Quite the hack, here.

GOST 34.10 public keys use a funky encoding. There is no standard for
PKCS #8 format private keys, so the obvious choice is to act exactly
the same as ECDSA/ECDH (following the rule of thumb that if you're
going to make up a random non-standard thing, at least try to copy
something that's standard for something else). However the public key
encoding uses a weird scheme for encoding the OID in the algorithm
identifier, which we don't want to use for the PKCS #8 encoding.

Add a new function to Private_Key, pkcs8_algorithm_identifier, which
by default just calls algorithm_identifier(). However
GOST_3410_PrivateKey overrides it, and calls
EC_PublicKey::algorithm_identifier(), basically skipping over the
virtual function hierarchy, so it doesn't pick up the funky format
from the public key's version of algorithm_identifier().

3 files changed, 11 insertions, 1 deletions

diff --git a/src/pubkey/gost_3410/gost_3410.h b/src/pubkey/gost_3410/gost_3410.h
index 696daf0a7..669ed130f 100644
--- a/src/pubkey/gost_3410/gost_3410.h
+++ b/src/pubkey/gost_3410/gost_3410.h
@@ -103,6 +103,9 @@ class BOTAN_DLL GOST_3410_PrivateKey : public GOST_3410_PublicKey,
       GOST_3410_PrivateKey(const EC_Domain_Params& domain, const BigInt& x) :
          EC_PrivateKey(domain, x) {}
 
+      AlgorithmIdentifier pkcs8_algorithm_identifier() const
+         { return EC_PublicKey::algorithm_identifier(); }
+
       /**
       * Sign a message with this key.
       * @param message the byte array representing the message to be signed
diff --git a/src/pubkey/pk_keys.h b/src/pubkey/pk_keys.h
index 4e0f58b38..8015c1076 100644
--- a/src/pubkey/pk_keys.h
+++ b/src/pubkey/pk_keys.h
@@ -87,6 +87,13 @@ class BOTAN_DLL Private_Key : public virtual Public_Key
       */
       virtual MemoryVector<byte> pkcs8_private_key() const = 0;
 
+      /**
+      * @return PKCS #8 AlgorithmIdentifier for this key
+      * Might be different from the X.509 identifier, but normally is not
+      */
+      virtual AlgorithmIdentifier pkcs8_algorithm_identifier() const
+         { return algorithm_identifier(); }
+
    protected:
       void load_check(RandomNumberGenerator&) const;
       void gen_check(RandomNumberGenerator&) const;
diff --git a/src/pubkey/pkcs8.cpp b/src/pubkey/pkcs8.cpp
index c89431fca..400fdbb48 100644
--- a/src/pubkey/pkcs8.cpp
+++ b/src/pubkey/pkcs8.cpp
@@ -144,7 +144,7 @@ void encode(const Private_Key& key, Pipe& pipe, X509_Encoding encoding)
       DER_Encoder()
          .start_cons(SEQUENCE)
             .encode(PKCS8_VERSION)
-            .encode(key.algorithm_identifier())
+            .encode(key.pkcs8_algorithm_identifier())
             .encode(key.pkcs8_private_key(), OCTET_STRING)
          .end_cons()
       .get_contents();