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1 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
2  * All rights reserved.
3  *
4  * This package is an SSL implementation written
5  * by Eric Young (eay@cryptsoft.com).
6  * The implementation was written so as to conform with Netscapes SSL.
7  *
8  * This library is free for commercial and non-commercial use as long as
9  * the following conditions are aheared to.  The following conditions
10  * apply to all code found in this distribution, be it the RC4, RSA,
11  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
12  * included with this distribution is covered by the same copyright terms
13  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
14  *
15  * Copyright remains Eric Young's, and as such any Copyright notices in
16  * the code are not to be removed.
17  * If this package is used in a product, Eric Young should be given attribution
18  * as the author of the parts of the library used.
19  * This can be in the form of a textual message at program startup or
20  * in documentation (online or textual) provided with the package.
21  *
22  * Redistribution and use in source and binary forms, with or without
23  * modification, are permitted provided that the following conditions
24  * are met:
25  * 1. Redistributions of source code must retain the copyright
26  *    notice, this list of conditions and the following disclaimer.
27  * 2. Redistributions in binary form must reproduce the above copyright
28  *    notice, this list of conditions and the following disclaimer in the
29  *    documentation and/or other materials provided with the distribution.
30  * 3. All advertising materials mentioning features or use of this software
31  *    must display the following acknowledgement:
32  *    "This product includes cryptographic software written by
33  *     Eric Young (eay@cryptsoft.com)"
34  *    The word 'cryptographic' can be left out if the rouines from the library
35  *    being used are not cryptographic related :-).
36  * 4. If you include any Windows specific code (or a derivative thereof) from
37  *    the apps directory (application code) you must include an acknowledgement:
38  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
39  *
40  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
41  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
44  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
45  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
46  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
49  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50  * SUCH DAMAGE.
51  *
52  * The licence and distribution terms for any publically available version or
53  * derivative of this code cannot be changed.  i.e. this code cannot simply be
54  * copied and put under another distribution licence
55  * [including the GNU Public Licence.]
56  *
57  * The DSS routines are based on patches supplied by
58  * Steven Schoch <schoch@sheba.arc.nasa.gov>. */
59 
60 #ifndef OPENSSL_HEADER_DSA_H
61 #define OPENSSL_HEADER_DSA_H
62 
63 #include <openssl/base.h>
64 
65 #include <openssl/engine.h>
66 #include <openssl/ex_data.h>
67 #include <openssl/thread.h>
68 
69 #if defined(__cplusplus)
70 extern "C" {
71 #endif
72 
73 
74 // DSA contains functions for signing and verifying with the Digital Signature
75 // Algorithm.
76 //
77 // This module is deprecated and retained for legacy reasons only. It is not
78 // considered a priority for performance or hardening work. Do not use it in
79 // new code. Use Ed25519, ECDSA with P-256, or RSA instead.
80 
81 
82 // Allocation and destruction.
83 
84 // DSA_new returns a new, empty DSA object or NULL on error.
85 OPENSSL_EXPORT DSA *DSA_new(void);
86 
87 // DSA_free decrements the reference count of |dsa| and frees it if the
88 // reference count drops to zero.
89 OPENSSL_EXPORT void DSA_free(DSA *dsa);
90 
91 // DSA_up_ref increments the reference count of |dsa| and returns one.
92 OPENSSL_EXPORT int DSA_up_ref(DSA *dsa);
93 
94 
95 // Properties.
96 
97 // DSA_get0_pub_key returns |dsa|'s public key.
98 OPENSSL_EXPORT const BIGNUM *DSA_get0_pub_key(const DSA *dsa);
99 
100 // DSA_get0_priv_key returns |dsa|'s private key, or NULL if |dsa| is a public
101 // key.
102 OPENSSL_EXPORT const BIGNUM *DSA_get0_priv_key(const DSA *dsa);
103 
104 // DSA_get0_p returns |dsa|'s group modulus.
105 OPENSSL_EXPORT const BIGNUM *DSA_get0_p(const DSA *dsa);
106 
107 // DSA_get0_q returns the size of |dsa|'s subgroup.
108 OPENSSL_EXPORT const BIGNUM *DSA_get0_q(const DSA *dsa);
109 
110 // DSA_get0_g returns |dsa|'s group generator.
