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: Dr Stephen Henson <steve@openssl.org>
(cherry picked from commit ed383f847156940e93f256fed78599873a4a9b28)

Conflicts:
	doc/crypto/EC_KEY_new.pod

diff --git a/crypto/ec/ec_asn1.c b/crypto/ec/ec_asn1.c
index 4e6a74cfaded393a46c74a48dcf018bd99f260fc..c2f01c31c4a3501228829e4e653760a41ee685c7 100644 (file)
--- a/crypto/ec/ec_asn1.c
+++ b/crypto/ec/ec_asn1.c
@@ -1167,19 +1167,20 @@ EC_KEY *d2i_ECPrivateKey(EC_KEY **a, const unsigned char **in, long len)
                goto err;
                }
 
+       if (ret->pub_key)
+               EC_POINT_clear_free(ret->pub_key);
+       ret->pub_key = EC_POINT_new(ret->group);
+       if (ret->pub_key == NULL)
+               {
+               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;
 
-               if (ret->pub_key)
-                       EC_POINT_clear_free(ret->pub_key);
-               ret->pub_key = EC_POINT_new(ret->group);
-               if (ret->pub_key == NULL)
-                       {
-                       ECerr(EC_F_D2I_ECPRIVATEKEY, ERR_R_EC_LIB);
-                       goto err;
-                       }
                pub_oct     = M_ASN1_STRING_data(priv_key->publicKey);
                pub_oct_len = M_ASN1_STRING_length(priv_key->publicKey);
                /* save the point conversion form */
@@ -1191,6 +1192,16 @@ 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: