/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/*
* CMS encryptedData methods.
*/
#include "cmslocal.h"
#include "keyhi.h"
#include "secasn1.h"
#include "secitem.h"
#include "secoid.h"
#include "pk11func.h"
#include "prtime.h"
#include "secerr.h"
#include "secpkcs5.h"
#include "smime.h"
/*
* NSS_CMSEncryptedData_Create - create an empty encryptedData object.
*
* "algorithm" specifies the bulk encryption algorithm to use.
* "keysize" is the key size.
*
* An error results in a return value of NULL and an error set.
* (Retrieve specific errors via PORT_GetError()/XP_GetError().)
*/
NSSCMSEncryptedData *
NSS_CMSEncryptedData_Create(NSSCMSMessage *cmsg, SECOidTag algorithm,
int keysize)
{
void *mark;
NSSCMSEncryptedData *encd;
PLArenaPool *poolp;
SECAlgorithmID *pbe_algid;
SECStatus rv;
poolp = cmsg->poolp;
mark = PORT_ArenaMark(poolp);
encd = PORT_ArenaZNew(poolp, NSSCMSEncryptedData);
if (encd == NULL)
goto loser;
encd->cmsg = cmsg;
/* version is set in NSS_CMSEncryptedData_Encode_BeforeStart() */
if (!SEC_PKCS5IsAlgorithmPBEAlgTag(algorithm)) {
rv = NSS_CMSContentInfo_SetContentEncAlg(poolp, &(encd->contentInfo),
algorithm, NULL, keysize);
}
else {
/* Assume password-based-encryption.
* Note: we can't generate pkcs5v2 from this interface.
* PK11_CreateBPEAlgorithmID generates pkcs5v2 by accepting
* non-PBE oids and assuming that they are pkcs5v2 oids, but
* NSS_CMSEncryptedData_Create accepts non-PBE oids as regular
* CMS encrypted data, so we can't tell NSS_CMS_EncryptedData_Create
* to create pkcs5v2 PBEs */
pbe_algid = PK11_CreatePBEAlgorithmID(algorithm, 1, NULL);
if (pbe_algid == NULL) {
rv = SECFailure;
}
else {
rv = NSS_CMSContentInfo_SetContentEncAlgID(poolp,
&(encd->contentInfo),
pbe_algid, keysize);
SECOID_DestroyAlgorithmID(pbe_algid, PR_TRUE);
}
}
if (rv != SECSuccess)
goto loser;
PORT_ArenaUnmark(poolp, mark);
return encd;
loser:
PORT_ArenaRelease(poolp, mark);
return NULL;
}
/*
* NSS_CMSEncryptedData_Destroy - destroy an encryptedData object
*/
void
NSS_CMSEncryptedData_Destroy(NSSCMSEncryptedData *encd)
{
/* everything's in a pool, so don't worry about the storage */
if (encd != NULL) {
NSS_CMSContentInfo_Destroy(&(encd->contentInfo));
}
return;
}
/*
* NSS_CMSEncryptedData_GetContentInfo - return pointer to encryptedData object's contentInfo
*/
NSSCMSContentInfo *
NSS_CMSEncryptedData_GetContentInfo(NSSCMSEncryptedData *encd)
{
return &(encd->contentInfo);
}
/*
* NSS_CMSEncryptedData_Encode_BeforeStart - do all the necessary things to a EncryptedData
* before encoding begins.
*
* In particular:
* - set the correct version value.
* - get the encryption key
*/
SECStatus
NSS_CMSEncryptedData_Encode_BeforeStart(NSSCMSEncryptedData *encd)
{
int version;
PK11SymKey *bulkkey = NULL;
SECItem *dummy;
NSSCMSContentInfo *cinfo = &(encd->contentInfo);
SECAlgorithmID *algid = NULL;
if (NSS_CMSArray_IsEmpty((
void **)encd->unprotectedAttr))
version = NSS_CMS_ENCRYPTED_DATA_VERSION;
else
version = NSS_CMS_ENCRYPTED_DATA_VERSION_UPATTR;
dummy = SEC_ASN1EncodeInteger(encd->cmsg->poolp, &(encd->version), version);
if (dummy == NULL)
return SECFailure;
/* now get content encryption key (bulk key) by using our cmsg callback */
if (encd->cmsg->decrypt_key_cb) {
algid = NSS_CMSContentInfo_GetContentEncAlg(cinfo);
bulkkey = (*encd->cmsg->decrypt_key_cb)(encd->cmsg->decrypt_key_cb_arg, algid);
}
if ((bulkkey == NULL) || (algid == NULL))
return SECFailure;
/* store the bulk key in the contentInfo so that the encoder can find it */
NSS_CMSContentInfo_SetBulkKey(cinfo, bulkkey);
PK11_FreeSymKey(bulkkey);
return SECSuccess;
}
/*
* NSS_CMSEncryptedData_Encode_BeforeData - set up encryption
*/
SECStatus
NSS_CMSEncryptedData_Encode_BeforeData(NSSCMSEncryptedData *encd)
{
NSSCMSContentInfo *cinfo;
PK11SymKey *bulkkey = NULL;
SECAlgorithmID *algid;
SECStatus rv = SECFailure;
cinfo = &(encd->contentInfo);
/* find bulkkey and algorithm - must have been set by NSS_CMSEncryptedData_Encode_BeforeStart */
bulkkey = NSS_CMSContentInfo_GetBulkKey(cinfo);
if (bulkkey == NULL) {
goto loser;
}
algid = NSS_CMSContentInfo_GetContentEncAlg(cinfo);
if (algid == NULL) {
goto loser;
}
rv = NSS_CMSContentInfo_Private_Init(cinfo);
if (rv != SECSuccess) {
goto loser;
}
if (!NSS_SMIMEUtil_EncryptionAllowed(algid, bulkkey)) {
goto loser;
}
/* this may modify algid (with IVs generated in a token).
