text: /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   * All rights reserved.
   *
   * This package is an SSL implementation written
   * by Eric Young (eay@cryptsoft.com).
   * The implementation was written so as to conform with Netscapes SSL.
   *
   * This library is free for commercial and non-commercial use as long as
   * the following conditions are aheared to.  The following conditions
   * apply to all code found in this distribution, be it the RC4, RSA,
   * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
   * included with this distribution is covered by the same copyright terms
   * except that the holder is Tim Hudson (tjh@cryptsoft.com).
   *
   * Copyright remains Eric Young's, and as such any Copyright notices in
   * the code are not to be removed.
   * If this package is used in a product, Eric Young should be given attribution
   * as the author of the parts of the library used.
   * This can be in the form of a textual message at program startup or
   * in documentation (online or textual) provided with the package.
   *
   * 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 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 acknowledgement:
   *    "This product includes cryptographic software written by
   *     Eric Young (eay@cryptsoft.com)"
   *    The word 'cryptographic' can be left out if the rouines from the library
   *    being used are not cryptographic related :-).
   * 4. If you include any Windows specific code (or a derivative thereof) from
   *    the apps directory (application code) you must include an acknowledgement:
   *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
   *
   * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
   * ANY EXPRESS 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 AUTHOR OR 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.
   *
   * The licence and distribution terms for any publically available version or
   * derivative of this code cannot be changed.  i.e. this code cannot simply be
   * copied and put under another distribution licence
   * [including the GNU Public Licence.]
   *
   * The DSS routines are based on patches supplied by
   * Steven Schoch <schoch@sheba.arc.nasa.gov>. */
  
  #ifndef OPENSSL_HEADER_DSA_H
  #define OPENSSL_HEADER_DSA_H
  
  #include <openssl_grpc/base.h>
  
  #include <openssl_grpc/engine.h>
  #include <openssl_grpc/ex_data.h>
  #include <openssl_grpc/thread.h>
  
  #if defined(__cplusplus)
  extern "C" {
  #endif
  
  
  // DSA contains functions for signing and verifying with the Digital Signature
  // Algorithm.
  //
  // This module is deprecated and retained for legacy reasons only. It is not
  // considered a priority for performance or hardening work. Do not use it in
  // new code. Use Ed25519, ECDSA with P-256, or RSA instead.
  
  
  // Allocation and destruction.
  
  // DSA_new returns a new, empty DSA object or NULL on error.
  OPENSSL_EXPORT DSA *DSA_new(void);
  
  // DSA_free decrements the reference count of |dsa| and frees it if the
  // reference count drops to zero.
  OPENSSL_EXPORT void DSA_free(DSA *dsa);
  
  // DSA_up_ref increments the reference count of |dsa| and returns one.
  OPENSSL_EXPORT int DSA_up_ref(DSA *dsa);
  
  
  // Properties.
  
  // DSA_get0_key sets |*out_pub_key| and |*out_priv_key|, if non-NULL, to |dsa|'s
  // public and private key, respectively. If |dsa| is a public key, the private
  // key will be set to NULL.
  OPENSSL_EXPORT void DSA_get0_key(const DSA *dsa, const BIGNUM **out_pub_key,
                                   const BIGNUM **out_priv_key);
  
  // DSA_get0_pqg sets |*out_p|, |*out_q|, and |*out_g|, if non-NULL, to |dsa|'s
  // p, q, and g parameters, respectively.
  OPENSSL_EXPORT void DSA_get0_pqg(const DSA *dsa, const BIGNUM **out_p,
                                   const BIGNUM **out_q, const BIGNUM **out_g);
  
  // DSA_set0_key sets |dsa|'s public and private key to |pub_key| and |priv_key|,
  // respectively, if non-NULL. On success, it takes ownership of each argument
  // and returns one. Otherwise, it returns zero.
  //
  // |priv_key| may be NULL, but |pub_key| must either be non-NULL or already
  // configured on |dsa|.
  OPENSSL_EXPORT int DSA_set0_key(DSA *dsa, BIGNUM *pub_key, BIGNUM *priv_key);
  
  // DSA_set0_pqg sets |dsa|'s parameters to |p|, |q|, and |g|, if non-NULL, and
  // takes ownership of them. On success, it takes ownership of each argument and
  // returns one. Otherwise, it returns zero.
  //
  // Each argument must either be non-NULL or already configured on |dsa|.
  OPENSSL_EXPORT int DSA_set0_pqg(DSA *dsa, BIGNUM *p, BIGNUM *q, BIGNUM *g);
  
  
  // Parameter generation.
  
