context.h

/*******************************************************************************
 *   Ledger App - Bitcoin Wallet
 *   (c) 2016-2019 Ledger
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 ********************************************************************************/

#pragma once

#include "cx.h"
#include "filesystem_tx.h"
#include "os.h"
#ifdef HAVE_NBGL
#include "nbgl_types.h"
#endif // HAVE_NBGL

#define MAX_OUTPUT_TO_CHECK 100
#define MAX_COIN_ID 13
#define MAX_SHORT_COIN_ID 5

#define MAGIC_TRUSTED_INPUT 0x32

/**
 * Current state of an untrusted transaction hashing
 */
enum transaction_state_e {
  /** No transaction in progress */
  TRANSACTION_NONE = 0x00,
  /** Transaction defined, waiting for an input to be hashed */
  TRANSACTION_DEFINED_WAIT_INPUT = 0x01,
  /** Transaction defined, input hashing in progress, pending input script
     data */
  TRANSACTION_INPUT_HASHING_IN_PROGRESS_INPUT_SCRIPT = 0x02,
  /** Transaction defined, input hashing done, pending output hashing for this
     input */
  TRANSACTION_INPUT_HASHING_DONE = 0x03,
  /** Transaction defined, waiting for an output to be hashed */
  TRANSACTION_DEFINED_WAIT_OUTPUT = 0x04,
  /** Transaction defined, output hashing in progress for a complex script,
     pending output script data */
  TRANSACTION_OUTPUT_HASHING_IN_PROGRESS_OUTPUT_SCRIPT = 0x05,
  /** Transaction defined, output hashing done, pending finalization */
  TRANSACTION_OUTPUT_HASHING_DONE = 0x06,
  /** Extra data present */
  TRANSACTION_PROCESS_EXTRA = 0x07,
  /** Transaction parsed */
  TRANSACTION_PARSED = 0x08,
  /** Transaction parsed, ready to prepare for signature after validating the
     user outputs */
  TRANSACTION_PRESIGN_READY = 0x09,
  /** Transaction fully parsed, ready to be signed */
  TRANSACTION_SIGN_READY = 0x0a,
};
typedef enum transaction_state_e transaction_state_t;

enum output_parsing_state_e {
  OUTPUT_PARSING_NONE = 0x00,
  OUTPUT_PARSING_NUMBER_OUTPUTS = 0x01,
  OUTPUT_PARSING_OUTPUT = 0x02,
  OUTPUT_FINALIZE_TX = 0x03,
  BIP44_CHANGE_PATH_VALIDATION = 0x04
};
typedef enum output_parsing_state_e output_parsing_state_t;

typedef union multi_hash {
  cx_sha256_t sha256;
  cx_blake2b_t blake2b;
} multi_hash;

struct segwit_hash_s {
  union multi_hash hashPrevouts;
};
struct segwit_cache_s {
  unsigned char hashedPrevouts[32];
  unsigned char hashedSequence[32];
  unsigned char hashedOutputs[32];
};

/**
 * Structure defining an operation on a transaction
 */
struct transaction_context_s {
  /** Transient over signing components */

  /** Remaining number of inputs/outputs to process for this transaction */
  unsigned long int transactionRemainingInputsOutputs;
  /** Index of the currently processed input/output for this transaction */
  unsigned long int transactionCurrentInputOutput;
  /** Remaining script bytes to process for the current input or output */
  unsigned long int scriptRemaining;

  /** Persistent over signing components */

  /** State of the transaction, type transaction_state_t */
  unsigned char transactionState;
  /** Computed sum of transaction inputs or value of the output to convert to
   * a trusted input */
  unsigned char transactionAmount[8];
  /** Flag indicating if this transaction has been processed before */
  unsigned char firstSigned;
  /** If the transaction is relaxed */
  unsigned char relaxed;
  /** If the transaction consumes a P2SH input */
  unsigned char consumeP2SH;
};
typedef struct transaction_context_s transaction_context_t;

struct tmp_output_s {
  /** Change address if initialized */
  unsigned char changeAddress[20];
  /** Flag set if the change address was initialized */
  unsigned char changeInitialized;
  /** Flag set if the change address was checked */
  unsigned char changeChecked;
  /** Flag set if the change address can be submitted */
  unsigned char changeAccepted;
  /** Flag set if the outputs have been fragmented */
  unsigned char multipleOutput;
};
typedef struct tmp_output_s tmp_output_t;

struct context_s {
  /** Index of the output to convert into a trusted input in a transaction */
  unsigned long int trustedInputIndex;
  /** (Integrity protected) transaction context */
  transaction_context_t transactionContext;

