/*
 * This file is part of the Trezor project, https://trezor.io/
 *
 * Copyright (C) 2014 Pavol Rusnak <stick@satoshilabs.com>
 *
 * This library is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This library 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "crypto.h"
#include <string.h>
#include "address.h"
#include "aes/aes.h"
#include "base58.h"
#include "bip32.h"
#include "coins.h"
#include "curves.h"
#include "hmac.h"
#include "layout.h"
#include "pbkdf2.h"
#include "secp256k1.h"
#include "segwit_addr.h"
#include "sha2.h"

#if !BITCOIN_ONLY
#include "cash_addr.h"
#endif

uint32_t ser_length(uint32_t len, uint8_t *out) {
  if (len < 253) {
    out[0] = len & 0xFF;
    return 1;
  }
  if (len < 0x10000) {
    out[0] = 253;
    out[1] = len & 0xFF;
    out[2] = (len >> 8) & 0xFF;
    return 3;
  }
  out[0] = 254;
  out[1] = len & 0xFF;
  out[2] = (len >> 8) & 0xFF;
  out[3] = (len >> 16) & 0xFF;
  out[4] = (len >> 24) & 0xFF;
  return 5;
}

uint32_t ser_length_hash(Hasher *hasher, uint32_t len) {
  if (len < 253) {
    hasher_Update(hasher, (const uint8_t *)&len, 1);
    return 1;
  }
  if (len < 0x10000) {
    uint8_t d = 253;
    hasher_Update(hasher, &d, 1);
    hasher_Update(hasher, (const uint8_t *)&len, 2);
    return 3;
  }
  uint8_t d = 254;
  hasher_Update(hasher, &d, 1);
  hasher_Update(hasher, (const uint8_t *)&len, 4);
  return 5;
}

uint32_t deser_length(const uint8_t *in, uint32_t *out) {
  if (in[0] < 253) {
    *out = in[0];
    return 1;
  }
  if (in[0] == 253) {
    *out = in[1] + (in[2] << 8);
    return 1 + 2;
  }
  if (in[0] == 254) {
    *out = in[1] + (in[2] << 8) + (in[3] << 16) + ((uint32_t)in[4] << 24);
    return 1 + 4;
  }
  *out = 0;  // ignore 64 bit
  return 1 + 8;
}

int sshMessageSign(HDNode *node, const uint8_t *message, size_t message_len,
                   uint8_t *signature) {
  signature[0] = 0;  // prefix: pad with zero, so all signatures are 65 bytes
  return hdnode_sign(node, message, message_len, HASHER_SHA2, signature + 1,
                     NULL, NULL);
}

int gpgMessageSign(HDNode *node, const uint8_t *message, size_t message_len,
                   uint8_t *signature) {
  signature[0] = 0;  // prefix: pad with zero, so all signatures are 65 bytes
  const curve_info *ed25519_curve_info = get_curve_by_name(ED25519_NAME);
  if (ed25519_curve_info && node->curve == ed25519_curve_info) {
    // GPG supports variable size digest for Ed25519 signatures
    return hdnode_sign(node, message, message_len, 0, signature + 1, NULL,
                       NULL);
  } else {
    // Ensure 256-bit digest before proceeding
    if (message_len != 32) {
      return 1;
    }
    return hdnode_sign_digest(node, message, signature + 1, NULL, NULL);
  }
}

int signifyMessageSign(HDNode *node, const uint8_t *message, size_t message_len,
                       uint8_t *signature) {
  signature[0] = 0;  // prefix: pad with zero, so all signatures are 65 bytes
  const curve_info *ed25519_curve_info = get_curve_by_name(ED25519_NAME);
  // only ed25519 is supported
  if (!ed25519_curve_info || node->curve != ed25519_curve_info) {
    return 1;
  }
  return hdnode_sign(node, message, message_len, 0, signature + 1, NULL, NULL);
}

static void cryptoMessageHash(const CoinInfo *coin, const uint8_t *message,
                              size_t message_len,
                              uint8_t hash[HASHER_DIGEST_LENGTH]) {
  Hasher hasher = {0};
  hasher_Init(&hasher, coin->curve->hasher_sign);
  hasher_Update(&hasher, (const uint8_t *)coin->signed_message_header,
                strlen(coin->signed_message_header));
  uint8_t varint[5] = {0};
  uint32_t l = ser_length(message_len, varint);
  hasher_Update(&hasher, varint, l);
  hasher_Update(&hasher, message, message_len);
  hasher_Final(&hasher, hash);
}

