Guard against DoS in name constraints handling.
[openssl.git] / crypto / x509v3 / v3_tlsf.c
1 /*
2  * Copyright 2015-2017 The OpenSSL Project Authors. All Rights Reserved.
3  *
4  * Licensed under the OpenSSL license (the "License").  You may not use
5  * this file except in compliance with the License.  You can obtain a copy
6  * in the file LICENSE in the source distribution or at
7  * https://www.openssl.org/source/license.html
8  */
9
10 #include "e_os.h"
11 #include "internal/cryptlib.h"
12 #include <stdio.h>
13 #include "internal/o_str.h"
14 #include <openssl/asn1t.h>
15 #include <openssl/conf.h>
16 #include <openssl/x509v3.h>
17 #include "ext_dat.h"
18
19 static STACK_OF(CONF_VALUE) *i2v_TLS_FEATURE(const X509V3_EXT_METHOD *method,
20                                              TLS_FEATURE *tls_feature,
21                                              STACK_OF(CONF_VALUE) *ext_list);
22 static TLS_FEATURE *v2i_TLS_FEATURE(const X509V3_EXT_METHOD *method,
23                                     X509V3_CTX *ctx,
24                                     STACK_OF(CONF_VALUE) *nval);
25
26 ASN1_ITEM_TEMPLATE(TLS_FEATURE) =
27         ASN1_EX_TEMPLATE_TYPE(ASN1_TFLG_SEQUENCE_OF, 0, TLS_FEATURE, ASN1_INTEGER)
28 static_ASN1_ITEM_TEMPLATE_END(TLS_FEATURE)
29
30 IMPLEMENT_ASN1_ALLOC_FUNCTIONS(TLS_FEATURE)
31
32 const X509V3_EXT_METHOD v3_tls_feature = {
33     NID_tlsfeature, 0,
34     ASN1_ITEM_ref(TLS_FEATURE),
35     0, 0, 0, 0,
36     0, 0,
37     (X509V3_EXT_I2V)i2v_TLS_FEATURE,
38     (X509V3_EXT_V2I)v2i_TLS_FEATURE,
39     0, 0,
40     NULL
41 };
42
43
44 typedef struct {
45     long num;
46     const char *name;
47 } TLS_FEATURE_NAME;
48
49 static TLS_FEATURE_NAME tls_feature_tbl[] = {
50     { 5, "status_request" },
51     { 17, "status_request_v2" }
52 };
53
54 /*
55  * i2v_TLS_FEATURE converts the TLS_FEATURE structure tls_feature into the
56  * STACK_OF(CONF_VALUE) structure ext_list. STACK_OF(CONF_VALUE) is the format
57  * used by the CONF library to represent a multi-valued extension.  ext_list is
58  * returned.
59  */
60 static STACK_OF(CONF_VALUE) *i2v_TLS_FEATURE(const X509V3_EXT_METHOD *method,
61                                              TLS_FEATURE *tls_feature,
62                                              STACK_OF(CONF_VALUE) *ext_list)
63 {
64     int i;
65     size_t j;
66     ASN1_INTEGER *ai;
67     long tlsextid;
68     for (i = 0; i < sk_ASN1_INTEGER_num(tls_feature); i++) {
69         ai = sk_ASN1_INTEGER_value(tls_feature, i);
70         tlsextid = ASN1_INTEGER_get(ai);
71         for (j = 0; j < OSSL_NELEM(tls_feature_tbl); j++)
72             if (tlsextid == tls_feature_tbl[j].num)
73                 break;
74         if (j < OSSL_NELEM(tls_feature_tbl))
75             X509V3_add_value(NULL, tls_feature_tbl[j].name, &ext_list);
76         else
77             X509V3_add_value_int(NULL, ai, &ext_list);
78     }
79     return ext_list;
80 }
81
82 /*
83  * v2i_TLS_FEATURE converts the multi-valued extension nval into a TLS_FEATURE
84  * structure, which is returned if the conversion is successful.  In case of
85  * error, NULL is returned.
86  */
87 static TLS_FEATURE *v2i_TLS_FEATURE(const X509V3_EXT_METHOD *method,
88                                     X509V3_CTX *ctx, STACK_OF(CONF_VALUE) *nval)
89 {
90     TLS_FEATURE *tlsf;
91     char *extval, *endptr;
92     ASN1_INTEGER *ai;
93     CONF_VALUE *val;
94     int i;
95     size_t j;
96     long tlsextid;
97
98     if ((tlsf = sk_ASN1_INTEGER_new_null()) == NULL) {
99         X509V3err(X509V3_F_V2I_TLS_FEATURE, ERR_R_MALLOC_FAILURE);
100         return NULL;
101     }
102
103     for (i = 0; i < sk_CONF_VALUE_num(nval); i++) {
104         val = sk_CONF_VALUE_value(nval, i);
105         if (val->value)
106             extval = val->value;
107         else
108             extval = val->name;
109
110         for (j = 0; j < OSSL_NELEM(tls_feature_tbl); j++)
111             if (strcasecmp(extval, tls_feature_tbl[j].name) == 0)
112                 break;
113         if (j < OSSL_NELEM(tls_feature_tbl))
114             tlsextid = tls_feature_tbl[j].num;
115         else {
116             tlsextid = strtol(extval, &endptr, 10);
117             if (((*endptr) != '\0') || (extval == endptr) || (tlsextid < 0) ||
118                 (tlsextid > 65535)) {
119                 X509V3err(X509V3_F_V2I_TLS_FEATURE, X509V3_R_INVALID_SYNTAX);
120                 X509V3_conf_err(val);
121                 goto err;
122             }
123         }
124
125         ai = ASN1_INTEGER_new();
126         if (ai == NULL) {
127             X509V3err(X509V3_F_V2I_TLS_FEATURE, ERR_R_MALLOC_FAILURE);
128             goto err;
129         }
130         ASN1_INTEGER_set(ai, tlsextid);
131         sk_ASN1_INTEGER_push(tlsf, ai);
132     }
133     return tlsf;
134
135  err:
136     sk_ASN1_INTEGER_pop_free(tlsf, ASN1_INTEGER_free);
137     return NULL;
138 }