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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 
78 // Allocation and destruction.
79 
80 // DSA_new returns a new, empty DSA object or NULL on error.
81 OPENSSL_EXPORT DSA *DSA_new(void);
82 
83 // DSA_free decrements the reference count of |dsa| and frees it if the
84 // reference count drops to zero.
85 OPENSSL_EXPORT void DSA_free(DSA *dsa);
86 
87 // DSA_up_ref increments the reference count of |dsa| and returns one.
88 OPENSSL_EXPORT int DSA_up_ref(DSA *dsa);
89 
90 
91 // Properties.
92 
93 // DSA_get0_key sets |*out_pub_key| and |*out_priv_key|, if non-NULL, to |dsa|'s
94 // public and private key, respectively. If |dsa| is a public key, the private
95 // key will be set to NULL.
96 OPENSSL_EXPORT void DSA_get0_key(const DSA *dsa, const BIGNUM **out_pub_key,
97                                  const BIGNUM **out_priv_key);
98 
99 // DSA_get0_pqg sets |*out_p|, |*out_q|, and |*out_g|, if non-NULL, to |dsa|'s
100 // p, q, and g parameters, respectively.
101 OPENSSL_EXPORT void DSA_get0_pqg(const DSA *dsa, const BIGNUM **out_p,
102                                  const BIGNUM **out_q, const BIGNUM **out_g);
103 
104 // DSA_set0_key sets |dsa|'s public and private key to |pub_key| and |priv_key|,
105 // respectively, if non-NULL. On success, it takes ownership of each argument
106 // and returns one. Otherwise, it returns zero.
107 //
108 // |priv_key| may be NULL, but |pub_key| must either be non-NULL or already
109 // configured on |dsa|.
110 OPENSSL_EXPORT int DSA_set0_key(DSA *dsa, BIGNUM *pub_key, BIGNUM *priv_key);
111 
112 // DSA_set0_pqg sets |dsa|'s parameters to |p|, |q|, and |g|, if non-NULL, and
113 // takes ownership of them. On success, it takes ownership of each argument and
114 // returns one. Otherwise, it returns zero.
115 //
116 // Each argument must either be non-NULL or already configured on |dsa|.
117 OPENSSL_EXPORT int DSA_set0_pqg(DSA *dsa, BIGNUM *p, BIGNUM *q, BIGNUM *g);
118 
119 
120 // Parameter generation.
121 
122 // DSA_generate_parameters_ex generates a set of DSA parameters by following
123 // the procedure given in FIPS 186-4, appendix A.
124 // (http://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.186-4.pdf)
125 //
126 // The larger prime will have a length of |bits| (e.g. 2048). The |seed| value
127 // allows others to generate and verify the same parameters and should be
128 // random input which is kept for reference. If |out_counter| or |out_h| are
129 // not NULL then the counter and h value used in the generation are written to
130 // them.
131 //
132 // The |cb| argument is passed to |BN_generate_prime_ex| and is thus called
133 // during the generation process in order to indicate progress. See the
134 // comments for that function for details. In addition to the calls made by
135 // |BN_generate_prime_ex|, |DSA_generate_parameters_ex| will call it with
136 // |event| equal to 2 and 3 at different stages of the process.
137 //
138 // It returns one on success and zero otherwise.
139 OPENSSL_EXPORT int DSA_generate_parameters_ex(DSA *dsa, unsigned bits,
140                                               const uint8_t *seed,
141                                               size_t seed_len, int *out_counter,
142                                               unsigned long *out_h,
143                                               BN_GENCB *cb);
144 
145 // DSAparams_dup returns a freshly allocated |DSA| that contains a copy of the
146 // parameters from |dsa|. It returns NULL on error.
147 OPENSSL_EXPORT DSA *DSAparams_dup(const DSA *dsa);
148 
149 
150 // Key generation.
151 
152 // DSA_generate_key generates a public/private key pair in |dsa|, which must
153 // already have parameters setup. It returns one on success and zero on
154 // error.
155 OPENSSL_EXPORT int DSA_generate_key(DSA *dsa);
156 
157 
158 // Signatures.
159 
160 // DSA_SIG_st (aka |DSA_SIG|) contains a DSA signature as a pair of integers.
161 struct DSA_SIG_st {
162   BIGNUM *r, *s;
163 };
164 
165 // DSA_SIG_new returns a freshly allocated, DIG_SIG structure or NULL on error.
166 // Both |r| and |s| in the signature will be NULL.
167 OPENSSL_EXPORT DSA_SIG *DSA_SIG_new(void);
168 
169 // DSA_SIG_free frees the contents of |sig| and then frees |sig| itself.
