diff options
Diffstat (limited to 'src/lib/gssapi/krb5/wrap_size_limit.c')
-rw-r--r-- | src/lib/gssapi/krb5/wrap_size_limit.c | 131 |
1 files changed, 44 insertions, 87 deletions
diff --git a/src/lib/gssapi/krb5/wrap_size_limit.c b/src/lib/gssapi/krb5/wrap_size_limit.c index f7fee73..1f2db4a 100644 --- a/src/lib/gssapi/krb5/wrap_size_limit.c +++ b/src/lib/gssapi/krb5/wrap_size_limit.c @@ -1,4 +1,28 @@ /* + * Copyright 2000 by the Massachusetts Institute of Technology. + * All Rights Reserved. + * + * Export of this software from the United States of America may + * require a specific license from the United States Government. + * It is the responsibility of any person or organization contemplating + * export to obtain such a license before exporting. + * + * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and + * distribute this software and its documentation for any purpose and + * without fee is hereby granted, provided that the above copyright + * notice appear in all copies and that both that copyright notice and + * this permission notice appear in supporting documentation, and that + * the name of M.I.T. not be used in advertising or publicity pertaining + * to distribution of the software without specific, written prior + * permission. Furthermore if you modify this software you must label + * your software as modified software and not distribute it in such a + * fashion that it might be confused with the original M.I.T. software. + * M.I.T. makes no representations about the suitability of + * this software for any purpose. It is provided "as is" without express + * or implied warranty. + * + */ +/* * Copyright 1993 by OpenVision Technologies, Inc. * * Permission to use, copy, modify, distribute, and sell this software @@ -65,7 +89,9 @@ krb5_gss_wrap_size_limit(minor_status, context_handle, conf_req_flag, { krb5_context context; krb5_gss_ctx_id_rec *ctx; - krb5_error_code code; + OM_uint32 data_size, conflen; + OM_uint32 ohlen; + int overhead; if (GSS_ERROR(kg_get_context(minor_status, &context))) return(GSS_S_FAILURE); @@ -88,92 +114,23 @@ krb5_gss_wrap_size_limit(minor_status, context_handle, conf_req_flag, return(GSS_S_NO_CONTEXT); } - if (ctx->gsskrb5_version == 2000) { - if (conf_req_flag) { - /* this is pretty gross. take the max output, and call - krb5_c_encrypt_length to see how much overhead is added - on. subtract that much, and see if it fits in the - requested space. If not, start subtracting 1 until it - does. This doesn't necessarily give us the optimal - packing, but I think that's ok (I could start adding 1 - until I went over, but that seems like it's not worth - the effort). This is probably O(blocksize), but that's - never going to be large. */ - - OM_uint32 headerlen, plainlen; - size_t enclen; - - headerlen = g_token_size((gss_OID) ctx->mech_used, 2); - plainlen = req_output_size - headerlen; - - if (code = krb5_c_encrypt_length(context, ctx->enc->enctype, - plainlen, &enclen)) { - *minor_status = code; - return(GSS_S_FAILURE); - } - - plainlen -= plainlen - (enclen - plainlen); - - if (code = krb5_c_encrypt_length(context, ctx->enc->enctype, - plainlen, &enclen)) { - *minor_status = code; - return(GSS_S_FAILURE); - } - - while (headerlen + enclen > req_output_size) { - plainlen--; - - if (code = krb5_c_encrypt_length(context, ctx->enc->enctype, - plainlen, &enclen)) { - *minor_status = code; - return(GSS_S_FAILURE); - } - } - - /* subtract off the fixed size inside the encrypted part */ - - plainlen -= 7; - - *max_input_size = plainlen; - } else { - size_t cksumlen; - OM_uint32 headerlen; - - if (code = krb5_c_checksum_length(context, ctx->ctypes[0], - &cksumlen)) { - *minor_status = code; - return(GSS_S_FAILURE); - } - - headerlen = g_token_size((gss_OID) ctx->mech_used, 13 + cksumlen); - - *max_input_size = req_output_size - headerlen; - } - } else { - OM_uint32 data_size, conflen; - OM_uint32 ohlen; - int overhead; - - /* Calculate the token size and subtract that from the output size */ - overhead = 7 + ctx->mech_used->length; - data_size = req_output_size; - if (conf_req_flag) { - conflen = kg_confounder_size(context, ctx->enc); - data_size = (conflen + data_size + 8) & (~7); - } - ohlen = g_token_size((gss_OID) ctx->mech_used, - (unsigned int) (data_size + ctx->cksum_size + 14)) - - req_output_size; - - if (ohlen+overhead < req_output_size) - /* - * Cannot have trailer length that will cause us to pad over - * our length - */ - *max_input_size = (req_output_size - ohlen - overhead) & (~7); - else - *max_input_size = 0; - } + /* Calculate the token size and subtract that from the output size */ + overhead = 7 + ctx->mech_used->length; + data_size = req_output_size; + conflen = kg_confounder_size(context, ctx->enc); + data_size = (conflen + data_size + 8) & (~(OM_uint32)7); + ohlen = g_token_size((gss_OID) ctx->mech_used, + (unsigned int) (data_size + ctx->cksum_size + 14)) + - req_output_size; + + if (ohlen+overhead < req_output_size) + /* + * Cannot have trailer length that will cause us to pad over our + * length. + */ + *max_input_size = (req_output_size - ohlen - overhead) & (~(OM_uint32)7); + else + *max_input_size = 0; *minor_status = 0; return(GSS_S_COMPLETE); |