/*
 * This program is provided under the terms of the Common Public License,
 * version 1.0 (CPL-1.0). Any use, reproduction or distribution for this
 * software constitutes recipient's acceptance of CPL-1.0 terms which can be
 * found in the file LICENSE file or at
 * https://opensource.org/licenses/cpl1.0.php
 */

/************************************************************************
*                                                                       *
*      Copyright:       Corrent Corporation (c) 2000-2003               *
*                                                                       *
*      Filename:        mech_dh.c                                       *
*      Created By:      Kapil Sood                                      *
*      Created On:      Jan 18, 2003                                    *
*      Description:     This is the file implementing Diffie-Hellman    *
*                       key pair generation and shared key derivation   *
*                       operations.                                     *
*                                                                       *
************************************************************************/

// File:  mech_dh.c
//
// Mechanisms for DH
//
// Routines contained within:

#include <pthread.h>
#include <string.h>             // for memcmp() et al
#include <stdlib.h>
#include <sys/syslog.h>
#include <stdio.h>

#include "pkcs11types.h"
#include "defs.h"
#include "host_defs.h"
#include "h_extern.h"
#include "attributes.h"
#include "tok_spec_struct.h"
#include "trace.h"

#ifndef NODH

//
//
CK_RV dh_pkcs_derive(STDLL_TokData_t *tokdata,
                     SESSION *sess,
                     CK_MECHANISM *mech,
                     OBJECT *base_key_obj,
                     CK_ATTRIBUTE *pTemplate,
                     CK_ULONG ulCount, CK_OBJECT_HANDLE *handle,
                     CK_BBOOL count_statistic)
{
    CK_RV rc;
    CK_ULONG keyclass = 0, keytype = 0;
    CK_ATTRIBUTE *new_attr;
    OBJECT *temp_obj = NULL;

    CK_BYTE secret_key_value[256];
    CK_ULONG secret_key_value_len = 256;

    // Prelim checking of sess, mech, pTemplate, and ulCount was
    // done in the calling function (key_mgr_derive_key).

    // Perform DH checking of parameters
    // Check the existance of the public-value in mechanism
    if (mech->pParameter == NULL || mech->ulParameterLen == 0) {
        TRACE_ERROR("%s\n", ock_err(ERR_MECHANISM_PARAM_INVALID));
        return (CKR_MECHANISM_PARAM_INVALID);
    }
    // Check valid object handle pointer of derived key
    if (handle == NULL) {
        TRACE_ERROR("%s\n", ock_err(ERR_KEY_HANDLE_INVALID));
        return CKR_KEY_HANDLE_INVALID;
    }
    // Extract the object class and keytype from the supplied template.
    rc = get_ulong_attribute_by_type(pTemplate, ulCount, CKA_CLASS,
                                     &keyclass);
    if (rc == CKR_ATTRIBUTE_VALUE_INVALID) {
        TRACE_ERROR("%s\n", ock_err(ERR_ATTRIBUTE_VALUE_INVALID));
        return CKR_ATTRIBUTE_VALUE_INVALID;
    }
    if (rc == CKR_OK && keyclass != CKO_SECRET_KEY) {
        TRACE_ERROR("This operation requires a secret key.\n");
        return CKR_KEY_FUNCTION_NOT_PERMITTED;
    }

    rc = get_ulong_attribute_by_type(pTemplate, ulCount, CKA_KEY_TYPE,
                                     &keytype);
    if (rc == CKR_ATTRIBUTE_VALUE_INVALID) {
        TRACE_ERROR("%s\n", ock_err(ERR_ATTRIBUTE_VALUE_INVALID));
        return CKR_ATTRIBUTE_VALUE_INVALID;
    }

    // Extract public-key from mechanism parameters. base-key contains the
    // private key, prime, and base. The return value will be in the handle.

    rc = ckm_dh_pkcs_derive(tokdata, sess,
                            mech->pParameter, mech->ulParameterLen,
                            base_key_obj, secret_key_value, &secret_key_value_len,
                            mech, count_statistic);
    if (rc != CKR_OK)
        return rc;

    // Build the attribute from the vales that were returned back
    rc = build_attribute(CKA_VALUE, secret_key_value, secret_key_value_len,
                         &new_attr);
    if (rc != CKR_OK) {
        TRACE_DEVEL("Failed to build the new attribute.\n");
        return rc;
    }
    // Create the object that will be passed back as a handle. This will
    // contain the new (computed) value of the attribute.

