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 verifing 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_new_method acts the same as |DH_new| but takes an explicit |ENGINE|. */ 84 OPENSSL_EXPORT DSA *DSA_new_method(const ENGINE *engine); 85 86 /* DSA_free decrements the reference count of |dsa| and frees it if the 87 * reference count drops to zero. */ 88 OPENSSL_EXPORT void DSA_free(DSA *dsa); 89 90 /* DSA_up_ref increments the reference count of |dsa|. */ 91 OPENSSL_EXPORT int DSA_up_ref(DSA *dsa); 92 93 94 /* Parameter generation. */ 95 96 /* DSA_generate_parameters_ex generates a set of DSA parameters by following 97 * the procedure given in FIPS 186-4, appendix A. 98 * (http://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.186-4.pdf) 99 * 100 * The larger prime will have a length of |bits| (e.g. 2048). The |seed| value 101 * allows others to generate and verify the same parameters and should be 102 * random input which is kept for reference. If |out_counter| or |out_h| are 103 * not NULL then the counter and h value used in the generation are written to 104 * them. 105 * 106 * The |cb| argument is passed to |BN_generate_prime_ex| and is thus called 107 * during the generation process in order to indicate progress. See the 108 * comments for that function for details. In addition to the calls made by 109 * |BN_generate_prime_ex|, |DSA_generate_parameters_ex| will call it with 110 * |event| equal to 2 and 3 at different stages of the process. 111 * 112 * It returns one on success and zero otherwise. */ 113 OPENSSL_EXPORT int DSA_generate_parameters_ex(DSA *dsa, unsigned bits, 114 const uint8_t *seed, 115 size_t seed_len, int *out_counter, 116 unsigned long *out_h, 117 BN_GENCB *cb); 118 119 /* DSAparams_dup returns a freshly allocated |DSA| that contains a copy of the 120 * parameters from |dsa|. It returns NULL on error. */ 121 OPENSSL_EXPORT DSA *DSAparams_dup(const DSA *dsa); 122 123 124 /* Key generation. */ 125 126 /* DSA_generate_key generates a public/private key pair in |dsa|, which must 127 * already have parameters setup. It returns one on success and zero on 128 * error. */ 129 OPENSSL_EXPORT int DSA_generate_key(DSA *dsa); 130 131 132 /* Signatures. */ 133 134 /* DSA_SIG contains a DSA signature as a pair of integers. */ 135 typedef struct DSA_SIG_st { 136 BIGNUM *r, *s; 137 } DSA_SIG; 138 139 /* DSA_SIG_new returns a freshly allocated, DIG_SIG structure or NULL on error. 140 * Both |r| and |s| in the signature will be NULL. */ 141 OPENSSL_EXPORT DSA_SIG *DSA_SIG_new(void); 142 143 /* DSA_SIG_free frees the contents of |sig| and then frees |sig| itself. */ 144 OPENSSL_EXPORT void DSA_SIG_free(DSA_SIG *sig); 145 146 /* DSA_do_sign returns a signature of the hash in |digest| by the key in |dsa| 147 * and returns an allocated, DSA_SIG structure, or NULL on error. */ 148 OPENSSL_EXPORT DSA_SIG *DSA_do_sign(const uint8_t *digest, size_t digest_len, 149 DSA *dsa); 150 151 /* DSA_do_verify verifies that |sig| is a valid signature, by the public key in 152 * |dsa|, of the hash in |digest|. It returns one if so, zero if invalid and -1 153 * on error. 154 * 155 * WARNING: do not use. This function returns -1 for error, 0 for invalid and 1 156 * for valid. However, this is dangerously different to the usual OpenSSL 157 * convention and could be a disaster if a user did |if (DSA_do_verify(...))|. 158 * Because of this, |DSA_check_signature| is a safer version of this. 159 * 160 * TODO(fork): deprecate. */ 161 OPENSSL_EXPORT int DSA_do_verify(const uint8_t *digest, size_t digest_len, 162 DSA_SIG *sig, const DSA *dsa); 163 164 /* DSA_do_check_signature sets |*out_valid| to zero. Then it verifies that |sig| 165 * is a valid signature, by the public key in |dsa| of the hash in |digest| 166 * and, if so, it sets |*out_valid| to one. 167 * 168 * It returns one if it was able to verify the signature as valid or invalid, 169 * and zero on error. */ 170 OPENSSL_EXPORT int DSA_do_check_signature(int *out_valid, const uint8_t *digest, 171 size_t digest_len, DSA_SIG *sig, 172 const DSA *dsa); 173 174 175 /* ASN.1 signatures. 