  // DSA_generate_parameters_ex generates a set of DSA parameters by following
  // the procedure given in FIPS 186-4, appendix A.
  // (http://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.186-4.pdf)
  //
  // The larger prime will have a length of |bits| (e.g. 2048). The |seed| value
  // allows others to generate and verify the same parameters and should be
  // random input which is kept for reference. If |out_counter| or |out_h| are
  // not NULL then the counter and h value used in the generation are written to
  // them.
  //
  // The |cb| argument is passed to |BN_generate_prime_ex| and is thus called
  // during the generation process in order to indicate progress. See the
  // comments for that function for details. In addition to the calls made by
  // |BN_generate_prime_ex|, |DSA_generate_parameters_ex| will call it with
  // |event| equal to 2 and 3 at different stages of the process.
  //
  // It returns one on success and zero otherwise.
  OPENSSL_EXPORT int DSA_generate_parameters_ex(DSA *dsa, unsigned bits,
                                                const uint8_t *seed,
                                                size_t seed_len, int *out_counter,
                                                unsigned long *out_h,
                                                BN_GENCB *cb);
  
  // DSAparams_dup returns a freshly allocated |DSA| that contains a copy of the
  // parameters from |dsa|. It returns NULL on error.
  OPENSSL_EXPORT DSA *DSAparams_dup(const DSA *dsa);
  
  
  // Key generation.
  
  // DSA_generate_key generates a public/private key pair in |dsa|, which must
  // already have parameters setup. It returns one on success and zero on
  // error.
  OPENSSL_EXPORT int DSA_generate_key(DSA *dsa);
  
  
  // Signatures.
  
  // DSA_SIG_st (aka |DSA_SIG|) contains a DSA signature as a pair of integers.
  struct DSA_SIG_st {
    BIGNUM *r, *s;
  };
  
  // DSA_SIG_new returns a freshly allocated, DIG_SIG structure or NULL on error.
  // Both |r| and |s| in the signature will be NULL.
  OPENSSL_EXPORT DSA_SIG *DSA_SIG_new(void);
  
  // DSA_SIG_free frees the contents of |sig| and then frees |sig| itself.
  OPENSSL_EXPORT void DSA_SIG_free(DSA_SIG *sig);
  
  // DSA_do_sign returns a signature of the hash in |digest| by the key in |dsa|
  // and returns an allocated, DSA_SIG structure, or NULL on error.
  OPENSSL_EXPORT DSA_SIG *DSA_do_sign(const uint8_t *digest, size_t digest_len,
                                      const DSA *dsa);
  
  // DSA_do_verify verifies that |sig| is a valid signature, by the public key in
  // |dsa|, of the hash in |digest|. It returns one if so, zero if invalid and -1
  // on error.
  //
  // WARNING: do not use. This function returns -1 for error, 0 for invalid and 1
  // for valid. However, this is dangerously different to the usual OpenSSL
  // convention and could be a disaster if a user did |if (DSA_do_verify(...))|.
  // Because of this, |DSA_check_signature| is a safer version of this.
  //
  // TODO(fork): deprecate.
  OPENSSL_EXPORT int DSA_do_verify(const uint8_t *digest, size_t digest_len,
                                   DSA_SIG *sig, const DSA *dsa);
  
  // DSA_do_check_signature sets |*out_valid| to zero. Then it verifies that |sig|
  // is a valid signature, by the public key in |dsa| of the hash in |digest|
  // and, if so, it sets |*out_valid| to one.
  //
  // It returns one if it was able to verify the signature as valid or invalid,
  // and zero on error.
  OPENSSL_EXPORT int DSA_do_check_signature(int *out_valid, const uint8_t *digest,
                                            size_t digest_len, DSA_SIG *sig,
                                            const DSA *dsa);
  
  
  // ASN.1 signatures.
  //
  // These functions also perform DSA signature operations, but deal with ASN.1
  // encoded signatures as opposed to raw |BIGNUM|s. If you don't know what
  // encoding a DSA signature is in, it's probably ASN.1.
  
