providers/implementations/signature/ecdsa.c - third_party/openssl - Git at Google

 /*
  * Copyright 2020 The OpenSSL Project Authors. All Rights Reserved.
  *
  * Licensed under the Apache License 2.0 (the "License").  You may not use
  * this file except in compliance with the License.  You can obtain a copy
  * in the file LICENSE in the source distribution or at
  * https://www.openssl.org/source/license.html
  */

 /*
  * ECDSA low level APIs are deprecated for public use, but still ok for
  * internal use.
  */
 #include "internal/deprecated.h"

 #include <string.h> /* memcpy */
 #include <openssl/crypto.h>
 #include <openssl/core_dispatch.h>
 #include <openssl/core_names.h>
 #include <openssl/dsa.h>
 #include <openssl/params.h>
 #include <openssl/evp.h>
 #include <openssl/err.h>
 #include "internal/nelem.h"
 #include "internal/sizes.h"
 #include "internal/cryptlib.h"
 #include "prov/providercommon.h"
 #include "prov/providercommonerr.h"
 #include "prov/implementations.h"
 #include "prov/provider_ctx.h"
 #include "prov/securitycheck.h"
 #include "crypto/ec.h"
 #include "prov/der_ec.h"

 static OSSL_FUNC_signature_newctx_fn ecdsa_newctx;
 static OSSL_FUNC_signature_sign_init_fn ecdsa_sign_init;
 static OSSL_FUNC_signature_verify_init_fn ecdsa_verify_init;
 static OSSL_FUNC_signature_sign_fn ecdsa_sign;
 static OSSL_FUNC_signature_verify_fn ecdsa_verify;
 static OSSL_FUNC_signature_digest_sign_init_fn ecdsa_digest_sign_init;
 static OSSL_FUNC_signature_digest_sign_update_fn ecdsa_digest_signverify_update;
 static OSSL_FUNC_signature_digest_sign_final_fn ecdsa_digest_sign_final;
 static OSSL_FUNC_signature_digest_verify_init_fn ecdsa_digest_verify_init;
 static OSSL_FUNC_signature_digest_verify_update_fn ecdsa_digest_signverify_update;
 static OSSL_FUNC_signature_digest_verify_final_fn ecdsa_digest_verify_final;
 static OSSL_FUNC_signature_freectx_fn ecdsa_freectx;
 static OSSL_FUNC_signature_dupctx_fn ecdsa_dupctx;
 static OSSL_FUNC_signature_get_ctx_params_fn ecdsa_get_ctx_params;
 static OSSL_FUNC_signature_gettable_ctx_params_fn ecdsa_gettable_ctx_params;
 static OSSL_FUNC_signature_set_ctx_params_fn ecdsa_set_ctx_params;
 static OSSL_FUNC_signature_settable_ctx_params_fn ecdsa_settable_ctx_params;
 static OSSL_FUNC_signature_get_ctx_md_params_fn ecdsa_get_ctx_md_params;
 static OSSL_FUNC_signature_gettable_ctx_md_params_fn ecdsa_gettable_ctx_md_params;
 static OSSL_FUNC_signature_set_ctx_md_params_fn ecdsa_set_ctx_md_params;
 static OSSL_FUNC_signature_settable_ctx_md_params_fn ecdsa_settable_ctx_md_params;

 /*
  * What's passed as an actual key is defined by the KEYMGMT interface.
  * We happen to know that our KEYMGMT simply passes DSA structures, so
  * we use that here too.
  */

 typedef struct {
     OSSL_LIB_CTX *libctx;
     char *propq;
     EC_KEY *ec;
     char mdname[OSSL_MAX_NAME_SIZE];

     /* The Algorithm Identifier of the combined signature algorithm */
     unsigned char aid_buf[OSSL_MAX_ALGORITHM_ID_SIZE];
     unsigned char *aid;
     size_t  aid_len;
     size_t mdsize;
     int operation;

     EVP_MD *md;
     EVP_MD_CTX *mdctx;
     /*
      * Internally used to cache the results of calling the EC group
      * sign_setup() methods which are then passed to the sign operation.
      * This is used by CAVS failure tests to terminate a loop if the signature
      * is not valid.
      * This could of also been done with a simple flag.
      */
     BIGNUM *kinv;
     BIGNUM *r;
 #if !defined(OPENSSL_NO_ACVP_TESTS)
     /*
      * This indicates that KAT (CAVS) test is running. Externally an app will
      * override the random callback such that the generated private key and k
      * are known.
      * Normal operation will loop to choose a new k if the signature is not
      * valid - but for this mode of operation it forces a failure instead.
      */
     unsigned int kattest;
 #endif
 } PROV_ECDSA_CTX;

 static void *ecdsa_newctx(void *provctx, const char *propq)
 {
     PROV_ECDSA_CTX *ctx;

     if (!ossl_prov_is_running())
         return NULL;

     ctx = OPENSSL_zalloc(sizeof(PROV_ECDSA_CTX));
     if (ctx == NULL)
         return NULL;

     ctx->libctx = PROV_LIBCTX_OF(provctx);
     if (propq != NULL && (ctx->propq = OPENSSL_strdup(propq)) == NULL) {
         OPENSSL_free(ctx);
         ctx = NULL;
         ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE);
     }
     return ctx;
 }

 static int ecdsa_signverify_init(void *vctx, void *ec, int operation)
 {
     PROV_ECDSA_CTX *ctx = (PROV_ECDSA_CTX *)vctx;

     if (!ossl_prov_is_running()
             || ctx == NULL
             || ec == NULL
             || !EC_KEY_up_ref(ec))
         return 0;
     EC_KEY_free(ctx->ec);
     ctx->ec = ec;
     ctx->operation = operation;
     return ec_check_key(ec, operation == EVP_PKEY_OP_SIGN);
 }

