|OPENSSL_ADD_ALL_ALGORITHMS(3)||Library Functions Manual||OPENSSL_ADD_ALL_ALGORITHMS(3)|
EVP_cleanup — add algorithms
to internal table
OpenSSL keeps an internal table of digest algorithms and ciphers. It uses this table to look up ciphers via functions such as EVP_get_cipherbyname(3).
adds all algorithms to the table (digests and ciphers).
adds all digest algorithms to the table.
adds all encryption algorithms to the table including password based
removes all ciphers and digests from the table.
A typical application will call
EVP_cleanup() before exiting.
An application does not need to add algorithms to use them explicitly, for example by EVP_sha1(3). It just needs to add them if it (or any of the functions it calls) needs to look up algorithms.
The cipher and digest lookup functions are used in many parts of the library. If the table is not initialized, several functions will misbehave and complain they cannot find algorithms. This includes the PEM, PKCS#12, SSL and S/MIME libraries. This is a common query in the OpenSSL mailing lists.
links in all algorithms: as a result a statically linked executable can be
quite large. If this is important, it is possible to just add the required
ciphers and digests.
Although the functions do not return error codes, it is possible for them to fail. This will only happen as a result of a memory allocation failure so this is not too much of a problem in practice.
|November 28, 2016||OpenBSD-6.1|