1 /*
2  * Copyright (c) 2021, 2022, 2024 Omar Polo <op@omarpolo.com>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include "compat.h"
18 
19 #include <limits.h>
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <string.h>
23 #include <unistd.h>
24 
25 #include "fs.h"
26 #include "tofu.h"
27 #include "utils.h"
28 #include "xwrapper.h"
29 
30 void
31 tofu_init(struct ohash *h, unsigned int sz, ptrdiff_t ko)
32 {
33 	struct ohash_info info = {
34 		.key_offset = ko,
35 		.calloc = hash_calloc,
36 		.free = hash_free,
37 		.alloc = hash_alloc,
38 	};
39 
40 	ohash_init(h, sz, &info);
41 }
42 
43 struct tofu_entry *
44 tofu_lookup(struct ohash *h, const char *domain, const char *port)
45 {
46 	char		buf[TOFU_URL_MAX_LEN];
47 	unsigned int	slot;
48 
49 	strlcpy(buf, domain, sizeof(buf));
50 	if (port != NULL && *port != '\0' && strcmp(port, "1965")) {
51 		strlcat(buf, ":", sizeof(buf));
52 		strlcat(buf, port, sizeof(buf));
53 	}
54 
55 	slot = ohash_qlookup(h, buf);
56 	return ohash_find(h, slot);
57 }
58 
59 void
60 tofu_add(struct ohash *h, struct tofu_entry *e)
61 {
62 	unsigned int	slot;
63 
64 	slot = ohash_qlookup(h, e->domain);
65 	ohash_insert(h, slot, e);
66 }
67 
68 int
69 tofu_save(struct ohash *h, struct tofu_entry *e)
70 {
71 	FILE *fp;
72 
73 	tofu_add(h, e);
74 
75 	if ((fp = fopen(known_hosts_file, "a")) == NULL)
76 		return -1;
77 	fprintf(fp, "%s %s %d\n", e->domain, e->hash, e->verified);
78 	fclose(fp);
79 	return 0;
80 }
81 
82 void
83 tofu_update(struct ohash *h, struct tofu_entry *e)
84 {
85 	struct tofu_entry *t;
86 
87 	if ((t = tofu_lookup(h, e->domain, NULL)) == NULL)
88 		tofu_add(h, e);
89 	else {
90 		strlcpy(t->hash, e->hash, sizeof(t->hash));
91 		t->verified = e->verified;
92 		free(e);
93 	}
94 }
95 
96 int
97 tofu_update_persist(struct ohash *h, struct tofu_entry *e)
98 {
99 	FILE	*tmp, *fp;
100 	char	 sfn[PATH_MAX], *line = NULL;
101 	size_t	 l, linesize = 0;
102 	ssize_t	 linelen;
103 	int	 fd, err;
104 
105 	tofu_update(h, e);
106 
107 	strlcpy(sfn, known_hosts_tmp, sizeof(sfn));
108 	if ((fd = mkstemp(sfn)) == -1 ||
109 	    (tmp = fdopen(fd, "w")) == NULL) {
110 		if (fd != -1) {
111 			unlink(sfn);
112 			close(fd);
113 		}
114 		return -1;
115 	}
116 
117 	if ((fp = fopen(known_hosts_file, "r")) == NULL) {
118 		unlink(sfn);
119 		fclose(tmp);
120 		return -1;
121 	}
122 
123 	l = strlen(e->domain);
124 	while ((linelen = getline(&line, &linesize, fp)) != -1) {
125 		if (!strncmp(line, e->domain, l))
126 			continue;
127 		if (linesize > 0 && line[linesize-1] == '\n')
128 			line[linesize-1] = '\0';
129 		fprintf(tmp, "%s\n", line);
130 	}
131 	fprintf(tmp, "%s %s %d\n", e->domain, e->hash, e->verified);
132 
133 	free(line);
134 	err = ferror(tmp);
135 	fclose(tmp);
136 	fclose(fp);
137 
138 	if (err) {
139 		unlink(sfn);
140 		return -1;
141 	}
142 
143 	if (rename(sfn, known_hosts_file) == -1)
144 		return -1;
145 	return 0;
146 }
147 
148 void
149 tofu_temp_trust(struct ohash *h, const char *host, const char *port,
150     const char *hash)
151 {
152 	struct tofu_entry *e;
153 
154 	e = xcalloc(1, sizeof(*e));
155 
156 	strlcpy(e->domain, host, sizeof(e->domain));
157 	if (*port != '\0' && strcmp(port, "1965")) {
158 		strlcat(e->domain, ":", sizeof(e->domain));
159 		strlcat(e->domain, port, sizeof(e->domain));
160 	}
161 	strlcpy(e->hash, hash, sizeof(e->hash));
162 	e->verified = -1;
163 
164 	tofu_update(h, e);
165 }