* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
+/*
+ * Copyright 2008 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.
+ */
#include "gssapiP_eap.h"
+/*
+ * Caller must provide TOKEN | DATA | PADDING | TRAILER, except
+ * for DCE in which case it can just provide TOKEN | DATA (must
+ * guarantee that DATA is padded)
+ */
+OM_uint32
+unwrapToken(OM_uint32 *minor,
+ gss_ctx_id_t ctx,
+ int *conf_state,
+ gss_qop_t *qop_state,
+ gss_iov_buffer_desc *iov,
+ int iov_count,
+ enum gss_eap_token_type toktype)
+{
+ OM_uint32 code;
+ gss_iov_buffer_t header;
+ gss_iov_buffer_t padding;
+ gss_iov_buffer_t trailer;
+ unsigned char acceptor_flag;
+ unsigned char *ptr = NULL;
+ int key_usage;
+ size_t rrc, ec;
+ size_t data_length, assoc_data_length;
+ uint64_t seqnum;
+ int valid = 0;
+ krb5_cksumtype cksumtype;
+ int conf_flag = 0;
+
+ *minor = 0;
+
+ if (qop_state != NULL)
+ *qop_state = GSS_C_QOP_DEFAULT;
+
+ header = gssEapLocateIov(iov, iov_count, GSS_IOV_BUFFER_TYPE_HEADER);
+ assert(header != NULL);
+
+ padding = gssEapLocateIov(iov, iov_count, GSS_IOV_BUFFER_TYPE_PADDING);
+ if (padding != NULL && padding->buffer.length != 0)
+ return GSS_S_DEFECTIVE_TOKEN;
+
+ trailer = gssEapLocateIov(iov, iov_count, GSS_IOV_BUFFER_TYPE_TRAILER);
+
+ acceptor_flag = CTX_IS_INITIATOR(ctx) ? TOK_FLAG_SENDER_IS_ACCEPTOR : 0;
+ key_usage = (toktype == TOK_TYPE_WRAP
+ ? (!CTX_IS_INITIATOR(ctx)
+ ? KEY_USAGE_INITIATOR_SEAL
+ : KEY_USAGE_ACCEPTOR_SEAL)
+ : (!CTX_IS_INITIATOR(ctx)
+ ? KEY_USAGE_INITIATOR_SIGN
+ : KEY_USAGE_ACCEPTOR_SIGN));
+
+ gssEapIovMessageLength(iov, iov_count, &data_length, &assoc_data_length);
+
+ ptr = (unsigned char *)header->buffer.value;
+
+ if (header->buffer.length < 16) {
+ *minor = 0;
+ return GSS_S_DEFECTIVE_TOKEN;
+ }
+
+ if ((ptr[2] & TOK_FLAG_SENDER_IS_ACCEPTOR) != acceptor_flag) {
+ return GSS_S_BAD_SIG;
+ }
+
+ if (ptr[2] & TOK_FLAG_ACCEPTOR_SUBKEY) {
+ return GSS_S_BAD_SIG;
+ }
+
+ if (toktype == TOK_TYPE_WRAP) {
+ unsigned int k5_trailerlen;
+
+ if (load_uint16_be(ptr) != TOK_TYPE_WRAP)
+ goto defective;
+ conf_flag = ((ptr[2] & TOK_FLAG_WRAP_CONFIDENTIAL) != 0);
+ if (ptr[3] != 0xFF)
+ goto defective;
+ ec = load_uint16_be(ptr + 4);
+ rrc = load_uint16_be(ptr + 6);
+ seqnum = load_uint64_be(ptr + 8);
+
+ code = krb5_c_crypto_length(ctx->kerberosCtx,
+ KRB_KEYTYPE(ctx->encryptionKey),
+ conf_flag ? KRB5_CRYPTO_TYPE_TRAILER :
+ KRB5_CRYPTO_TYPE_CHECKSUM,
+ &k5_trailerlen);
+ if (code != 0) {
+ *minor = code;
+ return GSS_S_FAILURE;
+ }
+
+ /* Deal with RRC */
+ if (trailer == NULL) {
+ size_t desired_rrc = k5_trailerlen;
+
+ if (conf_flag) {
+ desired_rrc += 16; /* E(Header) */
+
+ if ((ctx->gssFlags & GSS_C_DCE_STYLE) == 0)
+ desired_rrc += ec;
+ }
+
+ /* According to MS, we only need to deal with a fixed RRC for DCE */
+ if (rrc != desired_rrc)
+ goto defective;
+ } else if (rrc != 0) {
+ goto defective;
+ }
+
+ if (conf_flag) {
+ unsigned char *althdr;
+
+ /* Decrypt */
+ code = gssEapDecrypt(ctx->kerberosCtx,
+ ((ctx->gssFlags & GSS_C_DCE_STYLE) != 0),
+ ec, rrc, ctx->encryptionKey,
+ key_usage, 0, iov, iov_count);
+ if (code != 0) {
+ *minor = code;
+ return GSS_S_BAD_SIG;
+ }
+
+ /* Validate header integrity */
+ if (trailer == NULL)
+ althdr = (unsigned char *)header->buffer.value + 16 + ec;
+ else
+ althdr = (unsigned char *)trailer->buffer.value + ec;
+
+ if (load_uint16_be(althdr) != TOK_TYPE_WRAP
+ || althdr[2] != ptr[2]
+ || althdr[3] != ptr[3]
+ || memcmp(althdr + 8, ptr + 8, 8) != 0) {
+ *minor = 0;
+ return GSS_S_BAD_SIG;
+ }
+ } else {
+ /* Verify checksum: note EC is checksum size here, not padding */
+ if (ec != k5_trailerlen)
+ goto defective;
+
+ /* Zero EC, RRC before computing checksum */
+ store_uint16_be(0, ptr + 4);
+ store_uint16_be(0, ptr + 6);
+
+ code = gssEapVerify(ctx->kerberosCtx, cksumtype, rrc,
+ ctx->encryptionKey, key_usage,
+ iov, iov_count, &valid);
+ if (code != 0 || valid == FALSE) {
+ *minor = code;
+ return GSS_S_BAD_SIG;
+ }
+ }
+
+ code = sequenceCheck(&ctx->seqState, seqnum);
+ } else if (toktype == TOK_TYPE_MIC) {
+ if (load_uint16_be(ptr) != TOK_TYPE_MIC)
+ goto defective;
+
+ verify_mic_1:
+ if (ptr[3] != 0xFF)
+ goto defective;
+ seqnum = load_uint64_be(ptr + 8);
+
+ code = gssEapVerify(ctx->kerberosCtx, cksumtype, 0,
+ ctx->encryptionKey, key_usage,
+ iov, iov_count, &valid);
+ if (code != 0 || valid == FALSE) {
+ *minor = code;
+ return GSS_S_BAD_SIG;
+ }
+ code = sequenceCheck(&ctx->seqState, seqnum);
+ } else if (toktype == TOK_TYPE_DELETE) {
+ if (load_uint16_be(ptr) != TOK_TYPE_DELETE)
+ goto defective;
+ goto verify_mic_1;
+ } else {
+ goto defective;
+ }
+
+ *minor = 0;
+
+ if (conf_state != NULL)
+ *conf_state = conf_flag;
+
+ return code;
+
+defective:
+ *minor = 0;
+
+ return GSS_S_DEFECTIVE_TOKEN;
+}
+
+int
+rotateLeft(void *ptr, size_t bufsiz, size_t rc)
+{
+ void *tbuf;
+
+ if (bufsiz == 0)
+ return 0;
+ rc = rc % bufsiz;
+ if (rc == 0)
+ return 0;
+
+ tbuf = GSSEAP_MALLOC(rc);
+ if (tbuf == NULL)
+ return ENOMEM;
+
+ memcpy(tbuf, ptr, rc);
+ memmove(ptr, (char *)ptr + rc, bufsiz - rc);
+ memcpy((char *)ptr + bufsiz - rc, tbuf, rc);
+ GSSEAP_FREE(tbuf);
+
+ return 0;
+}
+
+/*
+ * Split a STREAM | SIGN_DATA | DATA into
+ * HEADER | SIGN_DATA | DATA | PADDING | TRAILER
+ */
+static OM_uint32
+unwrapStream(OM_uint32 *minor,
+ gss_ctx_id_t ctx,
+ int *conf_state,
+ gss_qop_t *qop_state,
+ gss_iov_buffer_desc *iov,
