=pod

=head1 NAME

PKCS12_newpass - change the password of a PKCS12 structure

=head1 SYNOPSIS

 #include <openssl/pkcs12.h>

 int PKCS12_newpass(PKCS12 *p12, const char *oldpass, const char *newpass);

=head1 DESCRIPTION

PKCS12_newpass() changes the password of a PKCS12 structure.

B<p12> is a pointer to a PKCS12 structure. B<oldpass> is the existing password
and B<newpass> is the new password.

=head1 RETURN VALUES

PKCS12_newpass() returns 1 on success or 0 on failure. Applications can
retrieve the most recent error from PKCS12_newpass() with ERR_get_error().

=head1 EXAMPLE

This example loads a PKCS#12 file, changes its password and writes out
the result to a new file.

 #include <stdio.h>
 #include <stdlib.h>
 #include <openssl/pem.h>
 #include <openssl/err.h>
 #include <openssl/pkcs12.h>

 int main(int argc, char **argv)
 {
    FILE *fp;
    PKCS12 *p12;
    if (argc != 5) {
        fprintf(stderr, "Usage: pkread p12file password newpass opfile\n");
        return 1;
    }
    if ((fp = fopen(argv[1], "rb")) == NULL) {
        fprintf(stderr, "Error opening file %s\n", argv[1]);
        return 1;
    }
    p12 = d2i_PKCS12_fp(fp, NULL);
    fclose(fp);
    if (p12 == NULL) {
        fprintf(stderr, "Error reading PKCS#12 file\n");
        ERR_print_errors_fp(stderr);
        return 1;
    }
    if (PKCS12_newpass(p12, argv[2], argv[3]) == 0) {
        fprintf(stderr, "Error changing password\n");
        ERR_print_errors_fp(stderr);
        PKCS12_free(p12);
        return 1;
    }
    if ((fp = fopen(argv[4], "wb")) == NULL) {
        fprintf(stderr, "Error opening file %s\n", argv[4]);
        PKCS12_free(p12);
        return 1;
    }
    i2d_PKCS12_fp(fp, p12);
    PKCS12_free(p12);
    fclose(fp);
    return 0;
 }


=head1 NOTES

If the PKCS#12 structure does not have a password, then you must use the empty
string "" for B<oldpass>. Using NULL for B<oldpass> will result in a
PKCS12_newpass() failure.

If the wrong password is used for B<oldpass> then the function will fail,
with a MAC verification error. In rare cases the PKCS12 structure does not
contain a MAC: in this case it will usually fail with a decryption padding
error.

=head1 BUGS

The password format is a NULL terminated ASCII string which is converted to
Unicode form internally. As a result some passwords cannot be supplied to
this function.

=head1 SEE ALSO

L<PKCS12_create(3)>, L<ERR_get_error(3)>

=cut
