diff options
Diffstat (limited to 'security/nss/lib/smime/smimeutil.c')
| -rw-r--r-- | security/nss/lib/smime/smimeutil.c | 714 |
1 files changed, 0 insertions, 714 deletions
diff --git a/security/nss/lib/smime/smimeutil.c b/security/nss/lib/smime/smimeutil.c deleted file mode 100644 index 7d98b6a09..000000000 --- a/security/nss/lib/smime/smimeutil.c +++ /dev/null @@ -1,714 +0,0 @@ -/* - * 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. - */ - -/* - * Stuff specific to S/MIME policy and interoperability. - * - * $Id$ - */ - -#include "secmime.h" -#include "secoid.h" -#include "pk11func.h" -#include "ciferfam.h" /* for CIPHER_FAMILY symbols */ -#include "secasn1.h" -#include "secitem.h" -#include "cert.h" -#include "key.h" -#include "secerr.h" -#include "cms.h" - -/* various integer's ASN.1 encoding */ -static unsigned char asn1_int40[] = { SEC_ASN1_INTEGER, 0x01, 0x28 }; -static unsigned char asn1_int64[] = { SEC_ASN1_INTEGER, 0x01, 0x40 }; -static unsigned char asn1_int128[] = { SEC_ASN1_INTEGER, 0x02, 0x00, 0x80 }; - -/* RC2 algorithm parameters (used in smime_cipher_map) */ -static SECItem param_int40 = { siBuffer, asn1_int40, sizeof(asn1_int40) }; -static SECItem param_int64 = { siBuffer, asn1_int64, sizeof(asn1_int64) }; -static SECItem param_int128 = { siBuffer, asn1_int128, sizeof(asn1_int128) }; - -/* - * XXX Would like the "parameters" field to be a SECItem *, but the - * encoder is having trouble with optional pointers to an ANY. Maybe - * once that is fixed, can change this back... - */ -typedef struct { - SECItem capabilityID; - SECItem parameters; - long cipher; /* optimization */ -} NSSSMIMECapability; - -static const SEC_ASN1Template NSSSMIMECapabilityTemplate[] = { - { SEC_ASN1_SEQUENCE, - 0, NULL, sizeof(NSSSMIMECapability) }, - { SEC_ASN1_OBJECT_ID, - offsetof(NSSSMIMECapability,capabilityID), }, - { SEC_ASN1_OPTIONAL | SEC_ASN1_ANY, - offsetof(NSSSMIMECapability,parameters), }, - { 0, } -}; - -static const SEC_ASN1Template NSSSMIMECapabilitiesTemplate[] = { - { SEC_ASN1_SEQUENCE_OF, 0, NSSSMIMECapabilityTemplate } -}; - -/* - * NSSSMIMEEncryptionKeyPreference - if we find one of these, it needs to prompt us - * to store this and only this certificate permanently for the sender email address. - */ -typedef enum { - NSSSMIMEEncryptionKeyPref_IssuerSN, - NSSSMIMEEncryptionKeyPref_RKeyID, - NSSSMIMEEncryptionKeyPref_SubjectKeyID -} NSSSMIMEEncryptionKeyPrefSelector; - -typedef struct { - NSSSMIMEEncryptionKeyPrefSelector selector; - union { - CERTIssuerAndSN *issuerAndSN; - NSSCMSRecipientKeyIdentifier *recipientKeyID; - SECItem *subjectKeyID; - } id; -} NSSSMIMEEncryptionKeyPreference; - -extern const SEC_ASN1Template NSSCMSRecipientKeyIdentifierTemplate[]; - -static const SEC_ASN1Template smime_encryptionkeypref_template[] = { - { SEC_ASN1_CHOICE, - offsetof(NSSSMIMEEncryptionKeyPreference,selector), NULL, - sizeof(NSSSMIMEEncryptionKeyPreference) }, - { SEC_ASN1_POINTER | SEC_ASN1_CONTEXT_SPECIFIC | 0, - offsetof(NSSSMIMEEncryptionKeyPreference,id.issuerAndSN), - CERT_IssuerAndSNTemplate, - NSSSMIMEEncryptionKeyPref_IssuerSN }, - { SEC_ASN1_POINTER | SEC_ASN1_CONTEXT_SPECIFIC | 1, - offsetof(NSSSMIMEEncryptionKeyPreference,id.recipientKeyID), - NSSCMSRecipientKeyIdentifierTemplate, - NSSSMIMEEncryptionKeyPref_IssuerSN }, - { SEC_ASN1_POINTER | SEC_ASN1_CONTEXT_SPECIFIC | 2, - offsetof(NSSSMIMEEncryptionKeyPreference,id.subjectKeyID), - SEC_OctetStringTemplate, - NSSSMIMEEncryptionKeyPref_SubjectKeyID }, - { 0, } -}; - -/* smime_cipher_map - map of SMIME symmetric "ciphers" to algtag & parameters */ -typedef struct { - unsigned long cipher; - SECOidTag algtag; - SECItem *parms; - PRBool enabled; /* in the user's preferences */ - PRBool allowed; /* per export policy */ -} smime_cipher_map_entry; - -/* global: list of supported SMIME symmetric ciphers, ordered roughly by increasing strength */ -static smime_cipher_map_entry smime_cipher_map[] = { -/* cipher algtag parms enabled allowed */ -/* ---------------------------------------------------------------------------------- */ - { SMIME_RC2_CBC_40, SEC_OID_RC2_CBC, ¶m_int40, PR_TRUE, PR_TRUE }, - { SMIME_DES_CBC_56, SEC_OID_DES_CBC, NULL, PR_TRUE, PR_TRUE }, - { SMIME_RC2_CBC_64, SEC_OID_RC2_CBC, ¶m_int64, PR_TRUE, PR_TRUE }, - { SMIME_RC2_CBC_128, SEC_OID_RC2_CBC, ¶m_int128, PR_TRUE, PR_TRUE }, - { SMIME_DES_EDE3_168, SEC_OID_DES_EDE3_CBC, NULL, PR_TRUE, PR_TRUE }, - { SMIME_FORTEZZA, SEC_OID_FORTEZZA_SKIPJACK, NULL, PR_TRUE, PR_TRUE } -}; -static const int smime_cipher_map_count = sizeof(smime_cipher_map) / sizeof(smime_cipher_map_entry); - -/* - * smime_mapi_by_cipher - find index into smime_cipher_map by cipher - */ -static int -smime_mapi_by_cipher(unsigned long cipher) -{ - int i; - - for (i = 0; i < smime_cipher_map_count; i++) { - if (smime_cipher_map[i].cipher == cipher) - return i; /* bingo */ - } - return -1; /* should not happen if we're consistent, right? */ -} - -/* - * NSS_SMIME_EnableCipher - this function locally records the user's preference - */ -SECStatus -NSS_SMIMEUtil_EnableCipher(unsigned long which, PRBool on) -{ - unsigned long mask; - int mapi; - - mask = which & CIPHER_FAMILYID_MASK; - - PORT_Assert (mask == CIPHER_FAMILYID_SMIME); - if (mask != CIPHER_FAMILYID_SMIME) - /* XXX set an error! */ - return SECFailure; - - mapi = smime_mapi_by_cipher(which); - if (mapi < 0) - /* XXX set an error */ - return SECFailure; - - /* do we try to turn on a forbidden cipher? */ - if (!smime_cipher_map[mapi].allowed && on) { - PORT_SetError (SEC_ERROR_BAD_EXPORT_ALGORITHM); - return SECFailure; - } - - if (smime_cipher_map[mapi].enabled != on) - smime_cipher_map[mapi].enabled = on; - - return SECSuccess; -} - - -/* - * this function locally records the export policy - */ -SECStatus -NSS_SMIMEUtil_AllowCipher(unsigned long which, PRBool on) -{ - unsigned long mask; - int mapi; - - mask = which & CIPHER_FAMILYID_MASK; - - PORT_Assert (mask == CIPHER_FAMILYID_SMIME); - if (mask != CIPHER_FAMILYID_SMIME) - /* XXX set an error! */ - return SECFailure; - - mapi = smime_mapi_by_cipher(which); - if (mapi < 0) - /* XXX set an error */ - return SECFailure; - - if (smime_cipher_map[mapi].allowed != on) - smime_cipher_map[mapi].allowed = on; - - return SECSuccess; -} - -/* - * Based on the given algorithm (including its parameters, in some cases!) - * and the given key (may or may not be inspected, depending on the - * algorithm), find the appropriate policy algorithm specification - * and return it. If no match can be made, -1 is returned. - */ -static SECStatus -nss_smime_get_cipher_for_alg_and_key(SECAlgorithmID *algid, PK11SymKey *key, unsigned long *cipher) -{ - SECOidTag algtag; - unsigned int keylen_bits; - SECStatus rv = SECSuccess; - unsigned long c; - - algtag = SECOID_GetAlgorithmTag(algid); - switch (algtag) { - case SEC_OID_RC2_CBC: - keylen_bits = PK11_GetKeyStrength(key, algid); - switch (keylen_bits) { - case 40: - c = SMIME_RC2_CBC_40; - case 64: - c = SMIME_RC2_CBC_64; - case 128: - c = SMIME_RC2_CBC_128; - default: - rv = SECFailure; - break; - } - break; - case SEC_OID_DES_CBC: - c = SMIME_DES_CBC_56; - case SEC_OID_DES_EDE3_CBC: - c = SMIME_DES_EDE3_168; - case SEC_OID_FORTEZZA_SKIPJACK: - c = SMIME_FORTEZZA; - default: - rv = SECFailure; - } - if (rv == SECSuccess) - *cipher = c; - return rv; -} - -static PRBool -nss_smime_cipher_allowed(unsigned long which) -{ - int mapi; - - mapi = smime_mapi_by_cipher(which); - if (mapi < 0) - return PR_FALSE; - return smime_cipher_map[mapi].allowed; -} - -PRBool -NSS_SMIMEUtil_DecryptionAllowed(SECAlgorithmID *algid, PK11SymKey *key) -{ - unsigned long which; - - if (nss_smime_get_cipher_for_alg_and_key(algid, key, &which) != SECSuccess) - return PR_FALSE; - - return nss_smime_cipher_allowed(which); -} - - -/* - * NSS_SMIME_EncryptionPossible - check if any encryption is allowed - * - * This tells whether or not *any* S/MIME encryption can be done, - * according to policy. Callers may use this to do nicer user interface - * (say, greying out a checkbox so a user does not even try to encrypt - * a message when they are not allowed to) or for any reason they want - * to check whether S/MIME encryption (or decryption, for that matter) - * may be done. - * - * It takes no arguments. The return value is a simple boolean: - * PR_TRUE means encryption (or decryption) is *possible* - * (but may still fail due to other reasons, like because we cannot - * find all the necessary certs, etc.; PR_TRUE is *not* a guarantee) - * PR_FALSE means encryption (or decryption) is not permitted - * - * There are no errors from this routine. - */ -PRBool -NSS_SMIMEUtil_EncryptionPossible(void) -{ - int i; - - for (i = 0; i < smime_cipher_map_count; i++) { - if (smime_cipher_map[i].allowed) - return PR_TRUE; - } - return PR_FALSE; -} - - -static int -nss_SMIME_FindCipherForSMIMECap(NSSSMIMECapability *cap) -{ - int i; - SECOidTag capIDTag; - - /* we need the OIDTag here */ - capIDTag = SECOID_FindOIDTag(&(cap->capabilityID)); - - /* go over all the SMIME ciphers we know and see if we find a match */ - for (i = 0; i < smime_cipher_map_count; i++) { - if (smime_cipher_map[i].algtag != capIDTag) - continue; - /* - * XXX If SECITEM_CompareItem allowed NULLs as arguments (comparing - * 2 NULLs as equal and NULL and non-NULL as not equal), we could - * use that here instead of all of the following comparison code. - */ - if (cap->parameters.data == NULL && smime_cipher_map[i].parms == NULL) - break; /* both empty: bingo */ - - if (cap->parameters.data != NULL && smime_cipher_map[i].parms != NULL && - cap->parameters.len == smime_cipher_map[i].parms->len && - PORT_Memcmp (cap->parameters.data, smime_cipher_map[i].parms->data, - cap->parameters.len) == 0) - { - break; /* both not empty, same length & equal content: bingo */ - } - } - - if (i == smime_cipher_map_count) - return 0; /* no match found */ - else - return smime_cipher_map[i].cipher; /* match found, point to cipher */ -} - -/* - * smime_choose_cipher - choose a cipher that works for all the recipients - * - * "scert" - sender's certificate - * "rcerts" - recipient's certificates - */ -static long -smime_choose_cipher(CERTCertificate *scert, CERTCertificate **rcerts) -{ - PRArenaPool *poolp; - long cipher; - long chosen_cipher; - int *cipher_abilities; - int *cipher_votes; - int weak_mapi; - int strong_mapi; - int rcount, mapi, max, i; - PRBool scert_is_fortezza = (scert == NULL) ? PR_FALSE : PK11_FortezzaHasKEA(scert); - - chosen_cipher = SMIME_RC2_CBC_40; /* the default, LCD */ - weak_mapi = smime_mapi_by_cipher(chosen_cipher); - - poolp = PORT_NewArena (1024); /* XXX what is right value? */ - if (poolp == NULL) - goto done; - - cipher_abilities = (int *)PORT_ArenaZAlloc(poolp, smime_cipher_map_count * sizeof(int)); - cipher_votes = (int *)PORT_ArenaZAlloc(poolp, smime_cipher_map_count * sizeof(int)); - if (cipher_votes == NULL || cipher_abilities == NULL) - goto done; - - /* If the user has the Fortezza preference turned on, make - * that the strong cipher. Otherwise, use triple-DES. */ - strong_mapi = smime_mapi_by_cipher (SMIME_DES_EDE3_168); - if (scert_is_fortezza) { - mapi = smime_mapi_by_cipher(SMIME_FORTEZZA); - if (mapi >= 0 && smime_cipher_map[mapi].enabled) - strong_mapi = mapi; - } - - /* walk all the recipient's certs */ - for (rcount = 0; rcerts[rcount] != NULL; rcount++) { - SECItem *profile; - NSSSMIMECapability **caps; - int pref; - - /* the first cipher that matches in the user's SMIME profile gets - * "smime_cipher_map_count" votes; the next one gets "smime_cipher_map_count" - 1 - * and so on. If every cipher matches, the last one gets 1 (one) vote */ - pref = smime_cipher_map_count; - - /* find recipient's SMIME profile */ - profile = CERT_FindSMimeProfile(rcerts[rcount]); - - if (profile != NULL && profile->data != NULL && profile->len > 0) { - /* we have a profile (still DER-encoded) */ - caps = NULL; - /* decode it */ - if (SEC_ASN1DecodeItem(poolp, &caps, NSSSMIMECapabilitiesTemplate, profile) == SECSuccess && - caps != NULL) - { - /* walk the SMIME capabilities for this recipient */ - for (i = 0; caps[i] != NULL; i++) { - cipher = nss_SMIME_FindCipherForSMIMECap(caps[i]); - mapi = smime_mapi_by_cipher(cipher); - if (mapi >= 0) { - /* found the cipher */ - cipher_abilities[mapi]++; - cipher_votes[mapi] += pref; - --pref; - } - } - } - } else { - /* no profile found - so we can only assume that the user can do - * the mandatory algorithms which is RC2-40 (weak crypto) and 3DES (strong crypto) */ - SECKEYPublicKey *key; - unsigned int pklen_bits; - - /* - * if recipient's public key length is > 512, vote for a strong cipher - * please not that the side effect of this is that if only one recipient - * has an export-level public key, the strong cipher is disabled. - * - * XXX This is probably only good for RSA keys. What I would - * really like is a function to just say; Is the public key in - * this cert an export-length key? Then I would not have to - * know things like the value 512, or the kind of key, or what - * a subjectPublicKeyInfo is, etc. - */ - key = CERT_ExtractPublicKey(rcerts[rcount]); - pklen_bits = 0; - if (key != NULL) { - pklen_bits = SECKEY_PublicKeyStrength (key) * 8; - SECKEY_DestroyPublicKey (key); - } - - if (pklen_bits > 512) { - /* cast votes for the strong algorithm */ - cipher_abilities[strong_mapi]++; - cipher_votes[strong_mapi] += pref; - pref--; - } - - /* always cast (possibly less) votes for the weak algorithm */ - cipher_abilities[weak_mapi]++; - cipher_votes[weak_mapi] += pref; - } - if (profile != NULL) - SECITEM_FreeItem(profile, PR_TRUE); - } - - /* find cipher that is agreeable by all recipients and that has the most votes */ - max = 0; - for (mapi = 0; mapi < smime_cipher_map_count; mapi++) { - /* if not all of the recipients can do this, forget it */ - if (cipher_abilities[mapi] != rcount) - continue; - /* if cipher is not enabled or not allowed by policy, forget it */ - if (!smime_cipher_map[mapi].enabled || !smime_cipher_map[mapi].allowed) - continue; - /* if we're not doing fortezza, but the cipher is fortezza, forget it */ - if (!scert_is_fortezza && (smime_cipher_map[mapi].cipher == SMIME_FORTEZZA)) - continue; - /* now see if