* it is therefore essential that algid is a pointer to the "real" contentEncAlg,
* not just to a copy */
cinfo->privateInfo->ciphcx = NSS_CMSCipherContext_StartEncrypt(encd->cmsg->poolp,
bulkkey, algid);
if (cinfo->privateInfo->ciphcx == NULL)
goto loser;
rv = SECSuccess;
loser:
if (bulkkey) {
PK11_FreeSymKey(bulkkey);
}
return rv;
}
/*
* NSS_CMSEncryptedData_Encode_AfterData - finalize this encryptedData for encoding
*/
SECStatus
NSS_CMSEncryptedData_Encode_AfterData(NSSCMSEncryptedData *encd)
{
if (encd->contentInfo.privateInfo && encd->contentInfo.privateInfo->ciphcx) {
NSS_CMSCipherContext_Destroy(encd->contentInfo.privateInfo->ciphcx);
encd->contentInfo.privateInfo->ciphcx = NULL;
}
/* nothing to do after data */
return SECSuccess;
}
/*
* NSS_CMSEncryptedData_Decode_BeforeData - find bulk key & set up decryption
*/
SECStatus
NSS_CMSEncryptedData_Decode_BeforeData(NSSCMSEncryptedData *encd)
{
PK11SymKey *bulkkey = NULL;
NSSCMSContentInfo *cinfo;
SECAlgorithmID *bulkalg;
SECStatus rv = SECFailure;
cinfo = &(encd->contentInfo);
bulkalg = NSS_CMSContentInfo_GetContentEncAlg(cinfo);
if (encd->cmsg->decrypt_key_cb == NULL)
/* no callback? no key../ */
goto loser;
bulkkey = (*encd->cmsg->decrypt_key_cb)(encd->cmsg->decrypt_key_cb_arg, bulkalg);
if (bulkkey == NULL)
/* no success finding a bulk key */
goto loser;
NSS_CMSContentInfo_SetBulkKey(cinfo, bulkkey);
rv = NSS_CMSContentInfo_Private_Init(cinfo);
if (rv != SECSuccess) {
goto loser;
}
rv = SECFailure;
if (!NSS_SMIMEUtil_DecryptionAllowed(bulkalg, bulkkey)) {
goto loser;
}
cinfo->privateInfo->ciphcx = NSS_CMSCipherContext_StartDecrypt(bulkkey, bulkalg);
if (cinfo->privateInfo->ciphcx == NULL)
goto loser;
/* error has been set by NSS_CMSCipherContext_StartDecrypt */
rv = SECSuccess;
loser:
if (bulkkey) {
PK11_FreeSymKey(bulkkey);
}
return rv;
}
/*
* NSS_CMSEncryptedData_Decode_AfterData - finish decrypting this encryptedData's content
*/
SECStatus
NSS_CMSEncryptedData_Decode_AfterData(NSSCMSEncryptedData *encd)
{
if (encd->contentInfo.privateInfo && encd->contentInfo.privateInfo->ciphcx) {
NSS_CMSCipherContext_Destroy(encd->contentInfo.privateInfo->ciphcx);
encd->contentInfo.privateInfo->ciphcx = NULL;
}
return SECSuccess;
}
/*
* NSS_CMSEncryptedData_Decode_AfterEnd - finish decoding this encryptedData
*/
SECStatus
NSS_CMSEncryptedData_Decode_AfterEnd(NSSCMSEncryptedData *encd)
{
/* apply final touches */
return SECSuccess;
}
