path: root/src/lib/gssapi/krb5/util_cksum.c

/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
/*
 * Copyright 1993 by OpenVision Technologies, Inc.
 *
 * Permission to use, copy, modify, distribute, and sell this software
 * and its documentation for any purpose is hereby granted without fee,
 * provided that the above copyright notice appears in all copies and
 * that both that copyright notice and this permission notice appear in
 * supporting documentation, and that the name of OpenVision not be used
 * in advertising or publicity pertaining to distribution of the software
 * without specific, written prior permission. OpenVision makes no
 * representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied warranty.
 *
 * OPENVISION DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 * EVENT SHALL OPENVISION BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
 * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
 * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */

#include "gssapiP_krb5.h"
#ifdef HAVE_MEMORY_H
#include <memory.h>
#endif

/* Checksumming the channel bindings always uses plain MD5.  */
krb5_error_code
kg_checksum_channel_bindings(context, cb, cksum)
    krb5_context context;
    gss_channel_bindings_t cb;
    krb5_checksum *cksum;
{
    struct k5buf buf;
    size_t sumlen;
    krb5_data plaind;
    krb5_error_code code;

    /* initialize the the cksum */
    code = krb5_c_checksum_length(context, CKSUMTYPE_RSA_MD5, &sumlen);
    if (code)
        return(code);

    cksum->checksum_type = CKSUMTYPE_RSA_MD5;
    cksum->length = sumlen;
    cksum->magic = KV5M_CHECKSUM;

    /* generate a buffer full of zeros if no cb specified */

    if (cb == GSS_C_NO_CHANNEL_BINDINGS) {
        if ((cksum->contents = (krb5_octet *) xmalloc(cksum->length)) == NULL) {
            return(ENOMEM);
        }
        memset(cksum->contents, '\0', cksum->length);
        return(0);
    }

    k5_buf_init_dynamic(&buf);
    k5_buf_add_uint32_le(&buf, cb->initiator_addrtype);
    k5_buf_add_uint32_le(&buf, cb->initiator_address.length);
    k5_buf_add_len(&buf, cb->initiator_address.value,
                   cb->initiator_address.length);
    k5_buf_add_uint32_le(&buf, cb->acceptor_addrtype);
    k5_buf_add_uint32_le(&buf, cb->acceptor_address.length);
    k5_buf_add_len(&buf, cb->acceptor_address.value,
                   cb->acceptor_address.length);
    k5_buf_add_uint32_le(&buf, cb->application_data.length);
    k5_buf_add_len(&buf, cb->application_data.value,
                   cb->application_data.length);
    code = k5_buf_status(&buf);
    if (code)
        return code;

    /* checksum the data */

    plaind = make_data(buf.data, buf.len);
    code = krb5_c_make_checksum(context, CKSUMTYPE_RSA_MD5, 0, 0,
                                &plaind, cksum);
    k5_buf_free(&buf);
    return code;
}

krb5_error_code
kg_make_checksum_iov_v1(krb5_context context,
                        krb5_cksumtype type,
                        size_t cksum_len,
                        krb5_key seq,
                        krb5_key enc,
                        krb5_keyusage sign_usage,
                        gss_iov_buffer_desc *iov,
                        int iov_count,
                        int toktype,
                        krb5_checksum *checksum)
{
    krb5_error_code code;
    gss_iov_buffer_desc *header;
    krb5_crypto_iov *kiov;
    int i = 0, j;
    size_t conf_len = 0, token_header_len;

    header = kg_locate_header_iov(iov, iov_count, toktype);
    assert(header != NULL);

    kiov = calloc(iov_count + 3, sizeof(krb5_crypto_iov));
    if (kiov == NULL)
        return ENOMEM;

    /* Checksum over ( Header | Confounder | Data | Pad ) */
    if (toktype == KG_TOK_WRAP_MSG)
        conf_len = kg_confounder_size(context, enc->keyblock.enctype);

    /* Checksum output */
    kiov[i].flags = KRB5_CRYPTO_TYPE_CHECKSUM;
    kiov[i].data.length = checksum->length;
    kiov[i].data.data = xmalloc(checksum->length);
    if (kiov[i].data.data == NULL) {
        xfree(kiov);
        return ENOMEM;
    }
    i++;

    /* Header | SND_SEQ | SGN_CKSUM | Confounder */
    token_header_len = 16 + cksum_len + conf_len;

    /* Header (calculate from end because of variable length ASN.1 header) */
    kiov[i].flags = KRB5_CRYPTO_TYPE_SIGN_ONLY;
    kiov[i].data.length = 8;
    kiov[i].data.data = (char *)header->buffer.value + header->buffer.length - token_header_len;
    i++;

