centos man page for evp_pkey_ctx_dup

EVP_PKEY_CTX_new(3)						      OpenSSL						       EVP_PKEY_CTX_new(3)

NAME
       EVP_PKEY_CTX_new, EVP_PKEY_CTX_new_id, EVP_PKEY_CTX_dup, EVP_PKEY_CTX_free - public key algorithm context functions.

SYNOPSIS
	#include <openssl/evp.h>

	EVP_PKEY_CTX *EVP_PKEY_CTX_new(EVP_PKEY *pkey, ENGINE *e);
	EVP_PKEY_CTX *EVP_PKEY_CTX_new_id(int id, ENGINE *e);
	EVP_PKEY_CTX *EVP_PKEY_CTX_dup(EVP_PKEY_CTX *ctx);
	void EVP_PKEY_CTX_free(EVP_PKEY_CTX *ctx);

DESCRIPTION
       The EVP_PKEY_CTX_new() function allocates public key algorithm context using the algorithm specified in pkey and ENGINE e.

       The EVP_PKEY_CTX_new_id() function allocates public key algorithm context using the algorithm specified by id and ENGINE e. It is normally
       used when no EVP_PKEY structure is associated with the operations, for example during parameter generation of key genration for some
       algorithms.

       EVP_PKEY_CTX_dup() duplicates the context ctx.

       EVP_PKEY_CTX_free() frees up the context ctx.

NOTES
       The EVP_PKEY_CTX structure is an opaque public key algorithm context used by the OpenSSL high level public key API. Contexts MUST NOT be
       shared between threads: that is it is not permissible to use the same context simultaneously in two threads.

RETURN VALUES
       EVP_PKEY_CTX_new(), EVP_PKEY_CTX_new_id(), EVP_PKEY_CTX_dup() returns either the newly allocated EVP_PKEY_CTX structure of NULL if an error
       occurred.

       EVP_PKEY_CTX_free() does not return a value.

SEE ALSO
       EVP_PKEY_new(3)

HISTORY
       These functions were first added to OpenSSL 1.0.0.

1.0.1e								    2013-02-11						       EVP_PKEY_CTX_new(3)