111 OPENSSL_EXPORT const BIGNUM *DSA_get0_g(const DSA *dsa);
112 
113 // DSA_get0_key sets |*out_pub_key| and |*out_priv_key|, if non-NULL, to |dsa|'s
114 // public and private key, respectively. If |dsa| is a public key, the private
115 // key will be set to NULL.
116 OPENSSL_EXPORT void DSA_get0_key(const DSA *dsa, const BIGNUM **out_pub_key,
117                                  const BIGNUM **out_priv_key);
118 
119 // DSA_get0_pqg sets |*out_p|, |*out_q|, and |*out_g|, if non-NULL, to |dsa|'s
120 // p, q, and g parameters, respectively.
121 OPENSSL_EXPORT void DSA_get0_pqg(const DSA *dsa, const BIGNUM **out_p,
122                                  const BIGNUM **out_q, const BIGNUM **out_g);
123 
124 // DSA_set0_key sets |dsa|'s public and private key to |pub_key| and |priv_key|,
125 // respectively, if non-NULL. On success, it takes ownership of each argument
126 // and returns one. Otherwise, it returns zero.
127 //
128 // |priv_key| may be NULL, but |pub_key| must either be non-NULL or already
129 // configured on |dsa|.
130 OPENSSL_EXPORT int DSA_set0_key(DSA *dsa, BIGNUM *pub_key, BIGNUM *priv_key);
131 
132 // DSA_set0_pqg sets |dsa|'s parameters to |p|, |q|, and |g|, if non-NULL, and
133 // takes ownership of them. On success, it takes ownership of each argument and
134 // returns one. Otherwise, it returns zero.
135 //
136 // Each argument must either be non-NULL or already configured on |dsa|.
137 OPENSSL_EXPORT int DSA_set0_pqg(DSA *dsa, BIGNUM *p, BIGNUM *q, BIGNUM *g);
138 
139 
140 // Parameter generation.
141 
142 // DSA_generate_parameters_ex generates a set of DSA parameters by following
143 // the procedure given in FIPS 186-4, appendix A.
144 // (http://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.186-4.pdf)
145 //
146 // The larger prime will have a length of |bits| (e.g. 2048). The |seed| value
147 // allows others to generate and verify the same parameters and should be
148 // random input which is kept for reference. If |out_counter| or |out_h| are
149 // not NULL then the counter and h value used in the generation are written to
150 // them.
151 //
152 // The |cb| argument is passed to |BN_generate_prime_ex| and is thus called
153 // during the generation process in order to indicate progress. See the
154 // comments for that function for details. In addition to the calls made by
155 // |BN_generate_prime_ex|, |DSA_generate_parameters_ex| will call it with
156 // |event| equal to 2 and 3 at different stages of the process.
157 //
158 // It returns one on success and zero otherwise.
159 OPENSSL_EXPORT int DSA_generate_parameters_ex(DSA *dsa, unsigned bits,
160                                               const uint8_t *seed,
161                                               size_t seed_len, int *out_counter,
162                                               unsigned long *out_h,
163                                               BN_GENCB *cb);
164 
165 // DSAparams_dup returns a freshly allocated |DSA| that contains a copy of the
166 // parameters from |dsa|. It returns NULL on error.
167 OPENSSL_EXPORT DSA *DSAparams_dup(const DSA *dsa);
168 
169 
170 // Key generation.
171 
172 // DSA_generate_key generates a public/private key pair in |dsa|, which must
173 // already have parameters setup. It returns one on success and zero on
174 // error.
175 OPENSSL_EXPORT int DSA_generate_key(DSA *dsa);
176 
177 
178 // Signatures.
179 
180 // DSA_SIG_st (aka |DSA_SIG|) contains a DSA signature as a pair of integers.
181 struct DSA_SIG_st {
182   BIGNUM *r, *s;
183 };
184 
185 // DSA_SIG_new returns a freshly allocated, DIG_SIG structure or NULL on error.
186 // Both |r| and |s| in the signature will be NULL.
187 OPENSSL_EXPORT DSA_SIG *DSA_SIG_new(void);
188 
189 // DSA_SIG_free frees the contents of |sig| and then frees |sig| itself.
190 OPENSSL_EXPORT void DSA_SIG_free(DSA_SIG *sig);
191 
192 // DSA_SIG_get0 sets |*out_r| and |*out_s|, if non-NULL, to the two components
193 // of |sig|.
