text: /* ====================================================================
   * Copyright (c) 1998-2005 The OpenSSL Project.  All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in
   *    the documentation and/or other materials provided with the
   *    distribution.
   *
   * 3. All advertising materials mentioning features or use of this
   *    software must display the following acknowledgment:
   *    "This product includes software developed by the OpenSSL Project
   *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
   *
   * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
   *    endorse or promote products derived from this software without
   *    prior written permission. For written permission, please contact
   *    openssl-core@OpenSSL.org.
   *
   * 5. Products derived from this software may not be called "OpenSSL"
   *    nor may "OpenSSL" appear in their names without prior written
   *    permission of the OpenSSL Project.
   *
   * 6. Redistributions of any form whatsoever must retain the following
   *    acknowledgment:
   *    "This product includes software developed by the OpenSSL Project
   *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
   *
   * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
   * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
   * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
   * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
   * OF THE POSSIBILITY OF SUCH DAMAGE.
   * ====================================================================
   *
   * This product includes cryptographic software written by Eric Young
   * (eay@cryptsoft.com).  This product includes software written by Tim
   * Hudson (tjh@cryptsoft.com). */
  
  #ifndef OPENSSL_HEADER_ECDSA_H
  #define OPENSSL_HEADER_ECDSA_H
  
  #include <openssl_grpc/base.h>
  
  #include <openssl_grpc/ec_key.h>
  
  #if defined(__cplusplus)
  extern "C" {
  #endif
  
  
  // ECDSA contains functions for signing and verifying with the Digital Signature
  // Algorithm over elliptic curves.
  
  
  // Signing and verifying.
  
  // ECDSA_sign signs |digest_len| bytes from |digest| with |key| and writes the
  // resulting signature to |sig|, which must have |ECDSA_size(key)| bytes of
  // space. On successful exit, |*sig_len| is set to the actual number of bytes
  // written. The |type| argument should be zero. It returns one on success and
  // zero otherwise.
  //
  // WARNING: |digest| must be the output of some hash function on the data to be
  // signed. Passing unhashed inputs will not result in a secure signature scheme.
  OPENSSL_EXPORT int ECDSA_sign(int type, const uint8_t *digest,
                                size_t digest_len, uint8_t *sig,
                                unsigned int *sig_len, const EC_KEY *key);
  
  // ECDSA_verify verifies that |sig_len| bytes from |sig| constitute a valid
  // signature by |key| of |digest|. (The |type| argument should be zero.) It
  // returns one on success or zero if the signature is invalid or an error
  // occurred.
  //
  // WARNING: |digest| must be the output of some hash function on the data to be
  // verified. Passing unhashed inputs will not result in a secure signature
  // scheme.
  OPENSSL_EXPORT int ECDSA_verify(int type, const uint8_t *digest,
                                  size_t digest_len, const uint8_t *sig,
                                  size_t sig_len, const EC_KEY *key);
  
  // ECDSA_size returns the maximum size of an ECDSA signature using |key|. It
  // returns zero if |key| is NULL or if it doesn't have a group set.
  OPENSSL_EXPORT size_t ECDSA_size(const EC_KEY *key);
  
  
  // Low-level signing and verification.
  //
  // Low-level functions handle signatures as |ECDSA_SIG| structures which allow
  // the two values in an ECDSA signature to be handled separately.
  
  struct ecdsa_sig_st {
    BIGNUM *r;
    BIGNUM *s;
  };
  
  // ECDSA_SIG_new returns a fresh |ECDSA_SIG| structure or NULL on error.
  OPENSSL_EXPORT ECDSA_SIG *ECDSA_SIG_new(void);
  
  // ECDSA_SIG_free frees |sig| its member |BIGNUM|s.
  OPENSSL_EXPORT void ECDSA_SIG_free(ECDSA_SIG *sig);
  
  // ECDSA_SIG_get0_r returns the r component of |sig|.
  OPENSSL_EXPORT const BIGNUM *ECDSA_SIG_get0_r(const ECDSA_SIG *sig);
  
  // ECDSA_SIG_get0_s returns the s component of |sig|.
  OPENSSL_EXPORT const BIGNUM *ECDSA_SIG_get0_s(const ECDSA_SIG *sig);
  
  // ECDSA_SIG_get0 sets |*out_r| and |*out_s|, if non-NULL, to the two
  // components of |sig|.
  OPENSSL_EXPORT void ECDSA_SIG_get0(const ECDSA_SIG *sig, const BIGNUM **out_r,
                                     const BIGNUM **out_s);
  
  // ECDSA_SIG_set0 sets |sig|'s components to |r| and |s|, neither of which may
  // be NULL. On success, it takes ownership of each argument and returns one.
  // Otherwise, it returns zero.
  OPENSSL_EXPORT int ECDSA_SIG_set0(ECDSA_SIG *sig, BIGNUM *r, BIGNUM *s);
  
