Commit cf241395 authored by Dr. Stephen Henson's avatar Dr. Stephen Henson
Browse files

Add EC_KEY_oct2priv and EC_KEY_priv2oct 



New functions EC_KEY_oct2priv and EC_KEY_priv2oct. These are private key
equivalents of EC_POINT_oct2point and EC_POINT_point2oct which convert
between the private key octet format and EC_KEY.

Reviewed-by: default avatarViktor Dukhovni <viktor@openssl.org>
parent 26c255fc

crypto/ec/ec_key.c

+53 −0
Original line number Diff line number Diff line
@@ -548,3 +548,56 @@ int EC_KEY_oct2key(EC_KEY *key, const unsigned char *buf, size_t len, 
        return 0;

    return EC_POINT_oct2point(key->group, key->pub_key, buf, len, ctx);

}



size_t EC_KEY_priv2oct(const EC_KEY *eckey, unsigned char *buf, size_t len)

{

    size_t buf_len, bn_len;

    if (eckey->group == NULL || eckey->group->meth == NULL)

        return 0;



    buf_len = (EC_GROUP_get_degree(eckey->group) + 7) / 8;

    if (eckey->priv_key == NULL)

        return 0;

    if (buf == NULL)

        return buf_len;

    else if (len < buf_len)

        return 0;



    bn_len = (size_t)BN_num_bytes(eckey->priv_key);



    /* Octetstring may need leading zeros if BN is to short */



    if (bn_len > buf_len) {

        ECerr(EC_F_I2D_ECPRIVATEKEY, EC_R_BUFFER_TOO_SMALL);

        return 0;

    }



    if (!BN_bn2bin(eckey->priv_key, buf + buf_len - bn_len)) {

        ECerr(EC_F_I2D_ECPRIVATEKEY, ERR_R_BN_LIB);

        return 0;

    }



    if (buf_len - bn_len > 0)

        memset(buf, 0, buf_len - bn_len);



    return buf_len;

}



int EC_KEY_oct2priv(EC_KEY *eckey, unsigned char *buf, size_t len)

{

    if (eckey->group == NULL || eckey->group->meth == NULL)

        return 0;



    if (eckey->priv_key == NULL)

        eckey->priv_key = BN_secure_new();

    if (eckey->priv_key == NULL) {

        ECerr(EC_F_D2I_ECPRIVATEKEY, ERR_R_MALLOC_FAILURE);

        return 0;

    }

    eckey->priv_key = BN_bin2bn(buf, len, eckey->priv_key);

    if (eckey->priv_key == NULL) {

        ECerr(EC_F_D2I_ECPRIVATEKEY, ERR_R_BN_LIB);

        return 0;

    }

    return 1;

}

include/openssl/ec.h

+20 −0
Original line number Diff line number Diff line
@@ -934,6 +934,26 @@ size_t EC_KEY_key2buf(const EC_KEY *key, point_conversion_form_t form, 
int EC_KEY_oct2key(EC_KEY *key, const unsigned char *buf, size_t len,

                   BN_CTX *ctx);



/** Decodes an EC_KEY private key from an octet string

 *  \param  key    key to decode

 *  \param  buf    memory buffer with the encoded private key

 *  \param  len    length of the encoded key

 *  \return 1 on success and 0 if an error occurred

 */



int EC_KEY_oct2priv(EC_KEY *key, unsigned char *buf, size_t len);



/** Encodes a EC_KEY private key to an octet string

 *  \param  key    key to encode

 *  \param  buf    memory buffer for the result. If NULL the function returns

 *                 required buffer size.

 *  \param  len    length of the memory buffer

 *  \return the length of the encoded octet string or 0 if an error occurred

 */



size_t EC_KEY_priv2oct(const EC_KEY *key, unsigned char *buf, size_t len);





/********************************************************************/

/*        de- and encoding functions for SEC1 ECPrivateKey          */

/********************************************************************/