The Tor Browser: security/nss/lib/pkcs7/p7encode.c@7e26c7da4463 (annotated)

security/nss/lib/pkcs7/p7encode.c@7e26c7da4463 (annotated)

security/nss/lib/pkcs7/p7encode.c

Wed, 31 Dec 2014 06:55:50 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:55:50 +0100
changeset 2: 7e26c7da4463
permissions: -rw-r--r--

Added tag UPSTREAM_283F7C6 for changeset ca08bd8f51b2

 /* 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/. */
 /*
  * PKCS7 encoding.
  */
 #include "p7local.h"
 #include "cert.h"
 #include "cryptohi.h"
 #include "keyhi.h"
 #include "secasn1.h"
 #include "secoid.h"
 #include "secitem.h"
 #include "pk11func.h"
 #include "secerr.h"
 #include "sechash.h"	/* for HASH_GetHashObject() */
 struct sec_pkcs7_encoder_output {
     SEC_PKCS7EncoderOutputCallback outputfn;
     void *outputarg;
 };
 struct SEC_PKCS7EncoderContextStr {
     SEC_ASN1EncoderContext *ecx;
     SEC_PKCS7ContentInfo *cinfo;
     struct sec_pkcs7_encoder_output output;
     sec_PKCS7CipherObject *encryptobj;
     const SECHashObject *digestobj;
     void *digestcx;
 };
 /*
  * The little output function that the ASN.1 encoder calls to hand
  * us bytes which we in turn hand back to our caller (via the callback
  * they gave us).
  */
 static void
 sec_pkcs7_encoder_out(void *arg, const char *buf, unsigned long len,
 		      int depth, SEC_ASN1EncodingPart data_kind)
 {
     struct sec_pkcs7_encoder_output *output;
     output = (struct sec_pkcs7_encoder_output*)arg;
     output->outputfn (output->outputarg, buf, len);
 }
 static sec_PKCS7CipherObject *
 sec_pkcs7_encoder_start_encrypt (SEC_PKCS7ContentInfo *cinfo,
 						 PK11SymKey *orig_bulkkey)
 {
     SECOidTag kind;
     sec_PKCS7CipherObject *encryptobj;
     SEC_PKCS7RecipientInfo **recipientinfos, *ri;
     SEC_PKCS7EncryptedContentInfo *enccinfo;
     SECKEYPublicKey *publickey = NULL;
     SECKEYPrivateKey *ourPrivKey = NULL;
     PK11SymKey  *bulkkey;
     void *mark, *wincx;
     int i;
     PLArenaPool *arena = NULL;
     /* Get the context in case we need it below. */
     wincx = cinfo->pwfn_arg;
     kind = SEC_PKCS7ContentType (cinfo);
     switch (kind) {
       default:
       case SEC_OID_PKCS7_DATA:
       case SEC_OID_PKCS7_DIGESTED_DATA:
       case SEC_OID_PKCS7_SIGNED_DATA:
 	recipientinfos = NULL;
 	enccinfo = NULL;
 	break;
       case SEC_OID_PKCS7_ENCRYPTED_DATA:
 	{
 	    SEC_PKCS7EncryptedData *encdp;
 	    /* To do EncryptedData we *must* be given a bulk key. */
 	    PORT_Assert (orig_bulkkey != NULL);
 	    if (orig_bulkkey == NULL) {
 		/* XXX error? */
 		return NULL;
 	    }
 	    encdp = cinfo->content.encryptedData;
 	    recipientinfos = NULL;
 	    enccinfo = &(encdp->encContentInfo);
 	}
 	break;
       case SEC_OID_PKCS7_ENVELOPED_DATA:
 	{
 	    SEC_PKCS7EnvelopedData *envdp;
 	    envdp = cinfo->content.envelopedData;
 	    recipientinfos = envdp->recipientInfos;
 	    enccinfo = &(envdp->encContentInfo);
 	}
 	break;
       case SEC_OID_PKCS7_SIGNED_ENVELOPED_DATA:
 	{
 	    SEC_PKCS7SignedAndEnvelopedData *saedp;
 	    saedp = cinfo->content.signedAndEnvelopedData;
 	    recipientinfos = saedp->recipientInfos;
 	    enccinfo = &(saedp->encContentInfo);
 	}
 	break;
     }
     if (enccinfo == NULL)
 	return NULL;
     bulkkey = orig_bulkkey;
     if (bulkkey == NULL) {
 	CK_MECHANISM_TYPE type = PK11_AlgtagToMechanism(enccinfo->encalg);
 	PK11SlotInfo *slot;
 	slot = PK11_GetBestSlot(type,cinfo->pwfn_arg);
 	if (slot == NULL) {
 	    return NULL;
 	}
 	bulkkey = PK11_KeyGen(slot,type,NULL, enccinfo->keysize/8,
 			      cinfo->pwfn_arg);
 	PK11_FreeSlot(slot);
 	if (bulkkey == NULL) {
 	    return NULL;
 	}
     }
     encryptobj = NULL;
     mark = PORT_ArenaMark (cinfo->poolp);
     /*
      * Encrypt the bulk key with the public key of each recipient.
