xref: /openbsd-src/lib/libcrypto/dh/dh.h (revision a28daedfc357b214be5c701aa8ba8adb29a7f1c2)
1 /* crypto/dh/dh.h */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3  * All rights reserved.
4  *
5  * This package is an SSL implementation written
6  * by Eric Young (eay@cryptsoft.com).
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 (tjh@cryptsoft.com).
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 (eay@cryptsoft.com)"
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 (tjh@cryptsoft.com)"
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 #ifndef HEADER_DH_H
60 #define HEADER_DH_H
61 
62 #include <openssl/e_os2.h>
63 
64 #ifdef OPENSSL_NO_DH
65 #error DH is disabled.
66 #endif
67 
68 #ifndef OPENSSL_NO_BIO
69 #include <openssl/bio.h>
70 #endif
71 #include <openssl/ossl_typ.h>
72 #ifndef OPENSSL_NO_DEPRECATED
73 #include <openssl/bn.h>
74 #endif
75 
76 #ifndef OPENSSL_DH_MAX_MODULUS_BITS
77 # define OPENSSL_DH_MAX_MODULUS_BITS	10000
78 #endif
79 
80 #define OPENSSL_DH_FIPS_MIN_MODULUS_BITS 1024
81 
82 #define DH_FLAG_CACHE_MONT_P     0x01
83 #define DH_FLAG_NO_EXP_CONSTTIME 0x02 /* new with 0.9.7h; the built-in DH
84                                        * implementation now uses constant time
85                                        * modular exponentiation for secret exponents
86                                        * by default. This flag causes the
87                                        * faster variable sliding window method to
88                                        * be used for all exponents.
89                                        */
90 
91 #ifdef  __cplusplus
92 extern "C" {
93 #endif
94 
95 /* Already defined in ossl_typ.h */
96 /* typedef struct dh_st DH; */
97 /* typedef struct dh_method DH_METHOD; */
98 
99 struct dh_method
100 	{
101 	const char *name;
102 	/* Methods here */
103 	int (*generate_key)(DH *dh);
104 	int (*compute_key)(unsigned char *key,const BIGNUM *pub_key,DH *dh);
105 	int (*bn_mod_exp)(const DH *dh, BIGNUM *r, const BIGNUM *a,
106 				const BIGNUM *p, const BIGNUM *m, BN_CTX *ctx,
107 				BN_MONT_CTX *m_ctx); /* Can be null */
108 
109 	int (*init)(DH *dh);
110 	int (*finish)(DH *dh);
111 	int flags;
112 	char *app_data;
113 	/* If this is non-NULL, it will be used to generate parameters */
114 	int (*generate_params)(DH *dh, int prime_len, int generator, BN_GENCB *cb);
115 	};
116 
117 struct dh_st
118 	{
119 	/* This first argument is used to pick up errors when
120 	 * a DH is passed instead of a EVP_PKEY */
121 	int pad;
122 	int version;
123 	BIGNUM *p;
124 	BIGNUM *g;
125 	long length; /* optional */
126 	BIGNUM *pub_key;	/* g^x */
127 	BIGNUM *priv_key;	/* x */
128 
129 	int flags;
130 	BN_MONT_CTX *method_mont_p;
131 	/* Place holders if we want to do X9.42 DH */
132 	BIGNUM *q;
133 	BIGNUM *j;
134 	unsigned char *seed;
135 	int seedlen;
136 	BIGNUM *counter;
137 
138 	int references;
139 	CRYPTO_EX_DATA ex_data;
140 	const DH_METHOD *meth;
141 	ENGINE *engine;
142 	};
143 
144 #define DH_GENERATOR_2		2
145 /* #define DH_GENERATOR_3	3 */
146 #define DH_GENERATOR_5		5
147 
148 /* DH_check error codes */
149 #define DH_CHECK_P_NOT_PRIME		0x01
150 #define DH_CHECK_P_NOT_SAFE_PRIME	0x02
151 #define DH_UNABLE_TO_CHECK_GENERATOR	0x04
152 #define DH_NOT_SUITABLE_GENERATOR	0x08
153 
154 /* DH_check_pub_key error codes */
