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 #include <stdio.h>
11 #include <errno.h>
12 #include "bio_local.h"
13 #include "internal/cryptlib.h"
14 #include <openssl/evp.h>
15 
16 static int linebuffer_write(BIO *h, const char *buf, int num);
17 static int linebuffer_read(BIO *h, char *buf, int size);
18 static int linebuffer_puts(BIO *h, const char *str);
19 static int linebuffer_gets(BIO *h, char *str, int size);
20 static long linebuffer_ctrl(BIO *h, int cmd, long arg1, void *arg2);
21 static int linebuffer_new(BIO *h);
22 static int linebuffer_free(BIO *data);
23 static long linebuffer_callback_ctrl(BIO *h, int cmd, BIO_info_cb *fp);
24 
25 /* A 10k maximum should be enough for most purposes */
26 #define DEFAULT_LINEBUFFER_SIZE 1024*10
27 
28 /* #define DEBUG */
29 
30 static const BIO_METHOD methods_linebuffer = {
31     BIO_TYPE_LINEBUFFER,
32     "linebuffer",
33     /* TODO: Convert to new style write function */
34     bwrite_conv,
35     linebuffer_write,
36     /* TODO: Convert to new style read function */
37     bread_conv,
38     linebuffer_read,
39     linebuffer_puts,
40     linebuffer_gets,
41     linebuffer_ctrl,
42     linebuffer_new,
43     linebuffer_free,
44     linebuffer_callback_ctrl,
45 };
46 
BIO_f_linebuffer(void)47 const BIO_METHOD *BIO_f_linebuffer(void)
48 {
49     return &methods_linebuffer;
50 }
51 
52 typedef struct bio_linebuffer_ctx_struct {
53     char *obuf;                 /* the output char array */
54     int obuf_size;              /* how big is the output buffer */
55     int obuf_len;               /* how many bytes are in it */
56 } BIO_LINEBUFFER_CTX;
57 
linebuffer_new(BIO * bi)58 static int linebuffer_new(BIO *bi)
59 {
60     BIO_LINEBUFFER_CTX *ctx;
61 
62     if ((ctx = OPENSSL_malloc(sizeof(*ctx))) == NULL) {
63         BIOerr(BIO_F_LINEBUFFER_NEW, ERR_R_MALLOC_FAILURE);
64         return 0;
65     }
66     ctx->obuf = OPENSSL_malloc(DEFAULT_LINEBUFFER_SIZE);
67     if (ctx->obuf == NULL) {
68         BIOerr(BIO_F_LINEBUFFER_NEW, ERR_R_MALLOC_FAILURE);
69         OPENSSL_free(ctx);
70         return 0;
71     }
72     ctx->obuf_size = DEFAULT_LINEBUFFER_SIZE;
73     ctx->obuf_len = 0;
74 
75     bi->init = 1;
76     bi->ptr = (char *)ctx;
77     bi->flags = 0;
78     return 1;
79 }
80 
linebuffer_free(BIO * a)81 static int linebuffer_free(BIO *a)
82 {
83     BIO_LINEBUFFER_CTX *b;
84 
85     if (a == NULL)
86         return 0;
87     b = (BIO_LINEBUFFER_CTX *)a->ptr;
88     OPENSSL_free(b->obuf);
89     OPENSSL_free(a->ptr);
90     a->ptr = NULL;
91     a->init = 0;
92     a->flags = 0;
93     return 1;
94 }
95 
linebuffer_read(BIO * b,char * out,int outl)96 static int linebuffer_read(BIO *b, char *out, int outl)
97 {
98     int ret = 0;
99 
100     if (out == NULL)
101         return 0;
102     if (b->next_bio == NULL)
103         return 0;
104     ret = BIO_read(b->next_bio, out, outl);
105     BIO_clear_retry_flags(b);
106     BIO_copy_next_retry(b);
107     return ret;
108 }
109 
linebuffer_write(BIO * b,const char * in,int inl)110 static int linebuffer_write(BIO *b, const char *in, int inl)
111 {
112     int i, num = 0, foundnl;
113     BIO_LINEBUFFER_CTX *ctx;
114 
115     if ((in == NULL) || (inl <= 0))
116         return 0;
117     ctx = (BIO_LINEBUFFER_CTX *)b->ptr;
118     if ((ctx == NULL) || (b->next_bio == NULL))
119         return 0;
120 
121     BIO_clear_retry_flags(b);
122 
123     do {
124         const char *p;
125         char c;
126 
127         for (p = in, c = '\0'; p < in + inl && (c = *p) != '\n'; p++) ;
128         if (c == '\n') {
129             p++;
130             foundnl = 1;
131         } else
132             foundnl = 0;
133 
134         /*
135          * If a NL was found and we already have text in the save buffer,
136          * concatenate them and write
137          */
138         while ((foundnl || p - in > ctx->obuf_size - ctx->obuf_len)
139                && ctx->obuf_len > 0) {
140             int orig_olen = ctx->obuf_len;
141 
142             i = ctx->obuf_size - ctx->obuf_len;
143             if (p - in > 0) {
144                 if (i >= p - in) {
145                     memcpy(&(ctx->obuf[ctx->obuf_len]), in, p - in);
146                     ctx->obuf_len += p - in;
147                     inl -= p - in;
148                     num += p - in;
149                     in = p;
150                 } else {
151                     memcpy(&(ctx->obuf[ctx->obuf_len]), in, i);
152                     ctx->obuf_len += i;
153                     inl -= i;
154                     in += i;
155                     num += i;
156                 }
157             }
158             i = BIO_write(b->next_bio, ctx->obuf, ctx->obuf_len);
159             if (i <= 0) {
160                 ctx->obuf_len = orig_olen;
161                 BIO_copy_next_retry(b);
162 
163                 if (i < 0)
164                     return ((num > 0) ? num : i);
165                 if (i == 0)
166                     return num;
167             }
168             if (i < ctx->obuf_len)
169                 memmove(ctx->obuf, ctx->obuf + i, ctx->obuf_len - i);
170             ctx->obuf_len -= i;
171         }
172 
173         /*
174          * Now that the save buffer is emptied, let's write the input buffer
175          * if a NL was found and there is anything to write.
