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	diff --git a/g10/ecdh.c b/g10/ecdh.c
	index 6587cc4b4..661841686 100644
	--- a/g10/ecdh.c
	+++ b/g10/ecdh.c
	@@ -1,495 +1,475 @@
	/* ecdh.c - ECDH public key operations used in public key glue code
	* Copyright (C) 2010, 2011 Free Software Foundation, Inc.
	*
	* This file is part of GnuPG.
	*
	* GnuPG is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 3 of the License, or
	* (at your option) any later version.
	*
	* GnuPG is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, see <https://www.gnu.org/licenses/>.
	*/

	#include <config.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>
	#include <errno.h>

	#include "gpg.h"
	#include "../common/util.h"
	#include "pkglue.h"
	#include "main.h"
	#include "options.h"

	/* A table with the default KEK parameters used by GnuPG. */
	static const struct
	{
	unsigned int qbits;
	int openpgp_hash_id; /* KEK digest algorithm. */
	int openpgp_cipher_id; /* KEK cipher algorithm. */
	} kek_params_table[] =
	/* Note: Must be sorted by ascending values for QBITS. */
	{
	{ 256, DIGEST_ALGO_SHA256, CIPHER_ALGO_AES },
	{ 384, DIGEST_ALGO_SHA384, CIPHER_ALGO_AES256 },

	/* Note: 528 is 521 rounded to the 8 bit boundary */
	{ 528, DIGEST_ALGO_SHA512, CIPHER_ALGO_AES256 }
	};



	/* Return KEK parameters as an opaque MPI The caller must free the
	returned value. Returns NULL and sets ERRNO on error. */
	gcry_mpi_t
	pk_ecdh_default_params (unsigned int qbits)
	{
	byte *kek_params;
	int i;

	kek_params = xtrymalloc (4);
	if (!kek_params)
	return NULL;
	kek_params[0] = 3; /* Number of bytes to follow. */
	kek_params[1] = 1; /* Version for KDF+AESWRAP. */

	/* Search for matching KEK parameter. Defaults to the strongest
	possible choices. Performance is not an issue here, only
	interoperability. */
	for (i=0; i < DIM (kek_params_table); i++)
	{
	if (kek_params_table[i].qbits >= qbits
	\|\| i+1 == DIM (kek_params_table))
	{
	kek_params[2] = kek_params_table[i].openpgp_hash_id;
	kek_params[3] = kek_params_table[i].openpgp_cipher_id;
	break;
	}
	}
	log_assert (i < DIM (kek_params_table));
	if (DBG_CRYPTO)
	log_printhex (kek_params, sizeof(kek_params), "ECDH KEK params are");

	return gcry_mpi_set_opaque (NULL, kek_params, 4 * 8);
	}


	/* Encrypts/decrypts DATA using a key derived from the ECC shared
	point SHARED_MPI using the FIPS SP 800-56A compliant method
	key_derivation+key_wrapping. If IS_ENCRYPT is true the function
	encrypts; if false, it decrypts. PKEY is the public key and PK_FP
	the fingerprint of this public key. On success the result is
	stored at R_RESULT; on failure NULL is stored at R_RESULT and an
	error code returned. */
	gpg_error_t
	pk_ecdh_encrypt_with_shared_point (int is_encrypt, gcry_mpi_t shared_mpi,
	const byte pk_fp[MAX_FINGERPRINT_LEN],
	gcry_mpi_t data, gcry_mpi_t *pkey,
	gcry_mpi_t *r_result)
	{
	gpg_error_t err;
	byte *secret_x;
	int secret_x_size;
	- unsigned int nbits;
	+ unsigned int nbits, nbits1;
	const unsigned char *kek_params;
	size_t kek_params_size;
	int kdf_hash_algo;
	int kdf_encr_algo;
	unsigned char message[256];
	size_t message_size;

	*r_result = NULL;

	nbits = pubkey_nbits (PUBKEY_ALGO_ECDH, pkey);
	if (!nbits)
	return gpg_error (GPG_ERR_TOO_SHORT);

	{
	size_t nbytes;

