/*
* NSS_CMSEnvelopedData_Decode_BeforeData - find our recipientinfo,
* derive bulk key & set up our contentinfo
*/
SECStatus
NSS_CMSEnvelopedData_Decode_BeforeData(NSSCMSEnvelopedData *envd)
{
NSSCMSRecipientInfo *ri;
PK11SymKey *bulkkey = NULL;
SECOidTag bulkalgtag;
SECAlgorithmID *bulkalg;
SECStatus rv = SECFailure;
NSSCMSContentInfo *cinfo;
NSSCMSRecipient **recipient_list = NULL;
NSSCMSRecipient *recipient;
int rlIndex;
if (NSS_CMSArray_Count((void **)envd->recipientInfos) == 0) {
PORT_SetError(SEC_ERROR_BAD_DATA);
#if 0
PORT_SetErrorString("No recipient data in envelope.");
#endif
goto loser;
}
/* look if one of OUR cert's issuerSN is on the list of recipients, and if so, */
/* get the cert and private key for it right away */
recipient_list = nss_cms_recipient_list_create(envd->recipientInfos);
if (recipient_list == NULL)
goto loser;
/* what about multiple recipientInfos that match?
* especially if, for some reason, we could not produce a bulk key with the first match?!
* we could loop & feed partial recipient_list to PK11_FindCertAndKeyByRecipientList...
* maybe later... */
rlIndex = PK11_FindCertAndKeyByRecipientListNew(recipient_list, envd->cmsg->pwfn_arg);
/* if that fails, then we're not an intended recipient and cannot decrypt */
if (rlIndex < 0) {
PORT_SetError(SEC_ERROR_NOT_A_RECIPIENT);
#if 0
PORT_SetErrorString("Cannot decrypt data because proper key cannot be found.");
#endif
goto loser;
}
recipient = recipient_list[rlIndex];
if (!recipient->cert || !recipient->privkey) {
/* XXX should set an error code ?!? */
goto loser;
}
/* get a pointer to "our" recipientinfo */
ri = envd->recipientInfos[recipient->riIndex];
cinfo = &(envd->contentInfo);
bulkalgtag = NSS_CMSContentInfo_GetContentEncAlgTag(cinfo);
if (bulkalgtag == SEC_OID_UNKNOWN) {
PORT_SetError(SEC_ERROR_INVALID_ALGORITHM);
} else
bulkkey =
NSS_CMSRecipientInfo_UnwrapBulkKey(ri,recipient->subIndex,
recipient->cert,
recipient->privkey,
bulkalgtag);
if (bulkkey == NULL) {
/* no success finding a bulk key */
goto loser;
}
NSS_CMSContentInfo_SetBulkKey(cinfo, bulkkey);
bulkalg = NSS_CMSContentInfo_GetContentEncAlg(cinfo);
rv = NSS_CMSContentInfo_Private_Init(cinfo);
if (rv != SECSuccess) {
goto loser;
}
rv = SECFailure;
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);
if (recipient_list != NULL)
nss_cms_recipient_list_destroy(recipient_list);
return rv;
}
struct message *
smime_decrypt(struct message *m, const char *to, const char *cc, int signcall)
{
NSSCMSDecoderContext *ctx;
NSSCMSMessage *msg;
FILE *op, *hp, *bp;
char *buf = NULL;
size_t bufsize = 0, buflen, count;
char *cp;
struct str in, out;
FILE *yp;
long size;
int i, nlevels;
int binary = 0;
if ((yp = setinput(&mb, m, NEED_BODY)) == NULL)
return NULL;
if (nss_init() != OKAY)
return NULL;
if ((op = Ftemp(&cp, "Rp", "w+", 0600, 1)) == NULL) {
perror("tempfile");
return NULL;
}
rm(cp);
Ftfree(&cp);
if ((ctx = NSS_CMSDecoder_Start(NULL,
decoder_cb, op,
password_cb, "Pass phrase:",
NULL, NULL)) == NULL) {
fprintf(stderr, "Cannot start decoder.\n");
return NULL;
}
size = m->m_size;
if ((smime_split(yp, &hp, &bp, size, 1)) == STOP)
return NULL;
count = fsize(bp);
while (fgetline(&buf, &bufsize, &count, &buflen, bp, 0) != NULL) {
if (buf[0] == '\n')
break;
if ((cp = thisfield(buf, "content-transfer-encoding")) != NULL)
if (ascncasecmp(cp, "binary", 7) == 0)
binary = 1;
}
while (fgetline(&buf, &bufsize, &count, &buflen, bp, 0) != NULL) {
if (binary)
NSS_CMSDecoder_Update(ctx, buf, buflen);
else {
in.s = buf;
in.l = buflen;
mime_fromb64_b(&in, &out, 0, bp);
NSS_CMSDecoder_Update(ctx, out.s, out.l);
free(out.s);
}
}
free(buf);
if ((msg = NSS_CMSDecoder_Finish(ctx)) == NULL) {
fprintf(stderr, "Failed to decode message.\n");
Fclose(hp);
Fclose(bp);
return NULL;
}
nlevels = NSS_CMSMessage_ContentLevelCount(msg);
for (i = 0; i < nlevels; i++) {
NSSCMSContentInfo *content;
SECOidTag tag;
content = NSS_CMSMessage_ContentLevel(msg, i);
tag = NSS_CMSContentInfo_GetContentTypeTag(content);
if (tag == SEC_OID_PKCS7_DATA) {
const char *fld = "X-Encryption-Cipher";
SECOidTag alg;
int keysize;
alg = NSS_CMSContentInfo_GetContentEncAlgTag(content);
keysize = NSS_CMSContentInfo_GetBulkKeySize(content);
fseek(hp, 0L, SEEK_END);
switch (alg) {
case 0:
if (signcall) {
NSS_CMSMessage_Destroy(msg);
Fclose(hp);
Fclose(bp);
setinput(&mb, m, NEED_BODY);
return (struct message *)-1;
}
fprintf(hp, "%s: none\n", fld);
break;
case SEC_OID_RC2_CBC:
fprintf(hp, "%s: RC2, %d bits\n", fld, keysize);
break;
case SEC_OID_DES_CBC:
fprintf(hp, "%s: DES, 56 bits\n", fld);
break;
case SEC_OID_DES_EDE3_CBC:
fprintf(hp, "%s: 3DES, 112/168 bits\n", fld);
break;
case SEC_OID_FORTEZZA_SKIPJACK:
fprintf(hp, "%s: Fortezza\n", fld);
break;
default:
fprintf(hp, "%s: unknown type %lu\n", fld,
(unsigned long)alg);
}
fflush(hp);
rewind(hp);
}
}
NSS_CMSMessage_Destroy(msg);
fflush(op);
rewind(op);
Fclose(bp);
return smime_decrypt_assemble(m, hp, op);
}
/*
* NSS_CMSEnvelopedData_Encode_BeforeStart - prepare this envelopedData for encoding
*
* at this point, we need
* - recipientinfos set up with recipient's certificates
* - a content encryption algorithm (if none, 3DES will be used)
*
* this function will generate a random content encryption key (aka bulk key),
* initialize the recipientinfos with certificate identification and wrap the bulk key
* using the proper algorithm for every certificiate.