176          */
177         if ((foundnl || p - in > ctx->obuf_size) && p - in > 0) {
178             i = BIO_write(b->next_bio, in, p - in);
179             if (i <= 0) {
180                 BIO_copy_next_retry(b);
181                 if (i < 0)
182                     return ((num > 0) ? num : i);
183                 if (i == 0)
184                     return num;
185             }
186             num += i;
187             in += i;
188             inl -= i;
189         }
190     }
191     while (foundnl && inl > 0);
192     /*
193      * We've written as much as we can.  The rest of the input buffer, if
194      * any, is text that doesn't and with a NL and therefore needs to be
195      * saved for the next trip.
196      */
197     if (inl > 0) {
198         memcpy(&(ctx->obuf[ctx->obuf_len]), in, inl);
199         ctx->obuf_len += inl;
200         num += inl;
201     }
202     return num;
203 }
204 
linebuffer_ctrl(BIO * b,int cmd,long num,void * ptr)205 static long linebuffer_ctrl(BIO *b, int cmd, long num, void *ptr)
206 {
207     BIO *dbio;
208     BIO_LINEBUFFER_CTX *ctx;
209     long ret = 1;
210     char *p;
211     int r;
212     int obs;
213 
214     ctx = (BIO_LINEBUFFER_CTX *)b->ptr;
215 
216     switch (cmd) {
217     case BIO_CTRL_RESET:
218         ctx->obuf_len = 0;
219         if (b->next_bio == NULL)
220             return 0;
221         ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
222         break;
223     case BIO_CTRL_INFO:
224         ret = (long)ctx->obuf_len;
225         break;
226     case BIO_CTRL_WPENDING:
227         ret = (long)ctx->obuf_len;
228         if (ret == 0) {
229             if (b->next_bio == NULL)
230                 return 0;
231             ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
232         }
233         break;
234     case BIO_C_SET_BUFF_SIZE:
235         obs = (int)num;
236         p = ctx->obuf;
237         if ((obs > DEFAULT_LINEBUFFER_SIZE) && (obs != ctx->obuf_size)) {
238             p = OPENSSL_malloc((int)num);
239             if (p == NULL)
240                 goto malloc_error;
241         }
242         if (ctx->obuf != p) {
243             if (ctx->obuf_len > obs) {
244                 ctx->obuf_len = obs;
245             }
246             memcpy(p, ctx->obuf, ctx->obuf_len);
247             OPENSSL_free(ctx->obuf);
248             ctx->obuf = p;
249             ctx->obuf_size = obs;
250         }
251         break;
252     case BIO_C_DO_STATE_MACHINE:
253         if (b->next_bio == NULL)
254             return 0;
255         BIO_clear_retry_flags(b);
256         ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
257         BIO_copy_next_retry(b);
258         break;
259 
260     case BIO_CTRL_FLUSH:
261         if (b->next_bio == NULL)
262             return 0;
263         if (ctx->obuf_len <= 0) {
264             ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
265             break;
266         }
267 
268         for (;;) {
269             BIO_clear_retry_flags(b);
270             if (ctx->obuf_len > 0) {
271                 r = BIO_write(b->next_bio, ctx->obuf, ctx->obuf_len);
272                 BIO_copy_next_retry(b);
273                 if (r <= 0)
274                     return (long)r;
275                 if (r < ctx->obuf_len)
276                     memmove(ctx->obuf, ctx->obuf + r, ctx->obuf_len - r);
277                 ctx->obuf_len -= r;
278             } else {
279                 ctx->obuf_len = 0;
280                 break;
281             }
282         }
283         ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
284         break;
285     case BIO_CTRL_DUP:
286         dbio = (BIO *)ptr;
287         if (!BIO_set_write_buffer_size(dbio, ctx->obuf_size))
288             ret = 0;
289         break;
290     default:
291         if (b->next_bio == NULL)
292             return 0;
293         ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
294         break;
295     }
296     return ret;
297  malloc_error:
298     BIOerr(BIO_F_LINEBUFFER_CTRL, ERR_R_MALLOC_FAILURE);
299     return 0;
300 }
301 
linebuffer_callback_ctrl(BIO * b,int cmd,BIO_info_cb * fp)302 static long linebuffer_callback_ctrl(BIO *b, int cmd, BIO_info_cb *fp)
303 {
304     long ret = 1;
305 
306     if (b->next_bio == NULL)
307         return 0;
308     switch (cmd) {
309     default:
310         ret = BIO_callback_ctrl(b->next_bio, cmd, fp);
311         break;
312     }
313     return ret;
314 }
315 
linebuffer_gets(BIO * b,char * buf,int size)316 static int linebuffer_gets(BIO *b, char *buf, int size)
317 {
318     if (b->next_bio == NULL)
319         return 0;
320     return BIO_gets(b->next_bio, buf, size);
321 }
322 
linebuffer_puts(BIO * b,const char * str)323 static int linebuffer_puts(BIO *b, const char *str)
324 {
325     return linebuffer_write(b, str, strlen(str));
326 }
327