asn1_alt_name.cpp

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/*
* AlternativeName
* (C) 1999-2007 Jack Lloyd
*     2007 Yves Jerschow
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
 
#include <botan/pkix_types.h>
 
#include <botan/ber_dec.h>
#include <botan/der_enc.h>
#include <botan/internal/loadstor.h>
#include <botan/internal/parsing.h>
#include <botan/internal/stl_util.h>
 
#include <sstream>
 
namespace Botan {
 
/*
* Create an AlternativeName
*/
AlternativeName::AlternativeName(std::string_view email_addr,
                                 std::string_view uri,
                                 std::string_view dns,
                                 std::string_view ip) {
   add_attribute("RFC822", email_addr);
   add_attribute("DNS", dns);
   add_attribute("URI", uri);
   add_attribute("IP", ip);
}
 
/*
* Add an attribute to an alternative name
*/
void AlternativeName::add_attribute(std::string_view type, std::string_view value) {
   if(type.empty() || value.empty()) {
      return;
   }
 
   auto range = m_alt_info.equal_range(type);
   for(auto j = range.first; j != range.second; ++j) {
      if(j->second == value) {
         return;
      }
   }
 
   m_alt_info.emplace(type, value);
}
 
/*
* Add an OtherName field
*/
void AlternativeName::add_othername(const OID& oid, std::string_view value, ASN1_Type type) {
   if(value.empty()) {
      return;
   }
   multimap_insert(m_othernames, oid, ASN1_String(value, type));
}
 
/*
* Return all of the alternative names
*/
std::multimap<std::string, std::string> AlternativeName::contents() const {
   std::multimap<std::string, std::string> names;
 
   for(const auto& name : m_alt_info) {
      names.emplace(name.first, name.second);
   }
 
   for(const auto& othername : m_othernames) {
      multimap_insert(names, othername.first.to_formatted_string(), othername.second.value());
   }
 
   return names;
}
 
bool AlternativeName::has_field(std::string_view attr) const {
   auto range = m_alt_info.equal_range(attr);
   return (range.first != range.second);
}
 
std::string AlternativeName::get_first_attribute(std::string_view attr) const {
   auto i = m_alt_info.lower_bound(attr);
   if(i != m_alt_info.end() && i->first == attr) {
      return i->second;
   }
 
   return "";
}
 
std::vector<std::string> AlternativeName::get_attribute(std::string_view attr) const {
   std::vector<std::string> results;
   auto range = m_alt_info.equal_range(attr);
   for(auto i = range.first; i != range.second; ++i) {
      results.push_back(i->second);
   }
   return results;
}
 
X509_DN AlternativeName::dn() const {
   X509_DN dn;
   auto range = m_alt_info.equal_range("DN");
 
   for(auto i = range.first; i != range.second; ++i) {
      std::istringstream strm(i->second);
      strm >> dn;
   }
 
   return dn;
}
 
/*
* Return if this object has anything useful
*/
bool AlternativeName::has_items() const {
   return (!m_alt_info.empty() || !m_othernames.empty());
}
 
namespace {
 
/*
* DER encode an AlternativeName entry
*/
void encode_entries(DER_Encoder& encoder,
                    const std::multimap<std::string, std::string, std::less<>>& attr,
                    std::string_view type,
                    ASN1_Type tagging) {
   auto range = attr.equal_range(type);
 
   for(auto i = range.first; i != range.second; ++i) {
      if(type == "RFC822" || type == "DNS" || type == "URI") {
         ASN1_String asn1_string(i->second, ASN1_Type::Ia5String);
         encoder.add_object(tagging, ASN1_Class::ContextSpecific, asn1_string.value());
      } else if(type == "IP") {
         const uint32_t ip = string_to_ipv4(i->second);
         uint8_t ip_buf[4] = {0};
         store_be(ip, ip_buf);
         encoder.add_object(tagging, ASN1_Class::ContextSpecific, ip_buf, 4);
      } else if(type == "DN") {
         std::stringstream ss(i->second);
         X509_DN dn;
         ss >> dn;
         encoder.encode(dn);
      }
   }
}
 
}  // namespace
 
/*
* DER encode an AlternativeName extension
*/
void AlternativeName::encode_into(DER_Encoder& der) const {
   der.start_sequence();
 
   encode_entries(der, m_alt_info, "RFC822", ASN1_Type(1));
   encode_entries(der, m_alt_info, "DNS", ASN1_Type(2));
   encode_entries(der, m_alt_info, "DN", ASN1_Type(4));
   encode_entries(der, m_alt_info, "URI", ASN1_Type(6));
   encode_entries(der, m_alt_info, "IP", ASN1_Type(7));
 
   for(const auto& othername : m_othernames) {
      der.start_explicit(0)
         .encode(othername.first)
         .start_explicit(0)
         .encode(othername.second)
         .end_explicit()
         .end_explicit();
   }
 
   der.end_cons();
}
 
/*
* Decode a BER encoded AlternativeName
*/
void AlternativeName::decode_from(BER_Decoder& source) {
   BER_Decoder names = source.start_sequence();
 
   // FIXME this is largely a duplication of GeneralName::decode_from
 
   while(names.more_items()) {
      BER_Object obj = names.get_next_object();
 
      if(obj.is_a(0, ASN1_Class::ContextSpecific)) {
         BER_Decoder othername(obj);
 
         OID oid;
         othername.decode(oid);
         if(othername.more_items()) {
            BER_Object othername_value_outer = othername.get_next_object();
            othername.verify_end();
 
            if(othername_value_outer.is_a(0, ASN1_Class::ExplicitContextSpecific) == false) {
               throw Decoding_Error("Invalid tags on otherName value");
            }
 
            BER_Decoder othername_value_inner(othername_value_outer);
 
            BER_Object value = othername_value_inner.get_next_object();
            othername_value_inner.verify_end();
 
            if(ASN1_String::is_string_type(value.type()) && value.get_class() == ASN1_Class::Universal) {
               add_othername(oid, ASN1::to_string(value), value.type());
            }
         }
      }
      if(obj.is_a(1, ASN1_Class::ContextSpecific)) {
         add_attribute("RFC822", ASN1::to_string(obj));
      } else if(obj.is_a(2, ASN1_Class::ContextSpecific)) {
         add_attribute("DNS", ASN1::to_string(obj));
      } else if(obj.is_a(6, ASN1_Class::ContextSpecific)) {
         add_attribute("URI", ASN1::to_string(obj));
      } else if(obj.is_a(4, ASN1_Class::ContextSpecific | ASN1_Class::Constructed)) {
         BER_Decoder dec(obj);
         X509_DN dn;
         std::stringstream ss;
 
         dec.decode(dn);
         ss << dn;
 
         add_attribute("DN", ss.str());
      } else if(obj.is_a(7, ASN1_Class::ContextSpecific)) {
         if(obj.length() == 4) {
            const uint32_t ip = load_be<uint32_t>(obj.bits(), 0);
            add_attribute("IP", ipv4_to_string(ip));
         }
      }
   }
}
 
}  // namespace Botan