+ int iov_count,
+ enum gss_eap_token_type toktype)
+{
+ unsigned char *ptr;
+ OM_uint32 code = 0, major = GSS_S_FAILURE;
+ krb5_context context = ctx->kerberosCtx;
+ int conf_req_flag, toktype2;
+ int i = 0, j;
+ gss_iov_buffer_desc *tiov = NULL;
+ gss_iov_buffer_t stream, data = NULL;
+ gss_iov_buffer_t theader, tdata = NULL, tpadding, ttrailer;
+
+ assert(toktype == TOK_TYPE_WRAP);
+
+ if (toktype != TOK_TYPE_WRAP || (ctx->gssFlags & GSS_C_DCE_STYLE)) {
+ code = EINVAL;
+ goto cleanup;
+ }
+
+ stream = gssEapLocateIov(iov, iov_count, GSS_IOV_BUFFER_TYPE_STREAM);
+ assert(stream != NULL);
+
+ if (stream->buffer.length < 16) {
+ major = GSS_S_DEFECTIVE_TOKEN;
+ goto cleanup;
+ }
+
+ ptr = (unsigned char *)stream->buffer.value;
+ toktype2 = load_uint16_be(ptr);
+ ptr += 2;
+
+ tiov = (gss_iov_buffer_desc *)GSSEAP_CALLOC((size_t)iov_count + 2,
+ sizeof(gss_iov_buffer_desc));
+ if (tiov == NULL) {
+ code = ENOMEM;
+ goto cleanup;
+ }
+
+ /* HEADER */
+ theader = &tiov[i++];
+ theader->type = GSS_IOV_BUFFER_TYPE_HEADER;
+ theader->buffer.value = stream->buffer.value;
+ theader->buffer.length = 16;
+
+ /* n[SIGN_DATA] | DATA | m[SIGN_DATA] */
+ for (j = 0; j < iov_count; j++) {
+ OM_uint32 type = GSS_IOV_BUFFER_TYPE(iov[j].type);
+
+ if (type == GSS_IOV_BUFFER_TYPE_DATA) {
+ if (data != NULL) {
+ /* only a single DATA buffer can appear */
+ code = EINVAL;
+ goto cleanup;
+ }
+
+ data = &iov[j];
+ tdata = &tiov[i];
+ }
+ if (type == GSS_IOV_BUFFER_TYPE_DATA ||
+ type == GSS_IOV_BUFFER_TYPE_SIGN_ONLY)
+ tiov[i++] = iov[j];
+ }
+
+ if (data == NULL) {
+ /* a single DATA buffer must be present */
+ code = EINVAL;
+ goto cleanup;
+ }
+
+ /* PADDING | TRAILER */
+ tpadding = &tiov[i++];
+ tpadding->type = GSS_IOV_BUFFER_TYPE_PADDING;
+ tpadding->buffer.length = 0;
+ tpadding->buffer.value = NULL;
+
+ ttrailer = &tiov[i++];
+ ttrailer->type = GSS_IOV_BUFFER_TYPE_TRAILER;
+
+ {
+ size_t ec, rrc;
+ unsigned int k5_headerlen = 0;
+ unsigned int k5_trailerlen = 0;
+
+ conf_req_flag = ((ptr[0] & TOK_FLAG_WRAP_CONFIDENTIAL) != 0);
+ ec = conf_req_flag ? load_uint16_be(ptr + 2) : 0;
+ rrc = load_uint16_be(ptr + 4);
+
+ if (rrc != 0) {
+ code = rotateLeft((unsigned char *)stream->buffer.value + 16,
+ stream->buffer.length - 16, rrc);
+ if (code != 0)
+ goto cleanup;
+ store_uint16_be(0, ptr + 4); /* set RRC to zero */
+ }
+
+ if (conf_req_flag) {
+ code = krb5_c_crypto_length(context, ctx->encryptionType,
+ KRB5_CRYPTO_TYPE_HEADER, &k5_headerlen);
+ if (code != 0)
+ goto cleanup;
+ theader->buffer.length += k5_headerlen; /* length validated later */
+ }
+
+ /* no PADDING for CFX, EC is used instead */
+ code = krb5_c_crypto_length(context, ctx->encryptionType,