  /** Full transaction hash context */
  union multi_hash transactionHashFull;
  /** Authorization transaction hash context */
  cx_sha256_t transactionHashAuthorization;
  /** Current hash to perform (TRANSACTION_HASH_) */
  unsigned char transactionHashOption;

  /* Segregated Witness changes */

  union {
    struct segwit_hash_s hash;
    struct segwit_cache_s cache;
  } segwit;
  unsigned char transactionVersion[4];
  unsigned char inputValue[8];
  unsigned char usingSegwit;
  unsigned char usingCashAddr;
  unsigned char segwitParsedOnce;
  /** Prevents display of segwit input warning at each InputHashStart APDU */
  unsigned char segwitWarningSeen;

  /* /Segregated Witness changes */

  /** Size currently available to the transaction parser */
  unsigned char transactionDataRemaining;
  /** Current pointer to the transaction buffer for the transaction parser */
  unsigned char *transactionBufferPointer;
  /** Trusted Input index processed */
  unsigned char trustedInputProcessed;
  /** Transaction input to catch for a Trusted Input lookup */
  unsigned long int transactionTargetInput;

  /** Length of the incoming command */
  unsigned short inLength;
  /** Length of the outgoing command */
  unsigned short outLength;

  /** Status Word of the response */
  unsigned short sw;

  /** Current scratch buffer */
  unsigned char *tmp;

  // was previously in NVRAM
  transaction_summary_t transactionSummary;

  unsigned short hashedMessageLength;

  union {
    tmp_output_t output;
  } tmpCtx;

  unsigned char currentOutput[MAX_OUTPUT_TO_CHECK];
  unsigned short currentOutputOffset;
  unsigned int remainingOutputs;
  unsigned int totalOutputs;
  unsigned int discardSize;
  unsigned char outputParsingState;
  unsigned char totalOutputAmount[8];
  unsigned char changeOutputFound;

  /* Overwinter */
  unsigned char usingOverwinter;
  unsigned char overwinterSignReady;
  unsigned char nVersionGroupId[4];
  unsigned char nExpiryHeight[4];
  unsigned char nLockTime[4];
  unsigned char sigHashType[4];
};
typedef struct context_s context_t;

/**
 * Structure to configure the bitcoin application for a given altcoin
 *
 */
typedef enum coin_flags_e {
  FLAG_PEERCOIN_UNITS = 1,
  FLAG_PEERCOIN_SUPPORT = 2,
  FLAG_SEGWIT_CHANGE_SUPPORT = 4
} coin_flags_t;

typedef enum coin_kind_e {
  COIN_KIND_BITCOIN_TESTNET,
  COIN_KIND_BITCOIN,
  COIN_KIND_BITCOIN_CASH,
  COIN_KIND_BITCOIN_GOLD,
  COIN_KIND_LITECOIN,
  COIN_KIND_DOGE,
  COIN_KIND_DASH,
  COIN_KIND_ZCASH,
  COIN_KIND_KOMODO,
  COIN_KIND_RFU,
  COIN_KIND_STRATIS,
  COIN_KIND_PEERCOIN,
  COIN_KIND_PIVX,
  COIN_KIND_STEALTH,
  COIN_KIND_VIACOIN,
  COIN_KIND_VERTCOIN,
  COIN_KIND_DIGIBYTE,
  COIN_KIND_BITCOIN_PRIVATE,
  COIN_KIND_XRHODIUM,
  COIN_KIND_HORIZEN,
  COIN_KIND_GAMECREDITS,
  COIN_KIND_FIRO,
  COIN_KIND_ZCLASSIC,
  COIN_KIND_XSN,
  COIN_KIND_NIX,
  COIN_KIND_LBRY,
  COIN_KIND_RESISTANCE,
  COIN_KIND_RAVENCOIN,
  COIN_KIND_HYDRA,
  COIN_KIND_UNUSED
} coin_kind_t;

void context_init(void);

extern context_t context;