      */
     for (i = 0; recipientinfos && (ri = recipientinfos[i]) != NULL; i++) {
 	CERTCertificate *cert;
 	SECOidTag certalgtag, encalgtag;
 	SECStatus rv;
 	int data_len;
 	SECItem *params = NULL;
 	cert = ri->cert;
 	PORT_Assert (cert != NULL);
 	if (cert == NULL)
 	    continue;
 	/*
 	 * XXX Want an interface that takes a cert and some data and
 	 * fills in an algorithmID and encrypts the data with the public
 	 * key from the cert.  Or, give me two interfaces -- one which
 	 * gets the algorithm tag from a cert (I should not have to go
 	 * down into the subjectPublicKeyInfo myself) and another which
 	 * takes a public key and algorithm tag and data and encrypts
 	 * the data.  Or something like that.  The point is that all
 	 * of the following hardwired RSA stuff should be done elsewhere.
 	 */
 	certalgtag=SECOID_GetAlgorithmTag(&(cert->subjectPublicKeyInfo.algorithm));
 	switch (certalgtag) {
 	case SEC_OID_PKCS1_RSA_ENCRYPTION:
 	    encalgtag = certalgtag;
 	    publickey = CERT_ExtractPublicKey (cert);
 	    if (publickey == NULL) goto loser;
 	    data_len = SECKEY_PublicKeyStrength(publickey);
 	    ri->encKey.data =
 	        (unsigned char*)PORT_ArenaAlloc(cinfo->poolp ,data_len);
 	    ri->encKey.len = data_len;
 	    if (ri->encKey.data == NULL) goto loser;
 	    rv = PK11_PubWrapSymKey(PK11_AlgtagToMechanism(certalgtag),publickey,
 				bulkkey,&ri->encKey);
 	    SECKEY_DestroyPublicKey(publickey);
 	    publickey = NULL;
 	    if (rv != SECSuccess) goto loser;
 	    params = NULL; /* paranoia */
 	    break;
 	default:
 	    PORT_SetError (SEC_ERROR_INVALID_ALGORITHM);
 	    goto loser;
 	}
 	rv = SECOID_SetAlgorithmID(cinfo->poolp, &ri->keyEncAlg, encalgtag,
 			params);
 	if (rv != SECSuccess)
 	    goto loser;
 	if (arena) PORT_FreeArena(arena,PR_FALSE);
 	arena = NULL;
     }
     encryptobj = sec_PKCS7CreateEncryptObject (cinfo->poolp, bulkkey,
 					       enccinfo->encalg,
 					       &(enccinfo->contentEncAlg));
     if (encryptobj != NULL) {
 	PORT_ArenaUnmark (cinfo->poolp, mark);
 	mark = NULL;		/* good one; do not want to release */
     }
     /* fallthru */
 loser:
     if (arena) {
 	PORT_FreeArena(arena, PR_FALSE);
     }
     if (publickey) {
         SECKEY_DestroyPublicKey(publickey);
     }
     if (ourPrivKey) {
         SECKEY_DestroyPrivateKey(ourPrivKey);
     }
     if (mark != NULL) {
 	PORT_ArenaRelease (cinfo->poolp, mark);
     }
     if (orig_bulkkey == NULL) {
 	if (bulkkey) PK11_FreeSymKey(bulkkey);
     }
     return encryptobj;
 }
 static void
 sec_pkcs7_encoder_notify (void *arg, PRBool before, void *dest, int depth)
 {
     SEC_PKCS7EncoderContext *p7ecx;
     SEC_PKCS7ContentInfo *cinfo;
     SECOidTag kind;
     PRBool before_content;
     /*
      * We want to notice just before the content field.  After fields are
      * not interesting to us.
      */
     if (!before)
 	return;
     p7ecx = (SEC_PKCS7EncoderContext*)arg;
     cinfo = p7ecx->cinfo;
     before_content = PR_FALSE;
     /*
      * Watch for the content field, at which point we want to instruct
      * the ASN.1 encoder to start taking bytes from the buffer.
      *
      * XXX The following assumes the inner content type is data;
      * if/when we want to handle fully nested types, this will have
      * to recurse until reaching the innermost data content.