+ conf_req_flag
+ ? KRB5_CRYPTO_TYPE_TRAILER
+ : KRB5_CRYPTO_TYPE_CHECKSUM,
+ &k5_trailerlen);
+ if (code != 0)
+ goto cleanup;
+
+ ttrailer->buffer.length = ec + (conf_req_flag ? 16 : 0 /* E(Header) */) +
+ k5_trailerlen;
+ ttrailer->buffer.value = (unsigned char *)stream->buffer.value +
+ stream->buffer.length - ttrailer->buffer.length;
+ }
+
+ /* IOV: -----------0-------------+---1---+--2--+----------------3--------------*/
+ /* Old: GSS-Header | Conf | Data | Pad | */
+ /* CFX: GSS-Header | Kerb-Header | Data | | EC | E(Header) | Kerb-Trailer */
+ /* GSS: -------GSS-HEADER--------+-DATA--+-PAD-+----------GSS-TRAILER----------*/
+
+ /* validate lengths */
+ if (stream->buffer.length < theader->buffer.length +
+ tpadding->buffer.length +
+ ttrailer->buffer.length) {
+ code = KRB5_BAD_MSIZE;
+ major = GSS_S_DEFECTIVE_TOKEN;
+ goto cleanup;
+ }
+
+ /* setup data */
+ tdata->buffer.length = stream->buffer.length - ttrailer->buffer.length -
+ tpadding->buffer.length - theader->buffer.length;
+
+ assert(data != NULL);
+
+ if (data->type & GSS_IOV_BUFFER_FLAG_ALLOCATE) {
+ code = gssEapAllocIov(tdata, tdata->buffer.length);
+ if (code != 0)
+ goto cleanup;
+
+ memcpy(tdata->buffer.value,
+ (unsigned char *)stream->buffer.value + theader->buffer.length,
+ tdata->buffer.length);
+ } else {
+ tdata->buffer.value = (unsigned char *)stream->buffer.value +
+ theader->buffer.length;
+ }
+
+ assert(i <= iov_count + 2);
+
+ major = unwrapToken(&code, ctx, conf_state, qop_state,
+ tiov, i, toktype);
+ if (major == GSS_S_COMPLETE) {
+ *data = *tdata;
+ } else if (tdata->type & GSS_IOV_BUFFER_FLAG_ALLOCATED) {
+ OM_uint32 tmp;
+
+ gss_release_buffer(&tmp, &tdata->buffer);
+ tdata->type &= ~(GSS_IOV_BUFFER_FLAG_ALLOCATED);
+ }
+
+cleanup:
+ if (tiov != NULL)
+ GSSEAP_FREE(tiov);
+
+ *minor = code;
+
+ return major;
+}
+
+OM_uint32
+gssEapUnwrapOrVerifyMIC(OM_uint32 *minor,
+ gss_ctx_id_t ctx,
+ int *conf_state,
+ gss_qop_t *qop_state,
+ gss_iov_buffer_desc *iov,
+ int iov_count,
+ enum gss_eap_token_type toktype)
+{
+ OM_uint32 major;
+
+ if (!CTX_IS_ESTABLISHED(ctx))
+ return GSS_S_NO_CONTEXT;
+
+ if (gssEapLocateIov(iov, iov_count, GSS_IOV_BUFFER_TYPE_STREAM) != NULL) {
+ major = unwrapStream(minor, ctx, conf_state, qop_state,
+ iov, iov_count, toktype);
+ } else {
+ major = unwrapToken(minor, ctx, conf_state, qop_state,
+ iov, iov_count, toktype);
+ }
+
+ return major;
+}
+
+OM_uint32
+gss_unwrap_iov(OM_uint32 *minor,
+ gss_ctx_id_t ctx,
+ int *conf_state,
+ gss_qop_t *qop_state,
+ gss_iov_buffer_desc *iov,
+ int iov_count)
+{
+ return gssEapUnwrapOrVerifyMIC(minor, ctx, conf_state, qop_state,
+ iov, iov_count, TOK_TYPE_WRAP);
+}
projects / mech_eap.orig / blobdiff