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/* 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/base.h>
#include <openssl/engine.h>
#include <openssl/ex_data.h>
#include <openssl/thread.h>
#if defined(__cplusplus)
extern "C" {
#endif
/* DSA contains functions for signing and verifing with the Digital Signature
* Algorithm. */
/* 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|. */
OPENSSL_EXPORT int DSA_up_ref(DSA *dsa);
/* 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. */
typedef struct DSA_SIG_st {
BIGNUM *r, *s;
} DSA_SIG;
/* 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,
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,
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. */
/* 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|. If |*out_sig| is already non-NULL on entry then the result is
* written directly into |*out_sig|, otherwise a fresh |DSA_SIG| is allocated.
* However, one should not depend on writing into |*out_sig| because this
* behaviour is likely to change in the future. On successful exit, |*inp| is
* advanced past the DER structure. It returns the result or NULL on error. */
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. */
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|. If |*out| is already non-NULL on entry then the result is
* written directly into |*out|, otherwise a fresh |DSA| is allocated.
* However, one should not depend on writing into |*out| because this behaviour
* is likely to change in the future. On successful exit, |*inp| is advanced
* past the DER structure. It returns the result or NULL on error. */
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. */
OPENSSL_EXPORT int i2d_DSAPublicKey(const DSA *in, unsigned char **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|. If |*out| is already non-NULL on entry then the result is
* written directly into |*out|, otherwise a fresh |DSA| is allocated. However,
* one should not depend on writing into |*out| because this behaviour is
* likely to change in the future. On successful exit, |*inp| is advanced past
* the DER structure. It returns the result or NULL on error. */
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. */
OPENSSL_EXPORT int i2d_DSAPrivateKey(const DSA *in, unsigned char **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|. If |*out| is already non-NULL on entry then the result is written
* directly into |*out|, otherwise a fresh |DSA| is allocated. However, one
* should not depend on writing into |*out| because this behaviour is likely to
* change in the future. On successful exit, |*inp| is advanced past the DER
* structure. It returns the result or NULL on error. */
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. */
OPENSSL_EXPORT int i2d_DSAparams(const DSA *in, unsigned char **outp);
/* Precomputation. */
/* DSA_sign_setup precomputes the message independent part of the DSA signature
* and writes them to |*out_kinv| and |*out_r|. Returns one on success, zero on
* error.
*
* TODO(fork): decide what to do with this. Since making DSA* opaque there's no
* way for the user to install them. Also, it forces the DSA* not to be const
* when passing to the signing function. */
OPENSSL_EXPORT int DSA_sign_setup(const DSA *dsa, BN_CTX *ctx,
BIGNUM **out_kinv, BIGNUM **out_r);
/* 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_func,
CRYPTO_EX_free *free_func);
OPENSSL_EXPORT int DSA_set_ex_data(DSA *d, int idx, void *arg);
OPENSSL_EXPORT void *DSA_get_ex_data(const DSA *d, int idx);
struct dsa_st {
long version;
BIGNUM *p;
BIGNUM *q; /* == 20 */
BIGNUM *g;
BIGNUM *pub_key; /* y public key */
BIGNUM *priv_key; /* x private key */
BIGNUM *kinv; /* Signing pre-calc */
BIGNUM *r; /* Signing pre-calc */
int flags;
/* Normally used to cache montgomery values */
CRYPTO_MUTEX method_mont_p_lock;
BN_MONT_CTX *method_mont_p;
CRYPTO_refcount_t references;
CRYPTO_EX_DATA ex_data;
};
#if defined(__cplusplus)
} /* 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
#endif /* OPENSSL_HEADER_DSA_H */