      */
     kind = SEC_PKCS7ContentType (cinfo);
     switch (kind) {
       default:
       case SEC_OID_PKCS7_DATA:
 	if (dest == &(cinfo->content.data))
 	    before_content = PR_TRUE;
 	break;
       case SEC_OID_PKCS7_DIGESTED_DATA:
 	{
 	    SEC_PKCS7DigestedData *digd;
 	    digd = cinfo->content.digestedData;
 	    if (digd == NULL)
 		break;
 	    if (dest == &(digd->contentInfo.content))
 		before_content = PR_TRUE;
 	}
 	break;
       case SEC_OID_PKCS7_ENCRYPTED_DATA:
 	{
 	    SEC_PKCS7EncryptedData *encd;
 	    encd = cinfo->content.encryptedData;
 	    if (encd == NULL)
 		break;
 	    if (dest == &(encd->encContentInfo.encContent))
 		before_content = PR_TRUE;
 	}
 	break;
       case SEC_OID_PKCS7_ENVELOPED_DATA:
 	{
 	    SEC_PKCS7EnvelopedData *envd;
 	    envd = cinfo->content.envelopedData;
 	    if (envd == NULL)
 		break;
 	    if (dest == &(envd->encContentInfo.encContent))
 		before_content = PR_TRUE;
 	}
 	break;
       case SEC_OID_PKCS7_SIGNED_DATA:
 	{
 	    SEC_PKCS7SignedData *sigd;
 	    sigd = cinfo->content.signedData;
 	    if (sigd == NULL)
 		break;
 	    if (dest == &(sigd->contentInfo.content))
 		before_content = PR_TRUE;
 	}
 	break;
       case SEC_OID_PKCS7_SIGNED_ENVELOPED_DATA:
 	{
 	    SEC_PKCS7SignedAndEnvelopedData *saed;
 	    saed = cinfo->content.signedAndEnvelopedData;
 	    if (saed == NULL)
 		break;
 	    if (dest == &(saed->encContentInfo.encContent))
 		before_content = PR_TRUE;
 	}
 	break;
     }
     if (before_content) {
 	/*
 	 * This will cause the next SEC_ASN1EncoderUpdate to take the
 	 * contents bytes from the passed-in buffer.
 	 */
 	SEC_ASN1EncoderSetTakeFromBuf (p7ecx->ecx);
 	/*
 	 * And that is all we needed this notify function for.
 	 */
 	SEC_ASN1EncoderClearNotifyProc (p7ecx->ecx);
     }
 }
 static SEC_PKCS7EncoderContext *
 sec_pkcs7_encoder_start_contexts (SEC_PKCS7ContentInfo *cinfo,
 				  PK11SymKey *bulkkey)
 {
     SEC_PKCS7EncoderContext *p7ecx;
     SECOidTag kind;
     PRBool encrypt;
     SECItem **digests;
     SECAlgorithmID *digestalg, **digestalgs;
     p7ecx =
       (SEC_PKCS7EncoderContext*)PORT_ZAlloc (sizeof(SEC_PKCS7EncoderContext));
     if (p7ecx == NULL)
 	return NULL;
     digests = NULL;
     digestalg = NULL;
     digestalgs = NULL;
     encrypt = PR_FALSE;
     kind = SEC_PKCS7ContentType (cinfo);
     switch (kind) {
       default:
       case SEC_OID_PKCS7_DATA:
 	break;
       case SEC_OID_PKCS7_DIGESTED_DATA:
 	digestalg = &(cinfo->content.digestedData->digestAlg);
 	break;
       case SEC_OID_PKCS7_SIGNED_DATA:
 	digests = cinfo->content.signedData->digests;
 	digestalgs = cinfo->content.signedData->digestAlgorithms;
 	break;
       case SEC_OID_PKCS7_ENCRYPTED_DATA:
       case SEC_OID_PKCS7_ENVELOPED_DATA:
 	encrypt = PR_TRUE;
 	break;
       case SEC_OID_PKCS7_SIGNED_ENVELOPED_DATA:
 	digests = cinfo->content.signedAndEnvelopedData->digests;
 	digestalgs = cinfo->content.signedAndEnvelopedData->digestAlgorithms;
 	encrypt = PR_TRUE;
 	break;
     }
     if (encrypt) {
 	p7ecx->encryptobj = sec_pkcs7_encoder_start_encrypt (cinfo, bulkkey);
 	if (p7ecx->encryptobj == NULL) {
 	    PORT_Free (p7ecx);
 	    return NULL;
 	}
     }
     if (digestalgs != NULL) {
 	if (digests != NULL) {
 	    /* digests already created (probably for detached data) */
 	    digestalg = NULL;
 	} else {
 	    /*
 	     * XXX Some day we should handle multiple digests; for now,
 	     * assume only one will be done.