	/* Extract x component of the shared point: this is the actual
	shared secret. */
	nbytes = (mpi_get_nbits (pkey[1] /* public point */)+7)/8;
	- secret_x = xtrymalloc_secure (nbytes);
	- if (!secret_x)
	- return gpg_error_from_syserror ();
	-
	- err = gcry_mpi_print (GCRYMPI_FMT_USG, secret_x, nbytes,
	- &nbytes, shared_mpi);
	- if (err)
	- {
	- xfree (secret_x);
	- log_error ("ECDH ephemeral export of shared point failed: %s\n",
	- gpg_strerror (err));
	- return err;
	- }
	+ secret_x = gcry_mpi_get_opaque (shared_mpi, &nbits1);

	/* Expected size of the x component */
	secret_x_size = (nbits+7)/8;

	/* Extract X from the result. It must be in the format of:
	04 \|\| X \|\| Y
	40 \|\| X
	41 \|\| X

	Since it always comes with the prefix, it's larger than X. In
	old experimental version of libgcrypt, there is a case where it
	returns X with no prefix of 40, so, nbytes == secret_x_size
	is allowed. */
	if (nbytes < secret_x_size)
	{
	xfree (secret_x);
	return gpg_error (GPG_ERR_BAD_DATA);
	}

	/* Remove the prefix. */
	if ((nbytes & 1))
	memmove (secret_x, secret_x+1, secret_x_size);

	/* Clear the rest of data. */
	if (nbytes - secret_x_size)
	memset (secret_x+secret_x_size, 0, nbytes-secret_x_size);

	if (DBG_CRYPTO)
	log_printhex (secret_x, secret_x_size, "ECDH shared secret X is:");
	}

	/* We have now the shared secret bytes in secret_x. */

	/* At this point we are done with PK encryption and the rest of the
	* function uses symmetric key encryption techniques to protect the
	* input DATA. The following two sections will simply replace
	* current secret_x with a value derived from it. This will become
	* a KEK.
	*/
	if (!gcry_mpi_get_flag (pkey[2], GCRYMPI_FLAG_OPAQUE))
	{
	xfree (secret_x);
	return gpg_error (GPG_ERR_BUG);
	}
	kek_params = gcry_mpi_get_opaque (pkey[2], &nbits);
	kek_params_size = (nbits+7)/8;

	if (DBG_CRYPTO)
	log_printhex (kek_params, kek_params_size, "ecdh KDF params:");

	/* Expect 4 bytes 03 01 hash_alg symm_alg. */
	if (kek_params_size != 4 \|\| kek_params[0] != 3 \|\| kek_params[1] != 1)
	{
	- xfree (secret_x);
	return gpg_error (GPG_ERR_BAD_PUBKEY);
	}

	kdf_hash_algo = kek_params[2];
	kdf_encr_algo = kek_params[3];

	if (DBG_CRYPTO)
	log_debug ("ecdh KDF algorithms %s+%s with aeswrap\n",
	openpgp_md_algo_name (kdf_hash_algo),
	openpgp_cipher_algo_name (kdf_encr_algo));

	if (kdf_hash_algo != GCRY_MD_SHA256
	&& kdf_hash_algo != GCRY_MD_SHA384
	&& kdf_hash_algo != GCRY_MD_SHA512)
	{
	- xfree (secret_x);
	return gpg_error (GPG_ERR_BAD_PUBKEY);
	}
	if (kdf_encr_algo != CIPHER_ALGO_AES
	&& kdf_encr_algo != CIPHER_ALGO_AES192
	&& kdf_encr_algo != CIPHER_ALGO_AES256)
	{
	- xfree (secret_x);
	return gpg_error (GPG_ERR_BAD_PUBKEY);
	}

	/* Build kdf_params. */
	{
	IOBUF obuf;

	obuf = iobuf_temp();
	/* variable-length field 1, curve name OID */
	err = gpg_mpi_write_nohdr (obuf, pkey[0]);
	/* fixed-length field 2 */
	iobuf_put (obuf, PUBKEY_ALGO_ECDH);
	/* variable-length field 3, KDF params */
	err = (err ? err : gpg_mpi_write_nohdr (obuf, pkey[2]));
	/* fixed-length field 4 */
	iobuf_write (obuf, "Anonymous Sender ", 20);
	/* fixed-length field 5, recipient fp */
	iobuf_write (obuf, pk_fp, 20);

	message_size = iobuf_temp_to_buffer (obuf, message, sizeof message);
	iobuf_close (obuf);
	if (err)
	{
	- xfree (secret_x);
	return err;
	}

	if(DBG_CRYPTO)
	log_printhex (message, message_size, "ecdh KDF message params are:");
	}

	/* Derive a KEK (key wrapping key) using MESSAGE and SECRET_X. */
	{
	gcry_md_hd_t h;
	int old_size;

	err = gcry_md_open (&h, kdf_hash_algo, 0);
	if (err)
	{
	log_error ("gcry_md_open failed for kdf_hash_algo %d: %s",
	kdf_hash_algo, gpg_strerror (err));
	- xfree (secret_x);
	return err;
	}
	gcry_md_write(h, "\x00\x00\x00\x01", 4); /* counter = 1 */
	gcry_md_write(h, secret_x, secret_x_size); /* x of the point X */
	gcry_md_write(h, message, message_size); /* KDF parameters */

	gcry_md_final (h);

	log_assert( gcry_md_get_algo_dlen (kdf_hash_algo) >= 32 );

	memcpy (secret_x, gcry_md_read (h, kdf_hash_algo),
	gcry_md_get_algo_dlen (kdf_hash_algo));
	gcry_md_close (h);

	old_size = secret_x_size;
	log_assert( old_size >= gcry_cipher_get_algo_keylen( kdf_encr_algo ) );
	secret_x_size = gcry_cipher_get_algo_keylen( kdf_encr_algo );
	log_assert( secret_x_size <= gcry_md_get_algo_dlen (kdf_hash_algo) );

	/* We could have allocated more, so clean the tail before returning. */
	memset (secret_x+secret_x_size, 0, old_size - secret_x_size);
	if (DBG_CRYPTO)
	log_printhex (secret_x, secret_x_size, "ecdh KEK is:");
	}

	/* And, finally, aeswrap with key secret_x. */
	{
	gcry_cipher_hd_t hd;
	size_t nbytes;

	byte *data_buf;
	int data_buf_size;

	gcry_mpi_t result;

	err = gcry_cipher_open (&hd, kdf_encr_algo, GCRY_CIPHER_MODE_AESWRAP, 0);
	if (err)
	{
	log_error ("ecdh failed to initialize AESWRAP: %s\n",
	gpg_strerror (err));
	- xfree (secret_x);
	return err;
	}

	err = gcry_cipher_setkey (hd, secret_x, secret_x_size);
	- xfree (secret_x);
	- secret_x = NULL;
	if (err)
	{
	gcry_cipher_close (hd);
	log_error ("ecdh failed in gcry_cipher_setkey: %s\n",
	gpg_strerror (err));
	return err;
	}

	data_buf_size = (gcry_mpi_get_nbits(data)+7)/8;
	if ((data_buf_size & 7) != (is_encrypt ? 0 : 1))
	{
	log_error ("can't use a shared secret of %d bytes for ecdh\n",
	data_buf_size);
	return gpg_error (GPG_ERR_BAD_DATA);
	}

	data_buf = xtrymalloc_secure( 1 + 2*data_buf_size + 8);
	if (!data_buf)
	{
	err = gpg_error_from_syserror ();
	gcry_cipher_close (hd);
	return err;
	}

	if (is_encrypt)
	{
	byte *in = data_buf+1+data_buf_size+8;

	/* Write data MPI into the end of data_buf. data_buf is size
	aeswrap data. */
	err = gcry_mpi_print (GCRYMPI_FMT_USG, in,
	data_buf_size, &nbytes, data/in/);
	if (err)
	{
	log_error ("ecdh failed to export DEK: %s\n", gpg_strerror (err));
	gcry_cipher_close (hd);
	xfree (data_buf);
	return err;
	}

	if (DBG_CRYPTO)
	log_printhex (in, data_buf_size, "ecdh encrypting :");

