=pod =head1 NAME BN_CTX_start, BN_CTX_get, BN_CTX_end - use temporary BIGNUM variables =head1 SYNOPSIS #include void BN_CTX_start(BN_CTX *ctx); BIGNUM *BN_CTX_get(BN_CTX *ctx); void BN_CTX_end(BN_CTX *ctx); =head1 DESCRIPTION These functions are used to obtain temporary B variables from a B (which can been created by using L) in order to save the overhead of repeatedly creating and freeing Bs in functions that are called from inside a loop. A function must call BN_CTX_start() first. Then, BN_CTX_get() may be called repeatedly to obtain temporary Bs. All BN_CTX_get() calls must be made before calling any other functions that use the B as an argument. Finally, BN_CTX_end() must be called before returning from the function. When BN_CTX_end() is called, the B pointers obtained from BN_CTX_get() become invalid. =head1 RETURN VALUES BN_CTX_start() and BN_CTX_end() return no values. BN_CTX_get() returns a pointer to the B, or B on error. Once BN_CTX_get() has failed, the subsequent calls will return B as well, so it is sufficient to check the return value of the last BN_CTX_get() call. In case of an error, an error code is set, which can be obtained by L. =head1 SEE ALSO L =head1 COPYRIGHT Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved. Licensed under the OpenSSL license (the "License"). You may not use this file except in compliance with the License. You can obtain a copy in the file LICENSE in the source distribution or at L. =cut