text: /*
   * Copyright (c) 2019 Yubico AB. All rights reserved.
   * Use of this source code is governed by a BSD-style
   * license that can be found in the LICENSE file.
   */
  
  #include <openssl/bn.h>
  #include <openssl/ec.h>
  #include <openssl/evp.h>
  #include <openssl/obj_mac.h>
  
  #include <string.h>
  #include "fido.h"
  #include "fido/eddsa.h"
  
  #if defined(LIBRESSL_VERSION_NUMBER) || OPENSSL_VERSION_NUMBER < 0x10101000L
  EVP_PKEY *
  EVP_PKEY_new_raw_public_key(int type, ENGINE *e, const unsigned char *key,
      size_t keylen)
  {
  	(void)type;
  	(void)e;
  	(void)key;
  	(void)keylen;
  
  	fido_log_debug("%s: unimplemented", __func__);
  
  	return (NULL);
  }
  
  int
  EVP_PKEY_get_raw_public_key(const EVP_PKEY *pkey, unsigned char *pub,
      size_t *len)
  {
  	(void)pkey;
  	(void)pub;
  	(void)len;
  
  	fido_log_debug("%s: unimplemented", __func__);
  
  	return (0);
  }
  
  int
  EVP_DigestVerify(EVP_MD_CTX *ctx, const unsigned char *sigret, size_t siglen,
      const unsigned char *tbs, size_t tbslen)
  {
  	(void)ctx;
  	(void)sigret;
  	(void)siglen;
  	(void)tbs;
  	(void)tbslen;
  
  	fido_log_debug("%s: unimplemented", __func__);
  
  	return (0);
  }
  #endif /* LIBRESSL_VERSION_NUMBER || OPENSSL_VERSION_NUMBER < 0x10101000L */
  
  #if OPENSSL_VERSION_NUMBER < 0x10100000L
  EVP_MD_CTX *
  EVP_MD_CTX_new(void)
  {
  	fido_log_debug("%s: unimplemented", __func__);
  
  	return (NULL);
  }
  
  void
  EVP_MD_CTX_free(EVP_MD_CTX *ctx)
  {
  	(void)ctx;
  }
  #endif /* OPENSSL_VERSION_NUMBER < 0x10100000L */
  
  static int
  decode_coord(const cbor_item_t *item, void *xy, size_t xy_len)
  {
  	if (cbor_isa_bytestring(item) == false ||
  	    cbor_bytestring_is_definite(item) == false ||
  	    cbor_bytestring_length(item) != xy_len) {
  		fido_log_debug("%s: cbor type", __func__);
  		return (-1);
  	}
  
  	memcpy(xy, cbor_bytestring_handle(item), xy_len);
  
  	return (0);
  }
  
  static int
  decode_pubkey_point(const cbor_item_t *key, const cbor_item_t *val, void *arg)
  {
  	eddsa_pk_t *k = arg;
  
  	if (cbor_isa_negint(key) == false ||
  	    cbor_int_get_width(key) != CBOR_INT_8)
  		return (0); /* ignore */
  
  	switch (cbor_get_uint8(key)) {
  	case 1: /* x coordinate */
  		return (decode_coord(val, &k->x, sizeof(k->x)));
  	}
  
  	return (0); /* ignore */
  }
  
  int
  eddsa_pk_decode(const cbor_item_t *item, eddsa_pk_t *k)
  {
  	if (cbor_isa_map(item) == false ||
  	    cbor_map_is_definite(item) == false ||
  	    cbor_map_iter(item, k, decode_pubkey_point) < 0) {
  		fido_log_debug("%s: cbor type", __func__);
  		return (-1);
  	}
  
  	return (0);
  }
  
  eddsa_pk_t *
  eddsa_pk_new(void)
  {
  	return (calloc(1, sizeof(eddsa_pk_t)));
  }
  
  void
  eddsa_pk_free(eddsa_pk_t **pkp)
  {
  	eddsa_pk_t *pk;
  
  	if (pkp == NULL || (pk = *pkp) == NULL)
  		return;
  
  	explicit_bzero(pk, sizeof(*pk));
  	free(pk);
  
  	*pkp = NULL;
  }
  
  int
  eddsa_pk_from_ptr(eddsa_pk_t *pk, const void *ptr, size_t len)
  {
  	if (len < sizeof(*pk))
  		return (FIDO_ERR_INVALID_ARGUMENT);
  
  	memcpy(pk, ptr, sizeof(*pk));
  
  	return (FIDO_OK);
  }
  
  EVP_PKEY *
  eddsa_pk_to_EVP_PKEY(const eddsa_pk_t *k)
  {
  	EVP_PKEY *pkey = NULL;
  
  	if ((pkey = EVP_PKEY_new_raw_public_key(EVP_PKEY_ED25519, NULL, k->x,
  	    sizeof(k->x))) == NULL)
  		fido_log_debug("%s: EVP_PKEY_new_raw_public_key", __func__);
  
  	return (pkey);
  }
  
  int
  eddsa_pk_from_EVP_PKEY(eddsa_pk_t *pk, const EVP_PKEY *pkey)
  {
  	size_t len = 0;
  
  	if (EVP_PKEY_get_raw_public_key(pkey, NULL, &len) != 1 ||
  	    len != sizeof(pk->x))
  		return (FIDO_ERR_INTERNAL);
  	if (EVP_PKEY_get_raw_public_key(pkey, pk->x, &len) != 1 ||
  	    len != sizeof(pk->x))
  		return (FIDO_ERR_INTERNAL);
  
  	return (FIDO_OK);
  }
  