SSL_CTX_SET_DEFAULT_PASSWD_CB(3) OpenSSL SSL_CTX_SET_DEFAULT_PASSWD_CB(3)
NAME
SSL_CTX_set_default_passwd_cb, SSL_CTX_set_default_passwd_cb_userdata,
SSL_CTX_get_default_passwd_cb, SSL_CTX_get_default_passwd_cb_userdata,
SSL_set_default_passwd_cb, SSL_set_default_passwd_cb_userdata,
SSL_get_default_passwd_cb, SSL_get_default_passwd_cb_userdata - set or
get passwd callback for encrypted PEM file handling
SYNOPSIS
#include <openssl/ssl.h>
void SSL_CTX_set_default_passwd_cb(SSL_CTX *ctx, pem_password_cb *cb);
void SSL_CTX_set_default_passwd_cb_userdata(SSL_CTX *ctx, void *u);
pem_password_cb *SSL_CTX_get_default_passwd_cb(SSL_CTX *ctx);
void *SSL_CTX_get_default_passwd_cb_userdata(SSL_CTX *ctx);
void SSL_set_default_passwd_cb(SSL *s, pem_password_cb *cb);
void SSL_set_default_passwd_cb_userdata(SSL *s, void *u);
pem_password_cb *SSL_get_default_passwd_cb(SSL *s);
void *SSL_get_default_passwd_cb_userdata(SSL *s);
DESCRIPTION
SSL_CTX_set_default_passwd_cb() sets the default password callback
called when loading/storing a PEM certificate with encryption.
SSL_CTX_set_default_passwd_cb_userdata() sets a pointer to userdata, u,
which will be provided to the password callback on invocation.
SSL_CTX_get_default_passwd_cb() returns a function pointer to the
password callback currently set in ctx. If no callback was explicitly
set, the NULL pointer is returned.
SSL_CTX_get_default_passwd_cb_userdata() returns a pointer to the
userdata currently set in ctx. If no userdata was explicitly set, the
NULL pointer is returned.
SSL_set_default_passwd_cb(), SSL_set_default_passwd_cb_userdata(),
SSL_get_default_passwd_cb() and SSL_get_default_passwd_cb_userdata()
perform the same function as their SSL_CTX counterparts, but using an
SSL object.
The password callback, which must be provided by the application, hands
back the password to be used during decryption. On invocation a
pointer to userdata is provided. The function must store the password
into the provided buffer buf which is of size size. The actual length
of the password must be returned to the calling function. rwflag
indicates whether the callback is used for reading/decryption
(rwflag=0) or writing/encryption (rwflag=1). For more details, see
pem_password_cb(3).
NOTES
When loading or storing private keys, a password might be supplied to
protect the private key. The way this password can be supplied may
depend on the application. If only one private key is handled, it can
be practical to have the callback handle the password dialog
interactively. If several keys have to be handled, it can be practical
to ask for the password once, then keep it in memory and use it several
times. In the last case, the password could be stored into the userdata
storage and the callback only returns the password already stored.
When asking for the password interactively, the callback can use rwflag
to check, whether an item shall be encrypted (rwflag=1). In this case
the password dialog may ask for the same password twice for comparison
in order to catch typos, that would make decryption impossible.
Other items in PEM formatting (certificates) can also be encrypted, it
is however not usual, as certificate information is considered public.
RETURN VALUES
These functions do not provide diagnostic information.
EXAMPLES
The following example returns the password provided as userdata to the
calling function. The password is considered to be a '\0' terminated
string. If the password does not fit into the buffer, the password is
truncated.
int my_cb(char *buf, int size, int rwflag, void *u)
{
strncpy(buf, (char *)u, size);
buf[size - 1] = '\0';
return strlen(buf);
}
SEE ALSO
ssl(7), SSL_CTX_use_certificate(3)
HISTORY
SSL_CTX_get_default_passwd_cb(),
SSL_CTX_get_default_passwd_cb_userdata(), SSL_set_default_passwd_cb()
and SSL_set_default_passwd_cb_userdata() were added in OpenSSL 1.1.0.
COPYRIGHT
Copyright 2000-2019 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
<https://www.openssl.org/source/license.html>.
1.1.1k 2021-03-25 SSL_CTX_SET_DEFAULT_PASSWD_CB(3)