Clarification between "pragma key = x'...'" and "pragma hexkey = ..."

[Willena]

Hi ! @utelle

Just a quick question:
In the 1.3.10 release, pragma hexkey/hexrekey was added.

Could you explain the differences between the "new" pragma hexkey and existing pragma key with raw values shown in the documentation website, pragma key section ?

Raw key data examples (taken from the doc):

-- Example of a raw key for the SQLCipher scheme  (no salt)
PRAGMA key = "x'54686973206973206D792076657279207365637265742070617373776F72642E'";
-- Example of a raw key for the sqleet scheme (no salt)
PRAGMA key = 'raw:54686973206973206D792076657279207365637265742070617373776F72642E';

-- Example of a raw key for the SQLCipher scheme (with salt)
PRAGMA key = "x'54686973206973206D792076657279207365637265742070617373776F72642E2E73616C7479206B65792073616C742E'";
-- Example of a raw key for the sqleet scheme (with salt)
PRAGMA key = 'raw:54686973206973206D792076657279207365637265742070617373776F72642E2E73616C7479206B65792073616C742E';

[utelle]

Just a quick question: In the 1.3.10 release, pragma hexkey/hexrekey was added.

Yes, this new pragma was added to provide better compatibility with the official SEE extension (see paragraph 6). If a passphrase contains binary data, it is cumbersome to specify it as a string value, if at all possible. PRAGMA hexkey= allows to specify a hexadecimal encoded string that is intercally decoded to binary data (which are then used to derive the actual encryption key).

Could you explain the differences between the "new" pragma hexkey and existing pragma key with raw values shown in the documentation website, pragma key section ?

The variants of PRAGMA key= with raw values were introduced to provide compatibility with SQLCipher resp sqleet. Both allow to provide raw key data (without performing key derivation). Only the SQLCipher and sqleet cipher schemes support this option and both require a specific syntax for the key data (as described in the examples). That is, it is the user's responsibility to perform key derivation with methods of his own choice.

In contrast, PRAGMA hexkey= does not circumvent key derivation.

I have to admit that the new pragma should be documented.

[Willena]

Thanks for the clarification !