pdf_writer.encrypt(user_pwd=None, owner_pwd=None, use_128bit=True)报错TypeError: unsupported operand type(s) for +: 'NoneType' and 'str'

这个错误提示是因为在调用pdf_writer.encrypt()方法时，传入的参数user_pwd或owner_pwd是None，而在方法中使用了字符串类型的操作。

解决方法是在调用方法时，确保传入的参数user_pwd和owner_pwd是字符串类型的，例如：

pdf_writer.encrypt(user_pwd='', owner_pwd='mypassword', use_128bit=True)

或者在方法内部增加类型判断和默认值，例如：

def encrypt(self, user_pwd=None, owner_pwd=None, use_128bit=True):
    if user_pwd is None:
        user_pwd = ''
    if owner_pwd is None:
        owner_pwd = ''
    ...

这样就可以避免该错误发生。

相关问题

grant execute on dbms_crypto to system; declare input_string VARCHAR2 (200) := 'Secret Message'; output_string VARCHAR2(2000); encrypted_raw RAW(2000); decrypted_raw RAW(2000); num_key_bytes NUMBER := 256/8; key_bytes_raw RAW(32); encryption_type PLS_INTEGER := DBMS_CRYPTO.ENCRYPT_AES256 + DBMS_CRYPTO.CHAIN_CBC + DBMS_CRYPTO.PAD_PKCS5; begin DBMS_OUTPUT.PUT_LINE(input_string); key_bytes_raw := DBMS_CRYPTO.RANDOMBYTES(num_key_bytes); encrypted_raw := DBMS_CRYPTO.ENCRYPT ( src => UTL_I18N.STRING_TO_RAW(input_string, 'AL32UTF8'), typ => encryption_type, key => key_bytes_raw ); decrypted_raw := DBMS_CRYPTO.DECRYPT ( src => encrypted_raw, typ => encryption_type, key => key_bytes_raw ); output_string := UTL_I18N.RAW_TO_CHAR(decrypted_raw, 'AL32UTF8'); DBMS_OUTPUT.PUT_LINE(output_string); end; declare l_src_data varchar2(20); l_type pls_integer :=DBMS_CRYPTO.ENCRYPT_AES128 + DBMS_CRYPTO.CHAIN_CBC + DBMS_CRYPTO.PAD_PKCS5; l_key varchar2(20) :='0123456789123456'; l_encval raw(2000); CURSOR secret_cursor IS select phonenumber from customer; begin OPEN secret_cursor; LOOP FETCH secret_cursor INTO l_src_data; l_encval :=dbms_crypto.encrypt( src=>utl_i18n.string_to_raw(l_src_data,'AL32UTF8'), typ=>l_type, key=>utl_i18n.string_to_raw(l_key,'AL32UTF8')); DBMS_OUTPUT.PUT_LINE (l_encval); EXIT WHEN secret_cursor%NOTFOUND; END LOOP; CLOSE secret_cursor; end; declare ;_src_data row(100) :=hextoraw("190248129038903853275ijdkvjkad'); l_type pls_integer :=dbms_crypto.encrypt_aes128+ + DBMS_CRYPTO.CHAIN_CBC + DBMS_CRYPTO.PAD_PKCS5; l_key varchar2(20) :='0123456789123456'; l_decval raw(200); begin l_decval :=dbms_crypto.decrypt( src=>l_src_data, typ=>l_type, key=>utl_i18n.string_to_raw(l_key,'AL32UTF8')); end; SELECT Price FROM PRODUCT WHERE ProductID = 5;修正这一段代码

以下是修正后的代码：

grant execute on dbms_crypto to system;

-- 第一个代码块
declare
  input_string       VARCHAR2 (200) := 'Secret Message';
  output_string      VARCHAR2(2000);
  encrypted_raw      RAW(2000);
  decrypted_raw      RAW(2000);
  num_key_bytes      NUMBER := 256/8;
  key_bytes_raw      RAW(32);
  encryption_type    PLS_INTEGER := DBMS_CRYPTO.ENCRYPT_AES256 + DBMS_CRYPTO.CHAIN_CBC + DBMS_CRYPTO.PAD_PKCS5;
begin
  DBMS_OUTPUT.PUT_LINE(input_string);
  key_bytes_raw := DBMS_CRYPTO.RANDOMBYTES(num_key_bytes);
  encrypted_raw := DBMS_CRYPTO.ENCRYPT(src => UTL_I18N.STRING_TO_RAW(input_string, 'AL32UTF8'), typ => encryption_type, key => key_bytes_raw);
  decrypted_raw := DBMS_CRYPTO.DECRYPT(src => encrypted_raw, typ => encryption_type, key => key_bytes_raw);
  output_string := UTL_I18N.RAW_TO_CHAR(decrypted_raw, 'AL32UTF8');
  DBMS_OUTPUT.PUT_LINE(output_string);
end;

