xref: /openssl/ssl/s3_msg.c (revision 73243502)
1 /*
2  * Copyright 1995-2021 The OpenSSL Project Authors. All Rights Reserved.
3  *
4  * Licensed under the Apache License 2.0 (the "License").  You may not use
5  * this file except in compliance with the License.  You can obtain a copy
6  * in the file LICENSE in the source distribution or at
7  * https://www.openssl.org/source/license.html
8  */
9 
10 #include "ssl_local.h"
11 
ssl3_do_change_cipher_spec(SSL_CONNECTION * s)12 int ssl3_do_change_cipher_spec(SSL_CONNECTION *s)
13 {
14     int i;
15     SSL *ssl = SSL_CONNECTION_GET_SSL(s);
16 
17     if (s->server)
18         i = SSL3_CHANGE_CIPHER_SERVER_READ;
19     else
20         i = SSL3_CHANGE_CIPHER_CLIENT_READ;
21 
22     if (s->s3.tmp.key_block == NULL) {
23         if (s->session == NULL || s->session->master_key_length == 0) {
24             /* might happen if dtls1_read_bytes() calls this */
25             ERR_raise(ERR_LIB_SSL, SSL_R_CCS_RECEIVED_EARLY);
26             return 0;
27         }
28 
29         s->session->cipher = s->s3.tmp.new_cipher;
30         if (!ssl->method->ssl3_enc->setup_key_block(s)) {
31             /* SSLfatal() already called */
32             return 0;
33         }
34     }
35 
36     if (!ssl->method->ssl3_enc->change_cipher_state(s, i)) {
37         /* SSLfatal() already called */
38         return 0;
39     }
40 
41     return 1;
42 }
43 
ssl3_send_alert(SSL_CONNECTION * s,int level,int desc)44 int ssl3_send_alert(SSL_CONNECTION *s, int level, int desc)
45 {
46     SSL *ssl = SSL_CONNECTION_GET_SSL(s);
47 
48     /* Map tls/ssl alert value to correct one */
49     if (SSL_CONNECTION_TREAT_AS_TLS13(s))
50         desc = tls13_alert_code(desc);
51     else
52         desc = ssl->method->ssl3_enc->alert_value(desc);
53     if (s->version == SSL3_VERSION && desc == SSL_AD_PROTOCOL_VERSION)
54         desc = SSL_AD_HANDSHAKE_FAILURE; /* SSL 3.0 does not have
55                                           * protocol_version alerts */
56     if (desc < 0)
57         return -1;
58     if (s->shutdown & SSL_SENT_SHUTDOWN && desc != SSL_AD_CLOSE_NOTIFY)
59         return -1;
60     /* If a fatal one, remove from cache */
61     if ((level == SSL3_AL_FATAL) && (s->session != NULL))
62         SSL_CTX_remove_session(s->session_ctx, s->session);
63 
64     s->s3.alert_dispatch = SSL_ALERT_DISPATCH_PENDING;
65     s->s3.send_alert[0] = level;
66     s->s3.send_alert[1] = desc;
67     if (!RECORD_LAYER_write_pending(&s->rlayer)) {
68         /* data still being written out? */
69         return ssl->method->ssl_dispatch_alert(ssl);
70     }
71     /*
72      * else data is still being written out, we will get written some time in
73      * the future
74      */
75     return -1;
76 }
77 
ssl3_dispatch_alert(SSL * s)78 int ssl3_dispatch_alert(SSL *s)
79 {
80     int i, j;
81     void (*cb) (const SSL *ssl, int type, int val) = NULL;
82     SSL_CONNECTION *sc = SSL_CONNECTION_FROM_SSL(s);
83     OSSL_RECORD_TEMPLATE templ;
84 
85     if (sc == NULL)
86         return -1;
87 
88     if (sc->rlayer.wrlmethod == NULL) {
89         /* No write record layer so we can't sent and alert. We just ignore it */
90         sc->s3.alert_dispatch = SSL_ALERT_DISPATCH_NONE;
91         return 1;
92     }
93 
94     templ.type = SSL3_RT_ALERT;
95     templ.version = (sc->version == TLS1_3_VERSION) ? TLS1_2_VERSION
96                                                     : sc->version;
97     if (SSL_get_state(s) == TLS_ST_CW_CLNT_HELLO
98             && !sc->renegotiate
99             && TLS1_get_version(s) > TLS1_VERSION
100             && sc->hello_retry_request == SSL_HRR_NONE) {
101         templ.version = TLS1_VERSION;
102     }
103     templ.buf = &sc->s3.send_alert[0];
104     templ.buflen = 2;
105 
106     if (RECORD_LAYER_write_pending(&sc->rlayer)) {
107         if (sc->s3.alert_dispatch != SSL_ALERT_DISPATCH_RETRY) {
108             /*
109              * We have a write pending but it wasn't from a previous call to
110              * this function! Can we ever get here? Maybe via API misuse??
111              * Give up.
112              */
113             sc->s3.alert_dispatch = SSL_ALERT_DISPATCH_NONE;
114             return -1;
115         }
116         /* Retry what we've already got pending */
117         i = HANDLE_RLAYER_WRITE_RETURN(sc,
118                 sc->rlayer.wrlmethod->retry_write_records(sc->rlayer.wrl));
119         if (i <= 0) {
120             /* Could be NBIO. Keep alert_dispatch as SSL_ALERT_DISPATCH_RETRY */
121             return -1;
122         }
123         sc->rlayer.wpend_tot = 0;
124         sc->s3.alert_dispatch = SSL_ALERT_DISPATCH_NONE;
125         return 1;
126     }
127 
128     i = HANDLE_RLAYER_WRITE_RETURN(sc,
129             sc->rlayer.wrlmethod->write_records(sc->rlayer.wrl, &templ, 1));
130 
131     if (i <= 0) {
132         sc->s3.alert_dispatch = SSL_ALERT_DISPATCH_RETRY;
133         sc->rlayer.wpend_tot = templ.buflen;
134         sc->rlayer.wpend_type = templ.type;
135         sc->rlayer.wpend_buf = templ.buf;
136     } else {
137         /*
138          * Alert sent to BIO - now flush. If the message does not get sent due
139          * to non-blocking IO, we will not worry too much.
140          */
141         (void)BIO_flush(sc->wbio);
142         sc->s3.alert_dispatch = SSL_ALERT_DISPATCH_NONE;
143 
144         if (sc->msg_callback)
145             sc->msg_callback(1, sc->version, SSL3_RT_ALERT, sc->s3.send_alert,
146                              2, s, sc->msg_callback_arg);
147 
148         if (sc->info_callback != NULL)
149             cb = sc->info_callback;
150         else if (s->ctx->info_callback != NULL)
151             cb = s->ctx->info_callback;
152 
153         if (cb != NULL) {
154             j = (sc->s3.send_alert[0] << 8) | sc->s3.send_alert[1];
155             cb(s, SSL_CB_WRITE_ALERT, j);
156         }
157     }
158     return i;
159 }
160