176 * 177 * These functions also perform DSA signature operations, but deal with ASN.1 178 * encoded signatures as opposed to raw |BIGNUM|s. If you don't know what 179 * encoding a DSA signature is in, it's probably ASN.1. */ 180 181 /* DSA_sign signs |digest| with the key in |dsa| and writes the resulting 182 * signature, in ASN.1 form, to |out_sig| and the length of the signature to 183 * |*out_siglen|. There must be, at least, |DSA_size(dsa)| bytes of space in 184 * |out_sig|. It returns one on success and zero otherwise. 185 * 186 * (The |type| argument is ignored.) */ 187 OPENSSL_EXPORT int DSA_sign(int type, const uint8_t *digest, size_t digest_len, 188 uint8_t *out_sig, unsigned int *out_siglen, 189 DSA *dsa); 190 191 /* DSA_verify verifies that |sig| is a valid, ASN.1 signature, by the public 192 * key in |dsa|, of the hash in |digest|. It returns one if so, zero if invalid 193 * and -1 on error. 194 * 195 * (The |type| argument is ignored.) 196 * 197 * WARNING: do not use. This function returns -1 for error, 0 for invalid and 1 198 * for valid. However, this is dangerously different to the usual OpenSSL 199 * convention and could be a disaster if a user did |if (DSA_do_verify(...))|. 200 * Because of this, |DSA_check_signature| is a safer version of this. 201 * 202 * TODO(fork): deprecate. */ 203 OPENSSL_EXPORT int DSA_verify(int type, const uint8_t *digest, 204 size_t digest_len, const uint8_t *sig, 205 size_t sig_len, const DSA *dsa); 206 207 /* DSA_check_signature sets |*out_valid| to zero. Then it verifies that |sig| 208 * is a valid, ASN.1 signature, by the public key in |dsa|, of the hash in 209 * |digest|. If so, it sets |*out_valid| to one. 210 * 211 * It returns one if it was able to verify the signature as valid or invalid, 212 * and zero on error. */ 213 OPENSSL_EXPORT int DSA_check_signature(int *out_valid, const uint8_t *digest, 214 size_t digest_len, const uint8_t *sig, 215 size_t sig_len, const DSA *dsa); 216 217 /* DSA_size returns the size, in bytes, of an ASN.1 encoded, DSA signature 218 * generated by |dsa|. Parameters must already have been setup in |dsa|. */ 219 OPENSSL_EXPORT int DSA_size(const DSA *dsa); 220 221 222 /* ASN.1 encoding. */ 223 224 /* d2i_DSA_SIG parses an ASN.1, DER-encoded, DSA signature from |len| bytes at 225 * |*inp|. If |out_sig| is not NULL then, on exit, a pointer to the result is 226 * in |*out_sig|. If |*out_sig| is already non-NULL on entry then the result is 227 * written directly into |*out_sig|, otherwise a fresh |DSA_SIG| is allocated. 228 * On successful exit, |*inp| is advanced past the DER structure. It returns 229 * the result or NULL on error. */ 230 OPENSSL_EXPORT DSA_SIG *d2i_DSA_SIG(DSA_SIG **out_sig, const uint8_t **inp, 231 long len); 232 233 /* i2d_DSA_SIG marshals |in| to an ASN.1, DER structure. If |outp| is not NULL 234 * then the result is written to |*outp| and |*outp| is advanced just past the 235 * output. It returns the number of bytes in the result, whether written or not, 236 * or a negative value on error. */ 237 OPENSSL_EXPORT int i2d_DSA_SIG(const DSA_SIG *in, uint8_t **outp); 238 239 /* d2i_DSAPublicKey parses an ASN.1, DER-encoded, DSA public key from |len| 240 * bytes at |*inp|. If |out| is not NULL then, on exit, a pointer to the result 241 * is in |*out|. If |*out| is already non-NULL on entry then the result is 242 * written directly into |*out|, otherwise a fresh |DSA| is allocated. On 243 * successful exit, |*inp| is advanced past the DER structure. It returns the 244 * result or NULL on error. */ 245 OPENSSL_EXPORT DSA *d2i_DSAPublicKey(DSA **out, const uint8_t **inp, long len); 246 247 /* i2d_DSAPublicKey marshals a public key from |in| to an ASN.1, DER structure. 248 * If |outp| is not NULL then the result is written to |*outp| and |*outp| is 249 * advanced just past the output. It returns the number of bytes in the result, 250 * whether written or not, or a negative value on error. */ 251 OPENSSL_EXPORT int i2d_DSAPublicKey(const DSA *in, unsigned char **outp); 252 253 /* d2i_DSAPrivateKey parses an ASN.1, DER-encoded, DSA private key from |len| 254 * bytes at |*inp|. If |out| is not NULL then, on exit, a pointer to the result 255 * is in |*out|. If |*out| is already non-NULL on entry then the result is 256 * written directly into |*out|, otherwise a fresh |DSA| is allocated. On 257 * successful exit, |*inp| is advanced past the DER structure. It returns the 258 * result or NULL on error. */ 259 OPENSSL_EXPORT DSA *d2i_DSAPrivateKey(DSA **out, const uint8_t **inp, long len); 260 261 /* i2d_DSAPrivateKey marshals a private key from |in| to an ASN.1, DER structure. 