  // DSA_sign signs |digest| with the key in |dsa| and writes the resulting
  // signature, in ASN.1 form, to |out_sig| and the length of the signature to
  // |*out_siglen|. There must be, at least, |DSA_size(dsa)| bytes of space in
  // |out_sig|. It returns one on success and zero otherwise.
  //
  // (The |type| argument is ignored.)
  OPENSSL_EXPORT int DSA_sign(int type, const uint8_t *digest, size_t digest_len,
                              uint8_t *out_sig, unsigned int *out_siglen,
                              const DSA *dsa);
  
  // DSA_verify verifies that |sig| is a valid, ASN.1 signature, by the public
  // key in |dsa|, of the hash in |digest|. It returns one if so, zero if invalid
  // and -1 on error.
  //
  // (The |type| argument is ignored.)
  //
  // WARNING: do not use. This function returns -1 for error, 0 for invalid and 1
  // for valid. However, this is dangerously different to the usual OpenSSL
  // convention and could be a disaster if a user did |if (DSA_do_verify(...))|.
  // Because of this, |DSA_check_signature| is a safer version of this.
  //
  // TODO(fork): deprecate.
  OPENSSL_EXPORT int DSA_verify(int type, const uint8_t *digest,
                                size_t digest_len, const uint8_t *sig,
                                size_t sig_len, const DSA *dsa);
  
  // DSA_check_signature sets |*out_valid| to zero. Then it verifies that |sig|
  // is a valid, ASN.1 signature, by the public key in |dsa|, of the hash in
  // |digest|. If so, it sets |*out_valid| to one.
  //
  // It returns one if it was able to verify the signature as valid or invalid,
  // and zero on error.
  OPENSSL_EXPORT int DSA_check_signature(int *out_valid, const uint8_t *digest,
                                         size_t digest_len, const uint8_t *sig,
                                         size_t sig_len, const DSA *dsa);
  
  // DSA_size returns the size, in bytes, of an ASN.1 encoded, DSA signature
  // generated by |dsa|. Parameters must already have been setup in |dsa|.
  OPENSSL_EXPORT int DSA_size(const DSA *dsa);
  
  
  // ASN.1 encoding.
  
  // DSA_SIG_parse parses a DER-encoded DSA-Sig-Value structure from |cbs| and
  // advances |cbs|. It returns a newly-allocated |DSA_SIG| or NULL on error.
  OPENSSL_EXPORT DSA_SIG *DSA_SIG_parse(CBS *cbs);
  
  // DSA_SIG_marshal marshals |sig| as a DER-encoded DSA-Sig-Value and appends the
  // result to |cbb|. It returns one on success and zero on error.
  OPENSSL_EXPORT int DSA_SIG_marshal(CBB *cbb, const DSA_SIG *sig);
  
  // DSA_parse_public_key parses a DER-encoded DSA public key from |cbs| and
  // advances |cbs|. It returns a newly-allocated |DSA| or NULL on error.
  OPENSSL_EXPORT DSA *DSA_parse_public_key(CBS *cbs);
  
  // DSA_marshal_public_key marshals |dsa| as a DER-encoded DSA public key and
  // appends the result to |cbb|. It returns one on success and zero on
  // failure.
  OPENSSL_EXPORT int DSA_marshal_public_key(CBB *cbb, const DSA *dsa);
  
  // DSA_parse_private_key parses a DER-encoded DSA private key from |cbs| and
  // advances |cbs|. It returns a newly-allocated |DSA| or NULL on error.
  OPENSSL_EXPORT DSA *DSA_parse_private_key(CBS *cbs);
  