* it will finally set the bulk algorithm and key so that the encode step can find it.
*/
SECStatus
NSS_CMSEnvelopedData_Encode_BeforeStart(NSSCMSEnvelopedData *envd)
{
int version;
NSSCMSRecipientInfo **recipientinfos;
NSSCMSContentInfo *cinfo;
PK11SymKey *bulkkey = NULL;
SECOidTag bulkalgtag;
CK_MECHANISM_TYPE type;
PK11SlotInfo *slot;
SECStatus rv;
SECItem *dummy;
PLArenaPool *poolp;
extern const SEC_ASN1Template NSSCMSRecipientInfoTemplate[];
void *mark = NULL;
int i;
poolp = envd->cmsg->poolp;
cinfo = &(envd->contentInfo);
recipientinfos = envd->recipientInfos;
if (recipientinfos == NULL) {
PORT_SetError(SEC_ERROR_BAD_DATA);
#if 0
PORT_SetErrorString("Cannot find recipientinfos to encode.");
#endif
goto loser;
}
version = NSS_CMS_ENVELOPED_DATA_VERSION_REG;
if (envd->originatorInfo != NULL || envd->unprotectedAttr != NULL) {
version = NSS_CMS_ENVELOPED_DATA_VERSION_ADV;
} else {
for (i = 0; recipientinfos[i] != NULL; i++) {
if (NSS_CMSRecipientInfo_GetVersion(recipientinfos[i]) != 0) {
version = NSS_CMS_ENVELOPED_DATA_VERSION_ADV;
break;
}
}
}
dummy = SEC_ASN1EncodeInteger(poolp, &(envd->version), version);
if (dummy == NULL)
goto loser;
/* now we need to have a proper content encryption algorithm
* on the SMIME level, we would figure one out by looking at SMIME capabilities
* we cannot do that on our level, so if none is set already, we'll just go
* with one of the mandatory algorithms (3DES) */
if ((bulkalgtag = NSS_CMSContentInfo_GetContentEncAlgTag(cinfo)) == SEC_OID_UNKNOWN) {
rv = NSS_CMSContentInfo_SetContentEncAlg(poolp, cinfo, SEC_OID_DES_EDE3_CBC, NULL, 168);
if (rv != SECSuccess)
goto loser;
bulkalgtag = SEC_OID_DES_EDE3_CBC;
}
/* generate a random bulk key suitable for content encryption alg */
type = PK11_AlgtagToMechanism(bulkalgtag);
slot = PK11_GetBestSlot(type, envd->cmsg->pwfn_arg);
if (slot == NULL)
goto loser; /* error has been set by PK11_GetBestSlot */
/* this is expensive... */
bulkkey = PK11_KeyGen(slot, type, NULL, NSS_CMSContentInfo_GetBulkKeySize(cinfo) / 8, envd->cmsg->pwfn_arg);
PK11_FreeSlot(slot);
if (bulkkey == NULL)
goto loser; /* error has been set by PK11_KeyGen */
mark = PORT_ArenaMark(poolp);
/* Encrypt the bulk key with the public key of each recipient. */
for (i = 0; recipientinfos[i] != NULL; i++) {
rv = NSS_CMSRecipientInfo_WrapBulkKey(recipientinfos[i], bulkkey, bulkalgtag);
if (rv != SECSuccess)
goto loser; /* error has been set by NSS_CMSRecipientInfo_EncryptBulkKey */
/* could be: alg not supported etc. */
}
/* the recipientinfos are all finished. now sort them by DER for SET OF encoding */
rv = NSS_CMSArray_SortByDER((void **)envd->recipientInfos, NSSCMSRecipientInfoTemplate, NULL);
if (rv != SECSuccess)
goto loser; /* error has been set by NSS_CMSArray_SortByDER */
/* store the bulk key in the contentInfo so that the encoder can find it */
NSS_CMSContentInfo_SetBulkKey(cinfo, bulkkey);
PORT_ArenaUnmark(poolp, mark);
PK11_FreeSymKey(bulkkey);
return SECSuccess;
loser:
if (mark != NULL)
PORT_ArenaRelease (poolp, mark);
if (bulkkey)
PK11_FreeSymKey(bulkkey);
return SECFailure;
}
