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      1 /* ====================================================================
      2  * Copyright (c) 1998-2005 The OpenSSL Project.  All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions
      6  * are met:
      7  *
      8  * 1. Redistributions of source code must retain the above copyright
      9  *    notice, this list of conditions and the following disclaimer.
     10  *
     11  * 2. Redistributions in binary form must reproduce the above copyright
     12  *    notice, this list of conditions and the following disclaimer in
     13  *    the documentation and/or other materials provided with the
     14  *    distribution.
     15  *
     16  * 3. All advertising materials mentioning features or use of this
     17  *    software must display the following acknowledgment:
     18  *    "This product includes software developed by the OpenSSL Project
     19  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
     20  *
     21  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
     22  *    endorse or promote products derived from this software without
     23  *    prior written permission. For written permission, please contact
     24  *    openssl-core (at) OpenSSL.org.
     25  *
     26  * 5. Products derived from this software may not be called "OpenSSL"
     27  *    nor may "OpenSSL" appear in their names without prior written
     28  *    permission of the OpenSSL Project.
     29  *
     30  * 6. Redistributions of any form whatsoever must retain the following
     31  *    acknowledgment:
     32  *    "This product includes software developed by the OpenSSL Project
     33  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
     34  *
     35  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
     36  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     37  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     38  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
     39  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     40  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     41  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     42  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     43  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
     44  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     45  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
     46  * OF THE POSSIBILITY OF SUCH DAMAGE.
     47  * ====================================================================
     48  *
     49  * This product includes cryptographic software written by Eric Young
     50  * (eay (at) cryptsoft.com).  This product includes software written by Tim
     51  * Hudson (tjh (at) cryptsoft.com). */
     52 
     53 #ifndef OPENSSL_HEADER_ECDSA_H
     54 #define OPENSSL_HEADER_ECDSA_H
     55 
     56 #include <openssl/base.h>
     57 
     58 #include <openssl/ec_key.h>
     59 
     60 #if defined(__cplusplus)
     61 extern "C" {
     62 #endif
     63 
     64 
     65 /* ECDSA contains functions for signing and verifying with the Digital Signature
     66  * Algorithm over elliptic curves. */
     67 
     68 
     69 /* Signing and verifying. */
     70 
     71 /* ECDSA_sign signs |digest_len| bytes from |digest| with |key| and writes the
     72  * resulting signature to |sig|, which must have |ECDSA_size(key)| bytes of
     73  * space. On successful exit, |*sig_len| is set to the actual number of bytes
     74  * written. The |type| argument should be zero. It returns one on success and
     75  * zero otherwise. */
     76 OPENSSL_EXPORT int ECDSA_sign(int type, const uint8_t *digest,
     77                               size_t digest_len, uint8_t *sig,
     78                               unsigned int *sig_len, const EC_KEY *key);
     79 
     80 /* ECDSA_verify verifies that |sig_len| bytes from |sig| constitute a valid
     81  * signature by |key| of |digest|. (The |type| argument should be zero.) It
     82  * returns one on success or zero if the signature is invalid or an error
     83  * occurred. */
     84 OPENSSL_EXPORT int ECDSA_verify(int type, const uint8_t *digest,
     85                                 size_t digest_len, const uint8_t *sig,
     86                                 size_t sig_len, const EC_KEY *key);
     87 
     88 /* ECDSA_size returns the maximum size of an ECDSA signature using |key|. It
     89  * returns zero on error. */
     90 OPENSSL_EXPORT size_t ECDSA_size(const EC_KEY *key);
     91 
     92 
     93 /* Low-level signing and verification.
     94  *
     95  * Low-level functions handle signatures as |ECDSA_SIG| structures which allow
     96  * the two values in an ECDSA signature to be handled separately. */
     97 
     98 struct ecdsa_sig_st {
     99   BIGNUM *r;
    100   BIGNUM *s;
    101 };
    102 
    103 /* ECDSA_SIG_new returns a fresh |ECDSA_SIG| structure or NULL on error. */
    104 OPENSSL_EXPORT ECDSA_SIG *ECDSA_SIG_new(void);
    105 
    106 /* ECDSA_SIG_free frees |sig| its member |BIGNUM|s. */
    107 OPENSSL_EXPORT void ECDSA_SIG_free(ECDSA_SIG *sig);
    108 
    109 /* ECDSA_do_sign signs |digest_len| bytes from |digest| with |key| and returns
    110  * the resulting signature structure, or NULL on error. */
    111 OPENSSL_EXPORT ECDSA_SIG *ECDSA_do_sign(const uint8_t *digest,
    112                                         size_t digest_len, const EC_KEY *key);
    113 
    114 /* ECDSA_do_verify verifies that |sig| constitutes a valid signature by |key|
    115  * of |digest|. It returns one on success or zero if the signature is invalid
    116  * or on error. */
    117 OPENSSL_EXPORT int ECDSA_do_verify(const uint8_t *digest, size_t digest_len,
    118                                    const ECDSA_SIG *sig, const EC_KEY *key);
    119 
    120 
    121 /* Signing with precomputation.
    122  *
    123  * Parts of the ECDSA signature can be independent of the message to be signed
    124  * thus it's possible to precompute them and reduce the signing latency.
