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