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1 /*
2  * Copyright 1995-2018 The OpenSSL Project Authors. All Rights Reserved.
3  *
4  * Licensed under the OpenSSL license (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 /*****************************************************************************
11  *                                                                           *
12  * These structures should be considered PRIVATE to the record layer. No     *
13  * non-record layer code should be using these structures in any way.        *
14  *                                                                           *
15  *****************************************************************************/
16 
17 typedef struct ssl3_buffer_st {
18     /* at least SSL3_RT_MAX_PACKET_SIZE bytes, see ssl3_setup_buffers() */
19     unsigned char *buf;
20     /* default buffer size (or 0 if no default set) */
21     size_t default_len;
22     /* buffer size */
23     size_t len;
24     /* where to 'copy from' */
25     size_t offset;
26     /* how many bytes left */
27     size_t left;
28 } SSL3_BUFFER;
29 
30 #define SEQ_NUM_SIZE                            8
31 
32 typedef struct ssl3_record_st {
33     /* Record layer version */
34     /* r */
35     int rec_version;
36     /* type of record */
37     /* r */
38     int type;
39     /* How many bytes available */
40     /* rw */
41     size_t length;
42     /*
43      * How many bytes were available before padding was removed? This is used
44      * to implement the MAC check in constant time for CBC records.
45      */
46     /* rw */
47     size_t orig_len;
48     /* read/write offset into 'buf' */
49     /* r */
50     size_t off;
51     /* pointer to the record data */
52     /* rw */
53     unsigned char *data;
54     /* where the decode bytes are */
55     /* rw */
56     unsigned char *input;
57     /* only used with decompression - malloc()ed */
58     /* r */
59     unsigned char *comp;
60     /* Whether the data from this record has already been read or not */
61     /* r */
62     unsigned int read;
63     /* epoch number, needed by DTLS1 */
64     /* r */
65     unsigned long epoch;
66     /* sequence number, needed by DTLS1 */
67     /* r */
68     unsigned char seq_num[SEQ_NUM_SIZE];
69 } SSL3_RECORD;
70 
71 typedef struct dtls1_bitmap_st {
72     /* Track 32 packets on 32-bit systems and 64 - on 64-bit systems */
73     unsigned long map;
74     /* Max record number seen so far, 64-bit value in big-endian encoding */
75     unsigned char max_seq_num[SEQ_NUM_SIZE];
76 } DTLS1_BITMAP;
77 
78 typedef struct record_pqueue_st {
79     unsigned short epoch;
80     struct pqueue_st *q;
81 } record_pqueue;
82 
83 typedef struct dtls1_record_data_st {
84     unsigned char *packet;
85     size_t packet_length;
86     SSL3_BUFFER rbuf;
87     SSL3_RECORD rrec;
88 #ifndef OPENSSL_NO_SCTP
89     struct bio_dgram_sctp_rcvinfo recordinfo;
90 #endif
91 } DTLS1_RECORD_DATA;
92 
93 typedef struct dtls_record_layer_st {
94     /*
95      * The current data and handshake epoch.  This is initially
96      * undefined, and starts at zero once the initial handshake is
97      * completed
98      */
99     unsigned short r_epoch;
100     unsigned short w_epoch;
101     /* records being received in the current epoch */
102     DTLS1_BITMAP bitmap;
103     /* renegotiation starts a new set of sequence numbers */
104     DTLS1_BITMAP next_bitmap;
105     /* Received handshake records (processed and unprocessed) */
106     record_pqueue unprocessed_rcds;
107     record_pqueue processed_rcds;
108     /*
109      * Buffered application records. Only for records between CCS and
110      * Finished to prevent either protocol violation or unnecessary message
111      * loss.
112      */
113     record_pqueue buffered_app_data;
114     /* save last and current sequence numbers for retransmissions */
115     unsigned char last_write_sequence[8];
116     unsigned char curr_write_sequence[8];
117 } DTLS_RECORD_LAYER;
118 
119 /*****************************************************************************
120  *                                                                           *
121  * This structure should be considered "opaque" to anything outside of the   *
122  * record layer. No non-record layer code should be accessing the members of *
123  * this structure.                                                           *
124  *                                                                           *
125  *****************************************************************************/
126 
127 typedef struct record_layer_st {
128     /* The parent SSL structure */
129     SSL *s;
130     /*
131      * Read as many input bytes as possible (for
132      * non-blocking reads)
133      */
134     int read_ahead;
135     /* where we are when reading */
136     int rstate;
137     /* How many pipelines can be used to read data */
138     size_t numrpipes;
139     /* How many pipelines can be used to write data */
140     size_t numwpipes;
141     /* read IO goes into here */
142     SSL3_BUFFER rbuf;
143     /* write IO goes into here */
144     SSL3_BUFFER wbuf[SSL_MAX_PIPELINES];
