1 // Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 //     https://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14 
15 #include <openssl/x509.h>
16 
17 #include <limits.h>
18 
19 #include <openssl/asn1.h>
20 #include <openssl/asn1t.h>
21 #include <openssl/bytestring.h>
22 #include <openssl/err.h>
23 #include <openssl/evp.h>
24 #include <openssl/mem.h>
25 #include <openssl/obj.h>
26 
27 #include "../internal.h"
28 #include "internal.h"
29 
30 
x509_pubkey_changed(X509_PUBKEY * pub)31 static void x509_pubkey_changed(X509_PUBKEY *pub) {
32   EVP_PKEY_free(pub->pkey);
33   pub->pkey = NULL;
34 
35   // Re-encode the |X509_PUBKEY| to DER and parse it with EVP's APIs.
36   uint8_t *spki = NULL;
37   int spki_len = i2d_X509_PUBKEY(pub, &spki);
38   EVP_PKEY *pkey;
39   if (spki_len < 0) {
40     goto err;
41   }
42 
43   CBS cbs;
44   CBS_init(&cbs, spki, (size_t)spki_len);
45   pkey = EVP_parse_public_key(&cbs);
46   if (pkey == NULL || CBS_len(&cbs) != 0) {
47     EVP_PKEY_free(pkey);
48     goto err;
49   }
50 
51   pub->pkey = pkey;
52 
53 err:
54   OPENSSL_free(spki);
55   // If the operation failed, clear errors. An |X509_PUBKEY| whose key we cannot
56   // parse is still a valid SPKI. It just cannot be converted to an |EVP_PKEY|.
57   ERR_clear_error();
58 }
59 
pubkey_cb(int operation,ASN1_VALUE ** pval,const ASN1_ITEM * it,void * exarg)60 static int pubkey_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it,
61                      void *exarg) {
62   X509_PUBKEY *pubkey = (X509_PUBKEY *)*pval;
63   if (operation == ASN1_OP_FREE_POST) {
64     EVP_PKEY_free(pubkey->pkey);
65   } else if (operation == ASN1_OP_D2I_POST) {
66     x509_pubkey_changed(pubkey);
67   }
68   return 1;
69 }
70 
ASN1_SEQUENCE_cb(X509_PUBKEY,pubkey_cb)71 ASN1_SEQUENCE_cb(X509_PUBKEY, pubkey_cb) = {
72     ASN1_SIMPLE(X509_PUBKEY, algor, X509_ALGOR),
73     ASN1_SIMPLE(X509_PUBKEY, public_key, ASN1_BIT_STRING),
74 } ASN1_SEQUENCE_END_cb(X509_PUBKEY, X509_PUBKEY)
75 
76 IMPLEMENT_ASN1_FUNCTIONS_const(X509_PUBKEY)
77 
78 int X509_PUBKEY_set(X509_PUBKEY **x, EVP_PKEY *pkey) {
79   X509_PUBKEY *pk = NULL;
80   uint8_t *spki = NULL;
81   size_t spki_len;
82 
83   if (x == NULL) {
84     return 0;
85   }
86 
87   CBB cbb;
88   const uint8_t *p;
89   if (!CBB_init(&cbb, 0) ||  //
90       !EVP_marshal_public_key(&cbb, pkey) ||
91       !CBB_finish(&cbb, &spki, &spki_len) ||  //
92       spki_len > LONG_MAX) {
93     CBB_cleanup(&cbb);
94     OPENSSL_PUT_ERROR(X509, X509_R_PUBLIC_KEY_ENCODE_ERROR);
95     goto error;
96   }
97 
98   p = spki;
99   pk = d2i_X509_PUBKEY(NULL, &p, (long)spki_len);
100   if (pk == NULL || p != spki + spki_len) {
101     OPENSSL_PUT_ERROR(X509, X509_R_PUBLIC_KEY_DECODE_ERROR);
102     goto error;
103   }
104 
105   OPENSSL_free(spki);
106   X509_PUBKEY_free(*x);
107   *x = pk;
108 
109   return 1;
110 error:
111   X509_PUBKEY_free(pk);
112   OPENSSL_free(spki);
113   return 0;
114 }
115 
X509_PUBKEY_get0(const X509_PUBKEY * key)116 EVP_PKEY *X509_PUBKEY_get0(const X509_PUBKEY *key) {
117   if (key == NULL) {
118     return NULL;
119   }
120 
121   if (key->pkey == NULL) {
122     OPENSSL_PUT_ERROR(X509, X509_R_PUBLIC_KEY_DECODE_ERROR);
123     return NULL;
124   }
125 
126   return key->pkey;
127 }
128 
X509_PUBKEY_get(const X509_PUBKEY * key)129 EVP_PKEY *X509_PUBKEY_get(const X509_PUBKEY *key) {
130   EVP_PKEY *pkey = X509_PUBKEY_get0(key);
131   if (pkey != NULL) {
132     EVP_PKEY_up_ref(pkey);
133   }
134   return pkey;
135 }
136 
X509_PUBKEY_set0_param(X509_PUBKEY * pub,ASN1_OBJECT * obj,int param_type,void * param_value,uint8_t * key,int key_len)137 int X509_PUBKEY_set0_param(X509_PUBKEY *pub, ASN1_OBJECT *obj, int param_type,
138                            void *param_value, uint8_t *key, int key_len) {
139   if (!X509_ALGOR_set0(pub->algor, obj, param_type, param_value)) {
140     return 0;
141   }
142 
143   ASN1_STRING_set0(pub->public_key, key, key_len);
144   // Set the number of unused bits to zero.
145   pub->public_key->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07);
146   pub->public_key->flags |= ASN1_STRING_FLAG_BITS_LEFT;
147 
148   x509_pubkey_changed(pub);
149   return 1;
150 }
151 
X509_PUBKEY_get0_param(ASN1_OBJECT ** out_obj,const uint8_t ** out_key,int * out_key_len,X509_ALGOR ** out_alg,X509_PUBKEY * pub)152 int X509_PUBKEY_get0_param(ASN1_OBJECT **out_obj, const uint8_t **out_key,
153                            int *out_key_len, X509_ALGOR **out_alg,
154                            X509_PUBKEY *pub) {
155   if (out_obj != NULL) {
156     *out_obj = pub->algor->algorithm;
157   }
158   if (out_key != NULL) {
159     *out_key = pub->public_key->data;
160     *out_key_len = pub->public_key->length;
161   }
162   if (out_alg != NULL) {
163     *out_alg = pub->algor;
164   }
165   return 1;
166 }
167 
X509_PUBKEY_get0_public_key(const X509_PUBKEY * pub)168 const ASN1_BIT_STRING *X509_PUBKEY_get0_public_key(const X509_PUBKEY *pub) {
169   return pub->public_key;
170 }
171