 	     */
 	    PORT_Assert (digestalgs[0] != NULL && digestalgs[1] == NULL);
 	    digestalg = digestalgs[0];
 	}
     }
     if (digestalg != NULL) {
 	SECOidTag  oidTag = SECOID_FindOIDTag(&(digestalg->algorithm));
 	p7ecx->digestobj = HASH_GetHashObjectByOidTag(oidTag);
 	if (p7ecx->digestobj != NULL) {
 	    p7ecx->digestcx = (* p7ecx->digestobj->create) ();
 	    if (p7ecx->digestcx == NULL)
 		p7ecx->digestobj = NULL;
 	    else
 		(* p7ecx->digestobj->begin) (p7ecx->digestcx);
 	}
 	if (p7ecx->digestobj == NULL) {
 	    if (p7ecx->encryptobj != NULL)
 		sec_PKCS7DestroyEncryptObject (p7ecx->encryptobj);
 	    PORT_Free (p7ecx);
 	    return NULL;
 	}
     }
     p7ecx->cinfo = cinfo;
     return p7ecx;
 }
 SEC_PKCS7EncoderContext *
 SEC_PKCS7EncoderStart (SEC_PKCS7ContentInfo *cinfo,
 		       SEC_PKCS7EncoderOutputCallback outputfn,
 		       void *outputarg,
 		       PK11SymKey *bulkkey)
 {
     SEC_PKCS7EncoderContext *p7ecx;
     SECStatus rv;
     p7ecx = sec_pkcs7_encoder_start_contexts (cinfo, bulkkey);
     if (p7ecx == NULL)
 	return NULL;
     p7ecx->output.outputfn = outputfn;
     p7ecx->output.outputarg = outputarg;
     /*
      * Initialize the BER encoder.
      */
     p7ecx->ecx = SEC_ASN1EncoderStart (cinfo, sec_PKCS7ContentInfoTemplate,
 				       sec_pkcs7_encoder_out, &(p7ecx->output));
     if (p7ecx->ecx == NULL) {
 	PORT_Free (p7ecx);
 	return NULL;
     }
     /*
      * Indicate that we are streaming.  We will be streaming until we
      * get past the contents bytes.
      */
     SEC_ASN1EncoderSetStreaming (p7ecx->ecx);
     /*
      * The notify function will watch for the contents field.
      */
     SEC_ASN1EncoderSetNotifyProc (p7ecx->ecx, sec_pkcs7_encoder_notify, p7ecx);
     /*
      * This will encode everything up to the content bytes.  (The notify
      * function will then cause the encoding to stop there.)  Then our
      * caller can start passing contents bytes to our Update, which we
      * will pass along.
      */
     rv = SEC_ASN1EncoderUpdate (p7ecx->ecx, NULL, 0);
     if (rv != SECSuccess) {
 	PORT_Free (p7ecx);
 	return NULL;
     }
     return p7ecx;
 }
 /*
  * XXX If/when we support nested contents, this needs to be revised.
  */
 static SECStatus
 sec_pkcs7_encoder_work_data (SEC_PKCS7EncoderContext *p7ecx, SECItem *dest,
 			     const unsigned char *data, unsigned long len,
 			     PRBool final)
 {
     unsigned char *buf = NULL;
     SECStatus rv;
     rv = SECSuccess;		/* may as well be optimistic */
     /*
      * We should really have data to process, or we should be trying
      * to finish/flush the last block.  (This is an overly paranoid
      * check since all callers are in this file and simple inspection
      * proves they do it right.  But it could find a bug in future
      * modifications/development, that is why it is here.)
      */
     PORT_Assert ((data != NULL && len) || final);
     /*
      * Update the running digest.
      * XXX This needs modification if/when we handle multiple digests.
      */
     if (len && p7ecx->digestobj != NULL) {
 	(* p7ecx->digestobj->update) (p7ecx->digestcx, data, len);
     }
     /*
      * Encrypt this chunk.
      */
     if (p7ecx->encryptobj != NULL) {
 	/* XXX the following lengths should all be longs? */
 	unsigned int inlen;	/* length of data being encrypted */
 	unsigned int outlen;	/* length of encrypted data */
 	unsigned int buflen;	/* length available for encrypted data */
 	inlen = len;
 	buflen = sec_PKCS7EncryptLength (p7ecx->encryptobj, inlen, final);
 	if (buflen == 0) {
 	    /*
 	     * No output is expected, but the input data may be buffered
 	     * so we still have to call Encrypt.
 	     */
 	    rv = sec_PKCS7Encrypt (p7ecx->encryptobj, NULL, NULL, 0,
 				   data, inlen, final);
 	    if (final) {
 		len = 0;
 		goto done;
 	    }
 	    return rv;
 	}
 	if (dest != NULL)
 	    buf = (unsigned char*)PORT_ArenaAlloc(p7ecx->cinfo->poolp, buflen);
 	else
 	    buf = (unsigned char*)PORT_Alloc (buflen);
 	if (buf == NULL) {
 	    rv = SECFailure;
 	} else {
 	    rv = sec_PKCS7Encrypt (p7ecx->encryptobj, buf, &outlen, buflen,
 				   data, inlen, final);
 	    data = buf;
 	    len = outlen;
 	}
 	if (rv != SECSuccess) {
 	    if (final)
 		goto done;
 	    return rv;
 	}
     }
     if (p7ecx->ecx != NULL) {
 	/*
 	 * Encode the contents bytes.