int cryptoMessageSign(const CoinInfo *coin, HDNode *node,
                      InputScriptType script_type, bool no_script_type,
                      const uint8_t *message, size_t message_len,
                      uint8_t *signature) {
  uint8_t script_type_info = 0;
  switch (script_type) {
    case InputScriptType_SPENDADDRESS:
      // p2pkh
      script_type_info = 0;
      break;
    case InputScriptType_SPENDP2SHWITNESS:
      // segwit-in-p2sh
      script_type_info = 4;
      break;
    case InputScriptType_SPENDWITNESS:
      // segwit
      script_type_info = 8;
      break;
    default:
      // unsupported script type
      return 1;
  }

  if (no_script_type) {
    script_type_info = 0;
  }

  uint8_t hash[HASHER_DIGEST_LENGTH] = {0};
  cryptoMessageHash(coin, message, message_len, hash);

  uint8_t pby = 0;
  int result = hdnode_sign_digest(node, hash, signature + 1, &pby, NULL);
  if (result == 0) {
    signature[0] = 31 + pby + script_type_info;
  }
  return result;
}

// Determines the script type from a non-multisig address.
static InputScriptType address_to_script_type(const CoinInfo *coin,
                                              const char *address) {
  uint8_t addr_raw[MAX_ADDR_RAW_SIZE] = {0};
  size_t addr_raw_len = 0;

  // Native SegWit
  if (coin->bech32_prefix) {
    int witver = 0;
    if (segwit_addr_decode(&witver, addr_raw, &addr_raw_len,
                           coin->bech32_prefix, address)) {
      switch (witver) {
        case 0:
          return InputScriptType_SPENDWITNESS;
        case 1:
          return InputScriptType_SPENDTAPROOT;
        default:
          return InputScriptType_EXTERNAL;  // unknown script type
      }
    }
  }

#if !BITCOIN_ONLY
  if (coin->cashaddr_prefix &&
      cash_addr_decode(addr_raw, &addr_raw_len, coin->cashaddr_prefix,
                       address)) {
    return InputScriptType_SPENDADDRESS;
  }
#endif

  addr_raw_len = base58_decode_check(address, coin->curve->hasher_base58,
                                     addr_raw, sizeof(addr_raw));

  // P2PKH
  if (addr_raw_len > address_prefix_bytes_len(coin->address_type) &&
      address_check_prefix(addr_raw, coin->address_type)) {
    return InputScriptType_SPENDADDRESS;
  }

  // P2SH
  if (addr_raw_len > address_prefix_bytes_len(coin->address_type_p2sh) &&
      address_check_prefix(addr_raw, coin->address_type_p2sh)) {
    return InputScriptType_SPENDP2SHWITNESS;
  }

  return InputScriptType_EXTERNAL;  // unknown script type
}

int cryptoMessageVerify(const CoinInfo *coin, const uint8_t *message,
                        size_t message_len, const char *address,
                        const uint8_t *signature) {
  // check if the address is correct
  InputScriptType script_type = address_to_script_type(coin, address);
  if (script_type == InputScriptType_EXTERNAL) {
    return 1;  // invalid address
  }

  if (signature[0] >= 27 && signature[0] <= 34) {
    // p2pkh or no script type provided
    // use the script type from the address
  } else if (signature[0] >= 35 && signature[0] <= 38) {
    // segwit-in-p2sh
    if (script_type != InputScriptType_SPENDP2SHWITNESS) {
      return 2;  // script type mismatch
    }
  } else if (signature[0] >= 39 && signature[0] <= 42) {
    // segwit
    if (script_type != InputScriptType_SPENDWITNESS) {
      return 2;  // script type mismatch
    }
  } else {
    return 3;  // invalid signature prefix
  }

  uint8_t hash[HASHER_DIGEST_LENGTH] = {0};
  cryptoMessageHash(coin, message, message_len, hash);

  uint8_t recid = (signature[0] - 27) % 4;
  bool compressed = signature[0] >= 31;

  // check if signature verifies the digest and recover the public key
  uint8_t pubkey[65] = {0};
  if (ecdsa_recover_pub_from_sig(coin->curve->params, pubkey, signature + 1,
                                 hash, recid) != 0) {
    return 4;  // invalid signature data
  }