	err = gcry_cipher_encrypt (hd, data_buf+1, data_buf_size+8,
	in, data_buf_size);
	memset (in, 0, data_buf_size);
	gcry_cipher_close (hd);
	if (err)
	{
	log_error ("ecdh failed in gcry_cipher_encrypt: %s\n",
	gpg_strerror (err));
	xfree (data_buf);
	return err;
	}
	data_buf[0] = data_buf_size+8;

	if (DBG_CRYPTO)
	log_printhex (data_buf+1, data_buf[0], "ecdh encrypted to:");

	result = gcry_mpi_set_opaque (NULL, data_buf, 8 * (1+data_buf[0]));
	if (!result)
	{
	err = gpg_error_from_syserror ();
	xfree (data_buf);
	log_error ("ecdh failed to create an MPI: %s\n",
	gpg_strerror (err));
	return err;
	}

	*r_result = result;
	}
	else
	{
	byte *in;
	const void *p;

	p = gcry_mpi_get_opaque (data, &nbits);
	nbytes = (nbits+7)/8;
	if (!p \|\| nbytes > data_buf_size \|\| !nbytes)
	{
	xfree (data_buf);
	return gpg_error (GPG_ERR_BAD_MPI);
	}
	memcpy (data_buf, p, nbytes);
	if (data_buf[0] != nbytes-1)
	{
	log_error ("ecdh inconsistent size\n");
	xfree (data_buf);
	return gpg_error (GPG_ERR_BAD_MPI);
	}
	in = data_buf+data_buf_size;
	data_buf_size = data_buf[0];

	if (DBG_CRYPTO)
	log_printhex (data_buf+1, data_buf_size, "ecdh decrypting :");

	err = gcry_cipher_decrypt (hd, in, data_buf_size, data_buf+1,
	data_buf_size);
	gcry_cipher_close (hd);
	if (err)
	{
	log_error ("ecdh failed in gcry_cipher_decrypt: %s\n",
	gpg_strerror (err));
	xfree (data_buf);
	return err;
	}

	data_buf_size -= 8;

	if (DBG_CRYPTO)
	log_printhex (in, data_buf_size, "ecdh decrypted to :");

	/* Padding is removed later. */
	/* if (in[data_buf_size-1] > 8 ) */
	/* { */
	/* log_error ("ecdh failed at decryption: invalid padding." */
	/* " 0x%02x > 8\n", in[data_buf_size-1] ); */
	/* return gpg_error (GPG_ERR_BAD_KEY); */
	/* } */

	err = gcry_mpi_scan (&result, GCRYMPI_FMT_USG, in, data_buf_size, NULL);
	xfree (data_buf);
	if (err)
	{
	log_error ("ecdh failed to create a plain text MPI: %s\n",
	gpg_strerror (err));
	return err;
	}

	*r_result = result;
	}
	}

	return err;
	}


	static gcry_mpi_t
	gen_k (unsigned nbits)
	{
	gcry_mpi_t k;

	k = gcry_mpi_snew (nbits);
	if (DBG_CRYPTO)
	log_debug ("choosing a random k of %u bits\n", nbits);

	gcry_mpi_randomize (k, nbits-1, GCRY_STRONG_RANDOM);

	if (DBG_CRYPTO)
	{
	unsigned char *buffer;
	if (gcry_mpi_aprint (GCRYMPI_FMT_HEX, &buffer, NULL, k))
	BUG ();
	log_debug ("ephemeral scalar MPI #0: %s\n", buffer);
	gcry_free (buffer);
	}

	return k;
	}


	/* Generate an ephemeral key for the public ECDH key in PKEY. On
	success the generated key is stored at R_K; on failure NULL is
	stored at R_K and an error code returned. */
	gpg_error_t
	pk_ecdh_generate_ephemeral_key (gcry_mpi_t pkey, gcry_mpi_t r_k)
	{
	unsigned int nbits;
	gcry_mpi_t k;

	*r_k = NULL;

	nbits = pubkey_nbits (PUBKEY_ALGO_ECDH, pkey);
	if (!nbits)
	return gpg_error (GPG_ERR_TOO_SHORT);
	k = gen_k (nbits);
	if (!k)
	BUG ();

