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/*
* X.509 Certificate Authority
* (C) 1999-2010 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#include <botan/x509_ca.h>
#include <botan/pubkey.h>
#include <botan/der_enc.h>
#include <botan/ber_dec.h>
#include <botan/bigint.h>
#include <botan/parsing.h>
#include <botan/oids.h>
#include <botan/hash.h>
#include <botan/key_constraint.h>
#include <algorithm>
#include <typeinfo>
#include <iterator>
#include <set>
namespace Botan {
/*
* Load the certificate and private key
*/
X509_CA::X509_CA(const X509_Certificate& c,
const Private_Key& key,
const std::string& hash_fn) : m_cert(c)
{
if(!m_cert.is_CA_cert())
throw Invalid_Argument("X509_CA: This certificate is not for a CA");
m_signer = choose_sig_format(key, hash_fn, m_ca_sig_algo);
}
/*
* X509_CA Destructor
*/
X509_CA::~X509_CA()
{
delete m_signer;
}
/*
* Sign a PKCS #10 certificate request
*/
X509_Certificate X509_CA::sign_request(const PKCS10_Request& req,
RandomNumberGenerator& rng,
const X509_Time& not_before,
const X509_Time& not_after)
{
Key_Constraints constraints;
if(req.is_CA())
constraints = Key_Constraints(KEY_CERT_SIGN | CRL_SIGN);
else
{
std::unique_ptr<Public_Key> key(req.subject_public_key());
constraints = find_constraints(*key, req.constraints());
}
Extensions extensions;
extensions.add(
new Cert_Extension::Basic_Constraints(req.is_CA(), req.path_limit()),
true);
extensions.add(new Cert_Extension::Key_Usage(constraints), true);
extensions.add(new Cert_Extension::Authority_Key_ID(m_cert.subject_key_id()));
extensions.add(new Cert_Extension::Subject_Key_ID(req.raw_public_key()));
extensions.add(
new Cert_Extension::Subject_Alternative_Name(req.subject_alt_name()));
extensions.add(
new Cert_Extension::Extended_Key_Usage(req.ex_constraints()));
return make_cert(m_signer, rng, m_ca_sig_algo,
req.raw_public_key(),
not_before, not_after,
m_cert.subject_dn(), req.subject_dn(),
extensions);
}
/*
* Create a new certificate
*/
X509_Certificate X509_CA::make_cert(PK_Signer* signer,
RandomNumberGenerator& rng,
const AlgorithmIdentifier& sig_algo,
const std::vector<byte>& pub_key,
const X509_Time& not_before,
const X509_Time& not_after,
const X509_DN& issuer_dn,
const X509_DN& subject_dn,
const Extensions& extensions)
{
const size_t X509_CERT_VERSION = 3;
const size_t SERIAL_BITS = 128;
BigInt serial_no(rng, SERIAL_BITS);
// clang-format off
return X509_Certificate(X509_Object::make_signed(
signer, rng, sig_algo,
DER_Encoder().start_cons(SEQUENCE)
.start_explicit(0)
.encode(X509_CERT_VERSION-1)
.end_explicit()
.encode(serial_no)
.encode(sig_algo)
.encode(issuer_dn)
.start_cons(SEQUENCE)
.encode(not_before)
.encode(not_after)
.end_cons()
.encode(subject_dn)
.raw_bytes(pub_key)
.start_explicit(3)
.start_cons(SEQUENCE)
.encode(extensions)
.end_cons()
.end_explicit()
.end_cons()
.get_contents()
));;
// clang-format on
}
/*
* Create a new, empty CRL
*/
X509_CRL X509_CA::new_crl(RandomNumberGenerator& rng,
u32bit next_update) const
{
std::vector<CRL_Entry> empty;
return make_crl(empty, 1, next_update, rng);
}
/*
* Update a CRL with new entries
*/
X509_CRL X509_CA::update_crl(const X509_CRL& crl,
const std::vector<CRL_Entry>& new_revoked,
RandomNumberGenerator& rng,
u32bit next_update) const
{
std::vector<CRL_Entry> revoked = crl.get_revoked();
std::copy(new_revoked.begin(), new_revoked.end(),
std::back_inserter(revoked));
return make_crl(revoked, crl.crl_number() + 1, next_update, rng);
}
/*
* Create a CRL
*/
X509_CRL X509_CA::make_crl(const std::vector<CRL_Entry>& revoked,
u32bit crl_number, u32bit next_update,
RandomNumberGenerator& rng) const
{
const size_t X509_CRL_VERSION = 2;
if(next_update == 0)
next_update = timespec_to_u32bit("7d");
// Totally stupid: ties encoding logic to the return of std::time!!
auto current_time = std::chrono::system_clock::now();
auto expire_time = current_time + std::chrono::seconds(next_update);
Extensions extensions;
extensions.add(
new Cert_Extension::Authority_Key_ID(m_cert.subject_key_id()));
extensions.add(new Cert_Extension::CRL_Number(crl_number));
// clang-format off
const std::vector<byte> crl = X509_Object::make_signed(
m_signer, rng, m_ca_sig_algo,
DER_Encoder().start_cons(SEQUENCE)
.encode(X509_CRL_VERSION-1)
.encode(m_ca_sig_algo)
.encode(m_cert.issuer_dn())
.encode(X509_Time(current_time))
.encode(X509_Time(expire_time))
.encode_if(revoked.size() > 0,
DER_Encoder()
.start_cons(SEQUENCE)
.encode_list(revoked)
.end_cons()
)
.start_explicit(0)
.start_cons(SEQUENCE)
.encode(extensions)
.end_cons()
.end_explicit()
.end_cons()
.get_contents());
// clang-format on
return X509_CRL(crl);
}
/*
* Return the CA's certificate
*/
X509_Certificate X509_CA::ca_certificate() const
{
return m_cert;
}
/*
* Choose a signing format for the key
*/
PK_Signer* choose_sig_format(const Private_Key& key,
const std::string& hash_fn,
AlgorithmIdentifier& sig_algo)
{
const std::string algo_name = key.algo_name();
std::unique_ptr<HashFunction> hash(HashFunction::create(hash_fn));
if(!hash)
throw Algorithm_Not_Found(hash_fn);
if(key.max_input_bits() < hash->output_length() * 8)
throw Invalid_Argument("Key is too small for chosen hash function");
std::string padding;
if(algo_name == "RSA")
padding = "EMSA3";
else if(algo_name == "DSA" || algo_name == "ECDSA" )
padding = "EMSA1";
else
throw Invalid_Argument("Unknown X.509 signing key type: " + algo_name);
const Signature_Format format = (key.message_parts() > 1) ? DER_SEQUENCE : IEEE_1363;
padding = padding + "(" + hash->name() + ")";
sig_algo.oid = OIDS::lookup(algo_name + "/" + padding);
sig_algo.parameters = key.algorithm_identifier().parameters;
return new PK_Signer(key, padding, format);
}
}
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