dsa.h (16015B)
1 // Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved. 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // https://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 #ifndef OPENSSL_HEADER_DSA_H 16 #define OPENSSL_HEADER_DSA_H 17 18 #include <openssl/base.h> // IWYU pragma: export 19 20 #include <openssl/ex_data.h> 21 22 #if defined(__cplusplus) 23 extern "C" { 24 #endif 25 26 27 // DSA contains functions for signing and verifying with the Digital Signature 28 // Algorithm. 29 // 30 // This module is deprecated and retained for legacy reasons only. It is not 31 // considered a priority for performance or hardening work. Do not use it in 32 // new code. Use Ed25519, ECDSA with P-256, or RSA instead. 33 34 35 // Allocation and destruction. 36 // 37 // A |DSA| object represents a DSA key or group parameters. A given object may 38 // be used concurrently on multiple threads by non-mutating functions, provided 39 // no other thread is concurrently calling a mutating function. Unless otherwise 40 // documented, functions which take a |const| pointer are non-mutating and 41 // functions which take a non-|const| pointer are mutating. 42 43 // DSA_new returns a new, empty DSA object or NULL on error. 44 OPENSSL_EXPORT DSA *DSA_new(void); 45 46 // DSA_free decrements the reference count of |dsa| and frees it if the 47 // reference count drops to zero. 48 OPENSSL_EXPORT void DSA_free(DSA *dsa); 49 50 // DSA_up_ref increments the reference count of |dsa| and returns one. It does 51 // not mutate |dsa| for thread-safety purposes and may be used concurrently. 52 OPENSSL_EXPORT int DSA_up_ref(DSA *dsa); 53 54 55 // Properties. 56 57 // OPENSSL_DSA_MAX_MODULUS_BITS is the maximum supported DSA group modulus, in 58 // bits. 59 #define OPENSSL_DSA_MAX_MODULUS_BITS 10000 60 61 // DSA_bits returns the size of |dsa|'s group modulus, in bits. 62 OPENSSL_EXPORT unsigned DSA_bits(const DSA *dsa); 63 64 // DSA_get0_pub_key returns |dsa|'s public key. 65 OPENSSL_EXPORT const BIGNUM *DSA_get0_pub_key(const DSA *dsa); 66 67 // DSA_get0_priv_key returns |dsa|'s private key, or NULL if |dsa| is a public 68 // key. 69 OPENSSL_EXPORT const BIGNUM *DSA_get0_priv_key(const DSA *dsa); 70 71 // DSA_get0_p returns |dsa|'s group modulus. 72 OPENSSL_EXPORT const BIGNUM *DSA_get0_p(const DSA *dsa); 73 74 // DSA_get0_q returns the size of |dsa|'s subgroup. 75 OPENSSL_EXPORT const BIGNUM *DSA_get0_q(const DSA *dsa); 76 77 // DSA_get0_g returns |dsa|'s group generator. 78 OPENSSL_EXPORT const BIGNUM *DSA_get0_g(const DSA *dsa); 79 80 // DSA_get0_key sets |*out_pub_key| and |*out_priv_key|, if non-NULL, to |dsa|'s 81 // public and private key, respectively. If |dsa| is a public key, the private 82 // key will be set to NULL. 83 OPENSSL_EXPORT void DSA_get0_key(const DSA *dsa, const BIGNUM **out_pub_key, 84 const BIGNUM **out_priv_key); 85 86 // DSA_get0_pqg sets |*out_p|, |*out_q|, and |*out_g|, if non-NULL, to |dsa|'s 87 // p, q, and g parameters, respectively. 