    /* Confounder */
    if (toktype == KG_TOK_WRAP_MSG) {
        kiov[i].flags = KRB5_CRYPTO_TYPE_DATA;
        kiov[i].data.length = conf_len;
        kiov[i].data.data = (char *)header->buffer.value + header->buffer.length - conf_len;
        i++;
    }

    for (j = 0; j < iov_count; j++) {
        kiov[i].flags = kg_translate_flag_iov(iov[j].type);
        kiov[i].data.length = iov[j].buffer.length;
        kiov[i].data.data = (char *)iov[j].buffer.value;
        i++;
    }

    code = krb5_k_make_checksum_iov(context, type, seq, sign_usage, kiov, i);
    if (code == 0) {
        checksum->length = kiov[0].data.length;
        checksum->contents = (unsigned char *)kiov[0].data.data;
    } else
        free(kiov[0].data.data);

    xfree(kiov);

    return code;
}

static krb5_error_code
checksum_iov_v3(krb5_context context,
                krb5_cksumtype type,
                size_t rrc,
                krb5_key key,
                krb5_keyusage sign_usage,
                gss_iov_buffer_desc *iov,
                int iov_count,
                int toktype,
                krb5_boolean verify,
                krb5_boolean *valid)
{
    krb5_error_code code;
    gss_iov_buffer_desc *header;
    gss_iov_buffer_desc *trailer;
    krb5_crypto_iov *kiov;
    size_t kiov_count;
    int i = 0, j;
    unsigned int k5_checksumlen;

    if (verify)
        *valid = FALSE;

    code = krb5_c_crypto_length(context, key->keyblock.enctype, KRB5_CRYPTO_TYPE_CHECKSUM, &k5_checksumlen);
    if (code != 0)
        return code;

    header = kg_locate_header_iov(iov, iov_count, toktype);
    assert(header != NULL);

    trailer = kg_locate_iov(iov, iov_count, GSS_IOV_BUFFER_TYPE_TRAILER);
    assert(rrc != 0 || trailer != NULL);

    if (trailer == NULL) {
        if (rrc != k5_checksumlen)
            return KRB5_BAD_MSIZE;
        if (header->buffer.length != 16 + k5_checksumlen)
            return KRB5_BAD_MSIZE;
    } else if (trailer->buffer.length != k5_checksumlen)
        return KRB5_BAD_MSIZE;

    kiov_count = 2 + iov_count;
    kiov = (krb5_crypto_iov *)xmalloc(kiov_count * sizeof(krb5_crypto_iov));
    if (kiov == NULL)
        return ENOMEM;

    /* Checksum over ( Data | Header ) */

    /* Data */
    for (j = 0; j < iov_count; j++) {
        kiov[i].flags = kg_translate_flag_iov(iov[j].type);
        kiov[i].data.length = iov[j].buffer.length;
        kiov[i].data.data = (char *)iov[j].buffer.value;
        i++;
    }

    /* Header */
    kiov[i].flags = KRB5_CRYPTO_TYPE_SIGN_ONLY;
    kiov[i].data.length = 16;
    kiov[i].data.data = (char *)header->buffer.value;
    i++;

    /* Checksum */
    kiov[i].flags = KRB5_CRYPTO_TYPE_CHECKSUM;
    if (trailer == NULL) {
        kiov[i].data.length = header->buffer.length - 16;
        kiov[i].data.data = (char *)header->buffer.value + 16;
    } else {
        kiov[i].data.length = trailer->buffer.length;
        kiov[i].data.data = (char *)trailer->buffer.value;
    }
    i++;

    if (verify)
        code = krb5_k_verify_checksum_iov(context, type, key, sign_usage, kiov, kiov_count, valid);
    else
        code = krb5_k_make_checksum_iov(context, type, key, sign_usage, kiov, kiov_count);

    xfree(kiov);

    return code;
}

krb5_error_code
kg_make_checksum_iov_v3(krb5_context context,
                        krb5_cksumtype type,
                        size_t rrc,
                        krb5_key key,
                        krb5_keyusage sign_usage,
                        gss_iov_buffer_desc *iov,
                        int iov_count,
                        int toktype)
{
    return checksum_iov_v3(context, type, rrc, key,
                           sign_usage, iov, iov_count, toktype, 0, NULL);
}

krb5_error_code
kg_verify_checksum_iov_v3(krb5_context context,
                          krb5_cksumtype type,
                          size_t rrc,
                          krb5_key key,
                          krb5_keyusage sign_usage,
                          gss_iov_buffer_desc *iov,
                          int iov_count,
                          int toktype,
                          krb5_boolean *valid)
{
    return checksum_iov_v3(context, type, rrc, key,
                           sign_usage, iov, iov_count, toktype, 1, valid);
}