167 lines
6.7 KiB
Plaintext
167 lines
6.7 KiB
Plaintext
== SQLCipher ==
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SQLCipher is an SQLite extension that provides transparent 256-bit AES encryption of
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database files. Pages are encrypted before being written to disk and are decrypted
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when read back. Due to the small footprint and great performance it’s ideal for
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protecting embedded application databases and is well suited for mobile development.
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The official SQLCipher software site is http://sqlcipher.net
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SQLCipher was initially developed by Stephen Lombardo at Zetetic LLC
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(sjlombardo@zetetic.net) as the encrypted database layer for Strip,
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an iPhone data vault and password manager (http://getstrip.com).
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[Features]
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- Fast performance with as little as 5-15% overhead for encryption on many operations
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- 100% of data in the database file is encrypted
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- Good security practices (CBC mode, key derivation)
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- Zero-configuration and application level cryptography
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- Algorithms provided by the peer reviewed OpenSSL crypto library.
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[Compiling]
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Building SQLCipher is almost the same as compiling a regular version of
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SQLite with two small exceptions:
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1. You must define SQLITE_HAS_CODEC and SQLITE_TEMP_STORE=2 when building sqlcipher
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2. You need to link against a OpenSSL's libcrypto
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Example Static linking (replace /opt/local/lib with the path to libcrypto.a)
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$ ./configure --enable-tempstore=yes CFLAGS="-DSQLITE_HAS_CODEC" \
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LDFLAGS="/opt/local/lib/libcrypto.a"
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$ make
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Example Dynamic linking
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$ ./configure --enable-tempstore=yes CFLAGS="-DSQLITE_HAS_CODEC" \
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LDFLAGS="-lcrypto"
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$ make
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[Encrypting a database]
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To specify an encryption passphrase for the database via the SQL interface you
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use a pragma. The passphrase you enter is passed through PBKDF2 key derivation to
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obtain the encryption key for the database
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PRAGMA key = 'passphrase';
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Alternately, you can specify an exact byte sequence using a blob literal. If you
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use this method it is your responsibility to ensure that the data you provide a
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64 character hex string, which will be converted directly to 32 bytes (256 bits) of
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key data without key derivation.
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PRAGMA key = "x'2DD29CA851E7B56E4697B0E1F08507293D761A05CE4D1B628663F411A8086D99'";
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To encrypt a database programatically you can use the sqlite3_key function.
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The data provided in pKey is converted to an encryption key according to the
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same rules as PRAGMA key.
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int sqlite3_key(sqlite3 *db, const void *pKey, int nKey);
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PRAGMA key or sqlite3_key should be called as the first operation when a database is open.
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[Changing a database key]
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To change the encryption passphrase for an existing database you may use the rekey pragma
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after you've supplied the correct database password;
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PRAGMA key = 'passphrase'; -- start with the existing database passphrase
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PRAGMA rekey = 'new-passphrase'; -- rekey will reencrypt with the new passphrase
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The hexrekey pragma may be used to rekey to a specific binary value
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PRAGMA rekey = "x'2DD29CA851E7B56E4697B0E1F08507293D761A05CE4D1B628663F411A8086D99'";
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This can be accomplished programtically by using sqlite3_rekey;
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sqlite3_rekey(sqlite3 *db, const void *pKey, int nKey)
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[Support]
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The primary avenue for support and discussions is the SQLCipher users mailing list:
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http://groups.google.com/group/sqlcipher
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Issues or support questions on using SQLCipher should be entered into the
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GitHub Issue tracker:
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http://github.com/sjlombardo/sqlcipher/issues
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Please DO NOT post issues, support questions, or other problems to blog
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posts about SQLCipher as we do not monitor them frequently.
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If you are using SQLCipher in your own software please let us know at
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support@zetetic.net!
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[License]
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Copyright (c) 2008, ZETETIC LLC
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All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions are met:
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* Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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* Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in the
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documentation and/or other materials provided with the distribution.
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* Neither the name of the ZETETIC LLC nor the
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names of its contributors may be used to endorse or promote products
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derived from this software without specific prior written permission.
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THIS SOFTWARE IS PROVIDED BY ZETETIC LLC ''AS IS'' AND ANY
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EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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DISCLAIMED. IN NO EVENT SHALL ZETETIC LLC BE LIABLE FOR ANY
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DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
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ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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== End SQLCipher ==
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This directory contains source code to
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SQLite: An Embeddable SQL Database Engine
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To compile the project, first create a directory in which to place
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the build products. It is recommended, but not required, that the
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build directory be separate from the source directory. Cd into the
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build directory and then from the build directory run the configure
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script found at the root of the source tree. Then run "make".
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For example:
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tar xzf sqlite.tar.gz ;# Unpack the source tree into "sqlite"
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mkdir bld ;# Build will occur in a sibling directory
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cd bld ;# Change to the build directory
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../sqlite/configure ;# Run the configure script
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make ;# Run the makefile.
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make install ;# (Optional) Install the build products
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The configure script uses autoconf 2.61 and libtool. If the configure
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script does not work out for you, there is a generic makefile named
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"Makefile.linux-gcc" in the top directory of the source tree that you
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can copy and edit to suit your needs. Comments on the generic makefile
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show what changes are needed.
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The linux binaries on the website are created using the generic makefile,
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not the configure script. The windows binaries on the website are created
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using MinGW32 configured as a cross-compiler running under Linux. For
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details, see the ./publish.sh script at the top-level of the source tree.
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The developers do not use teh configure script.
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SQLite does not require TCL to run, but a TCL installation is required
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by the makefiles. SQLite contains a lot of generated code and TCL is
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used to do much of that code generation. The makefile also requires
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AWK.
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Contacts:
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http://www.sqlite.org/
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