	*r_k = k;
	return 0;
	}



	/* Perform ECDH decryption. */
	int
	pk_ecdh_decrypt (gcry_mpi_t * result, const byte sk_fp[MAX_FINGERPRINT_LEN],
	gcry_mpi_t data, gcry_mpi_t shared, gcry_mpi_t * skey)
	{
	if (!data)
	return gpg_error (GPG_ERR_BAD_MPI);
	return pk_ecdh_encrypt_with_shared_point (0 /=decryption/, shared,
	sk_fp, data/encr data as an MPI/,
	skey, result);
	}
	diff --git a/g10/pkglue.c b/g10/pkglue.c
	index 8021a94db..339db67f3 100644
	--- a/g10/pkglue.c
	+++ b/g10/pkglue.c
	@@ -1,422 +1,422 @@
	/* pkglue.c - public key operations glue code
	* Copyright (C) 2000, 2003, 2010 Free Software Foundation, Inc.
	* Copyright (C) 2014 Werner Koch
	*
	* This file is part of GnuPG.
	*
	* GnuPG is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 3 of the License, or
	* (at your option) any later version.
	*
	* GnuPG is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, see <https://www.gnu.org/licenses/>.
	*/

	#include <config.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>
	#include <errno.h>

	#include "gpg.h"
	#include "../common/util.h"
	#include "pkglue.h"
	#include "main.h"
	#include "options.h"

	/* FIXME: Better change the function name because mpi_ is used by
	gcrypt macros. */
	gcry_mpi_t
	get_mpi_from_sexp (gcry_sexp_t sexp, const char *item, int mpifmt)
	{
	gcry_sexp_t list;
	gcry_mpi_t data;

	list = gcry_sexp_find_token (sexp, item, 0);
	log_assert (list);
	data = gcry_sexp_nth_mpi (list, 1, mpifmt);
	log_assert (data);
	gcry_sexp_release (list);
	return data;
	}



	/****************
	* Emulate our old PK interface here - sometime in the future we might
	* change the internal design to directly fit to libgcrypt.
	*/
	int
	pk_verify (pubkey_algo_t pkalgo, gcry_mpi_t hash,
	gcry_mpi_t data, gcry_mpi_t pkey)
	{
	gcry_sexp_t s_sig, s_hash, s_pkey;
	int rc;
	unsigned int neededfixedlen = 0;

	/* Make a sexp from pkey. */
	if (pkalgo == PUBKEY_ALGO_DSA)
	{
	rc = gcry_sexp_build (&s_pkey, NULL,
	"(public-key(dsa(p%m)(q%m)(g%m)(y%m)))",
	pkey[0], pkey[1], pkey[2], pkey[3]);
	}
	else if (pkalgo == PUBKEY_ALGO_ELGAMAL_E \|\| pkalgo == PUBKEY_ALGO_ELGAMAL)
	{
	rc = gcry_sexp_build (&s_pkey, NULL,
	"(public-key(elg(p%m)(g%m)(y%m)))",
	pkey[0], pkey[1], pkey[2]);
	}
	else if (pkalgo == PUBKEY_ALGO_RSA \|\| pkalgo == PUBKEY_ALGO_RSA_S)
	{
	rc = gcry_sexp_build (&s_pkey, NULL,
	"(public-key(rsa(n%m)(e%m)))", pkey[0], pkey[1]);
	}
	else if (pkalgo == PUBKEY_ALGO_ECDSA)
	{
	char *curve = openpgp_oid_to_str (pkey[0]);
	if (!curve)
	rc = gpg_error_from_syserror ();
	else
	{
	rc = gcry_sexp_build (&s_pkey, NULL,
	"(public-key(ecdsa(curve %s)(q%m)))",
	curve, pkey[1]);
	xfree (curve);
	}
	}
	else if (pkalgo == PUBKEY_ALGO_EDDSA)
	{
	char *curve = openpgp_oid_to_str (pkey[0]);
	if (!curve)
	rc = gpg_error_from_syserror ();
	else
	{
	rc = gcry_sexp_build (&s_pkey, NULL,
	"(public-key(ecc(curve %s)"
	"(flags eddsa)(q%m)))",
	curve, pkey[1]);
	xfree (curve);
	}