 	 */
 	if(len) {
 	    rv = SEC_ASN1EncoderUpdate (p7ecx->ecx, (const char *)data, len);
 	}
     }
 done:
     if (p7ecx->encryptobj != NULL) {
 	if (final)
 	    sec_PKCS7DestroyEncryptObject (p7ecx->encryptobj);
 	if (dest != NULL) {
 	    dest->data = buf;
 	    dest->len = len;
 	} else if (buf != NULL) {
 	    PORT_Free (buf);
 	}
     }
     if (final && p7ecx->digestobj != NULL) {
 	SECItem *digest, **digests, ***digestsp;
 	unsigned char *digdata;
 	SECOidTag kind;
 	kind = SEC_PKCS7ContentType (p7ecx->cinfo);
 	switch (kind) {
 	  default:
 	    PORT_Assert (0);
 	    return SECFailure;
 	  case SEC_OID_PKCS7_DIGESTED_DATA:
 	    digest = &(p7ecx->cinfo->content.digestedData->digest);
 	    digestsp = NULL;
 	    break;
 	  case SEC_OID_PKCS7_SIGNED_DATA:
 	    digest = NULL;
 	    digestsp = &(p7ecx->cinfo->content.signedData->digests);
 	    break;
 	  case SEC_OID_PKCS7_SIGNED_ENVELOPED_DATA:
 	    digest = NULL;
 	    digestsp = &(p7ecx->cinfo->content.signedAndEnvelopedData->digests);
 	    break;
 	}
 	digdata = (unsigned char*)PORT_ArenaAlloc (p7ecx->cinfo->poolp,
 				   p7ecx->digestobj->length);
 	if (digdata == NULL)
 	    return SECFailure;
 	if (digestsp != NULL) {
 	    PORT_Assert (digest == NULL);
 	    digest = (SECItem*)PORT_ArenaAlloc (p7ecx->cinfo->poolp,
 						sizeof(SECItem));
 	    digests = (SECItem**)PORT_ArenaAlloc (p7ecx->cinfo->poolp,
 * sizeof(SECItem *));
 	    if (digests == NULL || digest == NULL)
 		return SECFailure;
 	    digests[0] = digest;
 	    digests[1] = NULL;
 	    *digestsp = digests;
 	}
 	PORT_Assert (digest != NULL);
 	digest->data = digdata;
 	digest->len = p7ecx->digestobj->length;
 	(* p7ecx->digestobj->end) (p7ecx->digestcx, digest->data,
 				   &(digest->len), digest->len);
 	(* p7ecx->digestobj->destroy) (p7ecx->digestcx, PR_TRUE);
     }
     return rv;
 }
 SECStatus
 SEC_PKCS7EncoderUpdate (SEC_PKCS7EncoderContext *p7ecx,
 			const char *data, unsigned long len)
 {
     /* XXX Error handling needs help.  Return what?  Do "Finish" on failure? */
     return sec_pkcs7_encoder_work_data (p7ecx, NULL,
 					(const unsigned char *)data, len,
 					PR_FALSE);
 }
 static SECStatus
 sec_pkcs7_encoder_sig_and_certs (SEC_PKCS7ContentInfo *cinfo,
 				 SECKEYGetPasswordKey pwfn, void *pwfnarg)
 {
     SECOidTag kind;
     CERTCertificate **certs;
     CERTCertificateList **certlists;
     SECAlgorithmID **digestalgs;
     SECItem **digests;
     SEC_PKCS7SignerInfo *signerinfo, **signerinfos;
     SECItem **rawcerts, ***rawcertsp;
     PLArenaPool *poolp;
     int certcount;
     int ci, cli, rci, si;
     kind = SEC_PKCS7ContentType (cinfo);
     switch (kind) {
       default:
       case SEC_OID_PKCS7_DATA:
       case SEC_OID_PKCS7_DIGESTED_DATA:
       case SEC_OID_PKCS7_ENCRYPTED_DATA:
       case SEC_OID_PKCS7_ENVELOPED_DATA:
 	certs = NULL;
 	certlists = NULL;
 	digestalgs = NULL;
 	digests = NULL;
 	signerinfos = NULL;
 	rawcertsp = NULL;
 	break;
       case SEC_OID_PKCS7_SIGNED_DATA:
 	{
 	    SEC_PKCS7SignedData *sdp;
 	    sdp = cinfo->content.signedData;
 	    certs = sdp->certs;
 	    certlists = sdp->certLists;
 	    digestalgs = sdp->digestAlgorithms;
 	    digests = sdp->digests;
 	    signerinfos = sdp->signerInfos;
 	    rawcertsp = &(sdp->rawCerts);
 	}
 	break;
       case SEC_OID_PKCS7_SIGNED_ENVELOPED_DATA:
 	{
 	    SEC_PKCS7SignedAndEnvelopedData *saedp;
 	    saedp = cinfo->content.signedAndEnvelopedData;
 	    certs = saedp->certs;
 	    certlists = saedp->certLists;
 	    digestalgs = saedp->digestAlgorithms;
 	    digests = saedp->digests;
 	    signerinfos = saedp->signerInfos;
 	    rawcertsp = &(saedp->rawCerts);
 	}
 	break;
     }
     if (certs == NULL && certlists == NULL && signerinfos == NULL)
 	return SECSuccess;		/* nothing for us to do! */
     poolp = cinfo->poolp;
     certcount = 0;
     if (signerinfos != NULL) {
 	SECOidTag digestalgtag;
 	int di;
 	SECStatus rv;
 	CERTCertificate *cert;
 	SECKEYPrivateKey *privkey;
 	SECItem signature;
 	SECOidTag signalgtag;
 	PORT_Assert (digestalgs != NULL && digests != NULL);
 	/*
 	 * If one fails, we bail right then.  If we want to continue and
 	 * try to do subsequent signatures, this loop, and the departures
 	 * from it, will need to be reworked.