  // DSA_marshal_private_key marshals |dsa| as a DER-encoded DSA private key and
  // appends the result to |cbb|. It returns one on success and zero on
  // failure.
  OPENSSL_EXPORT int DSA_marshal_private_key(CBB *cbb, const DSA *dsa);
  
  // DSA_parse_parameters parses a DER-encoded Dss-Parms structure (RFC 3279)
  // from |cbs| and advances |cbs|. It returns a newly-allocated |DSA| or NULL on
  // error.
  OPENSSL_EXPORT DSA *DSA_parse_parameters(CBS *cbs);
  
  // DSA_marshal_parameters marshals |dsa| as a DER-encoded Dss-Parms structure
  // (RFC 3447) and appends the result to |cbb|. It returns one on success and
  // zero on failure.
  OPENSSL_EXPORT int DSA_marshal_parameters(CBB *cbb, const DSA *dsa);
  
  
  // Conversion.
  
  // DSA_dup_DH returns a |DH| constructed from the parameters of |dsa|. This is
  // sometimes needed when Diffie-Hellman parameters are stored in the form of
  // DSA parameters. It returns an allocated |DH| on success or NULL on error.
  OPENSSL_EXPORT DH *DSA_dup_DH(const DSA *dsa);
  
  
  // ex_data functions.
  //
  // See |ex_data.h| for details.
  
  OPENSSL_EXPORT int DSA_get_ex_new_index(long argl, void *argp,
                                          CRYPTO_EX_unused *unused,
                                          CRYPTO_EX_dup *dup_unused,
                                          CRYPTO_EX_free *free_func);
  OPENSSL_EXPORT int DSA_set_ex_data(DSA *dsa, int idx, void *arg);
  OPENSSL_EXPORT void *DSA_get_ex_data(const DSA *dsa, int idx);
  
  
  // Deprecated functions.
  
  // d2i_DSA_SIG parses an ASN.1, DER-encoded, DSA signature from |len| bytes at
  // |*inp|. If |out_sig| is not NULL then, on exit, a pointer to the result is
  // in |*out_sig|. Note that, even if |*out_sig| is already non-NULL on entry, it
  // will not be written to. Rather, a fresh |DSA_SIG| is allocated and the
  // previous one is freed. On successful exit, |*inp| is advanced past the DER
  // structure. It returns the result or NULL on error.
  //
  // Use |DSA_SIG_parse| instead.
  OPENSSL_EXPORT DSA_SIG *d2i_DSA_SIG(DSA_SIG **out_sig, const uint8_t **inp,
                                      long len);
  
  // i2d_DSA_SIG marshals |in| to an ASN.1, DER structure. If |outp| is not NULL
  // then the result is written to |*outp| and |*outp| is advanced just past the
  // output. It returns the number of bytes in the result, whether written or not,
  // or a negative value on error.
  //
  // Use |DSA_SIG_marshal| instead.
  OPENSSL_EXPORT int i2d_DSA_SIG(const DSA_SIG *in, uint8_t **outp);
  
  // d2i_DSAPublicKey parses an ASN.1, DER-encoded, DSA public key from |len|
  // bytes at |*inp|. If |out| is not NULL then, on exit, a pointer to the result
  // is in |*out|. Note that, even if |*ou| is already non-NULL on entry, it will
  // not be written to. Rather, a fresh |DSA| is allocated and the previous one is
  // freed. On successful exit, |*inp| is advanced past the DER structure. It
  // returns the result or NULL on error.
  //
  // Use |DSA_parse_public_key| instead.
  OPENSSL_EXPORT DSA *d2i_DSAPublicKey(DSA **out, const uint8_t **inp, long len);
  
  // i2d_DSAPublicKey marshals a public key from |in| to an ASN.1, DER structure.
  // If |outp| is not NULL then the result is written to |*outp| and |*outp| is
  // advanced just past the output. It returns the number of bytes in the result,
  // whether written or not, or a negative value on error.
  //
  // Use |DSA_marshal_public_key| instead.
  OPENSSL_EXPORT int i2d_DSAPublicKey(const DSA *in, uint8_t **outp);
  