	if (openpgp_oid_is_ed25519 (pkey[0]))
	neededfixedlen = 256 / 8;
	}
	else
	return GPG_ERR_PUBKEY_ALGO;

	if (rc)
	BUG (); /* gcry_sexp_build should never fail. */

	/* Put hash into a S-Exp s_hash. */
	if (pkalgo == PUBKEY_ALGO_EDDSA)
	{
	if (gcry_sexp_build (&s_hash, NULL,
	"(data(flags eddsa)(hash-algo sha512)(value %m))",
	hash))
	BUG (); /* gcry_sexp_build should never fail. */
	}
	else
	{
	if (gcry_sexp_build (&s_hash, NULL, "%m", hash))
	BUG (); /* gcry_sexp_build should never fail. */
	}

	/* Put data into a S-Exp s_sig. */
	s_sig = NULL;
	if (pkalgo == PUBKEY_ALGO_DSA)
	{
	if (!data[0] \|\| !data[1])
	rc = gpg_error (GPG_ERR_BAD_MPI);
	else
	rc = gcry_sexp_build (&s_sig, NULL,
	"(sig-val(dsa(r%m)(s%m)))", data[0], data[1]);
	}
	else if (pkalgo == PUBKEY_ALGO_ECDSA)
	{
	if (!data[0] \|\| !data[1])
	rc = gpg_error (GPG_ERR_BAD_MPI);
	else
	rc = gcry_sexp_build (&s_sig, NULL,
	"(sig-val(ecdsa(r%m)(s%m)))", data[0], data[1]);
	}
	else if (pkalgo == PUBKEY_ALGO_EDDSA)
	{
	gcry_mpi_t r = data[0];
	gcry_mpi_t s = data[1];
	size_t rlen, slen, n; /* (bytes) */
	char buf[64];

	log_assert (neededfixedlen <= sizeof buf);

	if (!r \|\| !s)
	rc = gpg_error (GPG_ERR_BAD_MPI);
	else if ((rlen = (gcry_mpi_get_nbits (r)+7)/8) > neededfixedlen \|\| !rlen)
	rc = gpg_error (GPG_ERR_BAD_MPI);
	else if ((slen = (gcry_mpi_get_nbits (s)+7)/8) > neededfixedlen \|\| !slen)
	rc = gpg_error (GPG_ERR_BAD_MPI);
	else
	{
	/* We need to fixup the length in case of leading zeroes.
	* OpenPGP does not allow leading zeroes and the parser for
	* the signature packet has no information on the use curve,
	* thus we need to do it here. We won't do it for opaque
	* MPIs under the assumption that they are known to be fine;
	* we won't see them here anyway but the check is anyway
	* required. Fixme: A nifty feature for gcry_sexp_build
	* would be a format to left pad the value (e.g. "%M"). /
	rc = 0;

	if (rlen < neededfixedlen
	&& !gcry_mpi_get_flag (r, GCRYMPI_FLAG_OPAQUE)
	&& !(rc=gcry_mpi_print (GCRYMPI_FMT_USG, buf, sizeof buf, &n, r)))
	{
	log_assert (n < neededfixedlen);
	memmove (buf + (neededfixedlen - n), buf, n);
	memset (buf, 0, neededfixedlen - n);
	r = gcry_mpi_set_opaque_copy (NULL, buf, neededfixedlen * 8);
	}
	if (slen < neededfixedlen
	&& !gcry_mpi_get_flag (s, GCRYMPI_FLAG_OPAQUE)
	&& !(rc=gcry_mpi_print (GCRYMPI_FMT_USG, buf, sizeof buf, &n, s)))
	{
	log_assert (n < neededfixedlen);
	memmove (buf + (neededfixedlen - n), buf, n);
	memset (buf, 0, neededfixedlen - n);
	s = gcry_mpi_set_opaque_copy (NULL, buf, neededfixedlen * 8);
	}

	if (!rc)
	rc = gcry_sexp_build (&s_sig, NULL,
	"(sig-val(eddsa(r%M)(s%M)))", r, s);

