1 files changed, 176 insertions, 0 deletions
diff --git a/src/pubkey/pk_codecs/x509_key.cpp b/src/pubkey/pk_codecs/x509_key.cpp
new file mode 100644
index 000000000..455e627f3
--- /dev/null
+++ b/src/pubkey/pk_codecs/x509_key.cpp
@@ -0,0 +1,176 @@
+/*
+* X.509 Public Key
+* (C) 1999-2007 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#include <botan/x509_key.h>
+#include <botan/filters.h>
+#include <botan/asn1_obj.h>
+#include <botan/der_enc.h>
+#include <botan/ber_dec.h>
+#include <botan/pk_algs.h>
+#include <botan/oids.h>
+#include <botan/pem.h>
+#include <memory>
+
+namespace Botan {
+
+namespace X509 {
+
+/*
+* DER or PEM encode a X.509 public key
+*/
+void encode(const Public_Key& key, Pipe& pipe, X509_Encoding encoding)
+   {
+   std::auto_ptr<X509_Encoder> encoder(key.x509_encoder());
+   if(!encoder.get())
+      throw Encoding_Error("X509::encode: Key does not support encoding");
+
+   MemoryVector<byte> der =
+      DER_Encoder()
+         .start_cons(SEQUENCE)
+            .encode(encoder->alg_id())
+            .encode(encoder->key_bits(), BIT_STRING)
+         .end_cons()
+      .get_contents();
+
+   if(encoding == PEM)
+      pipe.write(PEM_Code::encode(der, "PUBLIC KEY"));
+   else
+      pipe.write(der);
+   }
+
+/*
+* PEM encode a X.509 public key
+*/
+std::string PEM_encode(const Public_Key& key)
+   {
+   Pipe pem;
+   pem.start_msg();
+   encode(key, pem, PEM);
+   pem.end_msg();
+   return pem.read_all_as_string();
+   }
+
+/*
+* Extract a public key and return it
+*/
+Public_Key* load_key(DataSource& source)
+   {
+   try {
+      AlgorithmIdentifier alg_id;
+      MemoryVector<byte> key_bits;
+
+      if(ASN1::maybe_BER(source) && !PEM_Code::matches(source))
+         {
+         BER_Decoder(source)
+            .start_cons(SEQUENCE)
+            .decode(alg_id)
+            .decode(key_bits, BIT_STRING)
+            .verify_end()
+         .end_cons();
+         }
+      else
+         {
+         DataSource_Memory ber(
+            PEM_Code::decode_check_label(source, "PUBLIC KEY")
+            );
+
+         BER_Decoder(ber)
+            .start_cons(SEQUENCE)
+            .decode(alg_id)
+            .decode(key_bits, BIT_STRING)
+            .verify_end()
+         .end_cons();
+         }
+
+      if(key_bits.is_empty())
+         throw Decoding_Error("X.509 public key decoding failed");
+
+      const std::string alg_name = OIDS::lookup(alg_id.oid);
+      if(alg_name == "")
+         throw Decoding_Error("Unknown algorithm OID: " +
+                              alg_id.oid.as_string());
+
+      std::auto_ptr<Public_Key> key_obj(get_public_key(alg_name));
+      if(!key_obj.get())
+         throw Decoding_Error("Unknown PK algorithm/OID: " + alg_name + ", " +
+                              alg_id.oid.as_string());
+
+      std::auto_ptr<X509_Decoder> decoder(key_obj->x509_decoder());
+
+      if(!decoder.get())
+         throw Decoding_Error("Key does not support X.509 decoding");
+
+      decoder->alg_id(alg_id);
+      decoder->key_bits(key_bits);
+
+      return key_obj.release();
+      }
+   catch(Decoding_Error)
+      {
+      throw Decoding_Error("X.509 public key decoding failed");
+      }
+   }
+
+/*
+* Extract a public key and return it
+*/
+Public_Key* load_key(const std::string& fsname)
+   {
+   DataSource_Stream source(fsname, true);
+   return X509::load_key(source);
+   }
+
+/*
+* Extract a public key and return it
+*/
+Public_Key* load_key(const MemoryRegion<byte>& mem)
+   {
+   DataSource_Memory source(mem);
+   return X509::load_key(source);
+   }
+
+/*
+* Make a copy of this public key
+*/
+Public_Key* copy_key(const Public_Key& key)
+   {
+   Pipe bits;
+   bits.start_msg();
+   X509::encode(key, bits, RAW_BER);
+   bits.end_msg();
+   DataSource_Memory source(bits.read_all());
+   return X509::load_key(source);
+   }
+
+/*
+* Find the allowable key constraints
+*/
+Key_Constraints find_constraints(const Public_Key& pub_key,
+                                 Key_Constraints limits)
+   {
+   const Public_Key* key = &pub_key;
+   u32bit constraints = 0;
+
+   if(dynamic_cast<const PK_Encrypting_Key*>(key))
+      constraints |= KEY_ENCIPHERMENT | DATA_ENCIPHERMENT;
+
+   if(dynamic_cast<const PK_Key_Agreement_Key*>(key))
+      constraints |= KEY_AGREEMENT;
+
+   if(dynamic_cast<const PK_Verifying_wo_MR_Key*>(key) ||
+      dynamic_cast<const PK_Verifying_with_MR_Key*>(key))
+      constraints |= DIGITAL_SIGNATURE | NON_REPUDIATION;
+
+   if(limits)
+      constraints &= limits;
+
+   return Key_Constraints(constraints);
+   }
+
+}
+
+}