diff options
Diffstat (limited to 'security/nss/lib/smime/cmspubkey.c')
| -rw-r--r-- | security/nss/lib/smime/cmspubkey.c | 285 |
1 files changed, 285 insertions, 0 deletions
diff --git a/security/nss/lib/smime/cmspubkey.c b/security/nss/lib/smime/cmspubkey.c new file mode 100644 index 000000000..bc3cd993e --- /dev/null +++ b/security/nss/lib/smime/cmspubkey.c @@ -0,0 +1,285 @@ +/* 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 public key crypto + */ + +#include "cmslocal.h" + +#include "cert.h" +#include "key.h" +#include "secasn1.h" +#include "secitem.h" +#include "secoid.h" +#include "pk11func.h" +#include "secerr.h" + +/* ====== RSA ======================================================================= */ + +/* + * NSS_CMSUtil_EncryptSymKey_RSA - wrap a symmetric key with RSA + * + * this function takes a symmetric key and encrypts it using an RSA public key + * according to PKCS#1 and RFC2633 (S/MIME) + */ +SECStatus +NSS_CMSUtil_EncryptSymKey_RSA(PLArenaPool *poolp, CERTCertificate *cert, + PK11SymKey *bulkkey, + SECItem *encKey) +{ + SECStatus rv; + SECKEYPublicKey *publickey; + + publickey = CERT_ExtractPublicKey(cert); + if (publickey == NULL) + return SECFailure; + + rv = NSS_CMSUtil_EncryptSymKey_RSAPubKey(poolp, publickey, bulkkey, encKey); + SECKEY_DestroyPublicKey(publickey); + return rv; +} + +SECStatus +NSS_CMSUtil_EncryptSymKey_RSAPubKey(PLArenaPool *poolp, + SECKEYPublicKey *publickey, + PK11SymKey *bulkkey, SECItem *encKey) +{ + SECStatus rv; + int data_len; + KeyType keyType; + void *mark = NULL; + + mark = PORT_ArenaMark(poolp); + if (!mark) + goto loser; + + /* sanity check */ + keyType = SECKEY_GetPublicKeyType(publickey); + PORT_Assert(keyType == rsaKey); + if (keyType != rsaKey) { + goto loser; + } + /* allocate memory for the encrypted key */ + data_len = SECKEY_PublicKeyStrength(publickey); /* block size (assumed to be > keylen) */ + encKey->data = (unsigned char *)PORT_ArenaAlloc(poolp, data_len); + encKey->len = data_len; + if (encKey->data == NULL) + goto loser; + + /* encrypt the key now */ + rv = PK11_PubWrapSymKey(PK11_AlgtagToMechanism(SEC_OID_PKCS1_RSA_ENCRYPTION), + publickey, bulkkey, encKey); + + if (rv != SECSuccess) + goto loser; + + PORT_ArenaUnmark(poolp, mark); + return SECSuccess; + +loser: + if (mark) { + PORT_ArenaRelease(poolp, mark); + } + return SECFailure; +} + +/* + * NSS_CMSUtil_DecryptSymKey_RSA - unwrap a RSA-wrapped symmetric key + * + * this function takes an RSA-wrapped symmetric key and unwraps it, returning a symmetric + * key handle. Please note that the actual unwrapped key data may not be allowed to leave + * a hardware token... + */ +PK11SymKey * +NSS_CMSUtil_DecryptSymKey_RSA(SECKEYPrivateKey *privkey, SECItem *encKey, SECOidTag bulkalgtag) +{ + /* that's easy */ + CK_MECHANISM_TYPE target; + PORT_Assert(bulkalgtag != SEC_OID_UNKNOWN); + target = PK11_AlgtagToMechanism(bulkalgtag); + if (bulkalgtag == SEC_OID_UNKNOWN || target == CKM_INVALID_MECHANISM) { + PORT_SetError(SEC_ERROR_INVALID_ALGORITHM); + return NULL; + } + return PK11_PubUnwrapSymKey(privkey, encKey, target, CKA_DECRYPT, 0); +} + +/* ====== ESDH (Ephemeral-Static Diffie-Hellman) ==================================== */ + +SECStatus +NSS_CMSUtil_EncryptSymKey_ESDH(PLArenaPool *poolp, CERTCertificate *cert, PK11SymKey *key, + SECItem *encKey, SECItem **ukm, SECAlgorithmID *keyEncAlg, + SECItem *pubKey) +{ +#if 0 /* not yet done */ + SECOidTag certalgtag; /* the certificate's encryption algorithm */ + SECOidTag encalgtag; /* the algorithm used for key exchange/agreement */ + SECStatus rv; + SECItem *params = NULL; + int data_len; + SECStatus err; + PK11SymKey *tek; + CERTCertificate *ourCert; + SECKEYPublicKey *ourPubKey; + NSSCMSKEATemplateSelector whichKEA = NSSCMSKEAInvalid; + + certalgtag = SECOID_GetAlgorithmTag(&(cert->subjectPublicKeyInfo.algorithm)); + PORT_Assert(certalgtag == SEC_OID_X942_DIFFIE_HELMAN_KEY); + + /* We really want to show our KEA tag as the key exchange algorithm tag. */ + encalgtag = SEC_OID_CMS_EPHEMERAL_STATIC_DIFFIE_HELLMAN; + + /* Get the public key of the recipient. */ + publickey = CERT_ExtractPublicKey(cert); + if (publickey == NULL) goto loser; + + /* XXXX generate a DH key pair on a PKCS11 module (XXX which parameters?) */ + /* XXXX */ourCert = PK11_FindBestKEAMatch(cert, wincx); + if (ourCert == NULL) goto loser; + + arena = PORT_NewArena(1024); + if (arena == NULL) goto loser; + + /* While we're here, extract the key pair's public key data and copy it into */ + /* the outgoing parameters. */ + /* XXXX */ourPubKey = CERT_ExtractPublicKey(ourCert); + if (ourPubKey == NULL) + { + goto loser; + } + SECITEM_CopyItem(arena, pubKey, /* XXX */&(ourPubKey->u.fortezza.KEAKey)); + SECKEY_DestroyPublicKey(ourPubKey); /* we only need the private key from now on */ + ourPubKey = NULL; + + /* Extract our private key in order to derive the KEA key. */ + ourPrivKey = PK11_FindKeyByAnyCert(ourCert,wincx); + CERT_DestroyCertificate(ourCert); /* we're done with this */ + if (!ourPrivKey) goto loser; + + /* If ukm desired, prepare it - allocate enough space (filled with zeros). */ + if (ukm) { + ukm->data = (unsigned char*)PORT_ArenaZAlloc(arena,/* XXXX */); + ukm->len = /* XXXX */; + } + + /* Generate the KEK (key exchange key) according to RFC2631 which we use + * to wrap the bulk encryption key. */ + kek = PK11_PubDerive(ourPrivKey, publickey, PR_TRUE, + ukm, NULL, + /* XXXX */CKM_KEA_KEY_DERIVE, /* XXXX */CKM_SKIPJACK_WRAP, + CKA_WRAP, 0, wincx); + + SECKEY_DestroyPublicKey(publickey); + SECKEY_DestroyPrivateKey(ourPrivKey); + publickey = NULL; + ourPrivKey = NULL; + + if (!kek) + goto loser; + + /* allocate space for the encrypted CEK (bulk key) */ + encKey->data = (unsigned char*)PORT_ArenaAlloc(poolp, SMIME_FORTEZZA_MAX_KEY_SIZE); + encKey->len = SMIME_FORTEZZA_MAX_KEY_SIZE; + + if (encKey->data == NULL) + { + PK11_FreeSymKey(kek); + goto loser; + } + + + /* Wrap the bulk key using CMSRC2WRAP or CMS3DESWRAP, depending on the */ + /* bulk encryption algorithm */ + switch (/* XXXX */PK11_AlgtagToMechanism(enccinfo->encalg)) + { + case /* XXXX */CKM_SKIPJACK_CFB8: + err = PK11_WrapSymKey(/* XXXX */CKM_CMS3DES_WRAP, NULL, kek, bulkkey, encKey); + whichKEA = NSSCMSKEAUsesSkipjack; + break; + case /* XXXX */CKM_SKIPJACK_CFB8: + err = PK11_WrapSymKey(/* XXXX */CKM_CMSRC2_WRAP, NULL, kek, bulkkey, encKey); + whichKEA = NSSCMSKEAUsesSkipjack; + break; + default: + /* XXXX what do we do here? Neither RC2 nor 3DES... */ + err = SECFailure; + /* set error */ + break; + } + + PK11_FreeSymKey(kek); /* we do not need the KEK anymore */ + if (err != SECSuccess) + goto loser; + + PORT_Assert(whichKEA != NSSCMSKEAInvalid); + + /* see RFC2630 12.3.1.1 "keyEncryptionAlgorithm must be ..." */ + /* params is the DER encoded key wrap algorithm (with parameters!) (XXX) */ + params = SEC_ASN1EncodeItem(arena, NULL, &keaParams, sec_pkcs7_get_kea_template(whichKEA)); + if (params == NULL) + goto loser; + + /* now set keyEncAlg */ + rv = SECOID_SetAlgorithmID(poolp, keyEncAlg, SEC_OID_CMS_EPHEMERAL_STATIC_DIFFIE_HELLMAN, params); + if (rv != SECSuccess) + goto loser; + + /* XXXXXXX this is not right yet */ +loser: + if (arena) { + PORT_FreeArena(arena, PR_FALSE); + } + if (publickey) { + SECKEY_DestroyPublicKey(publickey); + } + if (ourPrivKey) { + SECKEY_DestroyPrivateKey(ourPrivKey); + } +#endif + return SECFailure; +} + +PK11SymKey * +NSS_CMSUtil_DecryptSymKey_ESDH(SECKEYPrivateKey *privkey, SECItem *encKey, + SECAlgorithmID *keyEncAlg, SECOidTag bulkalgtag, + void *pwfn_arg) +{ +#if 0 /* not yet done */ + SECStatus err; + CK_MECHANISM_TYPE bulkType; + PK11SymKey *tek; + SECKEYPublicKey *originatorPubKey; + NSSCMSSMIMEKEAParameters keaParams; + + /* XXXX get originator's public key */ + originatorPubKey = PK11_MakeKEAPubKey(keaParams.originatorKEAKey.data, + keaParams.originatorKEAKey.len); + if (originatorPubKey == NULL) + goto loser; + + /* Generate the TEK (token exchange key) which we use to unwrap the bulk encryption key. + The Derive function generates a shared secret and combines it with the originatorRA + data to come up with an unique session key */ + tek = PK11_PubDerive(privkey, originatorPubKey, PR_FALSE, + &keaParams.originatorRA, NULL, + CKM_KEA_KEY_DERIVE, CKM_SKIPJACK_WRAP, + CKA_WRAP, 0, pwfn_arg); + SECKEY_DestroyPublicKey(originatorPubKey); /* not needed anymore */ + if (tek == NULL) + goto loser; + + /* Now that we have the TEK, unwrap the bulk key + with which to decrypt the message. */ + /* Skipjack is being used as the bulk encryption algorithm.*/ + /* Unwrap the bulk key. */ + bulkkey = PK11_UnwrapSymKey(tek, CKM_SKIPJACK_WRAP, NULL, + encKey, CKM_SKIPJACK_CBC64, CKA_DECRYPT, 0); + + return bulkkey; + +loser: +#endif + return NULL; +} |