1 /* This Source Code Form is subject to the terms of the Mozilla Public
2 * License, v. 2.0. If a copy of the MPL was not distributed with this
3 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
4 /*
5 * This file implements the Symkey wrapper and the PKCS context
6 * Interfaces.
7 */
8
9 #include <stddef.h>
10
11 #include "seccomon.h"
12 #include "secmod.h"
13 #include "nssilock.h"
14 #include "secmodi.h"
15 #include "secmodti.h"
16 #include "pkcs11.h"
17 #include "pk11func.h"
18 #include "secitem.h"
19 #include "keyhi.h"
20 #include "secasn1.h"
21 #include "sechash.h"
22 #include "cert.h"
23 #include "secerr.h"
24
25 /*
26 * find an RSA public key on a card
27 */
28 static CK_OBJECT_HANDLE
pk11_FindRSAPubKey(PK11SlotInfo * slot)29 pk11_FindRSAPubKey(PK11SlotInfo *slot)
30 {
31 CK_KEY_TYPE key_type = CKK_RSA;
32 CK_OBJECT_CLASS class_type = CKO_PUBLIC_KEY;
33 CK_ATTRIBUTE theTemplate[2];
34 size_t template_count = sizeof(theTemplate) / sizeof(theTemplate[0]);
35 CK_ATTRIBUTE *attrs = theTemplate;
36
37 PK11_SETATTRS(attrs, CKA_CLASS, &class_type, sizeof(class_type));
38 attrs++;
39 PK11_SETATTRS(attrs, CKA_KEY_TYPE, &key_type, sizeof(key_type));
40 attrs++;
41 template_count = attrs - theTemplate;
42 PR_ASSERT(template_count <= sizeof(theTemplate) / sizeof(CK_ATTRIBUTE));
43
44 return pk11_FindObjectByTemplate(slot, theTemplate, template_count);
45 }
46
47 PK11SymKey *
pk11_KeyExchange(PK11SlotInfo * slot,CK_MECHANISM_TYPE type,CK_ATTRIBUTE_TYPE operation,CK_FLAGS flags,PRBool isPerm,PK11SymKey * symKey)48 pk11_KeyExchange(PK11SlotInfo *slot, CK_MECHANISM_TYPE type,
49 CK_ATTRIBUTE_TYPE operation, CK_FLAGS flags,
50 PRBool isPerm, PK11SymKey *symKey)
51 {
52 PK11SymKey *newSymKey = NULL;
53 SECStatus rv;
54 /* performance improvement can go here --- use a generated key at startup
55 * to generate a per token wrapping key. If it exists, use it, otherwise
56 * do a full key exchange. */
57
58 /* find a common Key Exchange algorithm */
59 /* RSA */
60 if (PK11_DoesMechanism(symKey->slot, CKM_RSA_PKCS) &&
61 PK11_DoesMechanism(slot, CKM_RSA_PKCS)) {
62 CK_OBJECT_HANDLE pubKeyHandle = CK_INVALID_HANDLE;
63 CK_OBJECT_HANDLE privKeyHandle = CK_INVALID_HANDLE;
64 SECKEYPublicKey *pubKey = NULL;
65 SECKEYPrivateKey *privKey = NULL;
66 SECItem wrapData;
67 unsigned int symKeyLength = PK11_GetKeyLength(symKey);
68
69 wrapData.data = NULL;
70
71 /* find RSA Public Key on target */
72 pubKeyHandle = pk11_FindRSAPubKey(slot);
73 if (pubKeyHandle != CK_INVALID_HANDLE) {
74 privKeyHandle = PK11_MatchItem(slot, pubKeyHandle, CKO_PRIVATE_KEY);
75 }
76
77 /* if no key exists, generate a key pair */
78 if (privKeyHandle == CK_INVALID_HANDLE) {
79 PK11RSAGenParams rsaParams;
80
81 if (symKeyLength > 53) /* bytes */ {
82 /* we'd have to generate an RSA key pair > 512 bits long,
83 ** and that's too costly. Don't even try.
84 */
85 PORT_SetError(SEC_ERROR_CANNOT_MOVE_SENSITIVE_KEY);
86 goto rsa_failed;
87 }
88 rsaParams.keySizeInBits =
89 (symKeyLength > 21 || symKeyLength == 0) ? 512 : 256;
90 rsaParams.pe = 0x10001;
91 privKey = PK11_GenerateKeyPair(slot, CKM_RSA_PKCS_KEY_PAIR_GEN,
92 &rsaParams, &pubKey, PR_FALSE, PR_TRUE, symKey->cx);
93 } else {
94 /* if keys exist, build SECKEY data structures for them */
95 privKey = PK11_MakePrivKey(slot, nullKey, PR_TRUE, privKeyHandle,
96 symKey->cx);
97 if (privKey != NULL) {
98 pubKey = PK11_ExtractPublicKey(slot, rsaKey, pubKeyHandle);
99 if (pubKey && pubKey->pkcs11Slot) {
100 PK11_FreeSlot(pubKey->pkcs11Slot);
101 pubKey->pkcs11Slot = NULL;
102 pubKey->pkcs11ID = CK_INVALID_HANDLE;
103 }
104 }
105 }
106 if (privKey == NULL)
107 goto rsa_failed;
108 if (pubKey == NULL)
109 goto rsa_failed;
110
111 wrapData.len = SECKEY_PublicKeyStrength(pubKey);
112 if (!wrapData.len)
113 goto rsa_failed;
114 wrapData.data = PORT_Alloc(wrapData.len);
115 if (wrapData.data == NULL)
116 goto rsa_failed;
117
118 /* now wrap the keys in and out */
119 rv = PK11_PubWrapSymKey(CKM_RSA_PKCS, pubKey, symKey, &wrapData);
120 if (rv == SECSuccess) {
121 newSymKey = PK11_PubUnwrapSymKeyWithFlagsPerm(privKey,
122 &wrapData, type, operation,
123 symKeyLength, flags, isPerm);
124 /* make sure we wound up where we wanted to be! */
125 if (newSymKey && newSymKey->slot != slot) {
126 PK11_FreeSymKey(newSymKey);
127 newSymKey = NULL;
128 }
129 }
130 rsa_failed:
131 if (wrapData.data != NULL)
132 PORT_Free(wrapData.data);
133 if (privKey != NULL)
134 SECKEY_DestroyPrivateKey(privKey);
135 if (pubKey != NULL)
136 SECKEY_DestroyPublicKey(pubKey);
137
138 return newSymKey;
139 }
140 PORT_SetError(SEC_ERROR_NO_MODULE);
141 return NULL;
142 }
143