  // convert public key to compressed pubkey if necessary
  if (compressed) {
    pubkey[0] = 0x02 | (pubkey[64] & 1);
  }

  uint8_t addr_raw[MAX_ADDR_RAW_SIZE] = {0};
  uint8_t recovered_raw[MAX_ADDR_RAW_SIZE] = {0};

  if (script_type == InputScriptType_SPENDADDRESS) {
    // p2pkh
    size_t len = 0;
#if !BITCOIN_ONLY
    if (coin->cashaddr_prefix) {
      if (!cash_addr_decode(addr_raw, &len, coin->cashaddr_prefix, address)) {
        return 1;  // invalid address
      }
    } else
#endif
    {
      len = base58_decode_check(address, coin->curve->hasher_base58, addr_raw,
                                MAX_ADDR_RAW_SIZE);
    }
    ecdsa_get_address_raw(pubkey, coin->address_type,
                          coin->curve->hasher_pubkey, recovered_raw);
    if (memcmp(recovered_raw, addr_raw, len) != 0 ||
        len != address_prefix_bytes_len(coin->address_type) + 20) {
      return 5;  // signature does not match address and message
    }
  } else if (script_type == InputScriptType_SPENDP2SHWITNESS) {
    // segwit-in-p2sh
    size_t len = base58_decode_check(address, coin->curve->hasher_base58,
                                     addr_raw, MAX_ADDR_RAW_SIZE);
    ecdsa_get_address_segwit_p2sh_raw(pubkey, coin->address_type_p2sh,
                                      coin->curve->hasher_pubkey,
                                      recovered_raw);
    if (memcmp(recovered_raw, addr_raw, len) != 0 ||
        len != address_prefix_bytes_len(coin->address_type_p2sh) + 20) {
      return 5;  // signature does not match address and message
    }
  } else if (script_type == InputScriptType_SPENDWITNESS) {
    // segwit
    int witver = 0;
    size_t len = 0;
    if (!coin->bech32_prefix ||
        !segwit_addr_decode(&witver, recovered_raw, &len, coin->bech32_prefix,
                            address)) {
      return 1;  // invalid address
    }
    ecdsa_get_pubkeyhash(pubkey, coin->curve->hasher_pubkey, addr_raw);
    if (memcmp(recovered_raw, addr_raw, len) != 0 || witver != 0 || len != 20) {
      return 5;  // signature does not match address and message
    }
  } else {
    return 1;  // invalid address
  }

  return 0;
}

const HDNode *cryptoMultisigPubkey(const CoinInfo *coin,
                                   const MultisigRedeemScriptType *multisig,
                                   uint32_t index) {
  const HDNodeType *node_ptr = NULL;
  const uint32_t *address_n = NULL;
  uint32_t address_n_count = 0;
  if (multisig->nodes_count) {  // use multisig->nodes
    if (index >= multisig->nodes_count) {
      return 0;
    }
    node_ptr = &(multisig->nodes[index]);
    address_n = multisig->address_n;
    address_n_count = multisig->address_n_count;
  } else if (multisig->pubkeys_count) {  // use multisig->pubkeys
    if (index >= multisig->pubkeys_count) {
      return 0;
    }
    node_ptr = &(multisig->pubkeys[index].node);
    address_n = multisig->pubkeys[index].address_n;
    address_n_count = multisig->pubkeys[index].address_n_count;
  } else {
    return 0;
  }
  if (node_ptr->chain_code.size != 32) return 0;
  if (node_ptr->public_key.size != 33) return 0;
  static HDNode node;
  if (!hdnode_from_xpub(node_ptr->depth, node_ptr->child_num,
                        node_ptr->chain_code.bytes, node_ptr->public_key.bytes,
                        coin->curve_name, &node)) {
    return 0;
  }
  layoutProgressUpdate(true);
  for (uint32_t i = 0; i < address_n_count; i++) {
    if (!hdnode_public_ckd(&node, address_n[i])) {
      return 0;
    }
    layoutProgressUpdate(true);
  }
  return &node;
}

uint32_t cryptoMultisigPubkeyCount(const MultisigRedeemScriptType *multisig) {
  return multisig->nodes_count ? multisig->nodes_count
                               : multisig->pubkeys_count;
}

int cryptoMultisigPubkeyIndex(const CoinInfo *coin,
                              const MultisigRedeemScriptType *multisig,
                              const uint8_t *pubkey) {
  for (size_t i = 0; i < cryptoMultisigPubkeyCount(multisig); i++) {
    const HDNode *pubnode = cryptoMultisigPubkey(coin, multisig, i);
    if (pubnode && memcmp(pubnode->public_key, pubkey, 33) == 0) {
      return i;
    }
  }
  return -1;
}