    rc = object_mgr_create_skel(tokdata, sess,
                                pTemplate, ulCount,
                                MODE_DERIVE, keyclass, keytype, &temp_obj);
    if (rc != CKR_OK) {
        TRACE_DEVEL("Object Mgr create skeleton failed.\n");
        free(new_attr);
        return rc;
    }
    // Update the template in the object with the new attribute
    rc = template_update_attribute(temp_obj->template, new_attr);
    if (rc != CKR_OK) {
        TRACE_ERROR("template_update_attribute failed\n");
        free(new_attr);
        object_free(temp_obj);
        temp_obj = NULL;
        return rc;
    }

    // at this point, the derived key is fully constructed...assign an
    // object handle and store the key
    //
    rc = object_mgr_create_final(tokdata, sess, temp_obj, handle);
    if (rc != CKR_OK) {
        TRACE_DEVEL("Object Mgr create final failed.\n");
        object_free(temp_obj);
        temp_obj = NULL;
        return rc;
    }

    return rc;
}

//
// mechanisms
//

//
//
CK_RV ckm_dh_pkcs_derive(STDLL_TokData_t *tokdata,
                         SESSION *sess,
                         CK_VOID_PTR other_pubkey,
                         CK_ULONG other_pubkey_len,
                         OBJECT *base_key_obj,
                         CK_BYTE *secret_value, CK_ULONG *secret_value_len,
                         CK_MECHANISM_PTR mech,
                         CK_BBOOL count_statistic)
{
    CK_RV rc;
    CK_BYTE p[256];
    CK_ULONG p_len;
    CK_BYTE x[256];
    CK_ULONG x_len;
    CK_ATTRIBUTE *temp_attr;
    CK_BYTE *p_other_pubkey;

    // Extract secret (x) from base_key
    rc = template_attribute_get_non_empty(base_key_obj->template, CKA_VALUE,
                                          &temp_attr);
    if (rc != CKR_OK) {
        TRACE_ERROR("Could not find CKA_VALUE for the base key\n");
        goto done;
    }

    if (temp_attr->ulValueLen > sizeof(x)) {
        TRACE_ERROR("%s\n", ock_err(ERR_ATTRIBUTE_VALUE_INVALID));
        rc = CKR_ATTRIBUTE_VALUE_INVALID;
        goto done;
    }

    memset(x, 0, sizeof(x));
    x_len = temp_attr->ulValueLen;
    memcpy(x, (CK_BYTE *) temp_attr->pValue, x_len);

    // Extract prime (p) from base_key
    rc = template_attribute_get_non_empty(base_key_obj->template, CKA_PRIME,
                                          &temp_attr);
    if (rc != CKR_OK) {
        TRACE_ERROR("Could not find CKA_PRIME for the base key\n");
        goto done;
    }

    if (temp_attr->ulValueLen > sizeof(p)) {
        TRACE_ERROR("%s\n", ock_err(ERR_ATTRIBUTE_VALUE_INVALID));
        rc = CKR_ATTRIBUTE_VALUE_INVALID;
        goto done;
    }

    memset(p, 0, sizeof(p));
    p_len = temp_attr->ulValueLen;
    memcpy(p, (CK_BYTE *) temp_attr->pValue, p_len);

    p_other_pubkey = (CK_BYTE *) other_pubkey;

    // Perform: z = other_pubkey^x mod p
    rc = token_specific.t_dh_pkcs_derive(tokdata, secret_value,
                                         secret_value_len, p_other_pubkey,
                                         other_pubkey_len, x, x_len, p, p_len);
    if (rc != CKR_OK)
        TRACE_DEVEL("Token specific dh pkcs derive failed.\n");

done:
    if (count_statistic == TRUE && rc == CKR_OK)
        INC_COUNTER(tokdata, sess, mech, base_key_obj, POLICY_STRENGTH_IDX_0);

    return rc;
}

//
//
CK_RV ckm_dh_pkcs_key_pair_gen(STDLL_TokData_t *tokdata,
                               TEMPLATE *publ_tmpl, TEMPLATE *priv_tmpl)
{
    CK_RV rc;

    rc = token_specific.t_dh_pkcs_key_pair_gen(tokdata, publ_tmpl, priv_tmpl);
    if (rc != CKR_OK)
        TRACE_DEVEL("Token specific dh pkcs key pair gen failed.\n");

    return rc;
}

#endif