 static int ecdsa_sign_init(void *vctx, void *ec)
 {
     return ecdsa_signverify_init(vctx, ec, EVP_PKEY_OP_SIGN);
 }

 static int ecdsa_verify_init(void *vctx, void *ec)
 {
     return ecdsa_signverify_init(vctx, ec, EVP_PKEY_OP_VERIFY);
 }

 static int ecdsa_sign(void *vctx, unsigned char *sig, size_t *siglen,
                       size_t sigsize, const unsigned char *tbs, size_t tbslen)
 {
     PROV_ECDSA_CTX *ctx = (PROV_ECDSA_CTX *)vctx;
     int ret;
     unsigned int sltmp;
     size_t ecsize = ECDSA_size(ctx->ec);

     if (!ossl_prov_is_running())
         return 0;

     if (sig == NULL) {
         *siglen = ecsize;
         return 1;
     }

 #if !defined(OPENSSL_NO_ACVP_TESTS)
     if (ctx->kattest && !ECDSA_sign_setup(ctx->ec, NULL, &ctx->kinv, &ctx->r))
         return 0;
 #endif

     if (sigsize < (size_t)ecsize)
         return 0;

     if (ctx->mdsize != 0 && tbslen != ctx->mdsize)
         return 0;

     ret = ECDSA_sign_ex(0, tbs, tbslen, sig, &sltmp, ctx->kinv, ctx->r, ctx->ec);
     if (ret <= 0)
         return 0;

     *siglen = sltmp;
     return 1;
 }

 static int ecdsa_verify(void *vctx, const unsigned char *sig, size_t siglen,
                         const unsigned char *tbs, size_t tbslen)
 {
     PROV_ECDSA_CTX *ctx = (PROV_ECDSA_CTX *)vctx;

     if (!ossl_prov_is_running() || (ctx->mdsize != 0 && tbslen != ctx->mdsize))
         return 0;

     return ECDSA_verify(0, tbs, tbslen, sig, siglen, ctx->ec);
 }

 static void free_md(PROV_ECDSA_CTX *ctx)
 {
     OPENSSL_free(ctx->propq);
     EVP_MD_CTX_free(ctx->mdctx);
     EVP_MD_free(ctx->md);
     ctx->propq = NULL;
     ctx->mdctx = NULL;
     ctx->md = NULL;
     ctx->mdsize = 0;
 }

 static int ecdsa_digest_signverify_init(void *vctx, const char *mdname,
                                         void *ec, int operation)
 {
     PROV_ECDSA_CTX *ctx = (PROV_ECDSA_CTX *)vctx;
     int md_nid = NID_undef;
     WPACKET pkt;
     int sha1_allowed = (ctx->operation != EVP_PKEY_OP_SIGN);

     if (!ossl_prov_is_running())
         return 0;

     free_md(ctx);

     if (!ecdsa_signverify_init(vctx, ec, operation))
         return 0;

     ctx->md = EVP_MD_fetch(ctx->libctx, mdname, ctx->propq);
     md_nid = digest_get_approved_nid_with_sha1(ctx->md, sha1_allowed);
     if (md_nid == NID_undef)
         goto error;

     ctx->mdsize = EVP_MD_size(ctx->md);
     ctx->mdctx = EVP_MD_CTX_new();
     if (ctx->mdctx == NULL)
         goto error;

     /*
      * TODO(3.0) Should we care about DER writing errors?
      * All it really means is that for some reason, there's no
      * AlgorithmIdentifier to be had, but the operation itself is
      * still valid, just as long as it's not used to construct
      * anything that needs an AlgorithmIdentifier.
      */
     ctx->aid_len = 0;
     if (WPACKET_init_der(&pkt, ctx->aid_buf, sizeof(ctx->aid_buf))
         && ossl_DER_w_algorithmIdentifier_ECDSA_with_MD(&pkt, -1, ctx->ec,
                                                         md_nid)
         && WPACKET_finish(&pkt)) {
         WPACKET_get_total_written(&pkt, &ctx->aid_len);
         ctx->aid = WPACKET_get_curr(&pkt);
     }
     WPACKET_cleanup(&pkt);

     if (!EVP_DigestInit_ex(ctx->mdctx, ctx->md, NULL))
         goto error;
     return 1;
 error:
     free_md(ctx);
     return 0;
 }

 static int ecdsa_digest_sign_init(void *vctx, const char *mdname, void *ec)
 {
     return ecdsa_digest_signverify_init(vctx, mdname, ec, EVP_PKEY_OP_SIGN);
 }

 static int ecdsa_digest_verify_init(void *vctx, const char *mdname, void *ec)
 {
     return ecdsa_digest_signverify_init(vctx, mdname, ec, EVP_PKEY_OP_VERIFY);
 }

 int ecdsa_digest_signverify_update(void *vctx, const unsigned char *data,
                                    size_t datalen)
 {
     PROV_ECDSA_CTX *ctx = (PROV_ECDSA_CTX *)vctx;

     if (ctx == NULL || ctx->mdctx == NULL)
         return 0;

     return EVP_DigestUpdate(ctx->mdctx, data, datalen);
 }

 int ecdsa_digest_sign_final(void *vctx, unsigned char *sig, size_t *siglen,
                             size_t sigsize)
 {
     PROV_ECDSA_CTX *ctx = (PROV_ECDSA_CTX *)vctx;
     unsigned char digest[EVP_MAX_MD_SIZE];
     unsigned int dlen = 0;

     if (!ossl_prov_is_running() || ctx == NULL || ctx->mdctx == NULL)
         return 0;