int cryptoMultisigFingerprint(const MultisigRedeemScriptType *multisig,
                              uint8_t *hash) {
  static const HDNodeType *pubnodes[15], *swap;
  const uint32_t n = cryptoMultisigPubkeyCount(multisig);
  if (n < 1 || n > 15) {
    return 0;
  }
  if (multisig->m < 1 || multisig->m > 15) {
    return 0;
  }
  for (uint32_t i = 0; i < n; i++) {
    if (multisig->nodes_count) {  // use multisig->nodes
      pubnodes[i] = &(multisig->nodes[i]);
    } else if (multisig->pubkeys_count) {  // use multisig->pubkeys
      pubnodes[i] = &(multisig->pubkeys[i].node);
    } else {
      return 0;
    }
  }
  for (uint32_t i = 0; i < n; i++) {
    if (pubnodes[i]->public_key.size != 33) return 0;
    if (pubnodes[i]->chain_code.size != 32) return 0;
  }
  // minsort according to pubkey
  for (uint32_t i = 0; i < n - 1; i++) {
    for (uint32_t j = n - 1; j > i; j--) {
      if (memcmp(pubnodes[i]->public_key.bytes, pubnodes[j]->public_key.bytes,
                 33) > 0) {
        swap = pubnodes[i];
        pubnodes[i] = pubnodes[j];
        pubnodes[j] = swap;
      }
    }
  }
  // hash sorted nodes
  SHA256_CTX ctx = {0};
  sha256_Init(&ctx);
  sha256_Update(&ctx, (const uint8_t *)&(multisig->m), sizeof(uint32_t));
  for (uint32_t i = 0; i < n; i++) {
    sha256_Update(&ctx, (const uint8_t *)&(pubnodes[i]->depth),
                  sizeof(uint32_t));
    sha256_Update(&ctx, (const uint8_t *)&(pubnodes[i]->fingerprint),
                  sizeof(uint32_t));
    sha256_Update(&ctx, (const uint8_t *)&(pubnodes[i]->child_num),
                  sizeof(uint32_t));
    sha256_Update(&ctx, pubnodes[i]->chain_code.bytes, 32);
    sha256_Update(&ctx, pubnodes[i]->public_key.bytes, 33);
  }
  sha256_Update(&ctx, (const uint8_t *)&n, sizeof(uint32_t));
  sha256_Final(&ctx, hash);
  layoutProgressUpdate(true);
  return 1;
}

int cryptoIdentityFingerprint(const IdentityType *identity, uint8_t *hash) {
  SHA256_CTX ctx = {0};
  sha256_Init(&ctx);
  sha256_Update(&ctx, (const uint8_t *)&(identity->index), sizeof(uint32_t));
  if (identity->has_proto && identity->proto[0]) {
    sha256_Update(&ctx, (const uint8_t *)(identity->proto),
                  strlen(identity->proto));
    sha256_Update(&ctx, (const uint8_t *)"://", 3);
  }
  if (identity->has_user && identity->user[0]) {
    sha256_Update(&ctx, (const uint8_t *)(identity->user),
                  strlen(identity->user));
    sha256_Update(&ctx, (const uint8_t *)"@", 1);
  }
  if (identity->has_host && identity->host[0]) {
    sha256_Update(&ctx, (const uint8_t *)(identity->host),
                  strlen(identity->host));
  }
  if (identity->has_port && identity->port[0]) {
    sha256_Update(&ctx, (const uint8_t *)":", 1);
    sha256_Update(&ctx, (const uint8_t *)(identity->port),
                  strlen(identity->port));
  }
  if (identity->has_path && identity->path[0]) {
    sha256_Update(&ctx, (const uint8_t *)(identity->path),
                  strlen(identity->path));
  }
  sha256_Final(&ctx, hash);
  return 1;
}

static bool check_cointype(const CoinInfo *coin, uint32_t slip44, bool full) {
#if BITCOIN_ONLY
  (void)full;
#else
  if (!full) {
    // Some wallets such as Electron-Cash (BCH) store coins on Bitcoin paths.
    // We can allow spending these coins from Bitcoin paths if the coin has
    // implemented strong replay protection via SIGHASH_FORKID. However, we
    // cannot allow spending any testnet coins from Bitcoin paths, because
    // otherwise an attacker could trick the user into spending BCH on a Bitcoin
    // path by signing a seemingly harmless BCH Testnet transaction.
    if (slip44 == SLIP44_BITCOIN && coin->has_fork_id &&
        coin->coin_type != SLIP44_TESTNET) {
      return true;
    }
  }
#endif
  return coin->coin_type == slip44;
}

bool coin_path_check(const CoinInfo *coin, InputScriptType script_type,
                     uint32_t address_n_count, const uint32_t *address_n,
                     bool has_multisig, PathSchema unlock, bool full_check) {
  // This function checks that the path is a recognized path for the given coin.
  // Used by GetAddress to prevent ransom attacks where a user could be coerced
  // to use an address with an unenumerable path and used by SignTx to ensure
  // that a user cannot be coerced into signing a testnet transaction or a
  // Litecoin transaction which in fact spends Bitcoin. If full_check is true,
  // then this function also checks that the path fully matches the script type
  // and coin type. This is used to determine whether a warning should be shown.

