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sign.c
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1 /* demos/sign/sign.c */
2 /* Copyright (C) 1995-1998 Eric Young ([email protected])
3  * All rights reserved.
4  *
5  * This package is an SSL implementation written
6  * by Eric Young ([email protected]).
7  * The implementation was written so as to conform with Netscapes SSL.
8  *
9  * This library is free for commercial and non-commercial use as long as
10  * the following conditions are aheared to. The following conditions
11  * apply to all code found in this distribution, be it the RC4, RSA,
12  * lhash, DES, etc., code; not just the SSL code. The SSL documentation
13  * included with this distribution is covered by the same copyright terms
14  * except that the holder is Tim Hudson ([email protected]).
15  *
16  * Copyright remains Eric Young's, and as such any Copyright notices in
17  * the code are not to be removed.
18  * If this package is used in a product, Eric Young should be given attribution
19  * as the author of the parts of the library used.
20  * This can be in the form of a textual message at program startup or
21  * in documentation (online or textual) provided with the package.
22  *
23  * Redistribution and use in source and binary forms, with or without
24  * modification, are permitted provided that the following conditions
25  * are met:
26  * 1. Redistributions of source code must retain the copyright
27  * notice, this list of conditions and the following disclaimer.
28  * 2. Redistributions in binary form must reproduce the above copyright
29  * notice, this list of conditions and the following disclaimer in the
30  * documentation and/or other materials provided with the distribution.
31  * 3. All advertising materials mentioning features or use of this software
32  * must display the following acknowledgement:
33  * "This product includes cryptographic software written by
34  * Eric Young ([email protected])"
35  * The word 'cryptographic' can be left out if the rouines from the library
36  * being used are not cryptographic related :-).
37  * 4. If you include any Windows specific code (or a derivative thereof) from
38  * the apps directory (application code) you must include an acknowledgement:
39  * "This product includes software written by Tim Hudson ([email protected])"
40  *
41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51  * SUCH DAMAGE.
52  *
53  * The licence and distribution terms for any publically available version or
54  * derivative of this code cannot be changed. i.e. this code cannot simply be
55  * copied and put under another distribution licence
56  * [including the GNU Public Licence.]
57  */
58 
59 /* sign-it.cpp - Simple test app using SSLeay envelopes to sign data
60  29.9.1996, Sampo Kellomaki <[email protected]> */
61 
62 /* converted to C - eay :-) */
63 
64 /* reformated a bit and converted to use the more common functions: this was
65  * initially written at the dawn of time :-) - Steve.
66  */
67 
68 #include <stdio.h>
69 #include <openssl/rsa.h>
70 #include <openssl/evp.h>
71 #include <openssl/objects.h>
72 #include <openssl/x509.h>
73 #include <openssl/err.h>
74 #include <openssl/pem.h>
75 #include <openssl/ssl.h>
76 
77 int main ()
78 {
79  int err;
80  int sig_len;
81  unsigned char sig_buf [4096];
82  static char certfile[] = "cert.pem";
83  static char keyfile[] = "key.pem";
84  static char data[] = "I owe you...";
85  EVP_MD_CTX md_ctx;
86  EVP_PKEY * pkey;
87  FILE * fp;
88  X509 * x509;
89 
90  /* Just load the crypto library error strings,
91  * SSL_load_error_strings() loads the crypto AND the SSL ones */
92  /* SSL_load_error_strings();*/
94 
95  /* Read private key */
96 
97  fp = fopen (keyfile, "r");
98  if (fp == NULL) exit (1);
99  pkey = PEM_read_PrivateKey(fp, NULL, NULL, NULL);
100  fclose (fp);
101 
102  if (pkey == NULL) {
103  ERR_print_errors_fp (stderr);
104  exit (1);
105  }
106 
107  /* Do the signature */
108 
109  EVP_SignInit (&md_ctx, EVP_sha1());
110  EVP_SignUpdate (&md_ctx, data, strlen(data));
111  sig_len = sizeof(sig_buf);
112  err = EVP_SignFinal (&md_ctx, sig_buf, &sig_len, pkey);
113 
114  if (err != 1) {
115  ERR_print_errors_fp(stderr);
116  exit (1);
117  }
118 
119  EVP_PKEY_free (pkey);
120 
121  /* Read public key */
122 
123  fp = fopen (certfile, "r");
124  if (fp == NULL) exit (1);
125  x509 = PEM_read_X509(fp, NULL, NULL, NULL);
126  fclose (fp);
127 
128  if (x509 == NULL) {
129  ERR_print_errors_fp (stderr);
130  exit (1);
131  }
132 
133  /* Get public key - eay */
134  pkey=X509_get_pubkey(x509);
135  if (pkey == NULL) {
136  ERR_print_errors_fp (stderr);
137  exit (1);
138  }
139 
140  /* Verify the signature */
141 
142  EVP_VerifyInit (&md_ctx, EVP_sha1());
143  EVP_VerifyUpdate (&md_ctx, data, strlen((char*)data));
144  err = EVP_VerifyFinal (&md_ctx, sig_buf, sig_len, pkey);
145  EVP_PKEY_free (pkey);
146 
147  if (err != 1) {
148  ERR_print_errors_fp (stderr);
149  exit (1);
150  }
151  printf ("Signature Verified Ok.\n");
152  return(0);
153 }