155 #define DH_CHECK_PUBKEY_TOO_SMALL	0x01
156 #define DH_CHECK_PUBKEY_TOO_LARGE	0x02
157 
158 /* primes p where (p-1)/2 is prime too are called "safe"; we define
159    this for backward compatibility: */
160 #define DH_CHECK_P_NOT_STRONG_PRIME	DH_CHECK_P_NOT_SAFE_PRIME
161 
162 #define DHparams_dup(x) ASN1_dup_of_const(DH,i2d_DHparams,d2i_DHparams,x)
163 #define d2i_DHparams_fp(fp,x) (DH *)ASN1_d2i_fp((char *(*)())DH_new, \
164 		(char *(*)())d2i_DHparams,(fp),(unsigned char **)(x))
165 #define i2d_DHparams_fp(fp,x) ASN1_i2d_fp(i2d_DHparams,(fp), \
166 		(unsigned char *)(x))
167 #define d2i_DHparams_bio(bp,x) ASN1_d2i_bio_of(DH,DH_new,d2i_DHparams,bp,x)
168 #define i2d_DHparams_bio(bp,x) ASN1_i2d_bio_of_const(DH,i2d_DHparams,bp,x)
169 
170 const DH_METHOD *DH_OpenSSL(void);
171 
172 #ifdef OPENSSL_FIPS
173 DH *	FIPS_dh_new(void);
174 void	FIPS_dh_free(DH *dh);
175 #endif
176 
177 void DH_set_default_method(const DH_METHOD *meth);
178 const DH_METHOD *DH_get_default_method(void);
179 int DH_set_method(DH *dh, const DH_METHOD *meth);
180 DH *DH_new_method(ENGINE *engine);
181 
182 DH *	DH_new(void);
183 void	DH_free(DH *dh);
184 int	DH_up_ref(DH *dh);
185 int	DH_size(const DH *dh);
186 int DH_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
187 	     CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func);
188 int DH_set_ex_data(DH *d, int idx, void *arg);
189 void *DH_get_ex_data(DH *d, int idx);
190 
191 /* Deprecated version */
192 #ifndef OPENSSL_NO_DEPRECATED
193 DH *	DH_generate_parameters(int prime_len,int generator,
194 		void (*callback)(int,int,void *),void *cb_arg);
195 #endif /* !defined(OPENSSL_NO_DEPRECATED) */
196 
197 /* New version */
198 int	DH_generate_parameters_ex(DH *dh, int prime_len,int generator, BN_GENCB *cb);
199 
200 int	DH_check(const DH *dh,int *codes);
201 int	DH_check_pub_key(const DH *dh,const BIGNUM *pub_key, int *codes);
202 int	DH_generate_key(DH *dh);
203 int	DH_compute_key(unsigned char *key,const BIGNUM *pub_key,DH *dh);
204 DH *	d2i_DHparams(DH **a,const unsigned char **pp, long length);
205 int	i2d_DHparams(const DH *a,unsigned char **pp);
206 #ifndef OPENSSL_NO_FP_API
207 int	DHparams_print_fp(FILE *fp, const DH *x);
208 #endif
209 #ifndef OPENSSL_NO_BIO
210 int	DHparams_print(BIO *bp, const DH *x);
211 #else
212 int	DHparams_print(char *bp, const DH *x);
213 #endif
214 
215 /* BEGIN ERROR CODES */
216 /* The following lines are auto generated by the script mkerr.pl. Any changes
217  * made after this point may be overwritten when the script is next run.
218  */
219 void ERR_load_DH_strings(void);
220 
221 /* Error codes for the DH functions. */
222 
223 /* Function codes. */
224 #define DH_F_COMPUTE_KEY				 102
225 #define DH_F_DHPARAMS_PRINT				 100
226 #define DH_F_DHPARAMS_PRINT_FP				 101
227 #define DH_F_DH_BUILTIN_GENPARAMS			 106
228 #define DH_F_DH_COMPUTE_KEY				 107
229 #define DH_F_DH_GENERATE_KEY				 108
230 #define DH_F_DH_GENERATE_PARAMETERS			 109
231 #define DH_F_DH_NEW_METHOD				 105
232 #define DH_F_GENERATE_KEY				 103
233 #define DH_F_GENERATE_PARAMETERS			 104
234 
235 /* Reason codes. */
236 #define DH_R_BAD_GENERATOR				 101
237 #define DH_R_INVALID_PUBKEY				 102
238 #define DH_R_KEY_SIZE_TOO_SMALL				 104
239 #define DH_R_MODULUS_TOO_LARGE				 103
240 #define DH_R_NO_PRIVATE_VALUE				 100
241 
242 #ifdef  __cplusplus
243 }
244 #endif
245 #endif
246