	if (r != data[0])
	gcry_mpi_release (r);
	if (s != data[1])
	gcry_mpi_release (s);
	}
	}
	else if (pkalgo == PUBKEY_ALGO_ELGAMAL \|\| pkalgo == PUBKEY_ALGO_ELGAMAL_E)
	{
	if (!data[0] \|\| !data[1])
	rc = gpg_error (GPG_ERR_BAD_MPI);
	else
	rc = gcry_sexp_build (&s_sig, NULL,
	"(sig-val(elg(r%m)(s%m)))", data[0], data[1]);
	}
	else if (pkalgo == PUBKEY_ALGO_RSA \|\| pkalgo == PUBKEY_ALGO_RSA_S)
	{
	if (!data[0])
	rc = gpg_error (GPG_ERR_BAD_MPI);
	else
	rc = gcry_sexp_build (&s_sig, NULL, "(sig-val(rsa(s%m)))", data[0]);
	}
	else
	BUG ();

	if (!rc)
	rc = gcry_pk_verify (s_sig, s_hash, s_pkey);

	gcry_sexp_release (s_sig);
	gcry_sexp_release (s_hash);
	gcry_sexp_release (s_pkey);
	return rc;
	}




	/****************
	* Emulate our old PK interface here - sometime in the future we might
	* change the internal design to directly fit to libgcrypt.
	* PK is only required to compute the fingerprint for ECDH.
	*/
	int
	pk_encrypt (pubkey_algo_t algo, gcry_mpi_t *resarr, gcry_mpi_t data,
	PKT_public_key pk, gcry_mpi_t pkey)
	{
	gcry_sexp_t s_ciph = NULL;
	gcry_sexp_t s_data = NULL;
	gcry_sexp_t s_pkey = NULL;
	int rc;

	/* Make a sexp from pkey. */
	if (algo == PUBKEY_ALGO_ELGAMAL \|\| algo == PUBKEY_ALGO_ELGAMAL_E)
	{
	rc = gcry_sexp_build (&s_pkey, NULL,
	"(public-key(elg(p%m)(g%m)(y%m)))",
	pkey[0], pkey[1], pkey[2]);
	/* Put DATA into a simplified S-expression. */
	if (!rc)
	rc = gcry_sexp_build (&s_data, NULL, "%m", data);
	}
	else if (algo == PUBKEY_ALGO_RSA \|\| algo == PUBKEY_ALGO_RSA_E)
	{
	rc = gcry_sexp_build (&s_pkey, NULL,
	"(public-key(rsa(n%m)(e%m)))",
	pkey[0], pkey[1]);
	/* Put DATA into a simplified S-expression. */
	if (!rc)
	rc = gcry_sexp_build (&s_data, NULL, "%m", data);
	}
	else if (algo == PUBKEY_ALGO_ECDH)
	{
	gcry_mpi_t k;

	rc = pk_ecdh_generate_ephemeral_key (pkey, &k);
	if (!rc)
	{
	char *curve;

	curve = openpgp_oid_to_str (pkey[0]);
	if (!curve)
	rc = gpg_error_from_syserror ();
	else
	{
	int with_djb_tweak_flag = openpgp_oid_is_cv25519 (pkey[0]);

	/* Now use the ephemeral secret to compute the shared point. */
	rc = gcry_sexp_build (&s_pkey, NULL,
	with_djb_tweak_flag ?
	"(public-key(ecdh(curve%s)(flags djb-tweak)(q%m)))"
	: "(public-key(ecdh(curve%s)(q%m)))",
	curve, pkey[1]);
	xfree (curve);
	/* Put K into a simplified S-expression. */
	if (!rc)
	rc = gcry_sexp_build (&s_data, NULL, "%m", k);
	}
	gcry_mpi_release (k);
	}
	}
	else
	rc = gpg_error (GPG_ERR_PUBKEY_ALGO);

	/* Pass it to libgcrypt. */
	if (!rc)
	rc = gcry_pk_encrypt (&s_ciph, s_data, s_pkey);

	gcry_sexp_release (s_data);
	gcry_sexp_release (s_pkey);

	if (rc)
	;
	else if (algo == PUBKEY_ALGO_ECDH)
	{
	gcry_mpi_t shared, public, result;
	byte fp[MAX_FINGERPRINT_LEN];
	size_t fpn;