     /*
      * If sig is NULL then we're just finding out the sig size. Other fields
      * are ignored. Defer to ecdsa_sign.
      */
     if (sig != NULL) {
         /*
          * TODO(3.0): There is the possibility that some externally provided
          * digests exceed EVP_MAX_MD_SIZE. We should probably handle that somehow -
          * but that problem is much larger than just in DSA.
          */
         if (!EVP_DigestFinal_ex(ctx->mdctx, digest, &dlen))
             return 0;
     }

     return ecdsa_sign(vctx, sig, siglen, sigsize, digest, (size_t)dlen);
 }

 int ecdsa_digest_verify_final(void *vctx, const unsigned char *sig,
                               size_t siglen)
 {
     PROV_ECDSA_CTX *ctx = (PROV_ECDSA_CTX *)vctx;
     unsigned char digest[EVP_MAX_MD_SIZE];
     unsigned int dlen = 0;

     if (!ossl_prov_is_running() || ctx == NULL || ctx->mdctx == NULL)
         return 0;

     /*
      * TODO(3.0): There is the possibility that some externally provided
      * digests exceed EVP_MAX_MD_SIZE. We should probably handle that somehow -
      * but that problem is much larger than just in DSA.
      */
     if (!EVP_DigestFinal_ex(ctx->mdctx, digest, &dlen))
         return 0;

     return ecdsa_verify(ctx, sig, siglen, digest, (size_t)dlen);
 }

 static void ecdsa_freectx(void *vctx)
 {
     PROV_ECDSA_CTX *ctx = (PROV_ECDSA_CTX *)vctx;

     free_md(ctx);
     EC_KEY_free(ctx->ec);
     BN_clear_free(ctx->kinv);
     BN_clear_free(ctx->r);
     OPENSSL_free(ctx);
 }

 static void *ecdsa_dupctx(void *vctx)
 {
     PROV_ECDSA_CTX *srcctx = (PROV_ECDSA_CTX *)vctx;
     PROV_ECDSA_CTX *dstctx;

     if (!ossl_prov_is_running())
         return NULL;

     dstctx = OPENSSL_zalloc(sizeof(*srcctx));
     if (dstctx == NULL)
         return NULL;

     *dstctx = *srcctx;
     dstctx->ec = NULL;
     dstctx->md = NULL;
     dstctx->mdctx = NULL;

     if (srcctx->ec != NULL && !EC_KEY_up_ref(srcctx->ec))
         goto err;
     /* Test KATS should not need to be supported */
     if (srcctx->kinv != NULL || srcctx->r != NULL)
         goto err;
     dstctx->ec = srcctx->ec;

     if (srcctx->md != NULL && !EVP_MD_up_ref(srcctx->md))
         goto err;
     dstctx->md = srcctx->md;

     if (srcctx->mdctx != NULL) {
         dstctx->mdctx = EVP_MD_CTX_new();
         if (dstctx->mdctx == NULL
                 || !EVP_MD_CTX_copy_ex(dstctx->mdctx, srcctx->mdctx))
             goto err;
     }

     return dstctx;
  err:
     ecdsa_freectx(dstctx);
     return NULL;
 }

 static int ecdsa_get_ctx_params(void *vctx, OSSL_PARAM *params)
 {
     PROV_ECDSA_CTX *ctx = (PROV_ECDSA_CTX *)vctx;
     OSSL_PARAM *p;

     if (ctx == NULL || params == NULL)
         return 0;

     p = OSSL_PARAM_locate(params, OSSL_SIGNATURE_PARAM_ALGORITHM_ID);
     if (p != NULL && !OSSL_PARAM_set_octet_string(p, ctx->aid, ctx->aid_len))
         return 0;

     p = OSSL_PARAM_locate(params, OSSL_SIGNATURE_PARAM_DIGEST_SIZE);
     if (p != NULL && !OSSL_PARAM_set_size_t(p, ctx->mdsize))
         return 0;

     p = OSSL_PARAM_locate(params, OSSL_SIGNATURE_PARAM_DIGEST);
     if (p != NULL && !OSSL_PARAM_set_utf8_string(p, ctx->md == NULL
                                                     ? ctx->mdname
                                                     : EVP_MD_name(ctx->md)))
         return 0;

     return 1;
 }

 static const OSSL_PARAM known_gettable_ctx_params[] = {
     OSSL_PARAM_octet_string(OSSL_SIGNATURE_PARAM_ALGORITHM_ID, NULL, 0),
     OSSL_PARAM_size_t(OSSL_SIGNATURE_PARAM_DIGEST_SIZE, NULL),
     OSSL_PARAM_utf8_string(OSSL_SIGNATURE_PARAM_DIGEST, NULL, 0),
     OSSL_PARAM_END
 };

 static const OSSL_PARAM *ecdsa_gettable_ctx_params(ossl_unused void *provctx)
 {
     return known_gettable_ctx_params;
 }

 static int ecdsa_set_ctx_params(void *vctx, const OSSL_PARAM params[])
 {
     PROV_ECDSA_CTX *ctx = (PROV_ECDSA_CTX *)vctx;
     const OSSL_PARAM *p;
     char *mdname;

     if (ctx == NULL || params == NULL)
         return 0;

     if (ctx->md != NULL) {
         /*
          * You cannot set the digest name/size when doing a DigestSign or
          * DigestVerify.
          */
         return 1;
     }
 #if !defined(OPENSSL_NO_ACVP_TESTS)
     p = OSSL_PARAM_locate_const(params, OSSL_SIGNATURE_PARAM_KAT);
     if (p != NULL && !OSSL_PARAM_get_uint(p, &ctx->kattest))
         return 0;
 #endif

     p = OSSL_PARAM_locate_const(params, OSSL_SIGNATURE_PARAM_DIGEST_SIZE);
     if (p != NULL && !OSSL_PARAM_get_size_t(p, &ctx->mdsize))
         return 0;

