SSL_CTX_SET_DEFAULT_PASSWD_CBOpenSSL_CTX_SET_DEFAULT_PASSWD_CB(3)
SSL_CTX_set_default_passwd_cb,
SSL_CTX_set_default_passwd_cb_userdata - set 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);
int pem_passwd_cb(char *buf, int size, int rwflag, void *userdata);
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 which will be provided to the password callback on
invocation.
The pem_passwd_cb(), which must be provided by the applica-
tion, hands back the password to be used during decryption.
On invocation a pointer to userdata is provided. The
pem_passwd_cb must write 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).
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
pem_passwd_cb() 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 pem_passwd_cb()
only returns the password already stored.
When asking for the password interactively, pem_passwd_cb()
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
MirOS BSD #10-current 2005-02-05 1
SSL_CTX_SET_DEFAULT_PASSWD_CBOpenSSL_CTX_SET_DEFAULT_PASSWD_CB(3)
information is considered public.
SSL_CTX_set_default_passwd_cb() and
SSL_CTX_set_default_passwd_cb_userdata() do not provide
diagnostic information.
The following example returns the password provided as user-
data 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 pem_passwd_cb(char *buf, int size, int rwflag, void *password)
{
strncpy(buf, (char *)(password), size);
buf[size - 1] = '\0';
return(strlen(buf));
}
ssl(3), SSL_CTX_use_certificate(3)
MirOS BSD #10-current 2005-02-05 2
Generated on 2012-02-20 02:47:02 by $MirOS: src/scripts/roff2htm,v 1.70 2011/12/03 18:21:12 tg Exp $
These manual pages and other documentation are copyrighted by their respective writers;
their source is available at our CVSweb,
AnonCVS, and other mirrors. The rest is Copyright © 2002‒2011 The MirOS Project, Germany.
This product includes material
provided by Thorsten Glaser.
This manual page’s HTML representation is supposed to be valid XHTML/1.1; if not, please send a bug report – diffs preferred.