Add a new constructor to each public key algorithm (only the public

keys so far, private keys not changed) that takes an
AlgorithmIdentifier and a MemoryRegion<byte>&. This performs the X.509
decoding. It is not possible anymore to create uninitialized PK
objects.

2 files changed, 16 insertions, 0 deletions

diff --git a/src/pubkey/dl_algo/dl_algo.cpp b/src/pubkey/dl_algo/dl_algo.cpp
index f035f852f..bf7ab0a6a 100644
--- a/src/pubkey/dl_algo/dl_algo.cpp
+++ b/src/pubkey/dl_algo/dl_algo.cpp
@@ -23,6 +23,16 @@ MemoryVector<byte> DL_Scheme_PublicKey::x509_subject_public_key() const
    return DER_Encoder().encode(y).get_contents();
    }
 
+DL_Scheme_PublicKey::DL_Scheme_PublicKey(const AlgorithmIdentifier& alg_id,
+                                         const MemoryRegion<byte>& key_bits,
+                                         DL_Group::Format format)
+   {
+   DataSource_Memory source(alg_id.parameters);
+   group.BER_decode(source, format);
+
+   BER_Decoder(key_bits).decode(y);
+   }
+
 /*
 * Return the X.509 public key decoder
 */
diff --git a/src/pubkey/dl_algo/dl_algo.h b/src/pubkey/dl_algo/dl_algo.h
index 9e5e46e2a..7492dc3bd 100644
--- a/src/pubkey/dl_algo/dl_algo.h
+++ b/src/pubkey/dl_algo/dl_algo.h
@@ -68,7 +68,13 @@ class BOTAN_DLL DL_Scheme_PublicKey : public virtual Public_Key
       * values in this instance.
       */
       X509_Decoder* x509_decoder();
+
+      DL_Scheme_PublicKey(const AlgorithmIdentifier& alg_id,
+                          const MemoryRegion<byte>& key_bits,
+                          DL_Group::Format group_format);
+
    protected:
+      DL_Scheme_PublicKey() {}
       BigInt y;
       DL_Group group;
    private: