Typo fixes (experimental-spec)
[exim.git] / src / util / gen_pkcs3.c
CommitLineData
a799883d
PP
1/* Copyright (C) 2012 Phil Pennock.
2 * This is distributed as part of Exim and licensed under the GPL.
3 * See the file "NOTICE" for more details.
4 */
5
6/* Build with:
7 * c99 $(pkg-config --cflags openssl) gen_pkcs3.c $(pkg-config --libs openssl)
8 */
9
10#include <ctype.h>
11#include <errno.h>
12#include <stdbool.h>
13#include <stdio.h>
14#include <stdlib.h>
15#include <string.h>
16#include <unistd.h>
17
18#include <openssl/bio.h>
19#include <openssl/bn.h>
20#include <openssl/dh.h>
21#include <openssl/err.h>
22#include <openssl/pem.h>
23
24extern const char *__progname;
25
26
27void __attribute__((__noreturn__)) __attribute__((__format__(printf, 1, 2)))
28die(const char *fmt, ...)
29{
30 va_list ap;
31
32 fflush(NULL);
33 fprintf(stderr, "%s: ", __progname);
34 va_start(ap, fmt);
35 vfprintf(stderr, fmt, ap);
36 va_end(ap);
37 fprintf(stderr, "\n");
38 fflush(stderr);
39 exit(1);
40}
41
42
43void __attribute__((__noreturn__))
44die_openssl_err(const char *msg)
45{
46 char err_string[250];
47 unsigned long e;
48
49 ERR_error_string_n(ERR_get_error(), err_string, sizeof(err_string));
50 die("%s: %s", msg, err_string);
51}
52
53
54static BIGNUM *
55bn_from_text(const char *text)
56{
57 BIGNUM *b;
58 char *p, *spaceless;
59 const char *q, *end;
60 size_t len;
61 int rc;
62
63 len = strlen(text);
64 spaceless = malloc(len);
65 if (!spaceless)
66 die("malloc(%zu) failed: %s", len, strerror(errno));
67
68 for (p = spaceless, q = text, end = text + len;
69 q < end;
70 ++q) {
71 if (!isspace(*q))
72 *p++ = *q;
73 }
74
75 b = NULL;
76 rc = BN_hex2bn(&b, spaceless);
77
78 if (rc != p - spaceless)
79 die("BN_hex2bn did not convert entire input; took %d of %z bytes",
80 rc, p - spaceless);
81
82 return b;
83}
84
85
86static void
87our_dh_check(DH *dh)
88{
89 int rc, errflags = 0;
90
91 rc = DH_check(dh, &errflags);
92 if (!rc) die_openssl_err("DH_check() could not be performed");;
93
94 /* We ignore DH_UNABLE_TO_CHECK_GENERATOR because some of the invocations
95 * deliberately provide generators other than 2 or 5. */
96
97 if (errflags & DH_CHECK_P_NOT_SAFE_PRIME)
98 die("DH_check(): p not a safe prime");
99 if (errflags & DH_NOT_SUITABLE_GENERATOR)
100 die("DH_check(): g not suitable as generator");
101}
102
103
104static void
105emit_c_format_dh(FILE *stream, DH *dh)
106{
107 BIO *bio;
108 long length;
109 char *data, *end, *p, *nl;
110
111 bio = BIO_new(BIO_s_mem());
112 PEM_write_bio_DHparams(bio, dh);
113 length = BIO_get_mem_data(bio, &data);
114 if (!length)
115 die("no data in memory BIO to format for printing");
116 if (length < 0)
117 die("grr, negative length memory not supported");
118 end = data + length;
119
120 for (p = data; p < end; /**/) {
121 nl = strchr(p, '\n');
122 if (!nl) {
123 fprintf(stream, "\"%s\\n\"\n/* missing final newline */\n", p);
124 break;
125 }
126 *nl = '\0';
127 fprintf(stream, "\"%s\\n\"\n", p);
128 p = nl + 1;
129 }
130}
131
132
133void __attribute__((__noreturn__))
134usage(FILE *stream, int exitcode)
135{
136 fprintf(stream, "Usage: %s [-CPcst] <dh_p> <dh_g>\n"
137"Both dh_p and dh_g should be hex strings representing the numbers\n"
138"They may contain whitespace.\n"
139"\n"
140" -C show C string form of PEM result\n"
141" -P do not show PEM\n"
142" -c run OpenSSL DH_check() on the DH object\n"
143" -s show the parsed p and g\n"
144" -t show text form of certificate\n"
145
146 , __progname);
147 exit(exitcode);
148}
149
150
151int
152main(int argc, char *argv[])
153{
154 BIGNUM *p, *g;
155 DH *dh;
156 int ch;
157 bool perform_dh_check = false;
158 bool show_c_form = false;
159 bool show_numbers = false;
160 bool show_pem = true;
161 bool show_text = false;
162
163 while ((ch = getopt(argc, argv, "CPcsth")) != -1) {
164 switch (ch) {
165 case 'C':
166 show_c_form = true;
167 break;
168 case 'P':
169 show_pem = false;
170 break;
171 case 'c':
172 perform_dh_check = true;
173 break;
174 case 's':
175 show_numbers = true;
176 break;
177 case 't':
178 show_text = true;
179 break;
180
181 case 'h':
182 usage(stdout, 0);
183 case '?':
184 die("Unknown option or missing argument -%c", optopt);
185 default:
186 die("Unhandled option -%c", ch);
187 }
188 }
189
190 optind -= 1;
191 argc -= optind;
192 argv += optind;
193
194 if (argc != 3) {
195 fprintf(stderr, "argc: %d\n", argc);
196 usage(stderr, 1);
197 }
198
199 p = bn_from_text(argv[1]);
200 g = bn_from_text(argv[2]);
201
202 if (show_numbers) {
203 printf("p = ");
204 BN_print_fp(stdout, p);
205 printf("\ng = ");
206 BN_print_fp(stdout, g);
207 printf("\n");
208 }
209
210 dh = DH_new();
211 dh->p = p;
212 dh->g = g;
213
214 if (perform_dh_check)
215 our_dh_check(dh);
216
217 if (show_text)
218 DHparams_print_fp(stdout, dh);
219
220 if (show_pem) {
221 if (show_c_form)
222 emit_c_format_dh(stdout, dh);
223 else
224 PEM_write_DHparams(stdout, dh);
225 }
226
227 DH_free(dh); /* should free p & g too */
228 return 0;
229}