1 /* Copyright (C) 1995-1998 Eric Young (eay (at) cryptsoft.com) 2 * All rights reserved. 3 * 4 * This package is an SSL implementation written 5 * by Eric Young (eay (at) 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 (at) 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 (at) 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 (at) 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 (at) 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 68 #if defined(__cplusplus) 69 extern "C" { 70 #endif 71 72 73 /* DSA contains functions for signing and verifing with the Digital Signature 74 * Algorithm. */ 75 76 77 /* Allocation and destruction. */ 78 79 /* DSA_new returns a new, empty DSA object or NULL on error. */ 80 OPENSSL_EXPORT DSA *DSA_new(void); 81 82 /* DSA_new_method acts the same as |DH_new| but takes an explicit |ENGINE|. */ 83 OPENSSL_EXPORT DSA *DSA_new_method(const ENGINE *engine); 84 85 /* DSA_free decrements the reference count of |dsa| and frees it if the 86 * reference count drops to zero. */ 87 OPENSSL_EXPORT void DSA_free(DSA *dsa); 88 89 /* DSA_up_ref increments the reference count of |dsa|. */ 90 OPENSSL_EXPORT int DSA_up_ref(DSA *dsa); 91 92 93 /* Parameter generation. */ 94 95 /* DSA_generate_parameters_ex generates a set of DSA parameters by following 96 * the procedure given in FIPS 186-4, appendix A. 97 * (http://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.186-4.pdf) 98 * 99 * The larger prime will have a length of |bits| (e.g. 2048). The |seed| value 100 * allows others to generate and verify the same parameters and should be 101 * random input which is kept for reference. If |out_counter| or |out_h| are 102 * not NULL then the counter and h value used in the generation are written to 103 * them. 104 * 105 * The |cb| argument is passed to |BN_generate_prime_ex| and is thus called 106 * during the generation process in order to indicate progress. See the 107 * comments for that function for details. In addition to the calls made by 108 * |BN_generate_prime_ex|, |DSA_generate_parameters_ex| will call it with 109 * |event| equal to 2 and 3 at different stages of the process. 110 * 111 * It returns one on success and zero otherwise. */ 112 OPENSSL_EXPORT int DSA_generate_parameters_ex(DSA *dsa, unsigned bits, 113 const uint8_t *seed, 114 size_t seed_len, int *out_counter, 115 unsigned long *out_h, 116 BN_GENCB *cb); 117 118 /* DSAparams_dup returns a freshly allocated |DSA| that contains a copy of the 119 * parameters from |dsa|. It returns NULL on error. */ 120 OPENSSL_EXPORT DSA *DSAparams_dup(const DSA *dsa); 121 122 123 /* Key generation. */ 124 125 /* DSA_generate_key generates a public/private key pair in |dsa|, which must 126 * already have parameters setup. It returns one on success and zero on 127 * error. */ 128 OPENSSL_EXPORT int DSA_generate_key(DSA *dsa); 129 130 131 /* Signatures. */ 132 133 /* DSA_SIG contains a DSA signature as a pair of integers. */ 134 typedef struct DSA_SIG_st { 135 BIGNUM *r, *s; 136 } DSA_SIG; 137 138 /* DSA_SIG_new returns a freshly allocated, DIG_SIG structure or NULL on error. 