88 OPENSSL_EXPORT void DSA_get0_pqg(const DSA *dsa, const BIGNUM **out_p, 89 const BIGNUM **out_q, const BIGNUM **out_g); 90 91 // DSA_set0_key sets |dsa|'s public and private key to |pub_key| and |priv_key|, 92 // respectively, if non-NULL. On success, it takes ownership of each argument 93 // and returns one. Otherwise, it returns zero. 94 // 95 // |priv_key| may be NULL, but |pub_key| must either be non-NULL or already 96 // configured on |dsa|. 97 OPENSSL_EXPORT int DSA_set0_key(DSA *dsa, BIGNUM *pub_key, BIGNUM *priv_key); 98 99 // DSA_set0_pqg sets |dsa|'s parameters to |p|, |q|, and |g|, if non-NULL, and 100 // takes ownership of them. On success, it takes ownership of each argument and 101 // returns one. Otherwise, it returns zero. 102 // 103 // Each argument must either be non-NULL or already configured on |dsa|. 104 OPENSSL_EXPORT int DSA_set0_pqg(DSA *dsa, BIGNUM *p, BIGNUM *q, BIGNUM *g); 105 106 107 // Parameter generation. 108 109 // DSA_generate_parameters_ex generates a set of DSA parameters by following 110 // the procedure given in FIPS 186-4, appendix A. 111 // (http://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.186-4.pdf) 112 // 113 // The larger prime will have a length of |bits| (e.g. 2048). The |seed| value 114 // allows others to generate and verify the same parameters and should be 115 // random input which is kept for reference. If |out_counter| or |out_h| are 116 // not NULL then the counter and h value used in the generation are written to 117 // them. 118 // 119 // The |cb| argument is passed to |BN_generate_prime_ex| and is thus called 120 // during the generation process in order to indicate progress. See the 121 // comments for that function for details. In addition to the calls made by 122 // |BN_generate_prime_ex|, |DSA_generate_parameters_ex| will call it with 123 // |event| equal to 2 and 3 at different stages of the process. 124 // 125 // It returns one on success and zero otherwise. 126 OPENSSL_EXPORT int DSA_generate_parameters_ex(DSA *dsa, unsigned bits, 127 const uint8_t *seed, 128 size_t seed_len, int *out_counter, 129 unsigned long *out_h, 130 BN_GENCB *cb); 131 132 // DSAparams_dup returns a freshly allocated |DSA| that contains a copy of the 133 // parameters from |dsa|. It returns NULL on error. 134 OPENSSL_EXPORT DSA *DSAparams_dup(const DSA *dsa); 135 136 137 // Key generation. 138 139 // DSA_generate_key generates a public/private key pair in |dsa|, which must 140 // already have parameters setup. It returns one on success and zero on 141 // error. 142 OPENSSL_EXPORT int DSA_generate_key(DSA *dsa); 143 144 145 // Signatures. 146 147 // DSA_SIG_st (aka |DSA_SIG|) contains a DSA signature as a pair of integers. 148 struct DSA_SIG_st { 149 BIGNUM *r, *s; 150 }; 151 152 // DSA_SIG_new returns a freshly allocated, DIG_SIG structure or NULL on error. 153 // Both |r| and |s| in the signature will be NULL. 154 OPENSSL_EXPORT DSA_SIG *DSA_SIG_new(void); 155 156 // DSA_SIG_free frees the contents of |sig| and then frees |sig| itself. 157 OPENSSL_EXPORT void DSA_SIG_free(DSA_SIG *sig); 158 159 // DSA_SIG_get0 sets |*out_r| and |*out_s|, if non-NULL, to the two components 160 // of |sig|. 