  // ECDSA_do_sign signs |digest_len| bytes from |digest| with |key| and returns
  // the resulting signature structure, or NULL on error.
  //
  // WARNING: |digest| must be the output of some hash function on the data to be
  // signed. Passing unhashed inputs will not result in a secure signature scheme.
  OPENSSL_EXPORT ECDSA_SIG *ECDSA_do_sign(const uint8_t *digest,
                                          size_t digest_len, const EC_KEY *key);
  
  // ECDSA_do_verify verifies that |sig| constitutes a valid signature by |key|
  // of |digest|. It returns one on success or zero if the signature is invalid
  // or on error.
  //
  // WARNING: |digest| must be the output of some hash function on the data to be
  // verified. Passing unhashed inputs will not result in a secure signature
  // scheme.
  OPENSSL_EXPORT int ECDSA_do_verify(const uint8_t *digest, size_t digest_len,
                                     const ECDSA_SIG *sig, const EC_KEY *key);
  
  
  // ASN.1 functions.
  
  // ECDSA_SIG_parse parses a DER-encoded ECDSA-Sig-Value structure from |cbs| and
  // advances |cbs|. It returns a newly-allocated |ECDSA_SIG| or NULL on error.
  OPENSSL_EXPORT ECDSA_SIG *ECDSA_SIG_parse(CBS *cbs);
  
  // ECDSA_SIG_from_bytes parses |in| as a DER-encoded ECDSA-Sig-Value structure.
  // It returns a newly-allocated |ECDSA_SIG| structure or NULL on error.
  OPENSSL_EXPORT ECDSA_SIG *ECDSA_SIG_from_bytes(const uint8_t *in,
                                                 size_t in_len);
  
  // ECDSA_SIG_marshal marshals |sig| as a DER-encoded ECDSA-Sig-Value and appends
  // the result to |cbb|. It returns one on success and zero on error.
  OPENSSL_EXPORT int ECDSA_SIG_marshal(CBB *cbb, const ECDSA_SIG *sig);
  
  // ECDSA_SIG_to_bytes marshals |sig| as a DER-encoded ECDSA-Sig-Value and, on
  // success, sets |*out_bytes| to a newly allocated buffer containing the result
  // and returns one. Otherwise, it returns zero. The result should be freed with
  // |OPENSSL_free|.
  OPENSSL_EXPORT int ECDSA_SIG_to_bytes(uint8_t **out_bytes, size_t *out_len,
                                        const ECDSA_SIG *sig);
  
  // ECDSA_SIG_max_len returns the maximum length of a DER-encoded ECDSA-Sig-Value
  // structure for a group whose order is represented in |order_len| bytes, or
  // zero on overflow.
  OPENSSL_EXPORT size_t ECDSA_SIG_max_len(size_t order_len);
  
  
  // Testing-only functions.
  
  // ECDSA_sign_with_nonce_and_leak_private_key_for_testing behaves like
  // |ECDSA_do_sign| but uses |nonce| for the ECDSA nonce 'k', instead of a random
  // value. |nonce| is interpreted as a big-endian integer. It must be reduced
  // modulo the group order and padded with zeros up to |BN_num_bytes(order)|
  // bytes.
  //
  // WARNING: This function is only exported for testing purposes, when using test
  // vectors or fuzzing strategies. It must not be used outside tests and may leak
  // any private keys it is used with.
  OPENSSL_EXPORT ECDSA_SIG *
  ECDSA_sign_with_nonce_and_leak_private_key_for_testing(const uint8_t *digest,
                                                         size_t digest_len,
                                                         const EC_KEY *eckey,
                                                         const uint8_t *nonce,
                                                         size_t nonce_len);
  
  
  // Deprecated functions.
  
  // d2i_ECDSA_SIG parses aa DER-encoded ECDSA-Sig-Value structure from |len|
  // bytes at |*inp|, as described in |d2i_SAMPLE|.
  //
  // Use |ECDSA_SIG_parse| instead.
  OPENSSL_EXPORT ECDSA_SIG *d2i_ECDSA_SIG(ECDSA_SIG **out, const uint8_t **inp,
                                          long len);
  
  // i2d_ECDSA_SIG marshals |sig| as a DER-encoded ECDSA-Sig-Value, as described
  // in |i2d_SAMPLE|.
  //
  // Use |ECDSA_SIG_marshal| instead.
  OPENSSL_EXPORT int i2d_ECDSA_SIG(const ECDSA_SIG *sig, uint8_t **outp);
  
  
  #if defined(__cplusplus)
  }  // extern C
  
  extern "C++" {
  
  BSSL_NAMESPACE_BEGIN
  
  BORINGSSL_MAKE_DELETER(ECDSA_SIG, ECDSA_SIG_free)
  
  BSSL_NAMESPACE_END
  
  }  // extern C++
  
  #endif
  
  #define ECDSA_R_BAD_SIGNATURE 100
  #define ECDSA_R_MISSING_PARAMETERS 101
  #define ECDSA_R_NEED_NEW_SETUP_VALUES 102
  #define ECDSA_R_NOT_IMPLEMENTED 103
  #define ECDSA_R_RANDOM_NUMBER_GENERATION_FAILED 104
  #define ECDSA_R_ENCODE_ERROR 105
  
  #endif  // OPENSSL_HEADER_ECDSA_H
  