-- 第二个代码块
declare
  l_src_data varchar2(20);
  l_type pls_integer := DBMS_CRYPTO.ENCRYPT_AES128 + DBMS_CRYPTO.CHAIN_CBC + DBMS_CRYPTO.PAD_PKCS5;
  l_key varchar2(20) := '0123456789123456';
  l_encval raw(2000);
  cursor secret_cursor is select phonenumber from customer;
begin
  open secret_cursor;
  loop
    fetch secret_cursor into l_src_data;
    exit when secret_cursor%notfound;
    l_encval := dbms_crypto.encrypt(src => utl_i18n.string_to_raw(l_src_data,'AL32UTF8'), typ => l_type, key => utl_i18n.string_to_raw(l_key,'AL32UTF8'));
    dbms_output.put_line(l_encval);
  end loop;
  close secret_cursor;
end;

-- 第三个代码块
declare
  l_src_data raw(100) := hextoraw('190248129038903853275ijdkvjkad');
  l_type pls_integer := DBMS_CRYPTO.ENCRYPT_AES128 + DBMS_CRYPTO.CHAIN_CBC + DBMS_CRYPTO.PAD_PKCS5;
  l_key varchar2(20) := '0123456789123456';
  l_decval raw(200);
begin
  l_decval := dbms_crypto.decrypt(src => l_src_data, typ => l_type, key => utl_i18n.string_to_raw(l_key,'AL32UTF8'));
end;

-- SQL 查询语句
SELECT Price FROM PRODUCT WHERE ProductID = 5;

注意：第三个代码块中的 `l_src_data` 变量的赋值语句中，修正了单引号和双引号的不匹配问题。

declare l_src_data varchar2(20); l_type pls_integer :=DBMS_CRYPTO.ENCRYPT_AES128 + DBMS_CRYPTO.CHAIN_CBC + DBMS_CRYPTO.PAD_PKCS5; l_key varchar2(20) :='0123456789123456'; l_encval raw(2000); CURSOR secret_cursor IS select phonenumber from customer; begin OPEN secret_cursor; LOOP FETCH secret_cursor INTO l_src_data; l_encval :=dbms_crypto.encrypt( src=>utl_i18n.string_to_raw(l_src_data,'AL32UTF8'), typ=>l_type, key=>utl_i18n.string_to_raw(l_key,'AL32UTF8')); DBMS_OUTPUT.PUT_LINE (l_encval); EXIT WHEN secret_cursor%NOTFOUND; END LOOP; CLOSE secret_cursor; end; declare ;_src_data row(100) :=hextoraw("190248129038903853275ijdkvjkad'); l_type pls_integer :=dbms_crypto.encrypt_aes128+ + DBMS_CRYPTO.CHAIN_CBC + DBMS_CRYPTO.PAD_PKCS5; l_key varchar2(20) :='0123456789123456'; l_decval raw(200); begin l_decval :=dbms_crypto.decrypt( src=>l_src_data, typ=>l_type, key=>utl_i18n.string_to_raw(l_key,'AL32UTF8')); end;改错

有几个错误需要改正：

1. 在第一个代码块中，`raw(2000)` 应该改为 `raw(200)`，因为加密后的数据不会超过 200 个字节。

2. 在第二个代码块中，`row(100)` 应该改为 `raw(100)`，因为需要将十六进制字符串转换为原始二进制数据。

3. 在第一个代码块和第二个代码块中，加密类型 `DBMS_CRYPTO.ENCRYPT_AES128` 应该改为 `DBMS_CRYPTO.ENCRYPT_AES128 + DBMS_CRYPTO.CHAIN_CBC + DBMS_CRYPTO.PAD_PKCS5`，以保证使用 AES128 算法、CBC 模式和 PKCS5 填充。

4. 在第二个代码块中，`l_src_data` 应该改为 `_src_data`，因为变量名不一致。

修改后的代码如下：

declare
  l_src_data varchar2(20);
  l_type pls_integer := DBMS_CRYPTO.ENCRYPT_AES128
                       + DBMS_CRYPTO.CHAIN_CBC
                       + DBMS_CRYPTO.PAD_PKCS5;
  l_key varchar2(20) := '0123456789123456';
  l_encval raw(200);
  
  CURSOR secret_cursor IS
    select phonenumber from customer;
begin
  OPEN secret_cursor;
  LOOP
    FETCH secret_cursor INTO l_src_data;
    EXIT WHEN secret_cursor%NOTFOUND;
    
    l_encval := dbms_crypto.encrypt(
      src => utl_i18n.string_to_raw(l_src_data, 'AL32UTF8'),
      typ => l_type,
      key => utl_i18n.string_to_raw(l_key, 'AL32UTF8')
    );
    
    DBMS_OUTPUT.PUT_LINE(l_encval);
  END LOOP;
  
  CLOSE secret_cursor;
end;

declare
  _src_data raw(100) := hextoraw('190248129038903853275ijdkvjkad');
  l_type pls_integer := DBMS_CRYPTO.ENCRYPT_AES128
                       + DBMS_CRYPTO.CHAIN_CBC
                       + DBMS_CRYPTO.PAD_PKCS5;
  l_key varchar2(20) := '0123456789123456';
  l_decval raw(200);
begin
  l_decval := dbms_crypto.decrypt(
    src => _src_data,
    typ => l_type,
    key => utl_i18n.string_to_raw(l_key, 'AL32UTF8')
  );
end;