139 * Both |r| and |s| in the signature will be NULL. */ 140 OPENSSL_EXPORT DSA_SIG *DSA_SIG_new(void); 141 142 /* DSA_SIG_free frees the contents of |sig| and then frees |sig| itself. */ 143 OPENSSL_EXPORT void DSA_SIG_free(DSA_SIG *sig); 144 145 /* DSA_do_sign returns a signature of the hash in |digest| by the key in |dsa| 146 * and returns an allocated, DSA_SIG structure, or NULL on error. */ 147 OPENSSL_EXPORT DSA_SIG *DSA_do_sign(const uint8_t *digest, size_t digest_len, 148 DSA *dsa); 149 150 /* DSA_do_verify verifies that |sig| is a valid signature, by the public key in 151 * |dsa|, of the hash in |digest|. It returns one if so, zero if invalid and -1 152 * on error. 153 * 154 * WARNING: do not use. This function returns -1 for error, 0 for invalid and 1 155 * for valid. However, this is dangerously different to the usual OpenSSL 156 * convention and could be a disaster if a user did |if (DSA_do_verify(...))|. 157 * Because of this, |DSA_check_signature| is a safer version of this. 158 * 159 * TODO(fork): deprecate. */ 160 OPENSSL_EXPORT int DSA_do_verify(const uint8_t *digest, size_t digest_len, 161 DSA_SIG *sig, const DSA *dsa); 162 163 /* DSA_check_signature sets |*out_valid| to zero. Then it verifies that |sig| 164 * is a valid signature, by the public key in |dsa| of the hash in |digest| 165 * and, if so, it sets |*out_valid| to one. 166 * 167 * It returns one if it was able to verify the signature as valid or invalid, 168 * and zero on error. */ 169 OPENSSL_EXPORT int DSA_do_check_signature(int *out_valid, const uint8_t *digest, 170 size_t digest_len, DSA_SIG *sig, 171 const DSA *dsa); 172 173 174 /* ASN.1 signatures. 175 * 176 * These functions also perform DSA signature operations, but deal with ASN.1 177 * encoded signatures as opposed to raw |BIGNUM|s. If you don't know what 178 * encoding a DSA signature is in, it's probably ASN.1. */ 179 180 /* DSA_sign signs |digest| with the key in |dsa| and writes the resulting 181 * signature, in ASN.1 form, to |out_sig| and the length of the signature to 182 * |*out_siglen|. There must be, at least, |DSA_size(dsa)| bytes of space in 183 * |out_sig|. It returns one on success and zero otherwise. 184 * 185 * (The |type| argument is ignored.) */ 186 OPENSSL_EXPORT int DSA_sign(int type, const uint8_t *digest, size_t digest_len, 187 uint8_t *out_sig, unsigned int *out_siglen, 188 DSA *dsa); 189 190 /* DSA_verify verifies that |sig| is a valid, ASN.1 signature, by the public 191 * key in |dsa|, of the hash in |digest|. It returns one if so, zero if invalid 192 * and -1 on error. 193 * 194 * (The |type| argument is ignored.) 195 * 196 * WARNING: do not use. This function returns -1 for error, 0 for invalid and 1 197 * for valid. However, this is dangerously different to the usual OpenSSL 198 * convention and could be a disaster if a user did |if (DSA_do_verify(...))|. 199 * Because of this, |DSA_check_signature| is a safer version of this. 200 * 201 * TODO(fork): deprecate. */ 202 OPENSSL_EXPORT int DSA_verify(int type, const uint8_t *digest, 203 size_t digest_len, const uint8_t *sig, 204 size_t sig_len, const DSA *dsa); 205 206 /* DSA_check_signature sets |*out_valid| to zero. Then it verifies that |sig| 207 * is a valid, ASN.1 signature, by the public key in |dsa|, of the hash in 208 * |digest|. If so, it sets |*out_valid| to one. 209 * 210 * It returns one if it was able to verify the signature as valid or invalid, 211 * and zero on error. */ 212 OPENSSL_EXPORT int DSA_check_signature(int *out_valid, const uint8_t *digest, 213 size_t digest_len, const uint8_t *sig, 214 size_t sig_len, const DSA *dsa); 215 216 /* DSA_size returns the size, in bytes, of an ASN.1 encoded, DSA signature 217 * generated by |dsa|. Parameters must already have been setup in |dsa|. */ 218 OPENSSL_EXPORT int DSA_size(const DSA *dsa); 219 220 221 /* ASN.1 encoding. */ 222 223 /* d2i_DSA_SIG parses an ASN.1, DER-encoded, DSA signature from |len| bytes at 224 * |*inp|. If |out_sig| is not NULL then, on exit, a pointer to the result is 225 * in |*out_sig|. If |*out_sig| is already non-NULL on entry then the result is 226 * written directly into |*out_sig|, otherwise a fresh |DSA_SIG| is allocated. 