LMDB Encryption Helper API

Helpers for setting up encryption. More...

Data Structures
struct	MDB_crypto_funcs
	A structure for dynamically loaded crypto modules. More...

Typedefs
typedef int(	MDB_str2key_func )(const char *passwd, MDB_val *key)
	A function for converting a string into an encryption key.
typedef MDB_crypto_funcs *(	MDB_crypto_hooks )(void)
	The function that returns the MDB_crypto_funcs structure.

Functions
void *	mdb_modload (const char *file, const char *symname, MDB_crypto_funcs **mcf_ptr, char **errmsg)
	Load a dynamically loadable module.
void	mdb_modunload (void *handle)
	Unload a dynamically loaded module.
void	mdb_modsetup (MDB_env *env, MDB_crypto_funcs *mcf_ptr, const char *passphrase)
	Set an environment to use the given crypto functions.

Detailed Description

Helpers for setting up encryption.

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Data Structure Documentation

struct MDB_crypto_funcs

A structure for dynamically loaded crypto modules.

This is the information that the command line tools expect in order to operate on encrypted or checksummed environments.

Data Fields
MDB_str2key_func *	mcf_str2key
MDB_enc_func *	mcf_encfunc
MDB_sum_func *	mcf_sumfunc
int	mcf_keysize
int	mcf_esumsize
int	mcf_sumsize

Field Documentation

int MDB_crypto_funcs::mcf_keysize

The size of an encryption key, in bytes

int MDB_crypto_funcs::mcf_esumsize

The size of the MAC, for authenticated encryption

int MDB_crypto_funcs::mcf_sumsize

The size of the checksum, for plain checksums

Typedef Documentation

typedef int( MDB_str2key_func)(const char *passwd, MDB_val *key)

A function for converting a string into an encryption key.

Parameters

[in]	passwd	The string to be converted.
[in,out]	key	The resulting key. The caller must provide the space for the key.

Returns

0 on success, non-zero on failure.

typedef MDB_crypto_funcs*( MDB_crypto_hooks)(void)

The function that returns the MDB_crypto_funcs structure.

The command line tools expect this function to be named "MDB_crypto". It must be exported by the dynamic module so that the tools can use it.

Returns

A pointer to a MDB_crypto_funcs structure.

Function Documentation

void* mdb_modload	(	const char *	file,
		const char *	symname,
		MDB_crypto_funcs **	mcf_ptr,
		char **	errmsg
	)

Load a dynamically loadable module.

Parameters

[in]	file	The pathname of the module to load.
[in]	symname	The name of a symbol to resolve in the module.
[out]	mcf_ptr	The crypto hooks returned from the module.
[out]	errmsg	Messages for any errors from trying to load the module.

Returns

The handle to the loadable module that can be unloaded by mdb_modunload(), or NULL if loading failed.

void mdb_modunload

(

void *

handle

)

Unload a dynamically loaded module.

All environments that used the functions in the module must be closed before unloading the module.

Parameters

[in]

handle

The handle returned by mdb_modload().

void mdb_modsetup	(	MDB_env *	env,
		MDB_crypto_funcs *	mcf_ptr,
		const char *	passphrase
	)

Set an environment to use the given crypto functions.

This is just a wrapper around mdb_env_set_encrypt() to ease use of dynamically loaded crypto functions.

Parameters

[in]	env	An environment handle returned by mdb_env_create()
[in]	mcf_ptr	The crypto hooks retrieved by mdb_modload().
[in]	passphrase	The secret used to generate the encryption key for the environment.