145     /* each decoded record goes in here */
146     SSL3_RECORD rrec[SSL_MAX_PIPELINES];
147     /* used internally to point at a raw packet */
148     unsigned char *packet;
149     size_t packet_length;
150     /* number of bytes sent so far */
151     size_t wnum;
152     unsigned char handshake_fragment[4];
153     size_t handshake_fragment_len;
154     /* The number of consecutive empty records we have received */
155     size_t empty_record_count;
156     /* partial write - check the numbers match */
157     /* number bytes written */
158     size_t wpend_tot;
159     int wpend_type;
160     /* number of bytes submitted */
161     size_t wpend_ret;
162     const unsigned char *wpend_buf;
163     unsigned char read_sequence[SEQ_NUM_SIZE];
164     unsigned char write_sequence[SEQ_NUM_SIZE];
165     /* Set to true if this is the first record in a connection */
166     unsigned int is_first_record;
167     /* Count of the number of consecutive warning alerts received */
168     unsigned int alert_count;
169     DTLS_RECORD_LAYER *d;
170 } RECORD_LAYER;
171 
172 /*****************************************************************************
173  *                                                                           *
174  * The following macros/functions represent the libssl internal API to the   *
175  * record layer. Any libssl code may call these functions/macros             *
176  *                                                                           *
177  *****************************************************************************/
178 
179 #define MIN_SSL2_RECORD_LEN     9
180 
181 #define RECORD_LAYER_set_read_ahead(rl, ra)     ((rl)->read_ahead = (ra))
182 #define RECORD_LAYER_get_read_ahead(rl)         ((rl)->read_ahead)
183 #define RECORD_LAYER_get_packet(rl)             ((rl)->packet)
184 #define RECORD_LAYER_get_packet_length(rl)      ((rl)->packet_length)
185 #define RECORD_LAYER_add_packet_length(rl, inc) ((rl)->packet_length += (inc))
186 #define DTLS_RECORD_LAYER_get_w_epoch(rl)       ((rl)->d->w_epoch)
187 #define DTLS_RECORD_LAYER_get_processed_rcds(rl) \
188                                                 ((rl)->d->processed_rcds)
189 #define DTLS_RECORD_LAYER_get_unprocessed_rcds(rl) \
190                                                 ((rl)->d->unprocessed_rcds)
191 #define RECORD_LAYER_get_rbuf(rl)               (&(rl)->rbuf)
192 #define RECORD_LAYER_get_wbuf(rl)               ((rl)->wbuf)
193 
194 void RECORD_LAYER_init(RECORD_LAYER *rl, SSL *s);
195 void RECORD_LAYER_clear(RECORD_LAYER *rl);
196 void RECORD_LAYER_release(RECORD_LAYER *rl);
197 int RECORD_LAYER_read_pending(const RECORD_LAYER *rl);
198 int RECORD_LAYER_processed_read_pending(const RECORD_LAYER *rl);
199 int RECORD_LAYER_write_pending(const RECORD_LAYER *rl);
200 void RECORD_LAYER_reset_read_sequence(RECORD_LAYER *rl);
201 void RECORD_LAYER_reset_write_sequence(RECORD_LAYER *rl);
202 int RECORD_LAYER_is_sslv2_record(RECORD_LAYER *rl);
203 size_t RECORD_LAYER_get_rrec_length(RECORD_LAYER *rl);
204 __owur size_t ssl3_pending(const SSL *s);
205 __owur int ssl3_write_bytes(SSL *s, int type, const void *buf, size_t len,
206                             size_t *written);
207 int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
208                   size_t *pipelens, size_t numpipes,
209                   int create_empty_fragment, size_t *written);
210 __owur int ssl3_read_bytes(SSL *s, int type, int *recvd_type,
211                            unsigned char *buf, size_t len, int peek,
212                            size_t *readbytes);
213 __owur int ssl3_setup_buffers(SSL *s);
214 __owur int ssl3_enc(SSL *s, SSL3_RECORD *inrecs, size_t n_recs, int send);
215 __owur int n_ssl3_mac(SSL *ssl, SSL3_RECORD *rec, unsigned char *md, int send);
216 __owur int ssl3_write_pending(SSL *s, int type, const unsigned char *buf, size_t len,
217                               size_t *written);
218 __owur int tls1_enc(SSL *s, SSL3_RECORD *recs, size_t n_recs, int send);
219 __owur int tls1_mac(SSL *ssl, SSL3_RECORD *rec, unsigned char *md, int send);
220 __owur int tls13_enc(SSL *s, SSL3_RECORD *recs, size_t n_recs, int send);
221 int DTLS_RECORD_LAYER_new(RECORD_LAYER *rl);
222 void DTLS_RECORD_LAYER_free(RECORD_LAYER *rl);
223 void DTLS_RECORD_LAYER_clear(RECORD_LAYER *rl);
224 void DTLS_RECORD_LAYER_set_saved_w_epoch(RECORD_LAYER *rl, unsigned short e);
225 void DTLS_RECORD_LAYER_clear(RECORD_LAYER *rl);
226 void DTLS_RECORD_LAYER_set_write_sequence(RECORD_LAYER *rl, unsigned char *seq);
227 __owur int dtls1_read_bytes(SSL *s, int type, int *recvd_type,
228                             unsigned char *buf, size_t len, int peek,
229                             size_t *readbytes);
230 __owur int dtls1_write_bytes(SSL *s, int type, const void *buf, size_t len,
231                              size_t *written);
232 int do_dtls1_write(SSL *s, int type, const unsigned char *buf,
233                    size_t len, int create_empty_fragment, size_t *written);
234 void dtls1_reset_seq_numbers(SSL *s, int rw);
235 int dtls_buffer_listen_record(SSL *s, size_t len, unsigned char *seq,
236                               size_t off);
237