 	 */
 	for (si = 0; signerinfos[si] != NULL; si++) {
 	    signerinfo = signerinfos[si];
 	    /* find right digest */
 	    digestalgtag = SECOID_GetAlgorithmTag (&(signerinfo->digestAlg));
 	    for (di = 0; digestalgs[di] != NULL; di++) {
 		/* XXX Should I be comparing more than the tag? */
 		if (digestalgtag == SECOID_GetAlgorithmTag (digestalgs[di]))
 		    break;
 	    }
 	    if (digestalgs[di] == NULL) {
 		/* XXX oops; do what? set an error? */
 		return SECFailure;
 	    }
 	    PORT_Assert (digests[di] != NULL);
 	    cert = signerinfo->cert;
 	    privkey = PK11_FindKeyByAnyCert (cert, pwfnarg);
 	    if (privkey == NULL)
 		return SECFailure;
 	    /*
 	     * XXX I think there should be a cert-level interface for this,
 	     * so that I do not have to know about subjectPublicKeyInfo...
 	     */
 	    signalgtag = SECOID_GetAlgorithmTag (&(cert->subjectPublicKeyInfo.algorithm));
 	    if (signerinfo->authAttr != NULL) {
 		SEC_PKCS7Attribute *attr;
 		SECItem encoded_attrs;
 		SECItem *dummy;
 		SECOidTag algid;
 		/*
 		 * First, find and fill in the message digest attribute.
 		 */
 		attr = sec_PKCS7FindAttribute (signerinfo->authAttr,
 					       SEC_OID_PKCS9_MESSAGE_DIGEST,
 					       PR_TRUE);
 		PORT_Assert (attr != NULL);
 		if (attr == NULL) {
 		    SECKEY_DestroyPrivateKey (privkey);
 		    return SECFailure;
 		}
 		/*
 		 * XXX The second half of the following assertion prevents
 		 * the encoder from being called twice on the same content.
 		 * Either just remove the second half the assertion, or
 		 * change the code to check if the value already there is
 		 * the same as digests[di], whichever seems more right.
 		 */
 		PORT_Assert (attr->values != NULL && attr->values[0] == NULL);
 		attr->values[0] = digests[di];
 		/*
 		 * Before encoding, reorder the attributes so that when they
 		 * are encoded, they will be conforming DER, which is required
 		 * to have a specific order and that is what must be used for
 		 * the hash/signature.  We do this here, rather than building
 		 * it into EncodeAttributes, because we do not want to do
 		 * such reordering on incoming messages (which also uses
 		 * EncodeAttributes) or our old signatures (and other "broken"
 		 * implementations) will not verify.  So, we want to guarantee
 		 * that we send out good DER encodings of attributes, but not
 		 * to expect to receive them.
 		 */
 		rv = sec_PKCS7ReorderAttributes (signerinfo->authAttr);
 		if (rv != SECSuccess) {
 		    SECKEY_DestroyPrivateKey (privkey);
 		    return SECFailure;
 		}
 		encoded_attrs.data = NULL;
 		encoded_attrs.len = 0;
 		dummy = sec_PKCS7EncodeAttributes (NULL, &encoded_attrs,
 						   &(signerinfo->authAttr));
 		if (dummy == NULL) {
 		    SECKEY_DestroyPrivateKey (privkey);
 		    return SECFailure;
 		}
 	        algid = SEC_GetSignatureAlgorithmOidTag(privkey->keyType,
  							digestalgtag);
 		if (algid == SEC_OID_UNKNOWN) {
 		    PORT_SetError(SEC_ERROR_INVALID_ALGORITHM);
 		    SECKEY_DestroyPrivateKey (privkey);
 		    return SECFailure;
 		}
 		rv = SEC_SignData (&signature,
 				   encoded_attrs.data, encoded_attrs.len,
 				   privkey,
 				   algid);
 		SECITEM_FreeItem (&encoded_attrs, PR_FALSE);
 	    } else {
 		rv = SGN_Digest (privkey, digestalgtag, &signature,
 				 digests[di]);
 	    }
 	    SECKEY_DestroyPrivateKey (privkey);
 	    if (rv != SECSuccess)
 		return rv;
 	    rv = SECITEM_CopyItem (poolp, &(signerinfo->encDigest), &signature);
 	    if (rv != SECSuccess)
 		return rv;
 	    SECITEM_FreeItem (&signature, PR_FALSE);
 	    rv = SECOID_SetAlgorithmID (poolp, &(signerinfo->digestEncAlg),
 					signalgtag, NULL);
 	    if (rv != SECSuccess)
 		return SECFailure;
 	    /*
 	     * Count the cert chain for this signer.
