xref: /openbsd-src/usr.sbin/nsd/tsig-openssl.c (revision f2da64fbbbf1b03f09f390ab01267c93dfd77c4c)
1 /*
2  * tsig-openssl.h -- Interface to OpenSSL for TSIG support.
3  *
4  * Copyright (c) 2001-2006, NLnet Labs. All rights reserved.
5  *
6  * See LICENSE for the license.
7  *
8  */
9 
10 #include "config.h"
11 
12 #if defined(HAVE_SSL)
13 
14 #include "tsig-openssl.h"
15 #include "tsig.h"
16 #include "util.h"
17 
18 static void *create_context(region_type *region);
19 static void init_context(void *context,
20 			 tsig_algorithm_type *algorithm,
21 			 tsig_key_type *key);
22 static void update(void *context, const void *data, size_t size);
23 static void final(void *context, uint8_t *digest, size_t *size);
24 
25 static int
26 tsig_openssl_init_algorithm(region_type* region,
27 	const char* digest, const char* name, const char* wireformat)
28 {
29 	tsig_algorithm_type* algorithm;
30 	const EVP_MD *hmac_algorithm;
31 
32 	hmac_algorithm = EVP_get_digestbyname(digest);
33 	if (!hmac_algorithm) {
34 		/* skip but don't error */
35 		return 0;
36 	}
37 
38 	algorithm = (tsig_algorithm_type *) region_alloc(
39 		region, sizeof(tsig_algorithm_type));
40 	algorithm->short_name = name;
41 	algorithm->wireformat_name
42 		= dname_parse(region, wireformat);
43 	if (!algorithm->wireformat_name) {
44 		log_msg(LOG_ERR, "cannot parse %s algorithm", wireformat);
45 		return 0;
46 	}
47 	algorithm->maximum_digest_size = EVP_MD_size(hmac_algorithm);
48 	if(algorithm->maximum_digest_size < 20)
49 		algorithm->maximum_digest_size = EVP_MAX_MD_SIZE;
50 	algorithm->data = hmac_algorithm;
51 	algorithm->hmac_create_context = create_context;
52 	algorithm->hmac_init_context = init_context;
53 	algorithm->hmac_update = update;
54 	algorithm->hmac_final = final;
55 	tsig_add_algorithm(algorithm);
56 
57 	return 1;
58 }
59 
60 int
61 tsig_openssl_init(region_type *region)
62 {
63 	int count = 0;
64 	OpenSSL_add_all_digests();
65 
66 	count += tsig_openssl_init_algorithm(region,
67 	    "md5", "hmac-md5","hmac-md5.sig-alg.reg.int.");
68 	count += tsig_openssl_init_algorithm(region,
69 	    "sha1", "hmac-sha1", "hmac-sha1.");
70 	count += tsig_openssl_init_algorithm(region,
71 	    "sha224", "hmac-sha224", "hmac-sha224.");
72 	count += tsig_openssl_init_algorithm(region,
73 	    "sha256", "hmac-sha256", "hmac-sha256.");
74 	count += tsig_openssl_init_algorithm(region,
75 	    "sha384", "hmac-sha384", "hmac-sha384.");
76 	count += tsig_openssl_init_algorithm(region,
77 	    "sha512", "hmac-sha512", "hmac-sha512.");
78 
79 	return count;
80 }
81 
82 static void
83 cleanup_context(void *data)
84 {
85 	HMAC_CTX *context = (HMAC_CTX *) data;
86 #ifdef HAVE_HMAC_CTX_NEW
87 	HMAC_CTX_free(context);
88 #else
89 	HMAC_CTX_cleanup(context);
90 	free(context);
91 #endif
92 }
93 
94 static void *
95 create_context(region_type *region)
96 {
97 #ifdef HAVE_HMAC_CTX_NEW
98 	HMAC_CTX *context = HMAC_CTX_new();
99 #else
100 	HMAC_CTX *context = (HMAC_CTX *) malloc(sizeof(HMAC_CTX));
101 #endif
102 	region_add_cleanup(region, cleanup_context, context);
103 #ifdef HAVE_HMAC_CTX_RESET
104 	HMAC_CTX_reset(context);
105 #else
106 	HMAC_CTX_init(context);
107 #endif
108 	return context;
109 }
110 
111 static void
112 init_context(void *context,
113 			  tsig_algorithm_type *algorithm,
114 			  tsig_key_type *key)
115 {
116 	HMAC_CTX *ctx = (HMAC_CTX *) context;
117 	const EVP_MD *md = (const EVP_MD *) algorithm->data;
118 	HMAC_Init_ex(ctx, key->data, key->size, md, NULL);
119 }
120 
121 static void
122 update(void *context, const void *data, size_t size)
123 {
124 	HMAC_CTX *ctx = (HMAC_CTX *) context;
125 	HMAC_Update(ctx, (unsigned char *) data, (int) size);
126 }
127 
128 static void
129 final(void *context, uint8_t *digest, size_t *size)
130 {
131 	HMAC_CTX *ctx = (HMAC_CTX *) context;
132 	unsigned len = (unsigned) *size;
133 	HMAC_Final(ctx, digest, &len);
134 	*size = (size_t) len;
135 }
136 
137 void
138 tsig_openssl_finalize()
139 {
140 	EVP_cleanup();
141 }
142 
143 #endif /* defined(HAVE_SSL) */
144