if (GetPrivateKey (&privateKey))      break;    if (GetDigestAlgorithm (&digestAlgorithm))      break;    if ((status = R_SignInit (&context, digestAlgorithm)) != 0)      break;    while (!ReadUpdate (file, partIn, &partInLen, sizeof (partIn)))      if ((status = R_SignUpdate (&context, partIn, partInLen)) != 0)        break;    if (status)      break;    if ((status = R_SignFinal         (&context, signature, &signatureLen, privateKey)) != 0)      break;    if (WriteBlock        (signature, signatureLen, "  Enter filename to save the signature"))      break;  } while (0);  ReadFinal (file);  if (status)    PrintError ("signing file", status);  R_memset ((POINTER)&context, 0, sizeof (context));  R_memset ((POINTER)partIn, 0, sizeof (partIn));}static void DoVerifyFile (){  FILE *file;  R_RSA_PUBLIC_KEY *publicKey;  R_SIGNATURE_CTX context;  int digestAlgorithm, status;  unsigned char partIn[16], signature[MAX_SIGNATURE_LEN];  unsigned int partInLen, signatureLen;  status = 0;  if (ReadInit (&file, "  Enter name of file to verify"))    return;  do {    if (GetPublicKey (&publicKey))      break;    if (GetDigestAlgorithm (&digestAlgorithm))      break;    if (ReadBlock        (signature, &signatureLen, sizeof (signature),         "  Enter filename of signature"))      break;    if ((status = R_VerifyInit (&context, digestAlgorithm)) != 0)      break;    while (!ReadUpdate (file, partIn, &partInLen, sizeof (partIn)))      if ((status = R_VerifyUpdate (&context, partIn, partInLen)) != 0)        break;    if (status)      break;    if ((status = R_VerifyFinal         (&context, signature, signatureLen, publicKey)) != 0)      break;    PrintMessage ("Signature verified.");  } while (0);  ReadFinal (file);  if (status)    PrintError ("verifying file", status);  R_memset ((POINTER)&context, 0, sizeof (context));  R_memset ((POINTER)partIn, 0, sizeof (partIn));}static void DoSealFile (randomStruct)R_RANDOM_STRUCT *randomStruct;{  FILE *inFile, *outFile;  R_ENVELOPE_CTX context;  R_RSA_PUBLIC_KEY *publicKey;  int encryptionAlgorithm, status;  unsigned char encryptedKey[MAX_ENCRYPTED_KEY_LEN], *encryptedKeys[1],    iv[8], partIn[24], partOut[31];  unsigned int encryptedKeyLen, partInLen, partOutLen;  status = 0;  if (ReadInit (&inFile, "  Enter filename of content to seal"))    return;  if (WriteInit (&outFile, "  Enter filename to save the encrypted content")) {    ReadFinal (inFile);    return;  }  do {    if (GetPublicKey (&publicKey))      break;    if (GetEncryptionAlgorithm (&encryptionAlgorithm))      break;    encryptedKeys[0] = encryptedKey;    if ((status = R_SealInit         (&context, encryptedKeys, &encryptedKeyLen, iv, 1, &publicKey,          encryptionAlgorithm, randomStruct)) != 0)      break;    while (!ReadUpdate (inFile, partIn, &partInLen, sizeof (partIn))) {      if ((status = R_SealUpdate           (&context, partOut, &partOutLen, partIn, partInLen)) != 0)        break;      WriteUpdate (outFile, partOut, partOutLen);    }    if (status)      break;    if ((status = R_SealFinal (&context, partOut, &partOutLen)))      break;    WriteUpdate (outFile, partOut, partOutLen);      if (WriteBlock        (encryptedKey, encryptedKeyLen,         "  Enter filename to save the encrypted key"))      break;    if (WriteBlock        (iv, 8, "  Enter filename to save the initializing vector"))      break;  } while (0);    ReadFinal (inFile);  WriteFinal (outFile);  if (status)    PrintError ("sealing file", status);  R_memset ((POINTER)&context, 0, sizeof (context));  R_memset ((POINTER)partIn, 0, sizeof (partIn));}static void DoOpenFile (){  FILE *inFile, *outFile;  R_ENVELOPE_CTX context;  R_RSA_PRIVATE_KEY *privateKey;  int encryptionAlgorithm, status;  unsigned char encryptedKey[MAX_ENCRYPTED_KEY_LEN], iv[8], partIn[24],    partOut[31];  unsigned int encryptedKeyLen, ivLen, partInLen, partOutLen;  status = 0;  if (ReadInit (&inFile, "  Enter filename of encrypted content to open"))    return;  if (WriteInit (&outFile, "  Enter filename to save the recovered content")) {    ReadFinal (inFile);    return;  }  do {    if (GetPrivateKey (&privateKey))      break;    if (GetEncryptionAlgorithm (&encryptionAlgorithm))      break;    if (ReadBlock        (encryptedKey, &encryptedKeyLen, sizeof (encryptedKey),         "  Enter filename of the encrypted key"))      break;      if (ReadBlock        (iv, &ivLen, 8, "  Enter filename of the initializing vector"))      break;    if ((status = R_OpenInit         (&context, encryptionAlgorithm, encryptedKey, encryptedKeyLen, iv,          privateKey)) != 0)      break;        while (!ReadUpdate (inFile, partIn, &partInLen, sizeof (partIn))) {      if ((status = R_OpenUpdate           (&context, partOut, &partOutLen, partIn, partInLen)) != 0)        break;      WriteUpdate (outFile, partOut, partOutLen);    }    if (status)      break;    if ((status = R_OpenFinal (&context, partOut, &partOutLen)) != 0)      break;    WriteUpdate (outFile, partOut, partOutLen);  } while (0);    ReadFinal (inFile);  WriteFinal (outFile);  if (status)    PrintError ("opening file", status);  R_memset ((POINTER)&context, 0, sizeof (context));  R_memset ((POINTER)partOut, 0, sizeof (partOut));}static void DoGenerateKeys (randomStruct)R_RANDOM_STRUCT *randomStruct;{  R_RSA_PROTO_KEY protoKey;  char command[80];  int status, keySize;  GetCommand    (command, sizeof (command),     "  Enter key size in bits, (508 to 1024)");  if (! *command)    return;  sscanf (command, "%d", &keySize);    protoKey.bits = (unsigned int)keySize;  protoKey.useFermat4 = 1;    if (status = R_GeneratePEMKeys      (&PUBLIC_KEY3, &PRIVATE_KEY3, &protoKey, randomStruct)) {    PrintError ("generating keys", status);    return;  }  PrintMessage ("Public key 3 and private key 3 are now ready to use.");  KEYPAIR3_READY = 1;    WriteKeypair3 ();}static void WriteKeypair3 (){  FILE *file;  char filename[256];    while (1) {    GetCommand      (filename, sizeof (filename),       "  Enter filename to save the keypair");    if (! *filename)      return;        if (filename[0] == '-' && filename[1] == '\0') {      /* use stdout */      file = stdout;      break;    }    if ((file = fopen (filename, "w")) != NULL)      /* successfully opened */      break;        PrintError ("ERROR: Cannot open a file with that name.  Try again.", 0);  }  fprintf (file, "Public Key, %u bits:\n", PUBLIC_KEY3.bits);  fprintf (file, "  modulus: ");  WriteBigInteger (file, PUBLIC_KEY3.modulus, sizeof (PUBLIC_KEY3.modulus));  fprintf (file, "  exponent: ");  WriteBigInteger (file, PUBLIC_KEY3.exponent, sizeof (PUBLIC_KEY3.exponent));  fprintf (file, "\nPrivate Key, %u bits:\n", PRIVATE_KEY3.bits);  fprintf (file, "  modulus: ");  WriteBigInteger (file, PRIVATE_KEY3.modulus, sizeof (PRIVATE_KEY3.modulus));  fprintf (file, "  public exponent: ");  WriteBigInteger    (file, PRIVATE_KEY3.publicExponent, sizeof (PRIVATE_KEY3.publicExponent));  fprintf (file, "  exponent: ");  WriteBigInteger    (file, PRIVATE_KEY3.exponent, sizeof (PRIVATE_KEY3.exponent));  fprintf (file, "  prime 1: ");  WriteBigInteger    (file, PRIVATE_KEY3.prime[0], sizeof (PRIVATE_KEY3.prime[0]));  fprintf (file, "  prime 2: ");  WriteBigInteger    (file, PRIVATE_KEY3.prime[1], sizeof (PRIVATE_KEY3.prime[1]));  fprintf (file, "  prime exponent 1: ");  WriteBigInteger    (file, PRIVATE_KEY3.primeExponent[0],     sizeof (PRIVATE_KEY3.primeExponent[0]));  fprintf (file, "  prime exponent 2: ");  WriteBigInteger    (file, PRIVATE_KEY3.primeExponent[1],     sizeof (PRIVATE_KEY3.primeExponent[1]));  fprintf (file, "  coefficient: ");  WriteBigInteger    (file, PRIVATE_KEY3.coefficient, sizeof (PRIVATE_KEY3.coefficient));  if (file != stdout)    fclose (file);}/* Write the byte string 'integer' to 'file', skipping over leading zeros. */static void WriteBigInteger (file, integer, integerLen)FILE *file;unsigned char *integer;unsigned int integerLen;{  while (*integer == 0 && integerLen > 0) {    integer++;    integerLen--;  }    if (integerLen == 0) {    /* Special case, just print a zero. */    fprintf (file, "00\n");    return;  }    for (; integerLen > 0; integerLen--)    fprintf (file, "%02x ", (unsigned int)(*integer++));  fprintf (file, "\n");}/* Ask the user to use public key 1, 2 or 3 and point publicKey to     the answer.   Return 0 on success or 1 if user cancels by entering a blank. */static int GetPublicKey (publicKey)R_RSA_PUBLIC_KEY **publicKey;{  char command[80];    while (1) {    if (!KEYPAIR3_READY)      GetCommand (command, sizeof (command), "  Public key 1 or 2?");    else      GetCommand (command, sizeof (command), "  Public key 1, 2 or 3?");    switch (*command) {    case '\0':      return (1);          case '1':      *publicKey = &PUBLIC_KEY1;      return (0);          case '2':      *publicKey = &PUBLIC_KEY2;      return (0);          case '3':      if (!KEYPAIR3_READY)        break;      *publicKey = &PUBLIC_KEY3;      return (0);          default:      if (KEYPAIR3_READY)        PrintError ("ERROR: Please enter 1, 2 or 3.  Try again.", 0);      else        PrintError ("ERROR: Please enter 1 or 2.  Try again.", 0);      break;    }  }}/* Ask the user to use private key 1, 2 or 3 and point privateKey to     the answer.   Return 0 on success or 1 if user cancels by entering a blank.