    125  *
    126  * TODO(fork): remove support for this as it cannot support safe-randomness. */
    127 
    128 /* ECDSA_sign_setup precomputes parts of an ECDSA signing operation. It sets
    129  * |*kinv| and |*rp| to the precomputed values and uses the |ctx| argument, if
    130  * not NULL. It returns one on success and zero otherwise. */
    131 OPENSSL_EXPORT int ECDSA_sign_setup(const EC_KEY *eckey, BN_CTX *ctx,
    132                                     BIGNUM **kinv, BIGNUM **rp);
    133 
    134 /* ECDSA_do_sign_ex is the same as |ECDSA_do_sign| but takes precomputed values
    135  * as generated by |ECDSA_sign_setup|. */
    136 OPENSSL_EXPORT ECDSA_SIG *ECDSA_do_sign_ex(const uint8_t *digest,
    137                                            size_t digest_len,
    138                                            const BIGNUM *kinv, const BIGNUM *rp,
    139                                            const EC_KEY *eckey);
    140 
    141 /* ECDSA_sign_ex is the same as |ECDSA_sign| but takes precomputed values as
    142  * generated by |ECDSA_sign_setup|. */
    143 OPENSSL_EXPORT int ECDSA_sign_ex(int type, const uint8_t *digest,
    144                                  size_t digest_len, uint8_t *sig,
    145                                  unsigned int *sig_len, const BIGNUM *kinv,
    146                                  const BIGNUM *rp, const EC_KEY *eckey);
    147 
    148 
    149 /* ASN.1 functions. */
    150 
    151 /* ECDSA_SIG_parse parses a DER-encoded ECDSA-Sig-Value structure from |cbs| and
    152  * advances |cbs|. It returns a newly-allocated |ECDSA_SIG| or NULL on error. */
    153 OPENSSL_EXPORT ECDSA_SIG *ECDSA_SIG_parse(CBS *cbs);
    154 
    155 /* ECDSA_SIG_from_bytes parses |in| as a DER-encoded ECDSA-Sig-Value structure.
    156  * It returns a newly-allocated |ECDSA_SIG| structure or NULL on error. */
    157 OPENSSL_EXPORT ECDSA_SIG *ECDSA_SIG_from_bytes(const uint8_t *in,
    158                                                size_t in_len);
    159 
    160 /* ECDSA_SIG_marshal marshals |sig| as a DER-encoded ECDSA-Sig-Value and appends
    161  * the result to |cbb|. It returns one on success and zero on error. */
    162 OPENSSL_EXPORT int ECDSA_SIG_marshal(CBB *cbb, const ECDSA_SIG *sig);
    163 
    164 /* ECDSA_SIG_to_bytes marshals |sig| as a DER-encoded ECDSA-Sig-Value and, on
    165  * success, sets |*out_bytes| to a newly allocated buffer containing the result
    166  * and returns one. Otherwise, it returns zero. The result should be freed with
    167  * |OPENSSL_free|. */
    168 OPENSSL_EXPORT int ECDSA_SIG_to_bytes(uint8_t **out_bytes, size_t *out_len,
    169                                       const ECDSA_SIG *sig);
    170 
    171 /* ECDSA_SIG_max_len returns the maximum length of a DER-encoded ECDSA-Sig-Value
    172  * structure for a group whose order is represented in |order_len| bytes, or
    173  * zero on overflow. */
    174 OPENSSL_EXPORT size_t ECDSA_SIG_max_len(size_t order_len);
    175 
    176 
    177 /* Deprecated functions. */
    178 
    179 /* d2i_ECDSA_SIG parses an ASN.1, DER-encoded, signature from |len| bytes at
    180  * |*inp|. If |out| is not NULL then, on exit, a pointer to the result is in
    181  * |*out|. Note that, even if |*out| is already non-NULL on entry, it will not
    182  * be written to. Rather, a fresh |ECDSA_SIG| is allocated and the previous one
    183  * is freed. On successful exit, |*inp| is advanced past the DER structure. It
    184  * returns the result or NULL on error. */
    185 OPENSSL_EXPORT ECDSA_SIG *d2i_ECDSA_SIG(ECDSA_SIG **out, const uint8_t **inp,
    186                                         long len);
    187 
    188 /* i2d_ECDSA_SIG marshals a signature from |sig| to an ASN.1, DER
    189  * structure. If |outp| is not NULL then the result is written to |*outp| and
    190  * |*outp| is advanced just past the output. It returns the number of bytes in
    191  * the result, whether written or not, or a negative value on error. */
    192 OPENSSL_EXPORT int i2d_ECDSA_SIG(const ECDSA_SIG *sig, uint8_t **outp);
    193 
    194 
    195 #if defined(__cplusplus)
    196 }  /* extern C */
    197 
    198 extern "C++" {
    199 
    200 namespace bssl {
    201 
    202 BORINGSSL_MAKE_DELETER(ECDSA_SIG, ECDSA_SIG_free)
    203 
    204 }  // namespace bssl
    205 
    206 }  /* extern C++ */
    207 
    208 #endif
    209 
    210 #define ECDSA_R_BAD_SIGNATURE 100
    211 #define ECDSA_R_MISSING_PARAMETERS 101
    212 #define ECDSA_R_NEED_NEW_SETUP_VALUES 102
    213 #define ECDSA_R_NOT_IMPLEMENTED 103
    214 #define ECDSA_R_RANDOM_NUMBER_GENERATION_FAILED 104
    215 #define ECDSA_R_ENCODE_ERROR 105
    216 
    217 #endif  /* OPENSSL_HEADER_ECDSA_H */
    218