	/* Get the shared point and the ephemeral public key. */
	- shared = get_mpi_from_sexp (s_ciph, "s", GCRYMPI_FMT_USG);
	- public = get_mpi_from_sexp (s_ciph, "e", GCRYMPI_FMT_USG);
	+ shared = get_mpi_from_sexp (s_ciph, "s", GCRYMPI_FMT_OPAQUE);
	+ public = get_mpi_from_sexp (s_ciph, "e", GCRYMPI_FMT_OPAQUE);
	gcry_sexp_release (s_ciph);
	s_ciph = NULL;
	if (DBG_CRYPTO)
	{
	log_debug ("ECDH ephemeral key:");
	gcry_mpi_dump (public);
	log_printf ("\n");
	}

	result = NULL;
	fingerprint_from_pk (pk, fp, &fpn);
	if (fpn != 20)
	rc = gpg_error (GPG_ERR_INV_LENGTH);
	else
	rc = pk_ecdh_encrypt_with_shared_point (1 /=encrypton/, shared,
	fp, data, pkey, &result);
	gcry_mpi_release (shared);
	if (!rc)
	{
	resarr[0] = public;
	resarr[1] = result;
	}
	else
	{
	gcry_mpi_release (public);
	gcry_mpi_release (result);
	}
	}
	else /* Elgamal or RSA case. */
	{ /* Fixme: Add better error handling or make gnupg use
	S-expressions directly. */
	resarr[0] = get_mpi_from_sexp (s_ciph, "a", GCRYMPI_FMT_USG);
	if (!is_RSA (algo))
	resarr[1] = get_mpi_from_sexp (s_ciph, "b", GCRYMPI_FMT_USG);
	}

	gcry_sexp_release (s_ciph);
	return rc;
	}


	/* Check whether SKEY is a suitable secret key. */
	int
	pk_check_secret_key (pubkey_algo_t pkalgo, gcry_mpi_t *skey)
	{
	gcry_sexp_t s_skey;
	int rc;

	if (pkalgo == PUBKEY_ALGO_DSA)
	{
	rc = gcry_sexp_build (&s_skey, NULL,
	"(private-key(dsa(p%m)(q%m)(g%m)(y%m)(x%m)))",
	skey[0], skey[1], skey[2], skey[3], skey[4]);
	}
	else if (pkalgo == PUBKEY_ALGO_ELGAMAL \|\| pkalgo == PUBKEY_ALGO_ELGAMAL_E)
	{
	rc = gcry_sexp_build (&s_skey, NULL,
	"(private-key(elg(p%m)(g%m)(y%m)(x%m)))",
	skey[0], skey[1], skey[2], skey[3]);
	}
	else if (is_RSA (pkalgo))
	{
	rc = gcry_sexp_build (&s_skey, NULL,
	"(private-key(rsa(n%m)(e%m)(d%m)(p%m)(q%m)(u%m)))",
	skey[0], skey[1], skey[2], skey[3], skey[4],
	skey[5]);
	}
	else if (pkalgo == PUBKEY_ALGO_ECDSA \|\| pkalgo == PUBKEY_ALGO_ECDH)
	{
	char *curve = openpgp_oid_to_str (skey[0]);
	if (!curve)
	rc = gpg_error_from_syserror ();
	else
	{
	rc = gcry_sexp_build (&s_skey, NULL,
	"(private-key(ecc(curve%s)(q%m)(d%m)))",
	curve, skey[1], skey[2]);
	xfree (curve);
	}
	}
	else if (pkalgo == PUBKEY_ALGO_EDDSA)
	{
	char *curve = openpgp_oid_to_str (skey[0]);
	if (!curve)
	rc = gpg_error_from_syserror ();
	else
	{
	rc = gcry_sexp_build (&s_skey, NULL,
	"(private-key(ecc(curve %s)"
	"(flags eddsa)(q%m)(d%m)))",
	curve, skey[1], skey[2]);
	xfree (curve);
	}
	}
	else
	return GPG_ERR_PUBKEY_ALGO;

	if (!rc)
	{
	rc = gcry_pk_testkey (s_skey);
	gcry_sexp_release (s_skey);
	}
	return rc;
	}

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