 	     */
 	    if (signerinfo->certList != NULL)
 		certcount += signerinfo->certList->len;
 	}
     }
     if (certs != NULL) {
 	for (ci = 0; certs[ci] != NULL; ci++)
 	    certcount++;
     }
     if (certlists != NULL) {
 	for (cli = 0; certlists[cli] != NULL; cli++)
 	    certcount += certlists[cli]->len;
     }
     if (certcount == 0)
 	return SECSuccess;		/* signing done; no certs */
     /*
      * Combine all of the certs and cert chains into rawcerts.
      * Note: certcount is an upper bound; we may not need that many slots
      * but we will allocate anyway to avoid having to do another pass.
      * (The temporary space saving is not worth it.)
      */
     rawcerts = (SECItem**)PORT_ArenaAlloc (poolp,
 					(certcount + 1) * sizeof(SECItem *));
     if (rawcerts == NULL)
 	return SECFailure;
     /*
      * XXX Want to check for duplicates and not add *any* cert that is
      * already in the set.  This will be more important when we start
      * dealing with larger sets of certs, dual-key certs (signing and
      * encryption), etc.  For the time being we can slide by...
      */
     rci = 0;
     if (signerinfos != NULL) {
 	for (si = 0; signerinfos[si] != NULL; si++) {
 	    signerinfo = signerinfos[si];
 	    for (ci = 0; ci < signerinfo->certList->len; ci++)
 		rawcerts[rci++] = &(signerinfo->certList->certs[ci]);
 	}
     }
     if (certs != NULL) {
 	for (ci = 0; certs[ci] != NULL; ci++)
 	    rawcerts[rci++] = &(certs[ci]->derCert);
     }
     if (certlists != NULL) {
 	for (cli = 0; certlists[cli] != NULL; cli++) {
 	    for (ci = 0; ci < certlists[cli]->len; ci++)
 		rawcerts[rci++] = &(certlists[cli]->certs[ci]);
 	}
     }
     rawcerts[rci] = NULL;
     *rawcertsp = rawcerts;
     return SECSuccess;
 }
 SECStatus
 SEC_PKCS7EncoderFinish (SEC_PKCS7EncoderContext *p7ecx,
 			SECKEYGetPasswordKey pwfn, void *pwfnarg)
 {
     SECStatus rv;
     /*
      * Flush out any remaining data.
      */
     rv = sec_pkcs7_encoder_work_data (p7ecx, NULL, NULL, 0, PR_TRUE);
     /*
      * Turn off streaming stuff.
      */
     SEC_ASN1EncoderClearTakeFromBuf (p7ecx->ecx);
     SEC_ASN1EncoderClearStreaming (p7ecx->ecx);
     if (rv != SECSuccess)
 	goto loser;
     rv = sec_pkcs7_encoder_sig_and_certs (p7ecx->cinfo, pwfn, pwfnarg);
     if (rv != SECSuccess)
 	goto loser;
     rv = SEC_ASN1EncoderUpdate (p7ecx->ecx, NULL, 0);
 loser:
     SEC_ASN1EncoderFinish (p7ecx->ecx);
     PORT_Free (p7ecx);
     return rv;
 }
 /*
  * Abort the ASN.1 stream. Used by pkcs 12
  */
 void
 SEC_PKCS7EncoderAbort(SEC_PKCS7EncoderContext *p7ecx, int error)
 {
     PORT_Assert(p7ecx);
     SEC_ASN1EncoderAbort(p7ecx->ecx, error);
 }
 /*
  * After this routine is called, the entire PKCS7 contentInfo is ready
  * to be encoded.  This is used internally, but can also be called from
  * elsewhere for those who want to be able to just have pointers to
  * the ASN1 template for pkcs7 contentInfo built into their own encodings.