161 OPENSSL_EXPORT void DSA_SIG_get0(const DSA_SIG *sig, const BIGNUM **out_r, 162 const BIGNUM **out_s); 163 164 // DSA_SIG_set0 sets |sig|'s components to |r| and |s|, neither of which may be 165 // NULL. On success, it takes ownership of each argument and returns one. 166 // Otherwise, it returns zero. 167 OPENSSL_EXPORT int DSA_SIG_set0(DSA_SIG *sig, BIGNUM *r, BIGNUM *s); 168 169 // DSA_do_sign returns a signature of the hash in |digest| by the key in |dsa| 170 // and returns an allocated, DSA_SIG structure, or NULL on error. 171 OPENSSL_EXPORT DSA_SIG *DSA_do_sign(const uint8_t *digest, size_t digest_len, 172 const DSA *dsa); 173 174 // DSA_do_verify verifies that |sig| is a valid signature, by the public key in 175 // |dsa|, of the hash in |digest|. It returns one if so, zero if invalid and -1 176 // on error. 177 // 178 // WARNING: do not use. This function returns -1 for error, 0 for invalid and 1 179 // for valid. However, this is dangerously different to the usual OpenSSL 180 // convention and could be a disaster if a user did |if (DSA_do_verify(...))|. 181 // Because of this, |DSA_check_signature| is a safer version of this. 182 // 183 // TODO(fork): deprecate. 184 OPENSSL_EXPORT int DSA_do_verify(const uint8_t *digest, size_t digest_len, 185 const DSA_SIG *sig, const DSA *dsa); 186 187 // DSA_do_check_signature sets |*out_valid| to zero. Then it verifies that |sig| 188 // is a valid signature, by the public key in |dsa| of the hash in |digest| 189 // and, if so, it sets |*out_valid| to one. 190 // 191 // It returns one if it was able to verify the signature as valid or invalid, 192 // and zero on error. 193 OPENSSL_EXPORT int DSA_do_check_signature(int *out_valid, const uint8_t *digest, 194 size_t digest_len, const DSA_SIG *sig, 195 const DSA *dsa); 196 197 198 // ASN.1 signatures. 199 // 200 // These functions also perform DSA signature operations, but deal with ASN.1 201 // encoded signatures as opposed to raw |BIGNUM|s. If you don't know what 202 // encoding a DSA signature is in, it's probably ASN.1. 203 204 // DSA_sign signs |digest| with the key in |dsa| and writes the resulting 205 // signature, in ASN.1 form, to |out_sig| and the length of the signature to 206 // |*out_siglen|. There must be, at least, |DSA_size(dsa)| bytes of space in 207 // |out_sig|. It returns one on success and zero otherwise. 208 // 209 // (The |type| argument is ignored.) 210 OPENSSL_EXPORT int DSA_sign(int type, const uint8_t *digest, size_t digest_len, 211 uint8_t *out_sig, unsigned int *out_siglen, 212 const DSA *dsa); 213 214 // DSA_verify verifies that |sig| is a valid, ASN.1 signature, by the public 215 // key in |dsa|, of the hash in |digest|. It returns one if so, zero if invalid 216 // and -1 on error. 217 // 218 // (The |type| argument is ignored.) 219 // 220 // WARNING: do not use. This function returns -1 for error, 0 for invalid and 1 221 // for valid. However, this is dangerously different to the usual OpenSSL 222 // convention and could be a disaster if a user did |if (DSA_do_verify(...))|. 223 // Because of this, |DSA_check_signature| is a safer version of this. 224 // 225 // TODO(fork): deprecate. 