Commit f34a5720 authored by Emilia Kasper's avatar Emilia Kasper
Browse files

Explicitly check for empty ASN.1 strings in d2i_ECPrivateKey 



The old code implicitly relies on the ASN.1 code returning a \0-prefixed buffer
when the buffer length is 0. Change this to verify explicitly that the ASN.1 string
has positive length.

Reviewed-by: default avatarDr Stephen Henson <steve@openssl.org>
parent f063e30f

crypto/ec/ec_asn1.c

+9 −3
Original line number Diff line number Diff line
@@ -1195,14 +1195,20 @@ EC_KEY *d2i_ECPrivateKey(EC_KEY **a, const unsigned char **in, long len) 
	if (priv_key->publicKey)

		{

		const unsigned char *pub_oct;

		size_t pub_oct_len;

		int pub_oct_len;



		pub_oct     = M_ASN1_STRING_data(priv_key->publicKey);

		pub_oct_len = M_ASN1_STRING_length(priv_key->publicKey);

		/* save the point conversion form */

		/* The first byte - point conversion form - must be present. */

                if (pub_oct_len <= 0)

			{

			ECerr(EC_F_D2I_ECPRIVATEKEY, EC_R_BUFFER_TOO_SMALL);

			goto err;

			}

		/* Save the point conversion form. */

		ret->conv_form = (point_conversion_form_t)(pub_oct[0] & ~0x01);

		if (!EC_POINT_oct2point(ret->group, ret->pub_key,

			pub_oct, pub_oct_len, NULL))

					pub_oct, (size_t)(pub_oct_len), NULL))

			{

			ECerr(EC_F_D2I_ECPRIVATEKEY, ERR_R_EC_LIB);

			goto err;