227 * On successful exit, |*inp| is advanced past the DER structure. It returns 228 * the result or NULL on error. */ 229 OPENSSL_EXPORT DSA_SIG *d2i_DSA_SIG(DSA_SIG **out_sig, const uint8_t **inp, 230 long len); 231 232 /* i2d_DSA_SIG marshals |in| to an ASN.1, DER structure. If |outp| is not NULL 233 * then the result is written to |*outp| and |*outp| is advanced just past the 234 * output. It returns the number of bytes in the result, whether written or not, 235 * or a negative value on error. */ 236 OPENSSL_EXPORT int i2d_DSA_SIG(const DSA_SIG *in, uint8_t **outp); 237 238 /* d2i_DSAPublicKey parses an ASN.1, DER-encoded, DSA public key from |len| 239 * bytes at |*inp|. If |out| is not NULL then, on exit, a pointer to the result 240 * is in |*out|. If |*out| is already non-NULL on entry then the result is 241 * written directly into |*out|, otherwise a fresh |DSA| is allocated. On 242 * successful exit, |*inp| is advanced past the DER structure. It returns the 243 * result or NULL on error. */ 244 OPENSSL_EXPORT DSA *d2i_DSAPublicKey(DSA **out, const uint8_t **inp, long len); 245 246 /* i2d_DSAPublicKey marshals a public key from |in| to an ASN.1, DER structure. 247 * If |outp| is not NULL then the result is written to |*outp| and |*outp| is 248 * advanced just past the output. It returns the number of bytes in the result, 249 * whether written or not, or a negative value on error. */ 250 OPENSSL_EXPORT int i2d_DSAPublicKey(const DSA *in, unsigned char **outp); 251 252 /* d2i_DSAPrivateKey parses an ASN.1, DER-encoded, DSA private key from |len| 253 * bytes at |*inp|. If |out| is not NULL then, on exit, a pointer to the result 254 * is in |*out|. If |*out| is already non-NULL on entry then the result is 255 * written directly into |*out|, otherwise a fresh |DSA| is allocated. On 256 * successful exit, |*inp| is advanced past the DER structure. It returns the 257 * result or NULL on error. */ 258 OPENSSL_EXPORT DSA *d2i_DSAPrivateKey(DSA **out, const uint8_t **inp, long len); 259 260 /* i2d_DSAPrivateKey marshals a private key from |in| to an ASN.1, DER structure. 261 * If |outp| is not NULL then the result is written to |*outp| and |*outp| is 262 * advanced just past the output. It returns the number of bytes in the result, 263 * whether written or not, or a negative value on error. */ 264 OPENSSL_EXPORT int i2d_DSAPrivateKey(const DSA *in, unsigned char **outp); 265 266 /* d2i_DSAparams parses ASN.1, DER-encoded, DSA parameters from |len| bytes at 267 * |*inp|. If |out| is not NULL then, on exit, a pointer to the result is in 268 * |*out|. If |*out| is already non-NULL on entry then the result is written 269 * directly into |*out|, otherwise a fresh |DSA| is allocated. On successful 270 * exit, |*inp| is advanced past the DER structure. It returns the result or 271 * NULL on error. */ 272 OPENSSL_EXPORT DSA *d2i_DSAparams(DSA **out, const uint8_t **inp, long len); 273 274 /* i2d_DSAparams marshals DSA parameters from |in| to an ASN.1, DER structure. 