addr.s6_addr;
150
151 break;
152 #endif
153
154 case AF_INET:
155 sin = (struct sockaddr_in *) c->sockaddr;
156
157 len = sizeof(in_addr_t);
158 data = (u_char *) &sin->sin_addr;
159
160 break;
161 }
162 }
163
164 ngx_sha1_init(&sha1);
165 ngx_sha1_update(&sha1, data, len);
166 ngx_sha1_final(buf, &sha1);
167 }
168
169
170 ngx_int_t
171 ngx_quic_validate_token(ngx_connection_t *c, u_char *key,
172 ngx_quic_header_t *pkt)
173 {
174 int len, tlen, iv_len;
175 u_char *iv, *p;
176 time_t now, exp;
177 size_t total;
178 ngx_str_t odcid;
179 EVP_CIPHER_CTX *ctx;
180 const EVP_CIPHER *cipher;
181
182 u_char addr_hash[20];
183 u_char tdec[NGX_QUIC_MAX_TOKEN_SIZE];
184
185 /* Retry token or NEW_TOKEN in a previous connection */
186
187 cipher = EVP_aes_256_cbc();
188 iv = pkt->token.data;
189 iv_len = EVP_CIPHER_iv_length(cipher);
190
191 /* sanity checks */
192
193 if (pkt->token.len < (size_t) iv_len + EVP_CIPHER_block_size(cipher)) {
194 goto garbage;
195 }
196
197 if (pkt->token.len > (size_t) iv_len + NGX_QUIC_MAX_TOKEN_SIZE) {
198 goto garbage;
199 }
200
201 ctx = EVP_CIPHER_CTX_new();
202 if (ctx == NULL) {
203 return NGX_ERROR;
204 }
205
206 if (!EVP_DecryptInit_ex(ctx, cipher, NULL, key, iv)) {
207 EVP_CIPHER_CTX_free(ctx);
208 return NGX_ERROR;
209 }
210
211 p = pkt->token.data + iv_len;
212 len = pkt->token.len - iv_len;
213
214 if (EVP_DecryptUpdate(ctx, tdec, &len, p, len) != 1) {
215 EVP_CIPHER_CTX_free(ctx);
216 goto garbage;
217 }
218 total = len;
219
220 if (EVP_DecryptFinal_ex(ctx, tdec + len, &tlen) <= 0) {
221 EVP_CIPHER_CTX_free(ctx);
222 goto garbage;
223 }
224 total += tlen;
225
226 EVP_CIPHER_CTX_free(ctx);
227
228 if (total < (20 + sizeof(time_t) + 2)) {
229 goto garbage;
230 }
231
232 p = tdec + 20;
233
234 ngx_memcpy(&exp, p, sizeof(time_t));
235 p += sizeof(time_t);
236
237 pkt->retried = (*p++ == 1);
238
239 ngx_quic_address_hash(c, !pkt->retried, addr_hash);
240
241 if (ngx_memcmp(tdec, addr_hash, 20) != 0) {
242 goto bad_token;
243 }
244
245 odcid.len = *p++;
246 if (odcid.len) {
247 if (odcid.len > NGX_QUIC_MAX_CID_LEN) {
248 goto bad_token;
249 }
250
251 if ((size_t)(tdec + total - p) < odcid.len) {
252 goto bad_token;
253 }
254
255 odcid.data = p;
256 p += odcid.len;
257 }
258
259 now = ngx_time();
260
261 if (now > exp) {
262 ngx_log_error(NGX_LOG_INFO, c->log, 0, "quic expired token");
263 return NGX_DECLINED;
264 }
265
266 if (odcid.len) {
267 pkt->odcid.len = odcid.len;
268 pkt->odcid.data = ngx_pstrdup(c->pool, &odcid);
269 if (pkt->odcid.data == NULL) {
270 return NGX_ERROR;
271 }
272
273 } else {
274 pkt->odcid = pkt->dcid;
275 }
276
277 pkt->validated = 1;
278
279 return NGX_OK;
280
281 garbage:
282
283 ngx_log_error(NGX_LOG_INFO, c->log, 0, "quic garbage token");
284
285 return NGX_ABORT;
286
287 bad_token:
288
289 ngx_log_error(NGX_LOG_INFO, c->log, 0, "quic invalid token");
290
291 return NGX_DECLINED;
292 }