170 OPENSSL_EXPORT void DSA_SIG_free(DSA_SIG *sig);
171 
172 // DSA_do_sign returns a signature of the hash in |digest| by the key in |dsa|
173 // and returns an allocated, DSA_SIG structure, or NULL on error.
174 OPENSSL_EXPORT DSA_SIG *DSA_do_sign(const uint8_t *digest, size_t digest_len,
175                                     const DSA *dsa);
176 
177 // DSA_do_verify verifies that |sig| is a valid signature, by the public key in
178 // |dsa|, of the hash in |digest|. It returns one if so, zero if invalid and -1
179 // on error.
180 //
181 // WARNING: do not use. This function returns -1 for error, 0 for invalid and 1
182 // for valid. However, this is dangerously different to the usual OpenSSL
183 // convention and could be a disaster if a user did |if (DSA_do_verify(...))|.
184 // Because of this, |DSA_check_signature| is a safer version of this.
185 //
186 // TODO(fork): deprecate.
187 OPENSSL_EXPORT int DSA_do_verify(const uint8_t *digest, size_t digest_len,
188                                  DSA_SIG *sig, const DSA *dsa);
189 
190 // DSA_do_check_signature sets |*out_valid| to zero. Then it verifies that |sig|
191 // is a valid signature, by the public key in |dsa| of the hash in |digest|
192 // and, if so, it sets |*out_valid| to one.
193 //
194 // It returns one if it was able to verify the signature as valid or invalid,
195 // and zero on error.
196 OPENSSL_EXPORT int DSA_do_check_signature(int *out_valid, const uint8_t *digest,
197                                           size_t digest_len, DSA_SIG *sig,
198                                           const DSA *dsa);
199 
200 
201 // ASN.1 signatures.
202 //
203 // These functions also perform DSA signature operations, but deal with ASN.1
204 // encoded signatures as opposed to raw |BIGNUM|s. If you don't know what
205 // encoding a DSA signature is in, it's probably ASN.1.
206 
207 // DSA_sign signs |digest| with the key in |dsa| and writes the resulting
208 // signature, in ASN.1 form, to |out_sig| and the length of the signature to
209 // |*out_siglen|. There must be, at least, |DSA_size(dsa)| bytes of space in
210 // |out_sig|. It returns one on success and zero otherwise.
211 //
212 // (The |type| argument is ignored.)
213 OPENSSL_EXPORT int DSA_sign(int type, const uint8_t *digest, size_t digest_len,
214                             uint8_t *out_sig, unsigned int *out_siglen,
215                             const DSA *dsa);
216 
217 // DSA_verify verifies that |sig| is a valid, ASN.1 signature, by the public
218 // key in |dsa|, of the hash in |digest|. It returns one if so, zero if invalid
219 // and -1 on error.
220 //
221 // (The |type| argument is ignored.)
222 //
223 // WARNING: do not use. This function returns -1 for error, 0 for invalid and 1
224 // for valid. However, this is dangerously different to the usual OpenSSL
225 // convention and could be a disaster if a user did |if (DSA_do_verify(...))|.
226 // Because of this, |DSA_check_signature| is a safer version of this.
227 //
228 // TODO(fork): deprecate.
229 OPENSSL_EXPORT int DSA_verify(int type, const uint8_t *digest,
230                               size_t digest_len, const uint8_t *sig,
231                               size_t sig_len, const DSA *dsa);
232 
233 // DSA_check_signature sets |*out_valid| to zero. Then it verifies that |sig|
234 // is a valid, ASN.1 signature, by the public key in |dsa|, of the hash in
235 // |digest|. If so, it sets |*out_valid| to one.
236 //
237 // It returns one if it was able to verify the signature as valid or invalid,
238 // and zero on error.
239 OPENSSL_EXPORT int DSA_check_signature(int *out_valid, const uint8_t *digest,
240                                        size_t digest_len, const uint8_t *sig,
241                                        size_t sig_len, const DSA *dsa);
242 
243 // DSA_size returns the size, in bytes, of an ASN.1 encoded, DSA signature
244 // generated by |dsa|. Parameters must already have been setup in |dsa|.
245 OPENSSL_EXPORT int DSA_size(const DSA *dsa);
246 
247 
248 // ASN.1 encoding.
249 
250 // DSA_SIG_parse parses a DER-encoded DSA-Sig-Value structure from |cbs| and
251 // advances |cbs|. It returns a newly-allocated |DSA_SIG| or NULL on error.
252 OPENSSL_EXPORT DSA_SIG *DSA_SIG_parse(CBS *cbs);
253 
254 // DSA_SIG_marshal marshals |sig| as a DER-encoded DSA-Sig-Value and appends the
255 // result to |cbb|. It returns one on success and zero on error.