  if (address_n_count == 0) {
    return false;
  }

  bool valid = true;
  // m/44' : BIP44 Legacy
  // m / purpose' / coin_type' / account' / change / address_index
  if (address_n[0] == PATH_HARDENED + 44) {
    valid = valid && (address_n_count == 5);
    valid = valid && check_cointype(coin, address_n[1], full_check);
    valid = valid && (address_n[2] & PATH_HARDENED);
    valid = valid && ((address_n[2] & PATH_UNHARDEN_MASK) <= PATH_MAX_ACCOUNT);
    valid = valid && (address_n[3] <= PATH_MAX_CHANGE);
    valid = valid && (address_n[4] <= PATH_MAX_ADDRESS_INDEX);
    if (full_check) {
      valid = valid && (script_type == InputScriptType_SPENDADDRESS);
      valid = valid && (!has_multisig);
    }
    return valid;
  }

  if (address_n[0] == PATH_HARDENED + 45 && address_n_count != 6) {
    if (address_n_count == 4) {
      // m/45' - BIP45 Copay Abandoned Multisig P2SH
      // m / purpose' / cosigner_index / change / address_index
      // Patterns without a coin_type field must be treated as Bitcoin paths.
      valid = valid && check_cointype(coin, SLIP44_BITCOIN, false);
      valid = valid && (address_n[1] <= 100);
      valid = valid && (address_n[2] <= PATH_MAX_CHANGE);
      valid = valid && (address_n[3] <= PATH_MAX_ADDRESS_INDEX);
    } else if (address_n_count == 5) {
      if (address_n[1] & PATH_HARDENED) {
        // Unchained Capital compatibility pattern. Will be removed in the
        // future.
        // m / 45' / coin_type' / account' / [0-1000000] / address_index
        valid = valid && check_cointype(coin, address_n[1], full_check);
        valid = valid && (address_n[2] & PATH_HARDENED);
        valid =
            valid && ((address_n[2] & PATH_UNHARDEN_MASK) <= PATH_MAX_ACCOUNT);
        valid = valid && (address_n[3] <= 1000000);
        valid = valid && (address_n[4] <= PATH_MAX_ADDRESS_INDEX);
      } else {
        // Casa proposed "universal multisig" pattern with unhardened parts.
        // m/45'/coin_type/account/change/address_index
        valid = valid &&
                check_cointype(coin, address_n[1] | PATH_HARDENED, full_check);
        valid = valid && (address_n[2] <= PATH_MAX_ACCOUNT);
        valid = valid && (address_n[3] <= PATH_MAX_CHANGE);
        valid = valid && (address_n[4] <= PATH_MAX_ADDRESS_INDEX);
      }
    } else {
      return false;
    }

    if (full_check) {
      valid = valid && (script_type == InputScriptType_SPENDADDRESS ||
                        script_type == InputScriptType_SPENDMULTISIG);
      valid = valid && has_multisig;
    }

    return valid;
  }

  if (address_n[0] == PATH_HARDENED + 45 && address_n_count == 6) {
    // Unchained Capital compatibility pattern.
    // m/45'/coin_type'/account'/[0-1000000]/change/address_index
    // m/45'/coin_type/account/[0-1000000]/change/address_index
    valid =
        valid && check_cointype(coin, PATH_HARDENED | address_n[1], full_check);
    valid = valid &&
            ((address_n[1] & PATH_HARDENED) == (address_n[2] & PATH_HARDENED));
    valid = valid && ((address_n[2] & PATH_UNHARDEN_MASK) <= PATH_MAX_ACCOUNT);
    valid = valid && (address_n[3] <= 1000000);
    valid = valid && (address_n[4] <= PATH_MAX_CHANGE);
    valid = valid && (address_n[5] <= PATH_MAX_ADDRESS_INDEX);

    if (full_check) {
      valid = valid && (script_type == InputScriptType_SPENDADDRESS ||
                        script_type == InputScriptType_SPENDMULTISIG ||
                        script_type == InputScriptType_SPENDWITNESS);
      valid = valid && has_multisig;
    }