262 * If |outp| is not NULL then the result is written to |*outp| and |*outp| is 263 * advanced just past the output. It returns the number of bytes in the result, 264 * whether written or not, or a negative value on error. */ 265 OPENSSL_EXPORT int i2d_DSAPrivateKey(const DSA *in, unsigned char **outp); 266 267 /* d2i_DSAparams parses ASN.1, DER-encoded, DSA parameters from |len| bytes at 268 * |*inp|. If |out| is not NULL then, on exit, a pointer to the result is in 269 * |*out|. If |*out| is already non-NULL on entry then the result is written 270 * directly into |*out|, otherwise a fresh |DSA| is allocated. On successful 271 * exit, |*inp| is advanced past the DER structure. It returns the result or 272 * NULL on error. */ 273 OPENSSL_EXPORT DSA *d2i_DSAparams(DSA **out, const uint8_t **inp, long len); 274 275 /* i2d_DSAparams marshals DSA parameters from |in| to an ASN.1, DER structure. 276 * If |outp| is not NULL then the result is written to |*outp| and |*outp| is 277 * advanced just past the output. It returns the number of bytes in the result, 278 * whether written or not, or a negative value on error. */ 279 OPENSSL_EXPORT int i2d_DSAparams(const DSA *in, unsigned char **outp); 280 281 282 /* Precomputation. */ 283 284 /* DSA_sign_setup precomputes the message independent part of the DSA signature 285 * and writes them to |*out_kinv| and |*out_r|. Returns one on success, zero on 286 * error. 287 * 288 * TODO(fork): decide what to do with this. Since making DSA* opaque there's no 289 * way for the user to install them. Also, it forces the DSA* not to be const 290 * when passing to the signing function. */ 291 OPENSSL_EXPORT int DSA_sign_setup(const DSA *dsa, BN_CTX *ctx, 292 BIGNUM **out_kinv, BIGNUM **out_r); 293 294 295 /* Conversion. */ 296 297 /* DSA_dup_DH returns a |DH| constructed from the parameters of |dsa|. This is 298 * sometimes needed when Diffie-Hellman parameters are stored in the form of 299 * DSA parameters. It returns an allocated |DH| on success or NULL on error. */ 300 OPENSSL_EXPORT DH *DSA_dup_DH(const DSA *dsa); 301 302 303 /* ex_data functions. 304 * 305 * See |ex_data.h| for details. */ 306 307 OPENSSL_EXPORT int DSA_get_ex_new_index(long argl, void *argp, 308 CRYPTO_EX_new *new_func, 309 CRYPTO_EX_dup *dup_func, 310 CRYPTO_EX_free *free_func); 311 OPENSSL_EXPORT int DSA_set_ex_data(DSA *d, int idx, void *arg); 312 OPENSSL_EXPORT void *DSA_get_ex_data(const DSA *d, int idx); 313 314 315 struct dsa_method { 316 struct openssl_method_common_st common; 317 318 void *app_data; 319 320 int (*init)(DSA *dsa); 321 int (*finish)(DSA *dsa); 322 323 DSA_SIG *(*sign)(const uint8_t *digest, size_t digest_len, DSA *dsa); 324 325 int (*sign_setup)(const DSA *dsa, BN_CTX *ctx_in, BIGNUM **kinvp, BIGNUM **rp, 326 const uint8_t *digest, size_t digest_len); 327 328 int (*verify)(int *out_valid, const uint8_t *digest, size_t digest_len, 329 DSA_SIG *sig, const DSA *dsa); 330 331 /* generate_parameters, if non-NULL, is used to generate DSA parameters. */ 332 int (*generate_parameters)(DSA *dsa, unsigned bits, const uint8_t *seed, 333 size_t seed_len, int *counter_ret, 334 unsigned long *h_ret, BN_GENCB *cb); 335 336 /* keygen, if non-NULL, is used to generate DSA keys. */ 337 int (*keygen)(DSA *dsa); 338 }; 339 340 struct dsa_st { 341 long version; 342 int write_params; 343 BIGNUM *p; 344 BIGNUM *q; /* == 20 */ 345 BIGNUM *g; 346 347 BIGNUM *pub_key; /* y public key */ 348 BIGNUM *priv_key; /* x private key */ 349 350 BIGNUM *kinv; /* Signing pre-calc */ 351 BIGNUM *r; /* Signing pre-calc */ 352 353 int flags; 354 /* Normally used to cache montgomery values */ 355 CRYPTO_MUTEX method_mont_p_lock; 356 BN_MONT_CTX *method_mont_p; 357 CRYPTO_refcount_t references; 358 CRYPTO_EX_DATA ex_data; 359 DSA_METHOD *meth; 360 /* functional reference if 'meth' is ENGINE-provided */ 361 ENGINE *engine; 362 }; 363 364 365 #if defined(__cplusplus) 366 } /* extern C */ 367 #endif 368 369 #define DSA_F_DSA_new_method 100 370 #define DSA_F_dsa_sig_cb 101 371 #define DSA_F_sign 102 372 #define DSA_F_sign_setup 103 373 #define DSA_F_verify 104 374 #define DSA_R_BAD_Q_VALUE 100 375 #define DSA_R_MISSING_PARAMETERS 101 376 #define DSA_R_MODULUS_TOO_LARGE 102 377 #define DSA_R_NEED_NEW_SETUP_VALUES 103 378 379 #endif /* OPENSSL_HEADER_DSA_H */ 380