256 OPENSSL_EXPORT int DSA_SIG_marshal(CBB *cbb, const DSA_SIG *sig);
257 
258 // DSA_parse_public_key parses a DER-encoded DSA public key from |cbs| and
259 // advances |cbs|. It returns a newly-allocated |DSA| or NULL on error.
260 OPENSSL_EXPORT DSA *DSA_parse_public_key(CBS *cbs);
261 
262 // DSA_marshal_public_key marshals |dsa| as a DER-encoded DSA public key and
263 // appends the result to |cbb|. It returns one on success and zero on
264 // failure.
265 OPENSSL_EXPORT int DSA_marshal_public_key(CBB *cbb, const DSA *dsa);
266 
267 // DSA_parse_private_key parses a DER-encoded DSA private key from |cbs| and
268 // advances |cbs|. It returns a newly-allocated |DSA| or NULL on error.
269 OPENSSL_EXPORT DSA *DSA_parse_private_key(CBS *cbs);
270 
271 // DSA_marshal_private_key marshals |dsa| as a DER-encoded DSA private key and
272 // appends the result to |cbb|. It returns one on success and zero on
273 // failure.
274 OPENSSL_EXPORT int DSA_marshal_private_key(CBB *cbb, const DSA *dsa);
275 
276 // DSA_parse_parameters parses a DER-encoded Dss-Parms structure (RFC 3279)
277 // from |cbs| and advances |cbs|. It returns a newly-allocated |DSA| or NULL on
278 // error.
279 OPENSSL_EXPORT DSA *DSA_parse_parameters(CBS *cbs);
280 
281 // DSA_marshal_parameters marshals |dsa| as a DER-encoded Dss-Parms structure
282 // (RFC 3447) and appends the result to |cbb|. It returns one on success and
283 // zero on failure.
284 OPENSSL_EXPORT int DSA_marshal_parameters(CBB *cbb, const DSA *dsa);
285 
286 
287 // Conversion.
288 
289 // DSA_dup_DH returns a |DH| constructed from the parameters of |dsa|. This is
290 // sometimes needed when Diffie-Hellman parameters are stored in the form of
291 // DSA parameters. It returns an allocated |DH| on success or NULL on error.
292 OPENSSL_EXPORT DH *DSA_dup_DH(const DSA *dsa);
293 
294 
295 // ex_data functions.
296 //
297 // See |ex_data.h| for details.
298 
299 OPENSSL_EXPORT int DSA_get_ex_new_index(long argl, void *argp,
300                                         CRYPTO_EX_unused *unused,
301                                         CRYPTO_EX_dup *dup_unused,
302                                         CRYPTO_EX_free *free_func);
303 OPENSSL_EXPORT int DSA_set_ex_data(DSA *dsa, int idx, void *arg);
304 OPENSSL_EXPORT void *DSA_get_ex_data(const DSA *dsa, int idx);
305 
306 
307 // Deprecated functions.
308 
309 // d2i_DSA_SIG parses an ASN.1, DER-encoded, DSA signature from |len| bytes at
310 // |*inp|. If |out_sig| is not NULL then, on exit, a pointer to the result is
311 // in |*out_sig|. Note that, even if |*out_sig| is already non-NULL on entry, it
312 // will not be written to. Rather, a fresh |DSA_SIG| is allocated and the
313 // previous one is freed. On successful exit, |*inp| is advanced past the DER
314 // structure. It returns the result or NULL on error.
315 //
316 // Use |DSA_SIG_parse| instead.
317 OPENSSL_EXPORT DSA_SIG *d2i_DSA_SIG(DSA_SIG **out_sig, const uint8_t **inp,
318                                     long len);
319 
320 // i2d_DSA_SIG marshals |in| to an ASN.1, DER structure. If |outp| is not NULL
321 // then the result is written to |*outp| and |*outp| is advanced just past the
322 // output. It returns the number of bytes in the result, whether written or not,
323 // or a negative value on error.
324 //
325 // Use |DSA_SIG_marshal| instead.
326 OPENSSL_EXPORT int i2d_DSA_SIG(const DSA_SIG *in, uint8_t **outp);
327 
328 // d2i_DSAPublicKey parses an ASN.1, DER-encoded, DSA public key from |len|
329 // bytes at |*inp|. If |out| is not NULL then, on exit, a pointer to the result
330 // is in |*out|. Note that, even if |*ou| is already non-NULL on entry, it will
331 // not be written to. Rather, a fresh |DSA| is allocated and the previous one is
332 // freed. On successful exit, |*inp| is advanced past the DER structure. It
333 // returns the result or NULL on error.
334 //
335 // Use |DSA_parse_public_key| instead.
336 OPENSSL_EXPORT DSA *d2i_DSAPublicKey(DSA **out, const uint8_t **inp, long len);
337 
338 // i2d_DSAPublicKey marshals a public key from |in| to an ASN.1, DER structure.
