Botan  2.1.0
Crypto and TLS for C++11
name_constraint.cpp
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1 /*
2 * X.509 Name Constraint
3 * (C) 2015 Kai Michaelis
4 *
5 * Botan is released under the Simplified BSD License (see license.txt)
6 */
7 
8 #include <botan/name_constraint.h>
9 #include <botan/ber_dec.h>
10 #include <botan/der_enc.h>
11 #include <botan/charset.h>
12 #include <botan/loadstor.h>
13 #include <botan/x509_dn.h>
14 #include <botan/x509cert.h>
15 #include <sstream>
16 
17 namespace Botan {
18 
19 GeneralName::GeneralName(const std::string& str) : GeneralName()
20  {
21  size_t p = str.find(':');
22 
23  if(p != std::string::npos)
24  {
25  m_type = str.substr(0, p);
26  m_name = str.substr(p + 1, std::string::npos);
27  }
28  else
29  {
30  throw Invalid_Argument("Failed to decode Name Constraint");
31  }
32  }
33 
35  {
36  throw Not_Implemented("GeneralName encoding");
37  }
38 
40  {
41  BER_Object obj = ber.get_next_object();
42  if((obj.class_tag != CONTEXT_SPECIFIC) &&
44  throw Decoding_Error("Invalid class tag while decoding GeneralName");
45 
46  const ASN1_Tag tag = obj.type_tag;
47 
48  if(tag == 1 || tag == 2 || tag == 6)
49  {
51 
52  if(tag == 1)
53  {
54  m_type = "RFC822";
55  }
56  else if(tag == 2)
57  {
58  m_type = "DNS";
59  }
60  else if(tag == 6)
61  {
62  m_type = "URI";
63  }
64  }
65  else if(tag == 4)
66  {
67  X509_DN dn;
68  std::multimap<std::string, std::string> nam;
69  BER_Decoder dec(obj.value);
70  std::stringstream ss;
71 
72  dn.decode_from(dec);
73  ss << dn;
74 
75  m_name = ss.str();
76  m_type = "DN";
77  }
78  else if(tag == 7)
79  {
80  if(obj.value.size() == 8)
81  {
82  const std::vector<uint8_t> ip(obj.value.begin(), obj.value.begin() + 4);
83  const std::vector<uint8_t> net(obj.value.begin() + 4, obj.value.end());
84  m_type = "IP";
85  m_name = ipv4_to_string(load_be<uint32_t>(ip.data(), 0)) + "/" + ipv4_to_string(load_be<uint32_t>(net.data(), 0));
86  }
87  else if(obj.value.size() == 32)
88  {
89  throw Decoding_Error("Unsupported IPv6 name constraint");
90  }
91  else
92  {
93  throw Decoding_Error("Invalid IP name constraint size " +
94  std::to_string(obj.value.size()));
95  }
96  }
97  else
98  {
99  throw Decoding_Error("Found unknown GeneralName type");
100  }
101  }
102 
104  {
105  std::vector<std::string> nam;
106  std::function<bool(const GeneralName*, const std::string&)> match_fn;
107 
108  if(type() == "DNS")
109  {
110  match_fn = std::mem_fn(&GeneralName::matches_dns);
111  nam = cert.subject_info("DNS");
112 
113  if(nam.empty())
114  {
115  nam = cert.subject_info("CN");
116  }
117  }
118  else if(type() == "DN")
119  {
120  match_fn = std::mem_fn(&GeneralName::matches_dn);
121 
122  std::stringstream ss;
123  ss << cert.subject_dn();
124  nam.push_back(ss.str());
125  }
126  else if(type() == "IP")
127  {
128  match_fn = std::mem_fn(&GeneralName::matches_ip);
129  nam = cert.subject_info("IP");
130  }
131  else
132  {
133  return MatchResult::UnknownType;
134  }
135 
136  if(nam.empty())
137  {
138  return MatchResult::NotFound;
139  }
140 
141  bool some = false;
142  bool all = true;
143 
144  for(const std::string& n: nam)
145  {
146  bool m = match_fn(this, n);
147 
148  some |= m;
149  all &= m;
150  }
151 
152  if(all)
153  {
154  return MatchResult::All;
155  }
156  else if(some)
157  {
158  return MatchResult::Some;
159  }
160  else
161  {
162  return MatchResult::None;
163  }
164  }
165 
166 bool GeneralName::matches_dns(const std::string& nam) const
167  {
168  if(nam.size() == name().size())
169  {
170  return nam == name();
171  }
172  else if(name().size() > nam.size())
173  {
174  return false;
175  }
176  else // name.size() < nam.size()
177  {
178  std::string constr = name().front() == '.' ? name() : "." + name();
179  // constr is suffix of nam
180  return constr == nam.substr(nam.size() - constr.size(), constr.size());
181  }
182  }
183 
184 bool GeneralName::matches_dn(const std::string& nam) const
185  {
186  std::stringstream ss(nam);
187  std::stringstream tt(name());
188  X509_DN nam_dn, my_dn;
189 
190  ss >> nam_dn;
191  tt >> my_dn;
192 
193  auto attr = nam_dn.get_attributes();
194  bool ret = true;
195  int trys = 0;
196 
197  for(const std::pair<OID,std::string>& c: my_dn.get_attributes())
198  {
199  auto i = attr.equal_range(c.first);
200 
201  if(i.first != i.second)
202  {
203  trys += 1;
204  ret &= i.first->second == c.second;
205  }
206  }
207 
208  return trys > 0 && ret;
209  }
210 
211 bool GeneralName::matches_ip(const std::string& nam) const
212  {
213  uint32_t ip = string_to_ipv4(nam);
214  std::vector<std::string> p = split_on(name(), '/');
215 
216  if(p.size() != 2)
217  throw Decoding_Error("failed to parse IPv4 address");
218 
219  uint32_t net = string_to_ipv4(p.at(0));
220  uint32_t mask = string_to_ipv4(p.at(1));
221 
222  return (ip & mask) == net;
223  }
224 
225 std::ostream& operator<<(std::ostream& os, const GeneralName& gn)
226  {
227  os << gn.type() << ":" << gn.name();
228  return os;
229  }
230 
232  {
233  size_t p0, p1;
234  size_t min = std::stoull(str, &p0, 10);
235  size_t max = std::stoull(str.substr(p0 + 1), &p1, 10);
236  GeneralName gn(str.substr(p0 + p1 + 2));
237 
238  if(p0 > 0 && p1 > 0)
239  {
240  m_minimum = min;
241  m_maximum = max;
242  m_base = gn;
243  }
244  else
245  {
246  throw Invalid_Argument("Failed to decode Name Constraint");
247  }
248  }
249 
251  {
252  throw Not_Implemented("General Subtree encoding");
253  }
254 
256  {
257  ber.start_cons(SEQUENCE)
258  .decode(m_base)
259  .decode_optional(m_minimum,ASN1_Tag(0), CONTEXT_SPECIFIC,size_t(0))
260  .end_cons();
261 
262  if(m_minimum != 0)
263  throw Decoding_Error("GeneralSubtree minimum must be 0");
264 
266  }
267 
268 std::ostream& operator<<(std::ostream& os, const GeneralSubtree& gs)
269  {
270  os << gs.minimum() << "," << gs.maximum() << "," << gs.base();
271  return os;
272  }
273 }
void decode_from(class BER_Decoder &) override
MatchResult matches(const X509_Certificate &cert) const
uint32_t load_be< uint32_t >(const uint8_t in[], size_t off)
Definition: loadstor.h:185
std::ostream & operator<<(std::ostream &out, const X509_DN &dn)
Definition: x509_dn.cpp:299
std::vector< std::string > split_on(const std::string &str, char delim)
Definition: parsing.cpp:138
BER_Decoder & decode(bool &v)
Definition: ber_dec.cpp:376
std::string to_string(const BER_Object &obj)
Definition: asn1_obj.cpp:47
std::string ipv4_to_string(uint32_t ip)
Definition: parsing.cpp:288
void decode_from(class BER_Decoder &) override
Definition: x509_dn.cpp:250
void encode_into(class DER_Encoder &) const override
BER_Decoder & decode_optional(T &out, ASN1_Tag type_tag, ASN1_Tag class_tag, const T &default_value=T())
Definition: ber_dec.h:213
size_t maximum() const
secure_vector< uint8_t > value
Definition: asn1_obj.h:94
BER_Decoder & end_cons()
Definition: ber_dec.cpp:272
std::string transcode(const std::string &str, Character_Set to, Character_Set from)
Definition: charset.cpp:103
ASN1_Tag
Definition: asn1_obj.h:22
void encode_into(class DER_Encoder &) const override
BER_Decoder start_cons(ASN1_Tag type_tag, ASN1_Tag class_tag=UNIVERSAL)
Definition: ber_dec.cpp:258
Definition: alg_id.cpp:13
X.509 GeneralName Type.
A single Name Constraint.
T max(T a, T b)
Definition: ct_utils.h:173
const std::string & name() const
BER_Object get_next_object()
Definition: ber_dec.cpp:210
GeneralName()=default
ASN1_Tag class_tag
Definition: asn1_obj.h:91
size_t minimum() const
const std::string & type() const
ASN1_Tag type_tag
Definition: asn1_obj.h:91
void decode_from(class BER_Decoder &) override
GeneralName base() const
std::vector< std::string > subject_info(const std::string &name) const
Definition: x509cert.cpp:198
T min(T a, T b)
Definition: ct_utils.h:180
uint32_t string_to_ipv4(const std::string &str)
Definition: parsing.cpp:263
X509_DN subject_dn() const
Definition: x509cert.cpp:449