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
#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);
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).
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.
These functions do not provide diagnostic information.
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);
}
ssl(7),
SSL_CTX_use_certificate(3)
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 2000-2019 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the Apache License 2.0 (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>.