226 OPENSSL_EXPORT int DSA_verify(int type, const uint8_t *digest, 227 size_t digest_len, const uint8_t *sig, 228 size_t sig_len, const DSA *dsa); 229 230 // DSA_check_signature sets |*out_valid| to zero. Then it verifies that |sig| 231 // is a valid, ASN.1 signature, by the public key in |dsa|, of the hash in 232 // |digest|. If so, it sets |*out_valid| to one. 233 // 234 // It returns one if it was able to verify the signature as valid or invalid, 235 // and zero on error. 236 OPENSSL_EXPORT int DSA_check_signature(int *out_valid, const uint8_t *digest, 237 size_t digest_len, const uint8_t *sig, 238 size_t sig_len, const DSA *dsa); 239 240 // DSA_size returns the size, in bytes, of an ASN.1 encoded, DSA signature 241 // generated by |dsa|. Parameters must already have been setup in |dsa|. 242 OPENSSL_EXPORT int DSA_size(const DSA *dsa); 243 244 245 // ASN.1 encoding. 246 247 // DSA_SIG_parse parses a DER-encoded DSA-Sig-Value structure from |cbs| and 248 // advances |cbs|. It returns a newly-allocated |DSA_SIG| or NULL on error. 249 OPENSSL_EXPORT DSA_SIG *DSA_SIG_parse(CBS *cbs); 250 251 // DSA_SIG_marshal marshals |sig| as a DER-encoded DSA-Sig-Value and appends the 252 // result to |cbb|. It returns one on success and zero on error. 253 OPENSSL_EXPORT int DSA_SIG_marshal(CBB *cbb, const DSA_SIG *sig); 254 255 // DSA_parse_public_key parses a DER-encoded DSA public key from |cbs| and 256 // advances |cbs|. It returns a newly-allocated |DSA| or NULL on error. 257 OPENSSL_EXPORT DSA *DSA_parse_public_key(CBS *cbs); 258 259 // DSA_marshal_public_key marshals |dsa| as a DER-encoded DSA public key and 260 // appends the result to |cbb|. It returns one on success and zero on 261 // failure. 262 OPENSSL_EXPORT int DSA_marshal_public_key(CBB *cbb, const DSA *dsa); 263 264 // DSA_parse_private_key parses a DER-encoded DSA private key from |cbs| and 265 // advances |cbs|. It returns a newly-allocated |DSA| or NULL on error. 266 OPENSSL_EXPORT DSA *DSA_parse_private_key(CBS *cbs); 267 268 // DSA_marshal_private_key marshals |dsa| as a DER-encoded DSA private key and 269 // appends the result to |cbb|. It returns one on success and zero on 270 // failure. 271 OPENSSL_EXPORT int DSA_marshal_private_key(CBB *cbb, const DSA *dsa); 272 273 // DSA_parse_parameters parses a DER-encoded Dss-Parms structure (RFC 3279) 274 // from |cbs| and advances |cbs|. It returns a newly-allocated |DSA| or NULL on 275 // error. 276 OPENSSL_EXPORT DSA *DSA_parse_parameters(CBS *cbs); 277 278 // DSA_marshal_parameters marshals |dsa| as a DER-encoded Dss-Parms structure 279 // (RFC 3279) and appends the result to |cbb|. It returns one on success and 280 // zero on failure. 281 OPENSSL_EXPORT int DSA_marshal_parameters(CBB *cbb, const DSA *dsa); 282 283 284 // Conversion. 285 286 // DSA_dup_DH returns a |DH| constructed from the parameters of |dsa|. This is 287 // sometimes needed when Diffie-Hellman parameters are stored in the form of 288 // DSA parameters. It returns an allocated |DH| on success or NULL on error. 289 OPENSSL_EXPORT DH *DSA_dup_DH(const DSA *dsa); 290 291 292 // ex_data functions. 293 // 294 // See |ex_data.h| for details. 295 296 OPENSSL_EXPORT int DSA_get_ex_new_index(long argl, void *argp, 297 CRYPTO_EX_unused *unused, 298 CRYPTO_EX_dup *dup_unused, 299 CRYPTO_EX_free *free_func); 300 OPENSSL_EXPORT int DSA_set_ex_data(DSA *dsa, int idx, void *arg); 301 OPENSSL_EXPORT void *DSA_get_ex_data(const DSA *dsa, int idx); 302 303 304 // Deprecated functions. 