339 // If |outp| is not NULL then the result is written to |*outp| and |*outp| is
340 // advanced just past the output. It returns the number of bytes in the result,
341 // whether written or not, or a negative value on error.
342 //
343 // Use |DSA_marshal_public_key| instead.
344 OPENSSL_EXPORT int i2d_DSAPublicKey(const DSA *in, uint8_t **outp);
345 
346 // d2i_DSAPrivateKey parses an ASN.1, DER-encoded, DSA private key from |len|
347 // bytes at |*inp|. If |out| is not NULL then, on exit, a pointer to the result
348 // is in |*out|. Note that, even if |*out| is already non-NULL on entry, it will
349 // not be written to. Rather, a fresh |DSA| is allocated and the previous one is
350 // freed. On successful exit, |*inp| is advanced past the DER structure. It
351 // returns the result or NULL on error.
352 //
353 // Use |DSA_parse_private_key| instead.
354 OPENSSL_EXPORT DSA *d2i_DSAPrivateKey(DSA **out, const uint8_t **inp, long len);
355 
356 // i2d_DSAPrivateKey marshals a private key from |in| to an ASN.1, DER
357 // structure. If |outp| is not NULL then the result is written to |*outp| and
358 // |*outp| is advanced just past the output. It returns the number of bytes in
359 // the result, whether written or not, or a negative value on error.
360 //
361 // Use |DSA_marshal_private_key| instead.
362 OPENSSL_EXPORT int i2d_DSAPrivateKey(const DSA *in, uint8_t **outp);
363 
364 // d2i_DSAparams parses ASN.1, DER-encoded, DSA parameters from |len| bytes at
365 // |*inp|. If |out| is not NULL then, on exit, a pointer to the result is in
366 // |*out|. Note that, even if |*out| is already non-NULL on entry, it will not
367 // be written to. Rather, a fresh |DSA| is allocated and the previous one is
368 // freed. On successful exit, |*inp| is advanced past the DER structure. It
369 // returns the result or NULL on error.
370 //
371 // Use |DSA_parse_parameters| instead.
372 OPENSSL_EXPORT DSA *d2i_DSAparams(DSA **out, const uint8_t **inp, long len);
373 
374 // i2d_DSAparams marshals DSA parameters from |in| to an ASN.1, DER structure.
375 // If |outp| is not NULL then the result is written to |*outp| and |*outp| is
376 // advanced just past the output. It returns the number of bytes in the result,
377 // whether written or not, or a negative value on error.
378 //
379 // Use |DSA_marshal_parameters| instead.
380 OPENSSL_EXPORT int i2d_DSAparams(const DSA *in, uint8_t **outp);
381 
382 // DSA_generate_parameters is a deprecated version of
383 // |DSA_generate_parameters_ex| that creates and returns a |DSA*|. Don't use
384 // it.
385 OPENSSL_EXPORT DSA *DSA_generate_parameters(int bits, unsigned char *seed,
386                                             int seed_len, int *counter_ret,
387                                             unsigned long *h_ret,
388                                             void (*callback)(int, int, void *),
389                                             void *cb_arg);
390 
391 
392 struct dsa_st {
393   long version;
394   BIGNUM *p;
395   BIGNUM *q;  // == 20
396   BIGNUM *g;
397 
398   BIGNUM *pub_key;   // y public key
399   BIGNUM *priv_key;  // x private key
400 
401   int flags;
402   // Normally used to cache montgomery values
403   CRYPTO_MUTEX method_mont_lock;
404   BN_MONT_CTX *method_mont_p;
405   BN_MONT_CTX *method_mont_q;
406   CRYPTO_refcount_t references;
407   CRYPTO_EX_DATA ex_data;
408 };
409 
410 
411 #if defined(__cplusplus)
412 }  // extern C
413 
414 extern "C++" {
415 
416 namespace bssl {
417 
418 BORINGSSL_MAKE_DELETER(DSA, DSA_free)
419 BORINGSSL_MAKE_DELETER(DSA_SIG, DSA_SIG_free)
420 
421 }  // namespace bssl
422 
423 }  // extern C++
424 
425 #endif
426 
427 #define DSA_R_BAD_Q_VALUE 100
428 #define DSA_R_MISSING_PARAMETERS 101
429 #define DSA_R_MODULUS_TOO_LARGE 102
430 #define DSA_R_NEED_NEW_SETUP_VALUES 103
431 #define DSA_R_BAD_VERSION 104
432 #define DSA_R_DECODE_ERROR 105
433 #define DSA_R_ENCODE_ERROR 106
434 
435 #endif  // OPENSSL_HEADER_DSA_H
436