tpm_changeauth.3

IBM开发的TPM的驱动, 有少量的例子可以供参考

.\" Copyright 2004 IBM (Jeff Kravitz)
.\"
.\" Written Mar 24 2004, Jeff Kravitz
.\"
.TH "TPM_ChangeAuth" 3  2004-03-24 "IBM" "TPM Library"
.SH NAME
TPM_ChangeAuth
.SH SYNOPSIS
.nf
.B #include <tpmfunc.h>
.sp
.BR "uint32_t TPM_ChangeAuth" "(uint32_t parhandle,"
                  unsigned char *parauth,
                  unsigned char *oldauth,
                  unsigned char *newauth,
                  keydata *key,
.fi
.SH DESCRIPTION
The \fBTPM_ChangeAuth()\fP function changes the authorization (password) value
for a specified key.
.SH ARGUMENTS
The arguments include...
.TP 10
.B parhandle
the parent key handle.
.TP 10
.B parauth
the parent key authorization data
(a 20 byte value which is usually calculated as the hash of a password).
If NULL, it will be assumed that no password is required.
.TP 10
.B oldauth
the existing key authorization data
(a 20 byte value which is usually calculated as the hash of a password).
.TP 10
.B newauth
the new key authorization data
(a 20 byte value which is usually calculated as the hash of a password).
.TP 10
.B keydata
a pointer to a keydata structure containing the key to be modified.
.SH NOTES
.P
If the operation completes successfully, the keydata structure pointed
to by the \fBkey\fP argument will have the private key element replaced by
the modified version.
.P
A key read in from external storage is usually in a binary format which
can be converted to a keydata structure via the \fBTSS_KeyExtract()\fP function.
.P
The modified keydata structure can be converted back to a binary object via
the \fBTPM_BuildKey()\fP function.
.SH "RETURN VALUE"
0 if the operation is successful. non-zero otherwise.
The non zero value can be converted to an error message via the function \fBTPM_GetErrMsg()\fP.
.SH "SEE ALSO"
.BR TSS_KeyExtract(3) , TPM_GetErrMsg(3) .
.SH AUTHOR
Jeff Kravitz, IBM T.J. Watson Research Center