Name

RAND_egd — query entropy gathering daemon

Library

libcrypto.lib

Synopsis

#include <openssl/rand.h>

int RAND_egd(const char *path);
int RAND_egd_bytes(const char *path, int bytes);

int RAND_query_egd_bytes(const char *path, unsigned char *buf, int bytes);

Detailed Description

RAND_egd() queries the entropy gathering daemon EGD on socket path. It queries 255 bytes and uses RAND_add() to seed the OpenSSL built-in PRNG. RAND_egd(path) is a wrapper for RAND_egd_bytes(path, 255);

RAND_egd_bytes() queries the entropy gathering daemon EGD on socket path. It queries bytes bytes and uses RAND_add() to seed the OpenSSL built-in PRNG. This function is more flexible than RAND_egd(). When only one secret key must be generated, it is not necessary to request the full amount 255 bytes from the EGD socket. This can be advantageous, since the amount of entropy that can be retrieved from EGD over time is limited.

RAND_query_egd_bytes() performs the actual query of the EGD daemon on socket path. If buf is given, bytes bytes are queried and written into buf. If buf is NULL, bytes bytes are queried and used to seed the OpenSSL built-in PRNG using RAND_add().

Return Values

The functions always return -1

See Also

rand(), RAND_add(), RAND_cleanup()

History

RAND_egd() is available since OpenSSL 0.9.5.

RAND_egd_bytes() is available since OpenSSL 0.9.6.

RAND_query_egd_bytes() is available since OpenSSL 0.9.7.

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