Commit 307a494e authored by ymlbright's avatar ymlbright Committed by Pauli
Browse files

fix out-of-bounds write in sm2_crypt.c 



asn1_encode has two form length octets: short form(1 byte), long form(1+n byte).

CLA: Trivial

Reviewed-by: default avatarNicola Tuveri <nic.tuv@gmail.com>
Reviewed-by: default avatarPaul Dale <paul.dale@oracle.com>
Reviewed-by: default avatarMatt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/7027)
parent 7d38ca3f

crypto/sm2/sm2_crypt.c

+8 −1
Original line number Diff line number Diff line
@@ -91,11 +91,18 @@ int sm2_ciphertext_size(const EC_KEY *key, const EVP_MD *digest, size_t msg_len, 
{

    const size_t field_size = ec_field_size(EC_KEY_get0_group(key));

    const int md_size = EVP_MD_size(digest);

    size_t sz;



    if (field_size == 0 || md_size < 0)

        return 0;



    *ct_size = 12 + 2 * field_size + (size_t)md_size + msg_len;

    /* Integer and string are simple type; set constructed = 0, means primitive and definite length encoding. */

    sz = 2 * ASN1_object_size(0, field_size + 1, V_ASN1_INTEGER)

         + ASN1_object_size(0, md_size, V_ASN1_OCTET_STRING)

         + ASN1_object_size(0, msg_len, V_ASN1_OCTET_STRING);

    /* Sequence is structured type; set constructed = 1, means constructed and definite length encoding. */

    *ct_size = ASN1_object_size(1, sz, V_ASN1_SEQUENCE);



    return 1;

}