How to get ECC signature size by public key?

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How to get ECC signature size by public key?

Dmitry Zhigulin

I have x509 asn1_decode - ed ECC certificate, and trying to parse public key:

EC_KEY *key = NULL;
key = o2i_ECPublicKey(NULL, &pk.value, pk.len);

return error. :(

but if I use similar fuction for RSA public key:

RSA *rsa = NULL;
rsa = d2i_RSAPublicKey(NULL,&pk.value, pk.len);

return ok

What is wrong?

And second question, all manipulations I need for getting signature size for
corresponding ECC public key.  Maybe is it other way to recognize signature
size for this key?
For example, maybe public key size and signature size is a dependent quantities.

OpenSSL 0.9.8e 23 Feb 2007

ECC asn1_decode - ed public key:
04 e0 fd c3 07 be 0e db 35 9c 05 c8 d7 82 36 fd 0d 97 a7 30 8f 73 89 e3 9e 66
ae 9b f7 cf 8a d1 e5 78 17 f8 94 57 ed 68 6d 85 fe 57 3f 4c 73 eb 6d
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