305 306 // d2i_DSA_SIG parses a DER-encoded DSA-Sig-Value structure from |len| bytes at 307 // |*inp|, as described in |d2i_SAMPLE|. 308 // 309 // Use |DSA_SIG_parse| instead. 310 OPENSSL_EXPORT DSA_SIG *d2i_DSA_SIG(DSA_SIG **out_sig, const uint8_t **inp, 311 long len); 312 313 // i2d_DSA_SIG marshals |in| to a DER-encoded DSA-Sig-Value structure, as 314 // described in |i2d_SAMPLE|. 315 // 316 // Use |DSA_SIG_marshal| instead. 317 OPENSSL_EXPORT int i2d_DSA_SIG(const DSA_SIG *in, uint8_t **outp); 318 319 // d2i_DSAPublicKey parses a DER-encoded DSA public key from |len| bytes at 320 // |*inp|, as described in |d2i_SAMPLE|. 321 // 322 // Use |DSA_parse_public_key| instead. 323 OPENSSL_EXPORT DSA *d2i_DSAPublicKey(DSA **out, const uint8_t **inp, long len); 324 325 // i2d_DSAPublicKey marshals |in| as a DER-encoded DSA public key, as described 326 // in |i2d_SAMPLE|. 327 // 328 // Use |DSA_marshal_public_key| instead. 329 OPENSSL_EXPORT int i2d_DSAPublicKey(const DSA *in, uint8_t **outp); 330 331 // d2i_DSAPrivateKey parses a DER-encoded DSA private key from |len| bytes at 332 // |*inp|, as described in |d2i_SAMPLE|. 333 // 334 // Use |DSA_parse_private_key| instead. 335 OPENSSL_EXPORT DSA *d2i_DSAPrivateKey(DSA **out, const uint8_t **inp, long len); 336 337 // i2d_DSAPrivateKey marshals |in| as a DER-encoded DSA private key, as 338 // described in |i2d_SAMPLE|. 339 // 340 // Use |DSA_marshal_private_key| instead. 341 OPENSSL_EXPORT int i2d_DSAPrivateKey(const DSA *in, uint8_t **outp); 342 343 // d2i_DSAparams parses a DER-encoded Dss-Parms structure (RFC 3279) from |len| 344 // bytes at |*inp|, as described in |d2i_SAMPLE|. 345 // 346 // Use |DSA_parse_parameters| instead. 347 OPENSSL_EXPORT DSA *d2i_DSAparams(DSA **out, const uint8_t **inp, long len); 348 349 // i2d_DSAparams marshals |in|'s parameters as a DER-encoded Dss-Parms structure 350 // (RFC 3279), as described in |i2d_SAMPLE|. 351 // 352 // Use |DSA_marshal_parameters| instead. 353 OPENSSL_EXPORT int i2d_DSAparams(const DSA *in, uint8_t **outp); 354 355 // DSA_generate_parameters is a deprecated version of 356 // |DSA_generate_parameters_ex| that creates and returns a |DSA*|. Don't use 357 // it. 358 OPENSSL_EXPORT DSA *DSA_generate_parameters(int bits, unsigned char *seed, 359 int seed_len, int *counter_ret, 360 unsigned long *h_ret, 361 void (*callback)(int, int, void *), 362 void *cb_arg); 363 364 365 #if defined(__cplusplus) 366 } // extern C 367 368 extern "C++" { 369 370 BSSL_NAMESPACE_BEGIN 371 372 BORINGSSL_MAKE_DELETER(DSA, DSA_free) 373 BORINGSSL_MAKE_UP_REF(DSA, DSA_up_ref) 374 BORINGSSL_MAKE_DELETER(DSA_SIG, DSA_SIG_free) 375 376 BSSL_NAMESPACE_END 377 378 } // extern C++ 379 380 #endif 381 382 #define DSA_R_BAD_Q_VALUE 100 383 #define DSA_R_MISSING_PARAMETERS 101 384 #define DSA_R_MODULUS_TOO_LARGE 102 385 #define DSA_R_NEED_NEW_SETUP_VALUES 103 386 #define DSA_R_BAD_VERSION 104 387 #define DSA_R_DECODE_ERROR 105 388 #define DSA_R_ENCODE_ERROR 106 389 #define DSA_R_INVALID_PARAMETERS 107 390 #define DSA_R_TOO_MANY_ITERATIONS 108 391 392 #endif // OPENSSL_HEADER_DSA_H