  */
 SECStatus
 SEC_PKCS7PrepareForEncode (SEC_PKCS7ContentInfo *cinfo,
 			   PK11SymKey *bulkkey,
 			   SECKEYGetPasswordKey pwfn,
 			   void *pwfnarg)
 {
     SEC_PKCS7EncoderContext *p7ecx;
     SECItem *content, *enc_content;
     SECStatus rv;
     p7ecx = sec_pkcs7_encoder_start_contexts (cinfo, bulkkey);
     if (p7ecx == NULL)
 	return SECFailure;
     content = SEC_PKCS7GetContent (cinfo);
     if (p7ecx->encryptobj != NULL) {
 	SECOidTag kind;
 	SEC_PKCS7EncryptedContentInfo *enccinfo;
 	kind = SEC_PKCS7ContentType (p7ecx->cinfo);
 	switch (kind) {
 	  default:
 	    PORT_Assert (0);
 	    rv = SECFailure;
 	    goto loser;
 	  case SEC_OID_PKCS7_ENCRYPTED_DATA:
 	    enccinfo = &(p7ecx->cinfo->content.encryptedData->encContentInfo);
 	    break;
 	  case SEC_OID_PKCS7_ENVELOPED_DATA:
 	    enccinfo = &(p7ecx->cinfo->content.envelopedData->encContentInfo);
 	    break;
 	  case SEC_OID_PKCS7_SIGNED_ENVELOPED_DATA:
 	    enccinfo = &(p7ecx->cinfo->content.signedAndEnvelopedData->encContentInfo);
 	    break;
 	}
 	enc_content = &(enccinfo->encContent);
     } else {
 	enc_content = NULL;
     }
     if (content != NULL && content->data != NULL && content->len) {
 	rv = sec_pkcs7_encoder_work_data (p7ecx, enc_content,
 					  content->data, content->len, PR_TRUE);
 	if (rv != SECSuccess)
 	    goto loser;
     }
     rv = sec_pkcs7_encoder_sig_and_certs (cinfo, pwfn, pwfnarg);
 loser:
     PORT_Free (p7ecx);
     return rv;
 }
 /*
  * Encode a PKCS7 object, in one shot.  All necessary components
  * of the object must already be specified.  Either the data has
  * already been included (via SetContent), or the data is detached,
  * or there is no data at all (certs-only).
  *
  * "cinfo" specifies the object to be encoded.
  *
  * "outputfn" is where the encoded bytes will be passed.
  *
  * "outputarg" is an opaque argument to the above callback.
  *
  * "bulkkey" specifies the bulk encryption key to use.   This argument
  * can be NULL if no encryption is being done, or if the bulk key should
  * be generated internally (usually the case for EnvelopedData but never
  * for EncryptedData, which *must* provide a bulk encryption key).
  *
  * "pwfn" is a callback for getting the password which protects the
  * private key of the signer.  This argument can be NULL if it is known
  * that no signing is going to be done.
  *
  * "pwfnarg" is an opaque argument to the above callback.
  */
 SECStatus
 SEC_PKCS7Encode (SEC_PKCS7ContentInfo *cinfo,
 		 SEC_PKCS7EncoderOutputCallback outputfn,
 		 void *outputarg,
 		 PK11SymKey *bulkkey,
 		 SECKEYGetPasswordKey pwfn,
 		 void *pwfnarg)
 {
     SECStatus rv;
     rv = SEC_PKCS7PrepareForEncode (cinfo, bulkkey, pwfn, pwfnarg);
     if (rv == SECSuccess) {
 	struct sec_pkcs7_encoder_output outputcx;
 	outputcx.outputfn = outputfn;
 	outputcx.outputarg = outputarg;
 	rv = SEC_ASN1Encode (cinfo, sec_PKCS7ContentInfoTemplate,
 			     sec_pkcs7_encoder_out, &outputcx);
     }
     return rv;
 }
 /*
  * Encode a PKCS7 object, in one shot.  All necessary components
  * of the object must already be specified.  Either the data has
  * already been included (via SetContent), or the data is detached,
  * or there is no data at all (certs-only).  The output, rather than
  * being passed to an output function as is done above, is all put
  * into a SECItem.
  *
  * "pool" specifies a pool from which to allocate the result.
  * It can be NULL, in which case memory is allocated generically.
  *
  * "dest" specifies a SECItem in which to put the result data.
  * It can be NULL, in which case the entire item is allocated, too.
  *
  * "cinfo" specifies the object to be encoded.
  *
  * "bulkkey" specifies the bulk encryption key to use.   This argument
  * can be NULL if no encryption is being done, or if the bulk key should
  * be generated internally (usually the case for EnvelopedData but never
  * for EncryptedData, which *must* provide a bulk encryption key).
  *
  * "pwfn" is a callback for getting the password which protects the
  * private key of the signer.  This argument can be NULL if it is known
  * that no signing is going to be done.
  *
  * "pwfnarg" is an opaque argument to the above callback.
  */
 SECItem *
 SEC_PKCS7EncodeItem (PLArenaPool *pool,
 		     SECItem *dest,
 		     SEC_PKCS7ContentInfo *cinfo,
 		     PK11SymKey *bulkkey,
 		     SECKEYGetPasswordKey pwfn,
 		     void *pwfnarg)
 {
     SECStatus rv;
     rv = SEC_PKCS7PrepareForEncode (cinfo, bulkkey, pwfn, pwfnarg);
     if (rv != SECSuccess)
 	return NULL;
     return SEC_ASN1EncodeItem (pool, dest, cinfo, sec_PKCS7ContentInfoTemplate);
 }

The Tor Browser / annotate

security/nss/lib/pkcs7/p7encode.c@7e26c7da4463 (annotated)

security/nss/lib/pkcs7/p7encode.c