     /*
      * We never actually use the mdname, but we do support getting it later.
      * This can be useful for applications that want to know the MD that they
      * previously set.
      */
     p = OSSL_PARAM_locate_const(params, OSSL_SIGNATURE_PARAM_DIGEST);
     mdname = ctx->mdname;
     if (p != NULL
             && !OSSL_PARAM_get_utf8_string(p, &mdname, sizeof(ctx->mdname)))
         return 0;

     return 1;
 }

 static const OSSL_PARAM known_settable_ctx_params[] = {
     OSSL_PARAM_size_t(OSSL_SIGNATURE_PARAM_DIGEST_SIZE, NULL),
     OSSL_PARAM_utf8_string(OSSL_SIGNATURE_PARAM_DIGEST, NULL, 0),
     OSSL_PARAM_uint(OSSL_SIGNATURE_PARAM_KAT, NULL),
     OSSL_PARAM_END
 };

 static const OSSL_PARAM *ecdsa_settable_ctx_params(ossl_unused void *provctx)
 {
     /*
      * TODO(3.0): Should this function return a different set of settable ctx
      * params if the ctx is being used for a DigestSign/DigestVerify? In that
      * case it is not allowed to set the digest size/digest name because the
      * digest is explicitly set as part of the init.
      */
     return known_settable_ctx_params;
 }

 static int ecdsa_get_ctx_md_params(void *vctx, OSSL_PARAM *params)
 {
     PROV_ECDSA_CTX *ctx = (PROV_ECDSA_CTX *)vctx;

     if (ctx->mdctx == NULL)
         return 0;

     return EVP_MD_CTX_get_params(ctx->mdctx, params);
 }

 static const OSSL_PARAM *ecdsa_gettable_ctx_md_params(void *vctx)
 {
     PROV_ECDSA_CTX *ctx = (PROV_ECDSA_CTX *)vctx;

     if (ctx->md == NULL)
         return 0;

     return EVP_MD_gettable_ctx_params(ctx->md);
 }

 static int ecdsa_set_ctx_md_params(void *vctx, const OSSL_PARAM params[])
 {
     PROV_ECDSA_CTX *ctx = (PROV_ECDSA_CTX *)vctx;

     if (ctx->mdctx == NULL)
         return 0;

     return EVP_MD_CTX_set_params(ctx->mdctx, params);
 }

 static const OSSL_PARAM *ecdsa_settable_ctx_md_params(void *vctx)
 {
     PROV_ECDSA_CTX *ctx = (PROV_ECDSA_CTX *)vctx;

     if (ctx->md == NULL)
         return 0;

     return EVP_MD_settable_ctx_params(ctx->md);
 }

 const OSSL_DISPATCH ecossl_dsa_signature_functions[] = {
     { OSSL_FUNC_SIGNATURE_NEWCTX, (void (*)(void))ecdsa_newctx },
     { OSSL_FUNC_SIGNATURE_SIGN_INIT, (void (*)(void))ecdsa_sign_init },
     { OSSL_FUNC_SIGNATURE_SIGN, (void (*)(void))ecdsa_sign },
     { OSSL_FUNC_SIGNATURE_VERIFY_INIT, (void (*)(void))ecdsa_verify_init },
     { OSSL_FUNC_SIGNATURE_VERIFY, (void (*)(void))ecdsa_verify },
     { OSSL_FUNC_SIGNATURE_DIGEST_SIGN_INIT,
       (void (*)(void))ecdsa_digest_sign_init },
     { OSSL_FUNC_SIGNATURE_DIGEST_SIGN_UPDATE,
       (void (*)(void))ecdsa_digest_signverify_update },
     { OSSL_FUNC_SIGNATURE_DIGEST_SIGN_FINAL,
       (void (*)(void))ecdsa_digest_sign_final },
     { OSSL_FUNC_SIGNATURE_DIGEST_VERIFY_INIT,
       (void (*)(void))ecdsa_digest_verify_init },
     { OSSL_FUNC_SIGNATURE_DIGEST_VERIFY_UPDATE,
       (void (*)(void))ecdsa_digest_signverify_update },
     { OSSL_FUNC_SIGNATURE_DIGEST_VERIFY_FINAL,
       (void (*)(void))ecdsa_digest_verify_final },
     { OSSL_FUNC_SIGNATURE_FREECTX, (void (*)(void))ecdsa_freectx },
     { OSSL_FUNC_SIGNATURE_DUPCTX, (void (*)(void))ecdsa_dupctx },
     { OSSL_FUNC_SIGNATURE_GET_CTX_PARAMS, (void (*)(void))ecdsa_get_ctx_params },
     { OSSL_FUNC_SIGNATURE_GETTABLE_CTX_PARAMS,
       (void (*)(void))ecdsa_gettable_ctx_params },
     { OSSL_FUNC_SIGNATURE_SET_CTX_PARAMS, (void (*)(void))ecdsa_set_ctx_params },
     { OSSL_FUNC_SIGNATURE_SETTABLE_CTX_PARAMS,
       (void (*)(void))ecdsa_settable_ctx_params },
     { OSSL_FUNC_SIGNATURE_GET_CTX_MD_PARAMS,
       (void (*)(void))ecdsa_get_ctx_md_params },
     { OSSL_FUNC_SIGNATURE_GETTABLE_CTX_MD_PARAMS,
       (void (*)(void))ecdsa_gettable_ctx_md_params },
     { OSSL_FUNC_SIGNATURE_SET_CTX_MD_PARAMS,
       (void (*)(void))ecdsa_set_ctx_md_params },
     { OSSL_FUNC_SIGNATURE_SETTABLE_CTX_MD_PARAMS,
       (void (*)(void))ecdsa_settable_ctx_md_params },
     { 0, NULL }
 };
	/*
	* Copyright 2020 The OpenSSL Project Authors. All Rights Reserved.
	*
	* Licensed under the Apache License 2.0 (the "License"). You may not use
	* this file except in compliance with the License. You can obtain a copy
	* in the file LICENSE in the source distribution or at
	* https://www.openssl.org/source/license.html
	*/

