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/*
* X.509 Name Constraint
* (C) 2015 Kai Michaelis
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#include <botan/name_constraint.h>
#include <botan/asn1_alt_name.h>
#include <botan/ber_dec.h>
#include <botan/loadstor.h>
#include <botan/x509_dn.h>
#include <botan/x509cert.h>
#include <botan/parsing.h>
#include <sstream>
namespace Botan {
class DER_Encoder;
GeneralName::GeneralName(const std::string& str) : GeneralName()
{
size_t p = str.find(':');
if(p != std::string::npos)
{
m_type = str.substr(0, p);
m_name = str.substr(p + 1, std::string::npos);
}
else
{
throw Invalid_Argument("Failed to decode Name Constraint");
}
}
void GeneralName::encode_into(DER_Encoder&) const
{
throw Not_Implemented("GeneralName encoding");
}
void GeneralName::decode_from(class BER_Decoder& ber)
{
BER_Object obj = ber.get_next_object();
if(obj.is_a(1, CONTEXT_SPECIFIC))
{
m_type = "RFC822";
m_name = ASN1::to_string(obj);
}
else if(obj.is_a(2, CONTEXT_SPECIFIC))
{
m_type = "DNS";
m_name = ASN1::to_string(obj);
}
else if(obj.is_a(6, CONTEXT_SPECIFIC))
{
m_type = "URI";
m_name = ASN1::to_string(obj);
}
else if(obj.is_a(4, ASN1_Tag(CONTEXT_SPECIFIC | CONSTRUCTED)))
{
m_type = "DN";
X509_DN dn;
BER_Decoder dec(obj);
std::stringstream ss;
dn.decode_from(dec);
ss << dn;
m_name = ss.str();
}
else if(obj.is_a(7, CONTEXT_SPECIFIC))
{
if(obj.length() == 8)
{
m_type = "IP";
m_name = ipv4_to_string(load_be<uint32_t>(obj.bits(), 0)) + "/" +
ipv4_to_string(load_be<uint32_t>(obj.bits(), 1));
}
else if(obj.length() == 32)
{
throw Decoding_Error("Unsupported IPv6 name constraint");
}
else
{
throw Decoding_Error("Invalid IP name constraint size " + std::to_string(obj.length()));
}
}
else
{
throw Decoding_Error("Found unknown GeneralName type");
}
}
GeneralName::MatchResult GeneralName::matches(const X509_Certificate& cert) const
{
std::vector<std::string> nam;
std::function<bool(const GeneralName*, const std::string&)> match_fn;
const X509_DN& dn = cert.subject_dn();
const AlternativeName& alt_name = cert.subject_alt_name();
if(type() == "DNS")
{
match_fn = std::mem_fn(&GeneralName::matches_dns);
nam = alt_name.get_attribute("DNS");
if(nam.empty())
{
nam = dn.get_attribute("CN");
}
}
else if(type() == "DN")
{
match_fn = std::mem_fn(&GeneralName::matches_dn);
std::stringstream ss;
ss << dn;
nam.push_back(ss.str());
}
else if(type() == "IP")
{
match_fn = std::mem_fn(&GeneralName::matches_ip);
nam = alt_name.get_attribute("IP");
}
else
{
return MatchResult::UnknownType;
}
if(nam.empty())
{
return MatchResult::NotFound;
}
bool some = false;
bool all = true;
for(const std::string& n: nam)
{
bool m = match_fn(this, n);
some |= m;
all &= m;
}
if(all)
{
return MatchResult::All;
}
else if(some)
{
return MatchResult::Some;
}
else
{
return MatchResult::None;
}
}
bool GeneralName::matches_dns(const std::string& nam) const
{
if(nam.size() == name().size())
{
return nam == name();
}
else if(name().size() > nam.size())
{
return false;
}
else // name.size() < nam.size()
{
std::string constr = name().front() == '.' ? name() : "." + name();
// constr is suffix of nam
return constr == nam.substr(nam.size() - constr.size(), constr.size());
}
}
bool GeneralName::matches_dn(const std::string& nam) const
{
std::stringstream ss(nam);
std::stringstream tt(name());
X509_DN nam_dn, my_dn;
ss >> nam_dn;
tt >> my_dn;
auto attr = nam_dn.get_attributes();
bool ret = true;
size_t trys = 0;
for(const auto& c: my_dn.dn_info())
{
auto i = attr.equal_range(c.first);
if(i.first != i.second)
{
trys += 1;
ret = ret && (i.first->second == c.second.value());
}
}
return trys > 0 && ret;
}
bool GeneralName::matches_ip(const std::string& nam) const
{
uint32_t ip = string_to_ipv4(nam);
std::vector<std::string> p = split_on(name(), '/');
if(p.size() != 2)
throw Decoding_Error("failed to parse IPv4 address");
uint32_t net = string_to_ipv4(p.at(0));
uint32_t mask = string_to_ipv4(p.at(1));
return (ip & mask) == net;
}
std::ostream& operator<<(std::ostream& os, const GeneralName& gn)
{
os << gn.type() << ":" << gn.name();
return os;
}
GeneralSubtree::GeneralSubtree(const std::string& str) : GeneralSubtree()
{
size_t p0, p1;
size_t min = std::stoull(str, &p0, 10);
size_t max = std::stoull(str.substr(p0 + 1), &p1, 10);
GeneralName gn(str.substr(p0 + p1 + 2));
if(p0 > 0 && p1 > 0)
{
m_minimum = min;
m_maximum = max;
m_base = gn;
}
else
{
throw Invalid_Argument("Failed to decode Name Constraint");
}
}
void GeneralSubtree::encode_into(DER_Encoder&) const
{
throw Not_Implemented("General Subtree encoding");
}
void GeneralSubtree::decode_from(class BER_Decoder& ber)
{
ber.start_cons(SEQUENCE)
.decode(m_base)
.decode_optional(m_minimum,ASN1_Tag(0), CONTEXT_SPECIFIC,size_t(0))
.end_cons();
if(m_minimum != 0)
throw Decoding_Error("GeneralSubtree minimum must be 0");
m_maximum = std::numeric_limits<std::size_t>::max();
}
std::ostream& operator<<(std::ostream& os, const GeneralSubtree& gs)
{
os << gs.minimum() << "," << gs.maximum() << "," << gs.base();
return os;
}
}
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