PostgreSQL有效地处理数据的加密和解密的常见方法

CREATE EXTENSION pgcrypto;

-- 加密
SELECT encrypt('Hello World', 'y_secret_key', 'aes');

-- 解密
SELECT decrypt(encrypt('Hello World', 'y_secret_key', 'aes'), 'y_secret_key', 'aes');

-- 生成 RSA 密钥对
SELECT gen_rsa_private_key(2048) AS private_key, gen_rsa_public_key(2048) AS public_key;

-- 加密
SELECT encrypt_rsa('Hello World', public_key) AS encrypted_data 
FROM (SELECT gen_rsa_public_key(2048) AS public_key) t;

-- 解密
SELECT decrypt_rsa(encrypted_data, private_key) AS decrypted_data
FROM (
    SELECT 
        encrypt_rsa('Hello World', gen_rsa_public_key(2048)) AS encrypted_data,
        gen_rsa_private_key(2048) AS private_key
) t;

CREATE OR REPLACE FUNCTION custom_encrypt(text_to_encrypt text)
RETURNS text AS $$
DECLARE
    encrypted_text text := '';
    char_code integer;
BEGIN
    FOR i IN 1..length(text_to_encrypt) LOOP
        char_code := ascii(substring(text_to_encrypt, i, 1)) + 1;
        encrypted_text := encrypted_text || chr(char_code);
    END LOOP;
    RETURN encrypted_text;
END;
$$ LANGUAGE plpgsql;
 
CREATE OR REPLACE FUNCTION custom_decrypt(encrypted_text text)
RETURNS text AS $$
DECLARE
    decrypted_text text := '';
    char_code integer;
BEGIN
    FOR i IN 1..length(encrypted_text) LOOP
        char_code := ascii(substring(encrypted_text, i, 1)) - 1;
        decrypted_text := decrypted_text || chr(char_code);
    END LOOP;
    RETURN decrypted_text;
END;
$$ LANGUAGE plpgsql;

SELECT custom_encrypt('Hello World');
SELECT custom_decrypt(custom_encrypt('Hello World'));