    return valid;
  }

  if (address_n[0] == PATH_HARDENED + 48) {
    valid = valid && (address_n_count == 5 || address_n_count == 6);
    valid = valid && check_cointype(coin, address_n[1], full_check);
    valid = valid && (address_n[2] & PATH_HARDENED);
    valid = valid && ((address_n[2] & PATH_UNHARDEN_MASK) <= PATH_MAX_ACCOUNT);
    if (address_n_count == 5) {
      // [OBSOLETE] m/48' Copay Multisig P2SH
      // m / purpose' / coin_type' / account' / change / address_index
      // NOTE: this pattern is not recognized by trezor-core
      valid = valid && (address_n[3] <= PATH_MAX_CHANGE);
      valid = valid && (address_n[4] <= PATH_MAX_ADDRESS_INDEX);
      if (full_check) {
        valid = valid && has_multisig;
        valid = valid && (script_type == InputScriptType_SPENDMULTISIG);
      }
    } else if (address_n_count == 6) {
      // BIP-48:
      // m / purpose' / coin_type' / account' / type' / change / address_index
      valid = valid && (address_n[3] & PATH_HARDENED);
      uint32_t type = address_n[3] & PATH_UNHARDEN_MASK;
      valid = valid && (type <= 2);
      valid = valid && (type == 0 || coin->has_segwit);
      valid = valid && (address_n[4] <= PATH_MAX_CHANGE);
      valid = valid && (address_n[5] <= PATH_MAX_ADDRESS_INDEX);
      if (full_check) {
        valid = valid && has_multisig;
        switch (type) {
          case 0:
            valid = valid && (script_type == InputScriptType_SPENDMULTISIG ||
                              script_type == InputScriptType_SPENDADDRESS);
            break;
          case 1:
            valid = valid && (script_type == InputScriptType_SPENDP2SHWITNESS);
            break;
          case 2:
            valid = valid && (script_type == InputScriptType_SPENDWITNESS);
            break;
          default:
            return false;
        }
      }
    } else {
      return false;
    }
    return valid;
  }

  // m/49' : BIP49 SegWit
  // m / purpose' / coin_type' / account' / change / address_index
  if (address_n[0] == PATH_HARDENED + 49) {
    valid = valid && coin->has_segwit;
    valid = valid && (address_n_count == 5);
    valid = valid && check_cointype(coin, address_n[1], full_check);
    valid = valid && (address_n[2] & PATH_HARDENED);
    valid = valid && ((address_n[2] & PATH_UNHARDEN_MASK) <= PATH_MAX_ACCOUNT);
    valid = valid && (address_n[3] <= PATH_MAX_CHANGE);
    valid = valid && (address_n[4] <= PATH_MAX_ADDRESS_INDEX);
    if (full_check) {
      valid = valid && (script_type == InputScriptType_SPENDP2SHWITNESS);
    }
    return valid;
  }

  // m/84' : BIP84 Native SegWit
  // m / purpose' / coin_type' / account' / change / address_index
  if (address_n[0] == PATH_HARDENED + 84) {
    valid = valid && coin->has_segwit;
    valid = valid && (coin->bech32_prefix != NULL);
    valid = valid && (address_n_count == 5);
    valid = valid && check_cointype(coin, address_n[1], full_check);
    valid = valid && (address_n[2] & PATH_HARDENED);
    valid = valid && ((address_n[2] & PATH_UNHARDEN_MASK) <= PATH_MAX_ACCOUNT);
    valid = valid && (address_n[3] <= PATH_MAX_CHANGE);
    valid = valid && (address_n[4] <= PATH_MAX_ADDRESS_INDEX);
    if (full_check) {
      valid = valid && (script_type == InputScriptType_SPENDWITNESS);
    }
    return valid;
  }

  // m/86' : BIP86 Taproot
  // m / purpose' / coin_type' / account' / change / address_index
  if (address_n[0] == PATH_HARDENED + 86) {
    valid = valid && coin->has_taproot;
    valid = valid && (coin->bech32_prefix != NULL);
    valid = valid && (address_n_count == 5);
    valid = valid && check_cointype(coin, address_n[1], full_check);
    valid = valid && (address_n[2] & PATH_HARDENED);
    valid = valid && ((address_n[2] & PATH_UNHARDEN_MASK) <= PATH_MAX_ACCOUNT);
    valid = valid && (address_n[3] <= PATH_MAX_CHANGE);
    valid = valid && (address_n[4] <= PATH_MAX_ADDRESS_INDEX);
    if (full_check) {
      // we do not support Multisig with Taproot yet
      valid = valid && !has_multisig;
      valid = valid && (script_type == InputScriptType_SPENDTAPROOT);
    }
    return valid;
  }

