/*
 * The contents of this file are subject to the Mozilla Public
 * License Version 1.1 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy of
 * the License at http://www.mozilla.org/MPL/
 * 
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 * 
 * The Original Code is the Netscape security libraries.
 * 
 * The Initial Developer of the Original Code is Netscape
 * Communications Corporation.  Portions created by Netscape are 
 * Copyright (C) 1994-2000 Netscape Communications Corporation.  All
 * Rights Reserved.
 * 
 * Contributor(s):
 * 
 * Alternatively, the contents of this file may be used under the
 * terms of the GNU General Public License Version 2 or later (the
 * "GPL"), in which case the provisions of the GPL are applicable 
 * instead of those above.  If you wish to allow use of your 
 * version of this file only under the terms of the GPL and not to
 * allow others to use your version of this file under the MPL,
 * indicate your decision by deleting the provisions above and
 * replace them with the notice and other provisions required by
 * the GPL.  If you do not delete the provisions above, a recipient
 * may use your version of this file under either the MPL or the
 * GPL.
 */
/*
 * This file implements the Symkey wrapper and the PKCS context
 * Interfaces.
 */

#include "seccomon.h"
#include "secmod.h"
#include "nssilock.h"
#include "secmodi.h"
#include "pkcs11.h"
#include "pk11func.h"
#include "secitem.h"
#include "key.h"
#include "secasn1.h"
#include "sechash.h"
#include "cert.h"
#include "secerr.h"

/*
 * find an RSA public key on a card
 */
static CK_OBJECT_HANDLE
pk11_FindRSAPubKey(PK11SlotInfo *slot)
{
    CK_KEY_TYPE key_type = CKK_RSA;
    CK_OBJECT_CLASS class_type = CKO_PUBLIC_KEY;
    CK_ATTRIBUTE theTemplate[2];
    int template_count = sizeof(theTemplate)/sizeof(theTemplate[0]);
    CK_ATTRIBUTE *attrs = theTemplate;

    PK11_SETATTRS(attrs,CKA_CLASS,&class_type,sizeof(class_type)); attrs++;
    PK11_SETATTRS(attrs,CKA_KEY_TYPE,&key_type,sizeof(key_type)); attrs++;
    template_count = attrs - theTemplate;
    PR_ASSERT(template_count <= sizeof(theTemplate)/sizeof(CK_ATTRIBUTE));

    return pk11_FindObjectByTemplate(slot,theTemplate,template_count);
}

PK11SymKey *
pk11_KeyExchange(PK11SlotInfo *slot,CK_MECHANISM_TYPE type,
		 	CK_ATTRIBUTE_TYPE operation, PK11SymKey *symKey)
{
    PK11SymKey *newSymKey = NULL;
    SECStatus rv;
    /* performance improvement can go here --- use a generated key to as a
     * per startup wrapping key. If it exists, use it, otherwise do a full
     * key exchange. */

    /* find a common Key Exchange algorithm */
    /* RSA */
    if (PK11_DoesMechanism(symKey->slot, CKM_RSA_PKCS) && 
				PK11_DoesMechanism(slot,CKM_RSA_PKCS)) {
	CK_OBJECT_HANDLE pubKeyHandle = CK_INVALID_HANDLE;
	CK_OBJECT_HANDLE privKeyHandle = CK_INVALID_HANDLE;
	SECKEYPublicKey *pubKey = NULL;
	SECKEYPrivateKey *privKey = NULL;
	SECItem wrapData;

	wrapData.data = NULL;

	/* find RSA Public Key on target */
	pubKeyHandle = pk11_FindRSAPubKey(slot);
	if (pubKeyHandle != CK_INVALID_HANDLE) {
	    privKeyHandle = PK11_MatchItem(slot,pubKeyHandle,CKO_PRIVATE_KEY);
	}

	/* if no key exists, generate a key pair */
	if (privKeyHandle == CK_INVALID_HANDLE) {
	    unsigned int     symKeyLength = PK11_GetKeyLength(symKey);
	    PK11RSAGenParams rsaParams;

	    if (symKeyLength > 60) /* bytes */ {
		/* we'd have to generate an RSA key pair > 512 bits long,
		** and that's too costly.  Don't even try. 
		*/
		PORT_SetError( SEC_ERROR_CANNOT_MOVE_SENSITIVE_KEY );
		goto rsa_failed;
	    }
	    rsaParams.keySizeInBits = 
	        (symKeyLength > 28 || symKeyLength == 0) ? 512 : 256;
	    rsaParams.pe  = 0x10001;
	    privKey = PK11_GenerateKeyPair(slot,CKM_RSA_PKCS_KEY_PAIR_GEN, 
			    &rsaParams, &pubKey,PR_FALSE,PR_TRUE,symKey->cx);
	} else {
	    /* if keys exist, build SECKEY data structures for them */
	    privKey = PK11_MakePrivKey(slot,nullKey, PR_TRUE, privKeyHandle,
					symKey->cx);
	    if (privKey != NULL) {
    		pubKey = PK11_ExtractPublicKey(slot, rsaKey, pubKeyHandle);
		if (pubKey && pubKey->pkcs11Slot) {
		    PK11_FreeSlot(pubKey->pkcs11Slot);
		    pubKey->pkcs11Slot = NULL;
		    pubKey->pkcs11ID = CK_INVALID_HANDLE;
		}
	    }
	}
	if (privKey == NULL) goto rsa_failed;
	if (pubKey == NULL)  goto rsa_failed;

        wrapData.len  = SECKEY_PublicKeyStrength(pubKey);
        if (!wrapData.len) goto rsa_failed;
        wrapData.data = PORT_Alloc(wrapData.len);
        if (wrapData.data == NULL) goto rsa_failed;

