Commit f063e30f authored by Matt Caswell's avatar Matt Caswell Committed by Emilia Kasper
Browse files

RT3065: automatically generate a missing EC public key 



When d2i_ECPrivateKey reads a private key with a missing (optional) public key,
generate one automatically from the group and private key.

Reviewed-by: default avatarDr Stephen Henson <steve@openssl.org>
parent 0388ac4c

crypto/ec/ec_asn1.c

+19 −8
Original line number Diff line number Diff line
@@ -1183,11 +1183,6 @@ EC_KEY *d2i_ECPrivateKey(EC_KEY **a, const unsigned char **in, long len) 
		goto err;

		}



	if (priv_key->publicKey)

		{

		const unsigned char *pub_oct;

		size_t pub_oct_len;



	if (ret->pub_key)

		EC_POINT_clear_free(ret->pub_key);

	ret->pub_key = EC_POINT_new(ret->group);
@@ -1196,6 +1191,12 @@ EC_KEY *d2i_ECPrivateKey(EC_KEY **a, const unsigned char **in, long len) 
		ECerr(EC_F_D2I_ECPRIVATEKEY, ERR_R_EC_LIB);

		goto err;

		}



	if (priv_key->publicKey)

		{

		const unsigned char *pub_oct;

		size_t pub_oct_len;



		pub_oct     = M_ASN1_STRING_data(priv_key->publicKey);

		pub_oct_len = M_ASN1_STRING_length(priv_key->publicKey);

		/* save the point conversion form */
@@ -1207,6 +1208,16 @@ EC_KEY *d2i_ECPrivateKey(EC_KEY **a, const unsigned char **in, long len) 
			goto err;

			}

		}

	else

		{

		if (!EC_POINT_mul(ret->group, ret->pub_key, ret->priv_key, NULL, NULL, NULL))

			{

			ECerr(EC_F_D2I_ECPRIVATEKEY, ERR_R_EC_LIB);

			goto err;

			}

		/* Remember the original private-key-only encoding. */

		ret->enc_flag |= EC_PKEY_NO_PUBKEY;

		}



	ok = 1;

err:

doc/crypto/EC_KEY_new.pod

+5 −0
Original line number Diff line number Diff line
@@ -74,6 +74,11 @@ flags currently defined - EC_PKEY_NO_PARAMETERS and EC_PKEY_NO_PUBKEY. These fl 
converted into ASN1 in a call to i2d_ECPrivateKey. If EC_PKEY_NO_PARAMETERS is set then the public parameters for the curve are not encoded

along with the private key. If EC_PKEY_NO_PUBKEY is set then the public key is not encoded along with the private key.



When reading a private key encoded with EC_PKEY_NO_PUBKEY,

d2i_ECPrivateKey generates the missing public key

automatically. Private keys encoded with EC_PKEY_NO_PARAMETERS cannot

be loaded using d2i_ECPrivateKey.



The functions EC_KEY_get_conv_form and EC_KEY_set_conv_form get and set the point_conversion_form for the B<key>. For a description

of point_conversion_forms please refer to L<EC_POINT_new(3)|EC_POINT_new(3)>.