	/*
	* ECDSA low level APIs are deprecated for public use, but still ok for
	* internal use.
	*/
	#include "internal/deprecated.h"

	#include <string.h> /* memcpy */
	#include <openssl/crypto.h>
	#include <openssl/core_dispatch.h>
	#include <openssl/core_names.h>
	#include <openssl/dsa.h>
	#include <openssl/params.h>
	#include <openssl/evp.h>
	#include <openssl/err.h>
	#include "internal/nelem.h"
	#include "internal/sizes.h"
	#include "internal/cryptlib.h"
	#include "prov/providercommon.h"
	#include "prov/providercommonerr.h"
	#include "prov/implementations.h"
	#include "prov/provider_ctx.h"
	#include "prov/securitycheck.h"
	#include "crypto/ec.h"
	#include "prov/der_ec.h"

	static OSSL_FUNC_signature_newctx_fn ecdsa_newctx;
	static OSSL_FUNC_signature_sign_init_fn ecdsa_sign_init;
	static OSSL_FUNC_signature_verify_init_fn ecdsa_verify_init;
	static OSSL_FUNC_signature_sign_fn ecdsa_sign;
	static OSSL_FUNC_signature_verify_fn ecdsa_verify;
	static OSSL_FUNC_signature_digest_sign_init_fn ecdsa_digest_sign_init;
	static OSSL_FUNC_signature_digest_sign_update_fn ecdsa_digest_signverify_update;
	static OSSL_FUNC_signature_digest_sign_final_fn ecdsa_digest_sign_final;
	static OSSL_FUNC_signature_digest_verify_init_fn ecdsa_digest_verify_init;
	static OSSL_FUNC_signature_digest_verify_update_fn ecdsa_digest_signverify_update;
	static OSSL_FUNC_signature_digest_verify_final_fn ecdsa_digest_verify_final;
	static OSSL_FUNC_signature_freectx_fn ecdsa_freectx;
	static OSSL_FUNC_signature_dupctx_fn ecdsa_dupctx;
	static OSSL_FUNC_signature_get_ctx_params_fn ecdsa_get_ctx_params;
	static OSSL_FUNC_signature_gettable_ctx_params_fn ecdsa_gettable_ctx_params;
	static OSSL_FUNC_signature_set_ctx_params_fn ecdsa_set_ctx_params;
	static OSSL_FUNC_signature_settable_ctx_params_fn ecdsa_settable_ctx_params;
	static OSSL_FUNC_signature_get_ctx_md_params_fn ecdsa_get_ctx_md_params;
	static OSSL_FUNC_signature_gettable_ctx_md_params_fn ecdsa_gettable_ctx_md_params;
	static OSSL_FUNC_signature_set_ctx_md_params_fn ecdsa_set_ctx_md_params;
	static OSSL_FUNC_signature_settable_ctx_md_params_fn ecdsa_settable_ctx_md_params;

	/*
	* What's passed as an actual key is defined by the KEYMGMT interface.
	* We happen to know that our KEYMGMT simply passes DSA structures, so
	* we use that here too.
	*/

	typedef struct {
	OSSL_LIB_CTX *libctx;
	char *propq;
	EC_KEY *ec;
	char mdname[OSSL_MAX_NAME_SIZE];

	/* The Algorithm Identifier of the combined signature algorithm */
	unsigned char aid_buf[OSSL_MAX_ALGORITHM_ID_SIZE];
	unsigned char *aid;
	size_t aid_len;
	size_t mdsize;
	int operation;

	EVP_MD *md;
	EVP_MD_CTX *mdctx;
	/*
	* Internally used to cache the results of calling the EC group
	* sign_setup() methods which are then passed to the sign operation.
	* This is used by CAVS failure tests to terminate a loop if the signature
	* is not valid.
	* This could of also been done with a simple flag.
	*/
	BIGNUM *kinv;
	BIGNUM *r;
	#if !defined(OPENSSL_NO_ACVP_TESTS)
	/*
	* This indicates that KAT (CAVS) test is running. Externally an app will
	* override the random callback such that the generated private key and k
	* are known.
	* Normal operation will loop to choose a new k if the signature is not
	* valid - but for this mode of operation it forces a failure instead.
	*/
	unsigned int kattest;
	#endif
	} PROV_ECDSA_CTX;

	static void ecdsa_newctx(void provctx, const char *propq)
	{
	PROV_ECDSA_CTX *ctx;

	if (!ossl_prov_is_running())
	return NULL;

	ctx = OPENSSL_zalloc(sizeof(PROV_ECDSA_CTX));
	if (ctx == NULL)
	return NULL;

	ctx->libctx = PROV_LIBCTX_OF(provctx);
	if (propq != NULL && (ctx->propq = OPENSSL_strdup(propq)) == NULL) {
	OPENSSL_free(ctx);
	ctx = NULL;
	ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE);
	}
	return ctx;
	}

	static int ecdsa_signverify_init(void vctx, void ec, int operation)
	{
	PROV_ECDSA_CTX ctx = (PROV_ECDSA_CTX )vctx;

	if (!ossl_prov_is_running()
	\|\| ctx == NULL
	\|\| ec == NULL
	\|\| !EC_KEY_up_ref(ec))
	return 0;
	EC_KEY_free(ctx->ec);
	ctx->ec = ec;
	ctx->operation = operation;
	return ec_check_key(ec, operation == EVP_PKEY_OP_SIGN);
	}

	static int ecdsa_sign_init(void vctx, void ec)
	{
	return ecdsa_signverify_init(vctx, ec, EVP_PKEY_OP_SIGN);
	}

	static int ecdsa_verify_init(void vctx, void ec)
	{
	return ecdsa_signverify_init(vctx, ec, EVP_PKEY_OP_VERIFY);
	}

	static int ecdsa_sign(void vctx, unsigned char sig, size_t *siglen,
	size_t sigsize, const unsigned char *tbs, size_t tbslen)
	{
	PROV_ECDSA_CTX ctx = (PROV_ECDSA_CTX )vctx;
	int ret;
	unsigned int sltmp;
	size_t ecsize = ECDSA_size(ctx->ec);

	if (!ossl_prov_is_running())
	return 0;

	if (sig == NULL) {
	*siglen = ecsize;
	return 1;
	}

	#if !defined(OPENSSL_NO_ACVP_TESTS)
	if (ctx->kattest && !ECDSA_sign_setup(ctx->ec, NULL, &ctx->kinv, &ctx->r))
	return 0;
	#endif

	if (sigsize < (size_t)ecsize)
	return 0;

	if (ctx->mdsize != 0 && tbslen != ctx->mdsize)
	return 0;

	ret = ECDSA_sign_ex(0, tbs, tbslen, sig, &sltmp, ctx->kinv, ctx->r, ctx->ec);
	if (ret <= 0)
	return 0;

	*siglen = sltmp;
	return 1;
	}

	static int ecdsa_verify(void vctx, const unsigned char sig, size_t siglen,
	const unsigned char *tbs, size_t tbslen)
	{
	PROV_ECDSA_CTX ctx = (PROV_ECDSA_CTX )vctx;

	if (!ossl_prov_is_running() \|\| (ctx->mdsize != 0 && tbslen != ctx->mdsize))
	return 0;

	return ECDSA_verify(0, tbs, tbslen, sig, siglen, ctx->ec);
	}

	static void free_md(PROV_ECDSA_CTX *ctx)
	{
	OPENSSL_free(ctx->propq);
	EVP_MD_CTX_free(ctx->mdctx);
	EVP_MD_free(ctx->md);
	ctx->propq = NULL;
	ctx->mdctx = NULL;
	ctx->md = NULL;
	ctx->mdsize = 0;
	}

	static int ecdsa_digest_signverify_init(void vctx, const char mdname,
	void *ec, int operation)
	{
	PROV_ECDSA_CTX ctx = (PROV_ECDSA_CTX )vctx;
	int md_nid = NID_undef;
	WPACKET pkt;
	int sha1_allowed = (ctx->operation != EVP_PKEY_OP_SIGN);

	if (!ossl_prov_is_running())
	return 0;

	free_md(ctx);

	if (!ecdsa_signverify_init(vctx, ec, operation))
	return 0;

	ctx->md = EVP_MD_fetch(ctx->libctx, mdname, ctx->propq);
	md_nid = digest_get_approved_nid_with_sha1(ctx->md, sha1_allowed);
	if (md_nid == NID_undef)
	goto error;

	ctx->mdsize = EVP_MD_size(ctx->md);
	ctx->mdctx = EVP_MD_CTX_new();
	if (ctx->mdctx == NULL)
	goto error;

	/*
	* TODO(3.0) Should we care about DER writing errors?
	* All it really means is that for some reason, there's no
	* AlgorithmIdentifier to be had, but the operation itself is
	* still valid, just as long as it's not used to construct
	* anything that needs an AlgorithmIdentifier.
	*/
	ctx->aid_len = 0;
	if (WPACKET_init_der(&pkt, ctx->aid_buf, sizeof(ctx->aid_buf))
	&& ossl_DER_w_algorithmIdentifier_ECDSA_with_MD(&pkt, -1, ctx->ec,
	md_nid)
	&& WPACKET_finish(&pkt)) {
	WPACKET_get_total_written(&pkt, &ctx->aid_len);
	ctx->aid = WPACKET_get_curr(&pkt);
	}
	WPACKET_cleanup(&pkt);

	if (!EVP_DigestInit_ex(ctx->mdctx, ctx->md, NULL))
	goto error;
	return 1;
	error:
	free_md(ctx);
	return 0;
	}

	static int ecdsa_digest_sign_init(void vctx, const char mdname, void *ec)
	{
	return ecdsa_digest_signverify_init(vctx, mdname, ec, EVP_PKEY_OP_SIGN);
	}

	static int ecdsa_digest_verify_init(void vctx, const char mdname, void *ec)
	{
	return ecdsa_digest_signverify_init(vctx, mdname, ec, EVP_PKEY_OP_VERIFY);
	}

	int ecdsa_digest_signverify_update(void vctx, const unsigned char data,
	size_t datalen)
	{
	PROV_ECDSA_CTX ctx = (PROV_ECDSA_CTX )vctx;

	if (ctx == NULL \|\| ctx->mdctx == NULL)
	return 0;

	return EVP_DigestUpdate(ctx->mdctx, data, datalen);
	}

	int ecdsa_digest_sign_final(void vctx, unsigned char sig, size_t *siglen,
	size_t sigsize)
	{
	PROV_ECDSA_CTX ctx = (PROV_ECDSA_CTX )vctx;
	unsigned char digest[EVP_MAX_MD_SIZE];
	unsigned int dlen = 0;

	if (!ossl_prov_is_running() \|\| ctx == NULL \|\| ctx->mdctx == NULL)
	return 0;

	/*
	* If sig is NULL then we're just finding out the sig size. Other fields
	* are ignored. Defer to ecdsa_sign.
	*/
	if (sig != NULL) {
	/*
	* TODO(3.0): There is the possibility that some externally provided
	* digests exceed EVP_MAX_MD_SIZE. We should probably handle that somehow -
	* but that problem is much larger than just in DSA.
	*/
	if (!EVP_DigestFinal_ex(ctx->mdctx, digest, &dlen))
	return 0;
	}

	return ecdsa_sign(vctx, sig, siglen, sigsize, digest, (size_t)dlen);
	}

	int ecdsa_digest_verify_final(void vctx, const unsigned char sig,
	size_t siglen)
	{
	PROV_ECDSA_CTX ctx = (PROV_ECDSA_CTX )vctx;
	unsigned char digest[EVP_MAX_MD_SIZE];
	unsigned int dlen = 0;

	if (!ossl_prov_is_running() \|\| ctx == NULL \|\| ctx->mdctx == NULL)
	return 0;

	/*
	* TODO(3.0): There is the possibility that some externally provided
	* digests exceed EVP_MAX_MD_SIZE. We should probably handle that somehow -
	* but that problem is much larger than just in DSA.
	*/
	if (!EVP_DigestFinal_ex(ctx->mdctx, digest, &dlen))
	return 0;

	return ecdsa_verify(ctx, sig, siglen, digest, (size_t)dlen);
	}

	static void ecdsa_freectx(void *vctx)
	{
	PROV_ECDSA_CTX ctx = (PROV_ECDSA_CTX )vctx;

	free_md(ctx);
	EC_KEY_free(ctx->ec);
	BN_clear_free(ctx->kinv);
	BN_clear_free(ctx->r);
	OPENSSL_free(ctx);
	}

	static void ecdsa_dupctx(void vctx)
	{
	PROV_ECDSA_CTX srcctx = (PROV_ECDSA_CTX )vctx;
	PROV_ECDSA_CTX *dstctx;

	if (!ossl_prov_is_running())
	return NULL;

	dstctx = OPENSSL_zalloc(sizeof(*srcctx));
	if (dstctx == NULL)
	return NULL;

	dstctx = srcctx;
	dstctx->ec = NULL;
	dstctx->md = NULL;
	dstctx->mdctx = NULL;

	if (srcctx->ec != NULL && !EC_KEY_up_ref(srcctx->ec))
	goto err;
	/* Test KATS should not need to be supported */
	if (srcctx->kinv != NULL \|\| srcctx->r != NULL)
	goto err;
	dstctx->ec = srcctx->ec;

	if (srcctx->md != NULL && !EVP_MD_up_ref(srcctx->md))
	goto err;
	dstctx->md = srcctx->md;

	if (srcctx->mdctx != NULL) {
	dstctx->mdctx = EVP_MD_CTX_new();
	if (dstctx->mdctx == NULL
	\|\| !EVP_MD_CTX_copy_ex(dstctx->mdctx, srcctx->mdctx))
	goto err;
	}

	return dstctx;
	err:
	ecdsa_freectx(dstctx);
	return NULL;
	}

	static int ecdsa_get_ctx_params(void vctx, OSSL_PARAM params)
	{
	PROV_ECDSA_CTX ctx = (PROV_ECDSA_CTX )vctx;
	OSSL_PARAM *p;

	if (ctx == NULL \|\| params == NULL)
	return 0;

	p = OSSL_PARAM_locate(params, OSSL_SIGNATURE_PARAM_ALGORITHM_ID);
	if (p != NULL && !OSSL_PARAM_set_octet_string(p, ctx->aid, ctx->aid_len))
	return 0;

	p = OSSL_PARAM_locate(params, OSSL_SIGNATURE_PARAM_DIGEST_SIZE);
	if (p != NULL && !OSSL_PARAM_set_size_t(p, ctx->mdsize))
	return 0;

	p = OSSL_PARAM_locate(params, OSSL_SIGNATURE_PARAM_DIGEST);
	if (p != NULL && !OSSL_PARAM_set_utf8_string(p, ctx->md == NULL
	? ctx->mdname
	: EVP_MD_name(ctx->md)))
	return 0;

	return 1;
	}

	static const OSSL_PARAM known_gettable_ctx_params[] = {
	OSSL_PARAM_octet_string(OSSL_SIGNATURE_PARAM_ALGORITHM_ID, NULL, 0),
	OSSL_PARAM_size_t(OSSL_SIGNATURE_PARAM_DIGEST_SIZE, NULL),
	OSSL_PARAM_utf8_string(OSSL_SIGNATURE_PARAM_DIGEST, NULL, 0),
	OSSL_PARAM_END
	};

	static const OSSL_PARAM ecdsa_gettable_ctx_params(ossl_unused void provctx)
	{
	return known_gettable_ctx_params;
	}

	static int ecdsa_set_ctx_params(void *vctx, const OSSL_PARAM params[])
	{
	PROV_ECDSA_CTX ctx = (PROV_ECDSA_CTX )vctx;
	const OSSL_PARAM *p;
	char *mdname;

	if (ctx == NULL \|\| params == NULL)
	return 0;

	if (ctx->md != NULL) {
	/*
	* You cannot set the digest name/size when doing a DigestSign or
	* DigestVerify.
	*/
	return 1;
	}
	#if !defined(OPENSSL_NO_ACVP_TESTS)
	p = OSSL_PARAM_locate_const(params, OSSL_SIGNATURE_PARAM_KAT);
	if (p != NULL && !OSSL_PARAM_get_uint(p, &ctx->kattest))
	return 0;
	#endif

	p = OSSL_PARAM_locate_const(params, OSSL_SIGNATURE_PARAM_DIGEST_SIZE);
	if (p != NULL && !OSSL_PARAM_get_size_t(p, &ctx->mdsize))
	return 0;