275 * If |outp| is not NULL then the result is written to |*outp| and |*outp| is 276 * advanced just past the output. It returns the number of bytes in the result, 277 * whether written or not, or a negative value on error. */ 278 OPENSSL_EXPORT int i2d_DSAparams(const DSA *in, unsigned char **outp); 279 280 281 /* Precomputation. */ 282 283 /* DSA_sign_setup precomputes the message independent part of the DSA signature 284 * and writes them to |*out_kinv| and |*out_r|. Returns one on success, zero on 285 * error. 286 * 287 * TODO(fork): decide what to do with this. Since making DSA* opaque there's no 288 * way for the user to install them. Also, it forces the DSA* not to be const 289 * when passing to the signing function. */ 290 OPENSSL_EXPORT int DSA_sign_setup(const DSA *dsa, BN_CTX *ctx, 291 BIGNUM **out_kinv, BIGNUM **out_r); 292 293 294 /* Conversion. */ 295 296 /* DSA_dup_DH returns a |DH| constructed from the parameters of |dsa|. This is 297 * sometimes needed when Diffie-Hellman parameters are stored in the form of 298 * DSA parameters. It returns an allocated |DH| on success or NULL on error. */ 299 OPENSSL_EXPORT DH *DSA_dup_DH(const DSA *dsa); 300 301 302 /* ex_data functions. 303 * 304 * These functions are wrappers. See |ex_data.h| for details. */ 305 306 OPENSSL_EXPORT int DSA_get_ex_new_index(long argl, void *argp, 307 CRYPTO_EX_new *new_func, 308 CRYPTO_EX_dup *dup_func, 309 CRYPTO_EX_free *free_func); 310 OPENSSL_EXPORT int DSA_set_ex_data(DSA *d, int idx, void *arg); 311 OPENSSL_EXPORT void *DSA_get_ex_data(const DSA *d, int idx); 312 313 314 struct dsa_method { 315 struct openssl_method_common_st common; 316 317 void *app_data; 318 319 int (*init)(DSA *dsa); 320 int (*finish)(DSA *dsa); 321 322 DSA_SIG *(*sign)(const uint8_t *digest, size_t digest_len, DSA *dsa); 323 324 int (*sign_setup)(const DSA *dsa, BN_CTX *ctx_in, BIGNUM **kinvp, BIGNUM **rp, 325 const uint8_t *digest, size_t digest_len); 326 327 int (*verify)(int *out_valid, const uint8_t *digest, size_t digest_len, 328 DSA_SIG *sig, const DSA *dsa); 329 330 /* generate_parameters, if non-NULL, is used to generate DSA parameters. */ 331 int (*generate_parameters)(DSA *dsa, unsigned bits, const uint8_t *seed, 332 size_t seed_len, int *counter_ret, 333 unsigned long *h_ret, BN_GENCB *cb); 334 335 /* keygen, if non-NULL, is used to generate DSA keys. */ 336 int (*keygen)(DSA *dsa); 337 }; 338 339 struct dsa_st { 340 long version; 341 int write_params; 342 BIGNUM *p; 343 BIGNUM *q; /* == 20 */ 344 BIGNUM *g; 345 346 BIGNUM *pub_key; /* y public key */ 347 BIGNUM *priv_key; /* x private key */ 348 349 BIGNUM *kinv; /* Signing pre-calc */ 350 BIGNUM *r; /* Signing pre-calc */ 351 352 int flags; 353 /* Normally used to cache montgomery values */ 354 BN_MONT_CTX *method_mont_p; 355 int references; 356 CRYPTO_EX_DATA ex_data; 357 DSA_METHOD *meth; 358 /* functional reference if 'meth' is ENGINE-provided */ 359 ENGINE *engine; 360 }; 361 362 363 #if defined(__cplusplus) 364 } /* extern C */ 365 #endif 366 367 #define DSA_F_sign 100 368 #define DSA_F_verify 101 369 #define DSA_F_dsa_sig_cb 102 370 #define DSA_F_DSA_new_method 103 371 #define DSA_F_sign_setup 104 372 #define DSA_R_NEED_NEW_SETUP_VALUES 100 373 #define DSA_R_BAD_Q_VALUE 101 374 #define DSA_R_MODULUS_TOO_LARGE 102 375 #define DSA_R_MISSING_PARAMETERS 103 376 377 #endif /* OPENSSL_HEADER_DSA_H */ 378
