OpenSSL_add_all_digests - Add algorithms to internal table
void ); void OpenSSL_add_all_ciphers(
void ); void OpenSSL_add_all_digests(
void ); void EVP_cleanup(
OpenSSL keeps an internal table of digest algorithms and ciphers. It
uses this table to lookup ciphers via functions such as
The OpenSSL_add_all_digests() function adds all digest algorithms to
The OpenSSL_add_all_algorithms() function adds all algorithms to the
table (digests and ciphers).
The OpenSSL_add_all_ciphers() function adds all encryption algorithms
to the table including password based encryption algorithms.
The EVP_cleanup() function removes all ciphers and digests from the ta‐
A typical application will call the OpenSSL_add_all_algorithms() func‐
tion initially and the EVP_cleanup() function before exiting.
An application does not need to add algorithms to use them explicitly,
for example by EVP_sha1(). It needs to add them if it (or any of the
functions it calls) needs to lookup algorithms.
The cipher and digest lookup functions are used in many parts of the
library. If the table is not initialized several functions will not
work correctly 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.
Calling the OpenSSL_add_all_algorithms() function links all algorithms.
As a result, a statically linked executable can be quite large. If this
is important, it is possible to add only the required ciphers and
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 it is not much of a problem in practice.
None of the functions return a value.
Functions: evp(3), EVP_DigestInit(3), EVP_EncryptInit(3)OpenSSL_add_all_algorithms(3)