bf_prefix.c revision 1.1.1.1 
1/*
2 * Copyright 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 <string.h>
12#include <errno.h>
13#include <openssl/bio.h>
14#include "apps.h"
15
16static int prefix_write(BIO *b, const char *out, size_t outl,
17                        size_t *numwritten);
18static int prefix_read(BIO *b, char *buf, size_t size, size_t *numread);
19static int prefix_puts(BIO *b, const char *str);
20static int prefix_gets(BIO *b, char *str, int size);
21static long prefix_ctrl(BIO *b, int cmd, long arg1, void *arg2);
22static int prefix_create(BIO *b);
23static int prefix_destroy(BIO *b);
24static long prefix_callback_ctrl(BIO *b, int cmd, BIO_info_cb *fp);
25
26static BIO_METHOD *prefix_meth = NULL;
27
28BIO_METHOD *apps_bf_prefix(void)
29{
30    if (prefix_meth == NULL) {
31        if ((prefix_meth =
32             BIO_meth_new(BIO_TYPE_FILTER, "Prefix filter")) == NULL
33            || !BIO_meth_set_create(prefix_meth, prefix_create)
34            || !BIO_meth_set_destroy(prefix_meth, prefix_destroy)
35            || !BIO_meth_set_write_ex(prefix_meth, prefix_write)
36            || !BIO_meth_set_read_ex(prefix_meth, prefix_read)
37            || !BIO_meth_set_puts(prefix_meth, prefix_puts)
38            || !BIO_meth_set_gets(prefix_meth, prefix_gets)
39            || !BIO_meth_set_ctrl(prefix_meth, prefix_ctrl)
40            || !BIO_meth_set_callback_ctrl(prefix_meth, prefix_callback_ctrl)) {
41            BIO_meth_free(prefix_meth);
42            prefix_meth = NULL;
43        }
44    }
45    return prefix_meth;
46}
47
48typedef struct prefix_ctx_st {
49    char *prefix;
50    int linestart;               /* flag to indicate we're at the line start */
51} PREFIX_CTX;
52
53static int prefix_create(BIO *b)
54{
55    PREFIX_CTX *ctx = OPENSSL_zalloc(sizeof(*ctx));
56
57    if (ctx == NULL)
58        return 0;
59
60    ctx->prefix = NULL;
61    ctx->linestart = 1;
62    BIO_set_data(b, ctx);
63    BIO_set_init(b, 1);
64    return 1;
65}
66
67static int prefix_destroy(BIO *b)
68{
69    PREFIX_CTX *ctx = BIO_get_data(b);
70
71    OPENSSL_free(ctx->prefix);
72    OPENSSL_free(ctx);
73    return 1;
74}
75
76static int prefix_read(BIO *b, char *in, size_t size, size_t *numread)
77{
78    return BIO_read_ex(BIO_next(b), in, size, numread);
79}
80
81static int prefix_write(BIO *b, const char *out, size_t outl,
82                        size_t *numwritten)
83{
84    PREFIX_CTX *ctx = BIO_get_data(b);
85
86    if (ctx == NULL)
87        return 0;
88
89    /* If no prefix is set or if it's empty, we've got nothing to do here */
90    if (ctx->prefix == NULL || *ctx->prefix == '\0') {
91        /* We do note if what comes next will be a new line, though */
92        if (outl > 0)
93            ctx->linestart = (out[outl-1] == '\n');
94        return BIO_write_ex(BIO_next(b), out, outl, numwritten);
95    }
96
97    *numwritten = 0;
98
99    while (outl > 0) {
100        size_t i;
101        char c;
102
103        /* If we know that we're at the start of the line, output the prefix */
104        if (ctx->linestart) {
105            size_t dontcare;
106
107            if (!BIO_write_ex(BIO_next(b), ctx->prefix, strlen(ctx->prefix),
108                              &dontcare))
109                return 0;
110            ctx->linestart = 0;
111        }
112
113        /* Now, go look for the next LF, or the end of the string */
114        for (i = 0, c = '\0'; i < outl && (c = out[i]) != '\n'; i++)
115            continue;
116        if (c == '\n')
117            i++;
118
119        /* Output what we found so far */
120        while (i > 0) {
121            size_t num = 0;
122
123            if (!BIO_write_ex(BIO_next(b), out, i, &num))
124                return 0;
125            out += num;
126            outl -= num;
127            *numwritten += num;
128            i -= num;
129        }
130
131        /* If we found a LF, what follows is a new line, so take note */
132        if (c == '\n')
133            ctx->linestart = 1;
134    }
135
136    return 1;
137}
138
139static long prefix_ctrl(BIO *b, int cmd, long num, void *ptr)
140{
141    long ret = 0;
142
143    switch (cmd) {
144    case PREFIX_CTRL_SET_PREFIX:
145        {
146            PREFIX_CTX *ctx = BIO_get_data(b);
147
148            if (ctx == NULL)
149                break;
150
151            OPENSSL_free(ctx->prefix);
152            ctx->prefix = OPENSSL_strdup((const char *)ptr);
153            ret = ctx->prefix != NULL;
154        }
155        break;
156    default:
157        if (BIO_next(b) != NULL)
158            ret = BIO_ctrl(BIO_next(b), cmd, num, ptr);
159        break;
160    }
161    return ret;
162}
163
164static long prefix_callback_ctrl(BIO *b, int cmd, BIO_info_cb *fp)
165{
166    return BIO_callback_ctrl(BIO_next(b), cmd, fp);
167}
168
169static int prefix_gets(BIO *b, char *buf, int size)
170{
171    return BIO_gets(BIO_next(b), buf, size);
172}
173
174static int prefix_puts(BIO *b, const char *str)
175{
176    return BIO_write(b, str, strlen(str));
177}
178