diff options
Diffstat (limited to 'lib/gssapi/decapsulate.c')
| -rw-r--r-- | lib/gssapi/decapsulate.c | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/lib/gssapi/decapsulate.c b/lib/gssapi/decapsulate.c new file mode 100644 index 0000000..2425453 --- /dev/null +++ b/lib/gssapi/decapsulate.c @@ -0,0 +1,184 @@ +/* + * Copyright (c) 1997 - 2001 Kungliga Tekniska Högskolan + * (Royal Institute of Technology, Stockholm, Sweden). + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * 3. Neither the name of the Institute nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include "gssapi_locl.h" + +RCSID("$Id: decapsulate.c,v 1.7.6.1 2003/09/18 22:00:41 lha Exp $"); + +OM_uint32 +gssapi_krb5_verify_header(u_char **str, + size_t total_len, + char *type) +{ + size_t len, len_len, mech_len, foo; + int e; + u_char *p = *str; + + if (total_len < 1) + return GSS_S_DEFECTIVE_TOKEN; + if (*p++ != 0x60) + return GSS_S_DEFECTIVE_TOKEN; + e = der_get_length (p, total_len - 1, &len, &len_len); + if (e || 1 + len_len + len != total_len) + return GSS_S_DEFECTIVE_TOKEN; + p += len_len; + if (*p++ != 0x06) + return GSS_S_DEFECTIVE_TOKEN; + e = der_get_length (p, total_len - 1 - len_len - 1, + &mech_len, &foo); + if (e) + return GSS_S_DEFECTIVE_TOKEN; + p += foo; + if (mech_len != GSS_KRB5_MECHANISM->length) + return GSS_S_BAD_MECH; + if (memcmp(p, + GSS_KRB5_MECHANISM->elements, + GSS_KRB5_MECHANISM->length) != 0) + return GSS_S_BAD_MECH; + p += mech_len; + if (memcmp (p, type, 2) != 0) + return GSS_S_DEFECTIVE_TOKEN; + p += 2; + *str = p; + return GSS_S_COMPLETE; +} + +static ssize_t +gssapi_krb5_get_mech (const u_char *ptr, + size_t total_len, + const u_char **mech_ret) +{ + size_t len, len_len, mech_len, foo; + const u_char *p = ptr; + int e; + + if (total_len < 1) + return -1; + if (*p++ != 0x60) + return -1; + e = der_get_length (p, total_len - 1, &len, &len_len); + if (e || 1 + len_len + len != total_len) + return -1; + p += len_len; + if (*p++ != 0x06) + return -1; + e = der_get_length (p, total_len - 1 - len_len - 1, + &mech_len, &foo); + if (e) + return -1; + p += foo; + *mech_ret = p; + return mech_len; +} + +OM_uint32 +_gssapi_verify_mech_header(u_char **str, + size_t total_len) +{ + const u_char *p; + ssize_t mech_len; + + mech_len = gssapi_krb5_get_mech (*str, total_len, &p); + if (mech_len < 0) + return GSS_S_DEFECTIVE_TOKEN; + + if (mech_len != GSS_KRB5_MECHANISM->length) + return GSS_S_BAD_MECH; + if (memcmp(p, + GSS_KRB5_MECHANISM->elements, + GSS_KRB5_MECHANISM->length) != 0) + return GSS_S_BAD_MECH; + p += mech_len; + *str = (char *)p; + return GSS_S_COMPLETE; +} + +/* + * Remove the GSS-API wrapping from `in_token' giving `out_data. + * Does not copy data, so just free `in_token'. + */ + +OM_uint32 +gssapi_krb5_decapsulate( + OM_uint32 *minor_status, + gss_buffer_t input_token_buffer, + krb5_data *out_data, + char *type +) +{ + u_char *p; + OM_uint32 ret; + + p = input_token_buffer->value; + ret = gssapi_krb5_verify_header(&p, + input_token_buffer->length, + type); + if (ret) { + *minor_status = 0; + return ret; + } + + out_data->length = input_token_buffer->length - + (p - (u_char *)input_token_buffer->value); + out_data->data = p; + return GSS_S_COMPLETE; +} + +/* + * Verify padding of a gss wrapped message and return its length. + */ + +OM_uint32 +_gssapi_verify_pad(gss_buffer_t wrapped_token, + size_t datalen, + size_t *padlen) +{ + u_char *pad; + size_t padlength; + int i; + + pad = (u_char *)wrapped_token->value + wrapped_token->length - 1; + padlength = *pad; + + if (padlength > datalen) + return GSS_S_BAD_MECH; + + for (i = padlength; i > 0 && *pad == padlength; i--, pad--) + ; + if (i != 0) + return GSS_S_BAD_MIC; + + *padlen = padlength; + + return 0; +} |
