步骤归纳：
数据库解密：
步骤一：
安装sqlcipher命令,首先需要安装brew
1. 在终端输入 ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)" ，按Enter键继续
2. 提示“Press RETURN to continue or any other key to abort”时，按Enter键继续
3. 提示”Password”时，输入当前用户开机密码，按Enter键继续
4. 等待安装成功之后在终端在运行 brew install sqlcipher
步骤二：
解密目标数据库xxxxx.db，123456为数据库密码，解密后的数据库为plaintext.db
1. 使用终端切换到数据库的路径下，命令 cd /Users/xxxxxxx 或 cd (拖动数据库所在文件夹到终端)，按Enter键继续
2. 切换到数据库所在文件夹之后，输入 sqlcipher xxxxx.db ，按Enter键继续
3. 提示“Enter SQL statements terminated with a ";"” 时，
输入 PRAGMA key = '123456';
按Enter键继续
4. 输入
ATTACH DATABASE 'plaintext.db' AS plaintext KEY '';
按Enter键继续
5. 输入
SELECT sqlcipher_export('plaintext');
按Enter键继续
6. 输入
DETACH DATABASE plaintext;
7. 生成的plaintext.db 即为解密后的数据库，可直接打开
一.
1.安装sqlcipher命令,首先需要安装brew, 在终端输入
ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
成功之后在终端在运行
brew install sqlcipher
二.
1. 创建加密数据库
$ sqlcipher encrypted.db
SQLCipher version 3.8.4.3 2014-04-03 16:53:12
Enter ".help" for instructions
Enter SQL statements terminated with a ";"
sqlite> PRAGMA key = 'thisiskey';
sqlite> create table encrypted (id integer, name text);
sqlite> .schema
CREATE TABLE encrypted (id integer, name text);
sqlite> .q
2. 打开加密数据库
$ sqlcipher encrypted.db
SQLCipher version 3.8.4.3 2014-04-03 16:53:12
Enter ".help" for instructions
Enter SQL statements terminated with a ";"
sqlite> PRAGMA key = 'thisiskey';
sqlite> .schema
CREATE TABLE encrypted (id integer, name text);
3. 修改数据库密码
sqlite> PRAGMA rekey = 'newkey';
4. 加密已有的数据库
$ sqlcipher banklist.sqlite3
SQLCipher version 3.8.4.3 2014-04-03 16:53:12
Enter ".help" for instructions
Enter SQL statements terminated with a ";"
sqlite> ATTACH DATABASE 'encrypted.db' AS encrypted KEY 'thisiskey';
sqlite> SELECT sqlcipher_export('encrypted');
sqlite> DETACH DATABASE encrypted;
5. 解密数据库
$ sqlcipher encrypted.db
SQLCipher version 3.8.4.3 2014-04-03 16:53:12
Enter ".help" for instructions
Enter SQL statements terminated with a ";"
sqlite> PRAGMA key = 'thisiskey';
sqlite> ATTACH DATABASE 'plaintext.db' AS plaintext KEY '';
sqlite> SELECT sqlcipher_export('plaintext');
sqlite> DETACH DATABASE plaintext;
转自 ：
satckoverflow.com上有人提到过在
sqlite> sqlcipher-shell32.exe test.db
sqlite> PRAGMA KEY = '12345';
给刚打开的数据库设置密码后，马上接着往数据库执行create table和 insert操作。最后用
sqlite> .e
退出该数据库。但是下次再用
sqlite> sqlcipher-shell32.exe test.db
登录，在输入密码前执行了.schema等其他操作
sqlite>.schema
Error: file is encrypted or is not a database
sqlite> PRAGMA KEY = '12345';
Error: file is encrypted or is not a database
遭到提示：Error: file is encrypted or is not a database
just-in-time key derivation的要求，没有首先输密码解密再进行其他操作。
有图为证：
以下为正确操作过程：
SQLite version 3.7.15.2 2013-01-09 11:53:05
Enter ".help" for instructions
Enter SQL statements terminated with a ";"
sqlite> PRAGMA KEY = '12345';
sqlite> .schema
CREATE TABLE t(name text);
sqlite> select * from t;
n1
sqlite> ----------------以下为错误操作过程：
Enter SQL statements terminated with a ";"
sqlite> .schema
Error: file is encrypted or is not a database
sqlite> PRAGMA KEY = '12345';
sqlite> .schema
Error: file is encrypted or is not a database
sqlite>确实如此。
以上过程你可以自己亲自验证以下。
sqlcipher-shell32.exe）执行命令，与通过sqlite3 api调用操作sqlite3数据库，是一样的道理
参考：
https://www.zetetic.net/sqlcipher/sqlcipher-api/#key
SELECT, CREATE TABLE, UPDATE, etc.) and pages need to be read or written, the key is prepared for use.
The key itself can be a passphrase, which is converted to a key using PBKDF2 key derivation. The result is used as the encryption key for the database.
sqlite> PRAGMA key = 'passphrase';Alternatively, it is possible to specify an exact byte sequence using a blob literal. With this method, it is the calling application's responsibility to ensure that the data provided is a 64 character hex string, which will be converted directly to 32 bytes (256 bits) of key data.
sqlite> PRAGMA key = "x'2DD29CA851E7B56E4697B0E1F08507293D761A05CE4D1B628663F411A8086D99'";PRAGMA key
The easiest way to do this is select off the sqlite_master table, which will attempt to read the first page of the database and will parse the schema.
sqlite> PRAGMA key = 'passphrase';
sqlite> SELECT count(*) FROM sqlite_master; -- if this throws an error, the key was incorrect. If it succeeds and returns a numeric value, the key is correct;The same check can be implemented in C code
sqlite3_key(database, "test123", 7);
if (sqlite3_exec(database, "SELECT count(*) FROM sqlite_master;", NULL, NULL, NULL) == SQLITE_OK) {
// key is correct.
} else {
// key is incorrect
}PRAGMA key