  // Green Address compatibility pattern. Will be removed in the future.
  // m / [1,4] / address_index
  if (address_n[0] == 1 || address_n[0] == 4) {
    valid = valid && (coin->coin_type == SLIP44_BITCOIN);
    valid = valid && (address_n_count == 2);
    valid = valid && (address_n[1] <= PATH_MAX_ADDRESS_INDEX);
    if (full_check) {
      valid = valid && (script_type != InputScriptType_SPENDTAPROOT);
    }
    return valid;
  }

  // Green Address compatibility pattern. Will be removed in the future.
  // m / 3' / [1-100]' / [1,4] / address_index
  if (address_n[0] == PATH_HARDENED + 3) {
    valid = valid && (coin->coin_type == SLIP44_BITCOIN);
    valid = valid && (address_n_count == 4);
    valid = valid && (address_n[1] & PATH_HARDENED);
    valid = valid && ((address_n[1] & PATH_UNHARDEN_MASK) <= 100);
    valid = valid && (address_n[2] == 1 || address_n[2] == 4);
    valid = valid && (address_n[3] <= PATH_MAX_ADDRESS_INDEX);
    if (full_check) {
      valid = valid && (script_type != InputScriptType_SPENDTAPROOT);
    }
    return valid;
  }

  // Green Address compatibility patterns. Will be removed in the future.
  // m / 1195487518
  // m / 1195487518 / 6 / address_index
  if (address_n[0] == 1195487518) {
    valid = valid && (coin->coin_type == SLIP44_BITCOIN);
    if (address_n_count == 3) {
      valid = valid && (address_n[1] == 6);
      valid = valid && (address_n[2] <= PATH_MAX_ADDRESS_INDEX);
    } else if (address_n_count != 1) {
      return false;
    }
    if (full_check) {
      return false;
    }
    return valid;
  }

  // Casa compatibility pattern. Will be removed in the future.
  // m / 49 / coin_type / account / change / address_index
  if (address_n[0] == 49) {
    valid = valid && (address_n_count == 5);
    valid =
        valid && check_cointype(coin, PATH_HARDENED | address_n[1], full_check);
    valid = valid && ((address_n[1] & PATH_HARDENED) == 0);
    valid = valid && (address_n[2] <= PATH_MAX_ACCOUNT);
    valid = valid && (address_n[3] <= PATH_MAX_CHANGE);
    valid = valid && (address_n[4] <= PATH_MAX_ADDRESS_INDEX);
    if (full_check) {
      valid = valid && (script_type == InputScriptType_SPENDP2SHWITNESS);
    }
    return valid;
  }

  // m/10025' : SLIP25 CoinJoin
  // m / purpose' / coin_type' / account' / script_type' / change /
  // address_index
  if (address_n[0] == PATH_SLIP25_PURPOSE) {
    valid = valid && coin->has_taproot;
    valid = valid && (coin->bech32_prefix != NULL);
    valid = valid && (address_n_count == 6);
    valid = valid && check_cointype(coin, address_n[1], full_check);
    valid = valid && (address_n[2] == (PATH_HARDENED | 0));  // Only first acc.
    valid = valid && (address_n[3] == (PATH_HARDENED | 1));  // Only SegWit v1.
    valid = valid && (address_n[4] <= PATH_MAX_CHANGE);
    valid = valid &&
            ((unlock == SCHEMA_SLIP25_TAPROOT) ||
             (unlock == SCHEMA_SLIP25_TAPROOT_EXTERNAL && address_n[4] == 0));
    valid = valid && (address_n[5] <= PATH_MAX_ADDRESS_INDEX);
    if (full_check) {
      // we do not support Multisig for CoinJoin
      valid = valid && !has_multisig;
      valid = valid && (script_type == InputScriptType_SPENDTAPROOT);
    }
    return valid;
  }