  // d2i_DSAPrivateKey parses an ASN.1, DER-encoded, DSA private key from |len|
  // bytes at |*inp|. If |out| is not NULL then, on exit, a pointer to the result
  // is in |*out|. Note that, even if |*out| is already non-NULL on entry, it will
  // not be written to. Rather, a fresh |DSA| is allocated and the previous one is
  // freed. On successful exit, |*inp| is advanced past the DER structure. It
  // returns the result or NULL on error.
  //
  // Use |DSA_parse_private_key| instead.
  OPENSSL_EXPORT DSA *d2i_DSAPrivateKey(DSA **out, const uint8_t **inp, long len);
  
  // i2d_DSAPrivateKey marshals a private key from |in| to an ASN.1, DER
  // structure. If |outp| is not NULL then the result is written to |*outp| and
  // |*outp| is advanced just past the output. It returns the number of bytes in
  // the result, whether written or not, or a negative value on error.
  //
  // Use |DSA_marshal_private_key| instead.
  OPENSSL_EXPORT int i2d_DSAPrivateKey(const DSA *in, uint8_t **outp);
  
  // d2i_DSAparams parses ASN.1, DER-encoded, DSA parameters from |len| bytes at
  // |*inp|. If |out| is not NULL then, on exit, a pointer to the result is in
  // |*out|. Note that, even if |*out| is already non-NULL on entry, it will not
  // be written to. Rather, a fresh |DSA| is allocated and the previous one is
  // freed. On successful exit, |*inp| is advanced past the DER structure. It
  // returns the result or NULL on error.
  //
  // Use |DSA_parse_parameters| instead.
  OPENSSL_EXPORT DSA *d2i_DSAparams(DSA **out, const uint8_t **inp, long len);
  
  // i2d_DSAparams marshals DSA parameters from |in| to an ASN.1, DER structure.
  // If |outp| is not NULL then the result is written to |*outp| and |*outp| is
  // advanced just past the output. It returns the number of bytes in the result,
  // whether written or not, or a negative value on error.
  //
  // Use |DSA_marshal_parameters| instead.
  OPENSSL_EXPORT int i2d_DSAparams(const DSA *in, uint8_t **outp);
  
  // DSA_generate_parameters is a deprecated version of
  // |DSA_generate_parameters_ex| that creates and returns a |DSA*|. Don't use
  // it.
  OPENSSL_EXPORT DSA *DSA_generate_parameters(int bits, unsigned char *seed,
                                              int seed_len, int *counter_ret,
                                              unsigned long *h_ret,
                                              void (*callback)(int, int, void *),
                                              void *cb_arg);
  
  
  struct dsa_st {
    long version;
    BIGNUM *p;
    BIGNUM *q;  // == 20
    BIGNUM *g;
  
    BIGNUM *pub_key;   // y public key
    BIGNUM *priv_key;  // x private key
  
    int flags;
    // Normally used to cache montgomery values
    CRYPTO_MUTEX method_mont_lock;
    BN_MONT_CTX *method_mont_p;
    BN_MONT_CTX *method_mont_q;
    CRYPTO_refcount_t references;
    CRYPTO_EX_DATA ex_data;
  };
  
  
  #if defined(__cplusplus)
  }  // extern C
  
  extern "C++" {
  
  BSSL_NAMESPACE_BEGIN
  
  BORINGSSL_MAKE_DELETER(DSA, DSA_free)
  BORINGSSL_MAKE_UP_REF(DSA, DSA_up_ref)
  BORINGSSL_MAKE_DELETER(DSA_SIG, DSA_SIG_free)
  
  BSSL_NAMESPACE_END
  
  }  // extern C++
  
  #endif
  
  #define DSA_R_BAD_Q_VALUE 100
  #define DSA_R_MISSING_PARAMETERS 101
  #define DSA_R_MODULUS_TOO_LARGE 102
  #define DSA_R_NEED_NEW_SETUP_VALUES 103
  #define DSA_R_BAD_VERSION 104
  #define DSA_R_DECODE_ERROR 105
  #define DSA_R_ENCODE_ERROR 106
  #define DSA_R_INVALID_PARAMETERS 107
  
  #endif  // OPENSSL_HEADER_DSA_H
  