194 OPENSSL_EXPORT void DSA_SIG_get0(const DSA_SIG *sig, const BIGNUM **out_r,
195                                  const BIGNUM **out_s);
196 
197 // DSA_SIG_set0 sets |sig|'s components to |r| and |s|, neither of which may be
198 // NULL. On success, it takes ownership of each argument and returns one.
199 // Otherwise, it returns zero.
200 OPENSSL_EXPORT int DSA_SIG_set0(DSA_SIG *sig, BIGNUM *r, BIGNUM *s);
201 
202 // DSA_do_sign returns a signature of the hash in |digest| by the key in |dsa|
203 // and returns an allocated, DSA_SIG structure, or NULL on error.
204 OPENSSL_EXPORT DSA_SIG *DSA_do_sign(const uint8_t *digest, size_t digest_len,
205                                     const DSA *dsa);
206 
207 // DSA_do_verify verifies that |sig| is a valid signature, by the public key in
208 // |dsa|, of the hash in |digest|. It returns one if so, zero if invalid and -1
209 // on error.
210 //
211 // WARNING: do not use. This function returns -1 for error, 0 for invalid and 1
212 // for valid. However, this is dangerously different to the usual OpenSSL
213 // convention and could be a disaster if a user did |if (DSA_do_verify(...))|.
214 // Because of this, |DSA_check_signature| is a safer version of this.
215 //
216 // TODO(fork): deprecate.
217 OPENSSL_EXPORT int DSA_do_verify(const uint8_t *digest, size_t digest_len,
218                                  DSA_SIG *sig, const DSA *dsa);
219 
220 // DSA_do_check_signature sets |*out_valid| to zero. Then it verifies that |sig|
221 // is a valid signature, by the public key in |dsa| of the hash in |digest|
222 // and, if so, it sets |*out_valid| to one.
223 //
224 // It returns one if it was able to verify the signature as valid or invalid,
225 // and zero on error.
226 OPENSSL_EXPORT int DSA_do_check_signature(int *out_valid, const uint8_t *digest,
227                                           size_t digest_len, DSA_SIG *sig,
228                                           const DSA *dsa);
229 
230 
231 // ASN.1 signatures.
232 //
233 // These functions also perform DSA signature operations, but deal with ASN.1
234 // encoded signatures as opposed to raw |BIGNUM|s. If you don't know what
235 // encoding a DSA signature is in, it's probably ASN.1.
236 
237 // DSA_sign signs |digest| with the key in |dsa| and writes the resulting
238 // signature, in ASN.1 form, to |out_sig| and the length of the signature to
239 // |*out_siglen|. There must be, at least, |DSA_size(dsa)| bytes of space in
240 // |out_sig|. It returns one on success and zero otherwise.
241 //
242 // (The |type| argument is ignored.)
243 OPENSSL_EXPORT int DSA_sign(int type, const uint8_t *digest, size_t digest_len,
244                             uint8_t *out_sig, unsigned int *out_siglen,
245                             const DSA *dsa);
246 
247 // DSA_verify verifies that |sig| is a valid, ASN.1 signature, by the public
248 // key in |dsa|, of the hash in |digest|. It returns one if so, zero if invalid
249 // and -1 on error.
250 //
251 // (The |type| argument is ignored.)
252 //
253 // WARNING: do not use. This function returns -1 for error, 0 for invalid and 1
254 // for valid. However, this is dangerously different to the usual OpenSSL
255 // convention and could be a disaster if a user did |if (DSA_do_verify(...))|.
256 // Because of this, |DSA_check_signature| is a safer version of this.
257 //
258 // TODO(fork): deprecate.
259 OPENSSL_EXPORT int DSA_verify(int type, const uint8_t *digest,
260                               size_t digest_len, const uint8_t *sig,
261                               size_t sig_len, const DSA *dsa);
262 
263 // DSA_check_signature sets |*out_valid| to zero. Then it verifies that |sig|
264 // is a valid, ASN.1 signature, by the public key in |dsa|, of the hash in
265 // |digest|. If so, it sets |*out_valid| to one.
266 //
267 // It returns one if it was able to verify the signature as valid or invalid,
268 // and zero on error.
269 OPENSSL_EXPORT int DSA_check_signature(int *out_valid, const uint8_t *digest,
270                                        size_t digest_len, const uint8_t *sig,
271                                        size_t sig_len, const DSA *dsa);
272 
273 // DSA_size returns the size, in bytes, of an ASN.1 encoded, DSA signature
274 // generated by |dsa|. Parameters must already have been setup in |dsa|.
