Add a new extensible GSS-API layer which can support GSS-API plugins,

similar the the Solaris implementation. Repackage the krb5 GSS mechanism
as a plugin library for the new implementation. This also includes a
comprehensive set of manpages for the GSS-API functions with text mostly
taken from the RFC.

Reviewed by: Love Hörnquist Åstrand <lha@it.su.se>, ru (build system), des (openssh parts)

1 files changed, 221 insertions, 0 deletions

diff --git a/lib/libgssapi/gss_accept_sec_context.c b/lib/libgssapi/gss_accept_sec_context.c
new file mode 100644
index 0000000..9bc57ca
--- /dev/null
+++ b/lib/libgssapi/gss_accept_sec_context.c
@@ -0,0 +1,221 @@
+/*-
+ * Copyright (c) 2005 Doug Rabson
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ *
+ *	$FreeBSD$
+ */
+
+#include <gssapi/gssapi.h>
+#include <stdlib.h>
+#include <errno.h>
+
+#include "mech_switch.h"
+#include "context.h"
+#include "cred.h"
+#include "name.h"
+
+OM_uint32 gss_accept_sec_context(OM_uint32 *minor_status,
+    gss_ctx_id_t *context_handle,
+    const gss_cred_id_t acceptor_cred_handle,
+    const gss_buffer_t input_token,
+    const gss_channel_bindings_t input_chan_bindings,
+    gss_name_t *src_name,
+    gss_OID *mech_type,
+    gss_buffer_t output_token,
+    OM_uint32 *ret_flags,
+    OM_uint32 *time_rec,
+    gss_cred_id_t *delegated_cred_handle)
+{
+	OM_uint32 major_status;
+	struct _gss_mech_switch *m;
+	struct _gss_context *ctx = (struct _gss_context *) *context_handle;
+	struct _gss_cred *cred = (struct _gss_cred *) acceptor_cred_handle;
+	struct _gss_mechanism_cred *mc;
+	gss_cred_id_t acceptor_mc, delegated_mc;
+	gss_name_t src_mn;
+	int allocated_ctx;
+
+	*minor_status = 0;
+	if (src_name) *src_name = 0;
+	if (mech_type) *mech_type = 0;
+	if (ret_flags) *ret_flags = 0;
+	if (time_rec) *time_rec = 0;
+	if (delegated_cred_handle) *delegated_cred_handle = 0;
+	output_token->length = 0;
+	output_token->value = 0;
+
+	/*
+	 * If this is the first call (*context_handle is NULL), we must
+	 * parse the input token to figure out the mechanism to use.
+	 */
+	if (*context_handle == GSS_C_NO_CONTEXT) {
+		unsigned char *p = input_token->value;
+		size_t len = input_token->length;
+		size_t a, b;
+		gss_OID_desc mech_oid;
+
+		/*
+		 * Token must start with [APPLICATION 0] SEQUENCE.
+		 */
+		if (len == 0 || *p != 0x60)
+			return (GSS_S_DEFECTIVE_TOKEN);
+		p++;
+		len--;
+
+		/*
+		 * Decode the length and make sure it agrees with the
+		 * token length.
+		 */
+		if (len == 0)
+			return (GSS_S_DEFECTIVE_TOKEN);
+		if ((*p & 0x80) == 0) {
+			a = *p;
+			p++;
+			len--;
+		} else {
+			b = *p & 0x7f;
+			p++;
+			len--;
+			if (len < b)
+				return (GSS_S_DEFECTIVE_TOKEN);
+			a = 0;
+			while (b) {
+				a = (a << 8) | *p;
+				p++;
+				len--;
+				b--;
+			}
+		}
+		if (a != len)
+			return (GSS_S_DEFECTIVE_TOKEN);
+
+		/*
+		 * Decode the OID for the mechanism. Simplify life by
+		 * assuming that the OID length is less than 128 bytes.
+		 */
+		if (len < 2 || *p != 0x06)
+			return (GSS_S_DEFECTIVE_TOKEN);
+		if ((p[1] & 0x80) || p[1] > (len - 2))
+			return (GSS_S_DEFECTIVE_TOKEN);
+		mech_oid.length = p[1];
+		p += 2;
+		len -= 2;
+		mech_oid.elements = p;
+
+		/*
+		 * Now that we have a mechanism, we can find the
+		 * implementation.
+		 */
+		ctx = malloc(sizeof(struct _gss_context));
+		if (!ctx) {
+			*minor_status = ENOMEM;
+			return (GSS_S_DEFECTIVE_TOKEN);
+		}
+		memset(ctx, 0, sizeof(struct _gss_context));
+		m = ctx->gc_mech = _gss_find_mech_switch(&mech_oid);
+		if (!m) {
+			free(ctx);
+			return (GSS_S_BAD_MECH);
+		}
+		allocated_ctx = 1;
+	} else {
+		m = ctx->gc_mech;
+		allocated_ctx = 0;
+	}
+
+	if (cred) {
+		SLIST_FOREACH(mc, &cred->gc_mc, gmc_link)
+			if (mc->gmc_mech == m)
+				break;
+		if (!mc)
+			return (GSS_S_BAD_MECH);
+		acceptor_mc = mc->gmc_cred;
+	} else {
+		acceptor_mc = GSS_C_NO_CREDENTIAL;
+	}
+	delegated_mc = GSS_C_NO_CREDENTIAL;
+	
+	major_status = m->gm_accept_sec_context(minor_status,
+	    &ctx->gc_ctx,
+	    acceptor_mc,
+	    input_token,
+	    input_chan_bindings,
+	    &src_mn,
+	    mech_type,
+	    output_token,
+	    ret_flags,
+	    time_rec,
+	    &delegated_mc);
+	if (major_status != GSS_S_COMPLETE &&
+	    major_status != GSS_S_CONTINUE_NEEDED)
+		return (major_status);
+
+	if (!src_name) {
+		m->gm_release_name(minor_status, &src_mn);
+	} else {
+		/*
+		 * Make a new name and mark it as an MN.
+		 */
+		struct _gss_name *name = _gss_make_name(m, src_mn);
+
+		if (!name) {
+			m->gm_release_name(minor_status, &src_mn);
+			return (GSS_S_FAILURE);
+		}
+		*src_name = (gss_name_t) name;
+	}
+
+	if (*ret_flags & GSS_C_DELEG_FLAG) {
+		if (!delegated_cred_handle) {
+			m->gm_release_cred(minor_status, &delegated_mc);
+			*ret_flags &= ~GSS_C_DELEG_FLAG;
+		} else {
+			struct _gss_cred *cred;
+			struct _gss_mechanism_cred *mc;
+
+			cred = malloc(sizeof(struct _gss_cred));
+			if (!cred) {
+				*minor_status = ENOMEM;
+				return (GSS_S_FAILURE);
+			}
+			mc = malloc(sizeof(struct _gss_mechanism_cred));
+			if (!mc) {
+				free(cred);
+				*minor_status = ENOMEM;
+				return (GSS_S_FAILURE);
+			}
+			m->gm_inquire_cred(minor_status, delegated_mc,
+			    0, 0, &cred->gc_usage, 0);
+			mc->gmc_mech = m;
+			mc->gmc_mech_oid = &m->gm_mech_oid;
+			mc->gmc_cred = delegated_mc;
+			SLIST_INSERT_HEAD(&cred->gc_mc, mc, gmc_link);
+
+			*delegated_cred_handle = (gss_cred_id_t) cred;
+		}
+	}
+
+	*context_handle = (gss_ctx_id_t) ctx;
+	return (major_status);
+}