Commit cf517a6d authored by Dr. Stephen Henson's avatar Dr. Stephen Henson
Browse files

add ECDSA_size to ec_asn1.c 



Reviewed-by: default avatarRichard Levitte <levitte@openssl.org>
parent c5359791

crypto/ec/ec_asn1.c

+34 −0
Original line number Diff line number Diff line
@@ -1319,3 +1319,37 @@ void ECDSA_SIG_get0(BIGNUM **pr, BIGNUM **ps, ECDSA_SIG *sig) 
    if (ps)

        *ps = sig->s;

}



int ECDSA_size(const EC_KEY *r)

{

    int ret, i;

    ASN1_INTEGER bs;

    BIGNUM *order = NULL;

    unsigned char buf[4];

    const EC_GROUP *group;



    if (r == NULL)

        return 0;

    group = EC_KEY_get0_group(r);

    if (group == NULL)

        return 0;



    if ((order = BN_new()) == NULL)

        return 0;

    if (!EC_GROUP_get_order(group, order, NULL)) {

        BN_clear_free(order);

        return 0;

    }

    i = BN_num_bits(order);

    bs.length = (i + 7) / 8;

    bs.data = buf;

    bs.type = V_ASN1_INTEGER;

    /* If the top bit is set the asn1 encoding is 1 larger. */

    buf[0] = 0xff;



    i = i2d_ASN1_INTEGER(&bs, NULL);

    i += i;                     /* r and s */

    ret = ASN1_object_size(1, i, V_ASN1_SEQUENCE);

    BN_clear_free(order);

    return (ret);

}

include/openssl/ec.h

+6 −0
Original line number Diff line number Diff line
@@ -1089,6 +1089,12 @@ int ECDSA_sign_ex(int type, const unsigned char *dgst, int dgstlen, 
int ECDSA_verify(int type, const unsigned char *dgst, int dgstlen,

                 const unsigned char *sig, int siglen, EC_KEY *eckey);



/** Returns the maximum length of the DER encoded signature

 *  \param  eckey  EC_KEY object

 *  \return numbers of bytes required for the DER encoded signature

 */

int ECDSA_size(const EC_KEY *eckey);



# define ECParameters_dup(x) ASN1_dup_of(EC_KEY,i2d_ECParameters,d2i_ECParameters,x)



# ifndef __cplusplus