  // unknown path
  return false;
}

bool is_multisig_input_script_type(InputScriptType script_type) {
  // we do not support Multisig with Taproot yet
  if (script_type == InputScriptType_SPENDMULTISIG ||
      script_type == InputScriptType_SPENDP2SHWITNESS ||
      script_type == InputScriptType_SPENDWITNESS) {
    return true;
  }
  return false;
}

bool is_multisig_output_script_type(OutputScriptType script_type) {
  // we do not support Multisig with Taproot yet
  if (script_type == OutputScriptType_PAYTOMULTISIG ||
      script_type == OutputScriptType_PAYTOP2SHWITNESS ||
      script_type == OutputScriptType_PAYTOWITNESS) {
    return true;
  }
  return false;
}

bool is_internal_input_script_type(InputScriptType script_type) {
  if (script_type == InputScriptType_SPENDADDRESS ||
      script_type == InputScriptType_SPENDMULTISIG ||
      script_type == InputScriptType_SPENDP2SHWITNESS ||
      script_type == InputScriptType_SPENDWITNESS ||
      script_type == InputScriptType_SPENDTAPROOT) {
    return true;
  }
  return false;
}

bool is_change_output_script_type(OutputScriptType script_type) {
  if (script_type == OutputScriptType_PAYTOADDRESS ||
      script_type == OutputScriptType_PAYTOMULTISIG ||
      script_type == OutputScriptType_PAYTOP2SHWITNESS ||
      script_type == OutputScriptType_PAYTOWITNESS ||
      script_type == OutputScriptType_PAYTOTAPROOT) {
    return true;
  }
  return false;
}

bool is_segwit_input_script_type(InputScriptType script_type) {
  if (script_type == InputScriptType_SPENDP2SHWITNESS ||
      script_type == InputScriptType_SPENDWITNESS ||
      script_type == InputScriptType_SPENDTAPROOT) {
    return true;
  }
  return false;
}

bool is_segwit_output_script_type(OutputScriptType script_type) {
  if (script_type == OutputScriptType_PAYTOP2SHWITNESS ||
      script_type == OutputScriptType_PAYTOWITNESS ||
      script_type == OutputScriptType_PAYTOTAPROOT) {
    return true;
  }
  return false;
}

bool change_output_to_input_script_type(OutputScriptType output_script_type,
                                        InputScriptType *input_script_type) {
  switch (output_script_type) {
    case OutputScriptType_PAYTOADDRESS:
      *input_script_type = InputScriptType_SPENDADDRESS;
      return true;
    case OutputScriptType_PAYTOMULTISIG:
      *input_script_type = InputScriptType_SPENDMULTISIG;
      return true;
    case OutputScriptType_PAYTOWITNESS:
      *input_script_type = InputScriptType_SPENDWITNESS;
      return true;
    case OutputScriptType_PAYTOP2SHWITNESS:
      *input_script_type = InputScriptType_SPENDP2SHWITNESS;
      return true;
    case OutputScriptType_PAYTOTAPROOT:
      *input_script_type = InputScriptType_SPENDTAPROOT;
      return true;
    default:
      return false;
  }
}

void slip21_from_seed(const uint8_t *seed, int seed_len, Slip21Node *out) {
  hmac_sha512((uint8_t *)"Symmetric key seed", 18, seed, seed_len, out->data);
}

void slip21_derive_path(Slip21Node *inout, const uint8_t *label,
                        size_t label_len) {
  HMAC_SHA512_CTX hctx = {0};
  hmac_sha512_Init(&hctx, inout->data, 32);
  hmac_sha512_Update(&hctx, (uint8_t *)"\0", 1);
  hmac_sha512_Update(&hctx, label, label_len);
  hmac_sha512_Final(&hctx, inout->data);
}

const uint8_t *slip21_key(const Slip21Node *node) { return &node->data[32]; }

bool cryptoCosiVerify(const ed25519_signature signature, const uint8_t *message,
                      const size_t message_len, const int threshold,
                      const ed25519_public_key *pubkeys,
                      const int pubkeys_count, const uint8_t sigmask)

{
  if (sigmask == 0 || threshold < 1 || pubkeys_count < 1 || pubkeys_count > 8) {
    // invalid parameters:
    // - sigmask must specify at least one signer
    // - at least one signature must be required
    // - at least one pubkey must be provided
    // - at most 8 pubkeys are supported (bit size of sigmask)
    return false;
  }
  if (sigmask >= (1 << pubkeys_count)) {
    // sigmask indicates more signers than provided pubkeys
    return false;
  }

  ed25519_public_key selected_keys[8] = {0};
  int N = 0;
  for (int i = 0; i < pubkeys_count; i++) {
    if (sigmask & (1 << i)) {
      memcpy(selected_keys[N], pubkeys[i], sizeof(ed25519_public_key));
      N++;
    }
  }

  if (N < threshold) {
    // not enough signatures
    return false;
  }

  ed25519_public_key pk_combined = {0};
  int res = ed25519_cosi_combine_publickeys(pk_combined, selected_keys, N);
  if (res != 0) {
    // error combining public keys
    return false;
  }

  res = ed25519_sign_open(message, message_len, pk_combined, signature);
  return res == 0;
}