this one has more votes than the last best one */ - if (cipher_votes[mapi] >= max) { - /* if equal number of votes, prefer the ones further down in the list */ - /* with the expectation that these are higher rated ciphers */ - chosen_cipher = smime_cipher_map[mapi].cipher; - max = cipher_votes[mapi]; - } - } - /* if no common cipher was found, chosen_cipher stays at the default */ - -done: - if (poolp != NULL) - PORT_FreeArena (poolp, PR_FALSE); - - return chosen_cipher; -} - -/* - * XXX This is a hack for now to satisfy our current interface. - * Eventually, with more parameters needing to be specified, just - * looking up the keysize is not going to be sufficient. - */ -static int -smime_keysize_by_cipher (unsigned long which) -{ - int keysize; - - switch (which) { - case SMIME_RC2_CBC_40: - keysize = 40; - break; - case SMIME_RC2_CBC_64: - keysize = 64; - break; - case SMIME_RC2_CBC_128: - keysize = 128; - break; - case SMIME_DES_CBC_56: - case SMIME_DES_EDE3_168: - case SMIME_FORTEZZA: - /* - * These are special; since the key size is fixed, we actually - * want to *avoid* specifying a key size. - */ - keysize = 0; - break; - default: - keysize = -1; - break; - } - - return keysize; -} - -/* - * NSS_SMIMEUtil_FindBulkAlgForRecipients - find bulk algorithm suitable for all recipients - * - * it would be great for UI purposes if there would be a way to find out which recipients - * prevented a strong cipher from being used... - */ -SECStatus -NSS_SMIMEUtil_FindBulkAlgForRecipients(CERTCertificate **rcerts, SECOidTag *bulkalgtag, int *keysize) -{ - unsigned long cipher; - int mapi; - - cipher = smime_choose_cipher(NULL, rcerts); - mapi = smime_mapi_by_cipher(cipher); - - *bulkalgtag = smime_cipher_map[mapi].algtag; - *keysize = smime_keysize_by_cipher(smime_cipher_map[mapi].algtag); - - return SECSuccess; -} - -/* - * NSS_SMIMEUtil_CreateSMIMECapabilities - get S/MIME capabilities for this instance of NSS - * - * scans the list of allowed and enabled ciphers and construct a PKCS9-compliant - * S/MIME capabilities attribute value. - * - * XXX Please note that, in contradiction to RFC2633 2.5.2, the capabilities only include - * symmetric ciphers, NO signature algorithms or key encipherment algorithms. - * - * "poolp" - arena pool to create the S/MIME capabilities data on - * "dest" - SECItem to put the data in - * "includeFortezzaCiphers" - PR_TRUE if fortezza ciphers should be included - */ -SECStatus -NSS_SMIMEUtil_CreateSMIMECapabilities(PLArenaPool *poolp, SECItem *dest, PRBool includeFortezzaCiphers) -{ - NSSSMIMECapability *cap; - NSSSMIMECapability **smime_capabilities; - smime_cipher_map_entry *map; - SECOidData *oiddata; - SECItem *dummy; - int i, capIndex; - - /* if we have an old NSSSMIMECapability array, we'll reuse it (has the right size) */ - /* smime_cipher_map_count + 1 is an upper bound - we might end up with less */ - smime_capabilities = (NSSSMIMECapability **)PORT_ZAlloc((smime_cipher_map_count + 1) - * sizeof(NSSSMIMECapability *)); - if (smime_capabilities == NULL) - return SECFailure; - - capIndex = 0; - - /* Add all the symmetric ciphers - * We walk the cipher list backwards, as it is ordered by increasing strength, - * we prefer the stronger cipher over a weaker one, and we have to list the - * preferred algorithm first */ - for (i = smime_cipher_map_count - 1; i >= 0; i--) { - /* Find the corresponding entry in the cipher map. */ - map = &(smime_cipher_map[i]); - if (!map->enabled) - continue; - - /* If we're using a non-Fortezza cert, only advertise non-Fortezza - capabilities. (We advertise all capabilities if we have a - Fortezza cert.) */ - if ((!includeFortezzaCiphers) && (map->cipher == SMIME_FORTEZZA)) - continue; - - /* get next SMIME capability */ - cap = (NSSSMIMECapability *)PORT_ZAlloc(sizeof(NSSSMIMECapability)); - if (cap == NULL) - break; - smime_capabilities[capIndex++] = cap; - - oiddata = SECOID_FindOIDByTag(map->algtag); - if (oiddata == NULL) - break; - - cap->capabilityID.data = oiddata->oid.data; - cap->capabilityID.len = oiddata->oid.len; - cap->parameters.data = map->parms ? map->parms->data : NULL; - cap->parameters.len = map->parms ? map->parms->len : 0; - cap->cipher = smime_cipher_map[i].cipher; - } - - /* XXX add signature algorithms */ - /* XXX add key encipherment algorithms */ - - smime_capabilities[capIndex] = NULL; /* last one - now encode */ - dummy = SEC_ASN1EncodeItem(poolp, dest, &smime_capabilities, NSSSMIMECapabilitiesTemplate); - - /* now that we have the proper encoded SMIMECapabilities (or not), - * free the work data */ - for (i = 0; smime_capabilities[i] != NULL; i++) - PORT_Free(smime_capabilities[i]); - PORT_Free(smime_capabilities); - - return (dummy == NULL) ? SECFailure : SECSuccess; -} - -/* - * NSS_SMIMEUtil_CreateSMIMEEncKeyPrefs - create S/MIME encryption key preferences attr value - * - * "poolp" - arena pool to create the attr value on - * "dest" - SECItem to put the data in - * "cert" - certificate that should be marked as preferred encryption key - * cert is expected to have been verified for EmailRecipient usage. - */ -SECStatus -NSS_SMIMEUtil_CreateSMIMEEncKeyPrefs(PLArenaPool *poolp, SECItem *dest, CERTCertificate *cert) -{ - NSSSMIMEEncryptionKeyPreference ekp; - SECItem *dummy = NULL; - PLArenaPool *tmppoolp; - - if (cert == NULL) - goto loser; - - tmppoolp = PORT_NewArena(1024); - if (tmppoolp == NULL) - goto loser; - - /* XXX hardcoded IssuerSN choice for now */ - ekp.selector = NSSSMIMEEncryptionKeyPref_IssuerSN; - ekp.id.issuerAndSN = CERT_GetCertIssuerAndSN(tmppoolp, cert); - if (ekp.id.issuerAndSN == NULL) - goto loser; - - dummy = SEC_ASN1EncodeItem(poolp, dest, &ekp, smime_encryptionkeypref_template); - -loser: - if (tmppoolp) PORT_FreeArena(tmppoolp, PR_FALSE); - - return (dummy == NULL) ? SECFailure : SECSuccess; -} - -/* - * NSS_SMIMEUtil_GetCertFromEncryptionKeyPreference - - * find cert marked by EncryptionKeyPreference attribute - * - * "certdb" - handle for the cert database to look in - * "DERekp" - DER-encoded value of S/MIME Encryption Key Preference attribute - * - * if certificate is supposed to be found among the message's included certificates, - * they are assumed to have been imported already. - */ -CERTCertificate * -NSS_SMIMEUtil_GetCertFromEncryptionKeyPreference(CERTCertDBHandle *certdb, SECItem *DERekp) -{ - PLArenaPool *tmppoolp = NULL; - CERTCertificate *cert = NULL; - NSSSMIMEEncryptionKeyPreference ekp; - - tmppoolp = PORT_NewArena(1024); - if (tmppoolp == NULL) - return NULL; - - /* decode DERekp */ - if (SEC_ASN1DecodeItem(tmppoolp, &ekp, smime_encryptionkeypref_template, DERekp) != SECSuccess) - goto loser; - - /* find cert */ - switch (ekp.selector) { - case NSSSMIMEEncryptionKeyPref_IssuerSN: - cert = CERT_FindCertByIssuerAndSN(certdb, ekp.id.issuerAndSN); - break; - case NSSSMIMEEncryptionKeyPref_RKeyID: - case NSSSMIMEEncryptionKeyPref_SubjectKeyID: - /* XXX not supported yet - we need to be able to look up certs by SubjectKeyID */ - break; - default: - PORT_Assert(0); - } -loser: - if (tmppoolp) PORT_FreeArena(tmppoolp, PR_FALSE); - - return cert; -} |