ECDH- NID_X9_62_prime256v1 - EVP_RAND_instantiate()

[Damodhar Boddukuri via openssl-users]

Hi,

I am implementing ECDH- Group19 (NID_X9_62_prime256v1). I followed the below 
sequence.

  1.  ecdh_group = EC_GROUP_new_by_curve_name(NID_X9_62_prime256v1); // 
NID_X9_62_prime256v1 or  NID_secp256k1
  2.  ecdh_keys = EC_KEY_new();
  3.  ret = EC_KEY_set_group(ecdh_keys, ecdh_group);
  4.  ret = EC_KEY_generate_key(ecdh_keys);
At 4th step, function EVP_RAND_instantiate()  returning '1' for the 1st time. 
Then 2nd time onward it's returning '0'. Because of this reason 4th step is 
failing.

Could you please let me know the possible reasons for it.

Thanks & Regards,
Damodhar.



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