	/*
	* We never actually use the mdname, but we do support getting it later.
	* This can be useful for applications that want to know the MD that they
	* previously set.
	*/
	p = OSSL_PARAM_locate_const(params, OSSL_SIGNATURE_PARAM_DIGEST);
	mdname = ctx->mdname;
	if (p != NULL
	&& !OSSL_PARAM_get_utf8_string(p, &mdname, sizeof(ctx->mdname)))
	return 0;

	return 1;
	}

	static const OSSL_PARAM known_settable_ctx_params[] = {
	OSSL_PARAM_size_t(OSSL_SIGNATURE_PARAM_DIGEST_SIZE, NULL),
	OSSL_PARAM_utf8_string(OSSL_SIGNATURE_PARAM_DIGEST, NULL, 0),
	OSSL_PARAM_uint(OSSL_SIGNATURE_PARAM_KAT, NULL),
	OSSL_PARAM_END
	};

	static const OSSL_PARAM ecdsa_settable_ctx_params(ossl_unused void provctx)
	{
	/*
	* TODO(3.0): Should this function return a different set of settable ctx
	* params if the ctx is being used for a DigestSign/DigestVerify? In that
	* case it is not allowed to set the digest size/digest name because the
	* digest is explicitly set as part of the init.
	*/
	return known_settable_ctx_params;
	}

	static int ecdsa_get_ctx_md_params(void vctx, OSSL_PARAM params)
	{
	PROV_ECDSA_CTX ctx = (PROV_ECDSA_CTX )vctx;

	if (ctx->mdctx == NULL)
	return 0;

	return EVP_MD_CTX_get_params(ctx->mdctx, params);
	}

	static const OSSL_PARAM ecdsa_gettable_ctx_md_params(void vctx)
	{
	PROV_ECDSA_CTX ctx = (PROV_ECDSA_CTX )vctx;

	if (ctx->md == NULL)
	return 0;

	return EVP_MD_gettable_ctx_params(ctx->md);
	}

	static int ecdsa_set_ctx_md_params(void *vctx, const OSSL_PARAM params[])
	{
	PROV_ECDSA_CTX ctx = (PROV_ECDSA_CTX )vctx;

	if (ctx->mdctx == NULL)
	return 0;

	return EVP_MD_CTX_set_params(ctx->mdctx, params);
	}

	static const OSSL_PARAM ecdsa_settable_ctx_md_params(void vctx)
	{
	PROV_ECDSA_CTX ctx = (PROV_ECDSA_CTX )vctx;

	if (ctx->md == NULL)
	return 0;

	return EVP_MD_settable_ctx_params(ctx->md);
	}

	const OSSL_DISPATCH ecossl_dsa_signature_functions[] = {
	{ OSSL_FUNC_SIGNATURE_NEWCTX, (void (*)(void))ecdsa_newctx },
	{ OSSL_FUNC_SIGNATURE_SIGN_INIT, (void (*)(void))ecdsa_sign_init },
	{ OSSL_FUNC_SIGNATURE_SIGN, (void (*)(void))ecdsa_sign },
	{ OSSL_FUNC_SIGNATURE_VERIFY_INIT, (void (*)(void))ecdsa_verify_init },
	{ OSSL_FUNC_SIGNATURE_VERIFY, (void (*)(void))ecdsa_verify },
	{ OSSL_FUNC_SIGNATURE_DIGEST_SIGN_INIT,
	(void (*)(void))ecdsa_digest_sign_init },
	{ OSSL_FUNC_SIGNATURE_DIGEST_SIGN_UPDATE,
	(void (*)(void))ecdsa_digest_signverify_update },
	{ OSSL_FUNC_SIGNATURE_DIGEST_SIGN_FINAL,
	(void (*)(void))ecdsa_digest_sign_final },
	{ OSSL_FUNC_SIGNATURE_DIGEST_VERIFY_INIT,
	(void (*)(void))ecdsa_digest_verify_init },
	{ OSSL_FUNC_SIGNATURE_DIGEST_VERIFY_UPDATE,
	(void (*)(void))ecdsa_digest_signverify_update },
	{ OSSL_FUNC_SIGNATURE_DIGEST_VERIFY_FINAL,
	(void (*)(void))ecdsa_digest_verify_final },
	{ OSSL_FUNC_SIGNATURE_FREECTX, (void (*)(void))ecdsa_freectx },
	{ OSSL_FUNC_SIGNATURE_DUPCTX, (void (*)(void))ecdsa_dupctx },
	{ OSSL_FUNC_SIGNATURE_GET_CTX_PARAMS, (void (*)(void))ecdsa_get_ctx_params },
	{ OSSL_FUNC_SIGNATURE_GETTABLE_CTX_PARAMS,
	(void (*)(void))ecdsa_gettable_ctx_params },
	{ OSSL_FUNC_SIGNATURE_SET_CTX_PARAMS, (void (*)(void))ecdsa_set_ctx_params },
	{ OSSL_FUNC_SIGNATURE_SETTABLE_CTX_PARAMS,
	(void (*)(void))ecdsa_settable_ctx_params },
	{ OSSL_FUNC_SIGNATURE_GET_CTX_MD_PARAMS,
	(void (*)(void))ecdsa_get_ctx_md_params },
	{ OSSL_FUNC_SIGNATURE_GETTABLE_CTX_MD_PARAMS,
	(void (*)(void))ecdsa_gettable_ctx_md_params },
	{ OSSL_FUNC_SIGNATURE_SET_CTX_MD_PARAMS,
	(void (*)(void))ecdsa_set_ctx_md_params },
	{ OSSL_FUNC_SIGNATURE_SETTABLE_CTX_MD_PARAMS,
	(void (*)(void))ecdsa_settable_ctx_md_params },
	{ 0, NULL }
	};