	/* now wrap the keys in and out */
	rv = PK11_PubWrapSymKey(CKM_RSA_PKCS, pubKey, symKey, &wrapData);
	if (rv == SECSuccess) {
	    newSymKey = PK11_PubUnwrapSymKey(privKey,&wrapData,type,operation,
							symKey->size);
	}
rsa_failed:
	if (wrapData.data != NULL) PORT_Free(wrapData.data);
	if (privKey != NULL) SECKEY_DestroyPrivateKey(privKey);
	if (pubKey != NULL) SECKEY_DestroyPublicKey(pubKey);

	return  newSymKey;
    }
    /* KEA */
    if (PK11_DoesMechanism(symKey->slot, CKM_KEA_KEY_DERIVE) && 
				PK11_DoesMechanism(slot,CKM_KEA_KEY_DERIVE)) {
	CERTCertificate *certSource = NULL;
	CERTCertificate *certTarget = NULL;
	SECKEYPublicKey *pubKeySource = NULL;
	SECKEYPublicKey *pubKeyTarget = NULL;
	SECKEYPrivateKey *privKeySource = NULL;
	SECKEYPrivateKey *privKeyTarget = NULL;
	PK11SymKey *tekSource = NULL;
	PK11SymKey *tekTarget = NULL;
	SECItem Ra,wrap;

	/* can only exchange skipjack keys */
	if (type != CKM_SKIPJACK_CBC64) {
    	    PORT_SetError( SEC_ERROR_NO_MODULE );
	    goto kea_failed;
	}

	/* find a pair of certs we can use */
	rv = PK11_GetKEAMatchedCerts(symKey->slot,slot,&certSource,&certTarget);
	if (rv != SECSuccess) goto kea_failed;

	/* get all the key pairs */
	pubKeyTarget = CERT_ExtractPublicKey(certSource);
	pubKeySource = CERT_ExtractPublicKey(certTarget);
	privKeySource = 
		PK11_FindKeyByDERCert(symKey->slot,certSource,symKey->cx);
	privKeyTarget = 
		PK11_FindKeyByDERCert(slot,certTarget,symKey->cx);

	if ((pubKeySource == NULL) || (pubKeyTarget == NULL) ||
	  (privKeySource == NULL) || (privKeyTarget == NULL)) goto kea_failed;

	/* generate the wrapping TEK's */
	Ra.data = (unsigned char*)PORT_Alloc(128 /* FORTEZZA RA MAGIC */);
	Ra.len = 128;
	if (Ra.data == NULL) goto kea_failed;

	tekSource = PK11_PubDerive(privKeySource,pubKeyTarget,PR_TRUE,&Ra,NULL,
		CKM_SKIPJACK_WRAP, CKM_KEA_KEY_DERIVE,CKA_WRAP,0,symKey->cx);
	tekTarget = PK11_PubDerive(privKeyTarget,pubKeySource,PR_FALSE,&Ra,NULL,
		CKM_SKIPJACK_WRAP, CKM_KEA_KEY_DERIVE,CKA_WRAP,0,symKey->cx);
	PORT_Free(Ra.data);

	if ((tekSource == NULL) || (tekTarget == NULL)) { goto kea_failed; }

	/* wrap the key out of Source into target */
	wrap.data = (unsigned char*)PORT_Alloc(12); /* MAGIC SKIPJACK LEN */
	wrap.len = 12;

	/* paranoia to prevent infinite recursion on bugs */
	PORT_Assert(tekSource->slot == symKey->slot);
	if (tekSource->slot != symKey->slot) {
    	    PORT_SetError( SEC_ERROR_NO_MODULE );
	    goto kea_failed;
	}

	rv = PK11_WrapSymKey(CKM_SKIPJACK_WRAP,NULL,tekSource,symKey,&wrap);
	if (rv == SECSuccess) {
	    newSymKey = PK11_UnwrapSymKey(tekTarget, CKM_SKIPJACK_WRAP, NULL,
			&wrap, type, operation, symKey->size);
	}
	PORT_Free(wrap.data);
kea_failed:
	if (certSource == NULL) CERT_DestroyCertificate(certSource);
	if (certTarget == NULL) CERT_DestroyCertificate(certTarget);
	if (pubKeySource == NULL) SECKEY_DestroyPublicKey(pubKeySource);
	if (pubKeyTarget == NULL) SECKEY_DestroyPublicKey(pubKeyTarget);
	if (privKeySource == NULL) SECKEY_DestroyPrivateKey(privKeySource);
	if (privKeyTarget == NULL) SECKEY_DestroyPrivateKey(privKeyTarget);
	if (tekSource == NULL) PK11_FreeSymKey(tekSource);
	if (tekTarget == NULL) PK11_FreeSymKey(tekTarget);
	return newSymKey;
    }
    PORT_SetError( SEC_ERROR_NO_MODULE );
    return NULL;
}