275 OPENSSL_EXPORT int DSA_size(const DSA *dsa);
276 
277 
278 // ASN.1 encoding.
279 
280 // DSA_SIG_parse parses a DER-encoded DSA-Sig-Value structure from |cbs| and
281 // advances |cbs|. It returns a newly-allocated |DSA_SIG| or NULL on error.
282 OPENSSL_EXPORT DSA_SIG *DSA_SIG_parse(CBS *cbs);
283 
284 // DSA_SIG_marshal marshals |sig| as a DER-encoded DSA-Sig-Value and appends the
285 // result to |cbb|. It returns one on success and zero on error.
286 OPENSSL_EXPORT int DSA_SIG_marshal(CBB *cbb, const DSA_SIG *sig);
287 
288 // DSA_parse_public_key parses a DER-encoded DSA public key from |cbs| and
289 // advances |cbs|. It returns a newly-allocated |DSA| or NULL on error.
290 OPENSSL_EXPORT DSA *DSA_parse_public_key(CBS *cbs);
291 
292 // DSA_marshal_public_key marshals |dsa| as a DER-encoded DSA public key and
293 // appends the result to |cbb|. It returns one on success and zero on
294 // failure.
295 OPENSSL_EXPORT int DSA_marshal_public_key(CBB *cbb, const DSA *dsa);
296 
297 // DSA_parse_private_key parses a DER-encoded DSA private key from |cbs| and
298 // advances |cbs|. It returns a newly-allocated |DSA| or NULL on error.
299 OPENSSL_EXPORT DSA *DSA_parse_private_key(CBS *cbs);
300 
301 // DSA_marshal_private_key marshals |dsa| as a DER-encoded DSA private key and
302 // appends the result to |cbb|. It returns one on success and zero on
303 // failure.
304 OPENSSL_EXPORT int DSA_marshal_private_key(CBB *cbb, const DSA *dsa);
305 
306 // DSA_parse_parameters parses a DER-encoded Dss-Parms structure (RFC 3279)
307 // from |cbs| and advances |cbs|. It returns a newly-allocated |DSA| or NULL on
308 // error.
309 OPENSSL_EXPORT DSA *DSA_parse_parameters(CBS *cbs);
310 
311 // DSA_marshal_parameters marshals |dsa| as a DER-encoded Dss-Parms structure
312 // (RFC 3279) and appends the result to |cbb|. It returns one on success and
313 // zero on failure.
314 OPENSSL_EXPORT int DSA_marshal_parameters(CBB *cbb, const DSA *dsa);
315 
316 
317 // Conversion.
318 
319 // DSA_dup_DH returns a |DH| constructed from the parameters of |dsa|. This is
320 // sometimes needed when Diffie-Hellman parameters are stored in the form of
321 // DSA parameters. It returns an allocated |DH| on success or NULL on error.
322 OPENSSL_EXPORT DH *DSA_dup_DH(const DSA *dsa);
323 
324 
325 // ex_data functions.
326 //
327 // See |ex_data.h| for details.
328 
329 OPENSSL_EXPORT int DSA_get_ex_new_index(long argl, void *argp,
330                                         CRYPTO_EX_unused *unused,
331                                         CRYPTO_EX_dup *dup_unused,
332                                         CRYPTO_EX_free *free_func);
333 OPENSSL_EXPORT int DSA_set_ex_data(DSA *dsa, int idx, void *arg);
334 OPENSSL_EXPORT void *DSA_get_ex_data(const DSA *dsa, int idx);
335 
336 
337 // Deprecated functions.
338 
339 // d2i_DSA_SIG parses a DER-encoded DSA-Sig-Value structure from |len| bytes at
340 // |*inp|, as described in |d2i_SAMPLE|.
341 //
342 // Use |DSA_SIG_parse| instead.
343 OPENSSL_EXPORT DSA_SIG *d2i_DSA_SIG(DSA_SIG **out_sig, const uint8_t **inp,
344                                     long len);
345 
346 // i2d_DSA_SIG marshals |in| to a DER-encoded DSA-Sig-Value structure, as
347 // described in |i2d_SAMPLE|.
348 //
349 // Use |DSA_SIG_marshal| instead.
