d2i_X509_ALGOR, i2d_X509_ALGOR — AlgorithmIdentifier functions.
*d2i_X509_ALGOR(X509_ALGOR **a, unsigned char **pp, long length);
i2d_X509_ALGOR(X509_ALGOR *a, unsigned char **pp);
These functions decode and encode an X509_ALGOR structure
which is equivalent to the AlgorithmIdentifier structure.
Othewise these behave in a similar way to d2i_X509() and i2d_X509()
described in the d2i_X509(3) manual page.