350 OPENSSL_EXPORT int i2d_DSA_SIG(const DSA_SIG *in, uint8_t **outp);
351 
352 // d2i_DSAPublicKey parses a DER-encoded DSA public key from |len| bytes at
353 // |*inp|, as described in |d2i_SAMPLE|.
354 //
355 // Use |DSA_parse_public_key| instead.
356 OPENSSL_EXPORT DSA *d2i_DSAPublicKey(DSA **out, const uint8_t **inp, long len);
357 
358 // i2d_DSAPublicKey marshals |in| as a DER-encoded DSA public key, as described
359 // in |i2d_SAMPLE|.
360 //
361 // Use |DSA_marshal_public_key| instead.
362 OPENSSL_EXPORT int i2d_DSAPublicKey(const DSA *in, uint8_t **outp);
363 
364 // d2i_DSAPrivateKey parses a DER-encoded DSA private key from |len| bytes at
365 // |*inp|, as described in |d2i_SAMPLE|.
366 //
367 // Use |DSA_parse_private_key| instead.
368 OPENSSL_EXPORT DSA *d2i_DSAPrivateKey(DSA **out, const uint8_t **inp, long len);
369 
370 // i2d_DSAPrivateKey marshals |in| as a DER-encoded DSA private key, as
371 // described in |i2d_SAMPLE|.
372 //
373 // Use |DSA_marshal_private_key| instead.
374 OPENSSL_EXPORT int i2d_DSAPrivateKey(const DSA *in, uint8_t **outp);
375 
376 // d2i_DSAparams parses a DER-encoded Dss-Parms structure (RFC 3279) from |len|
377 // bytes at |*inp|, as described in |d2i_SAMPLE|.
378 //
379 // Use |DSA_parse_parameters| instead.
380 OPENSSL_EXPORT DSA *d2i_DSAparams(DSA **out, const uint8_t **inp, long len);
381 
382 // i2d_DSAparams marshals |in|'s parameters as a DER-encoded Dss-Parms structure
383 // (RFC 3279), as described in |i2d_SAMPLE|.
384 //
385 // Use |DSA_marshal_parameters| instead.
386 OPENSSL_EXPORT int i2d_DSAparams(const DSA *in, uint8_t **outp);
387 
388 // DSA_generate_parameters is a deprecated version of
389 // |DSA_generate_parameters_ex| that creates and returns a |DSA*|. Don't use
390 // it.
391 OPENSSL_EXPORT DSA *DSA_generate_parameters(int bits, unsigned char *seed,
392                                             int seed_len, int *counter_ret,
393                                             unsigned long *h_ret,
394                                             void (*callback)(int, int, void *),
395                                             void *cb_arg);
396 
397 
398 struct dsa_st {
399   long version;
400   BIGNUM *p;
401   BIGNUM *q;  // == 20
402   BIGNUM *g;
403 
404   BIGNUM *pub_key;   // y public key
405   BIGNUM *priv_key;  // x private key
406 
407   int flags;
408   // Normally used to cache montgomery values
409   CRYPTO_MUTEX method_mont_lock;
410   BN_MONT_CTX *method_mont_p;
411   BN_MONT_CTX *method_mont_q;
412   CRYPTO_refcount_t references;
413   CRYPTO_EX_DATA ex_data;
414 };
415 
416 
417 #if defined(__cplusplus)
418 }  // extern C
419 
420 extern "C++" {
421 
422 BSSL_NAMESPACE_BEGIN
423 
424 BORINGSSL_MAKE_DELETER(DSA, DSA_free)
425 BORINGSSL_MAKE_UP_REF(DSA, DSA_up_ref)
426 BORINGSSL_MAKE_DELETER(DSA_SIG, DSA_SIG_free)
427 
428 BSSL_NAMESPACE_END
429 
430 }  // extern C++
431 
432 #endif
433 
434 #define DSA_R_BAD_Q_VALUE 100
435 #define DSA_R_MISSING_PARAMETERS 101
436 #define DSA_R_MODULUS_TOO_LARGE 102
437 #define DSA_R_NEED_NEW_SETUP_VALUES 103
438 #define DSA_R_BAD_VERSION 104
439 #define DSA_R_DECODE_ERROR 105
440 #define DSA_R_ENCODE_ERROR 106
441 #define DSA_R_INVALID_PARAMETERS 107
442 
443 #endif  // OPENSSL_HEADER_DSA_H
444