#include "buffer.h"
#include "log.h"
#include "ssh2.h"
+#include "cipher.h"
+#include "key.h"
+#include "kex.h"
+#include <openssl/evp.h>
#include "ssh-gss.h"
extern u_char *session_id2;
extern u_int session_id2_len;
+typedef struct {
+ char *encoded;
+ gss_OID oid;
+} ssh_gss_kex_mapping;
+
+/*
+ * XXX - It would be nice to find a more elegant way of handling the
+ * XXX passing of the key exchange context to the userauth routines
+ */
+
+Gssctxt *gss_kex_context = NULL;
+
+static ssh_gss_kex_mapping *gss_enc2oid = NULL;
+
+int
+ssh_gssapi_oid_table_ok() {
+ return (gss_enc2oid != NULL);
+}
+
+/*
+ * Return a list of the gss-group1-sha1 mechanisms supported by this program
+ *
+ * We test mechanisms to ensure that we can use them, to avoid starting
+ * a key exchange with a bad mechanism
+ */
+
+char *
+ssh_gssapi_client_mechanisms(const char *host) {
+ gss_OID_set gss_supported;
+ OM_uint32 min_status;
+
+ gss_indicate_mechs(&min_status, &gss_supported);
+
+ return(ssh_gssapi_kex_mechs(gss_supported, ssh_gssapi_check_mechanism,
+ host));
+}
+
+char *
+ssh_gssapi_kex_mechs(gss_OID_set gss_supported, ssh_gssapi_check_fn *check,
+ const char *data) {
+ Buffer buf;
+ size_t i;
+ int oidpos, enclen;
+ char *mechs, *encoded;
+ u_char digest[EVP_MAX_MD_SIZE];
+ char deroid[2];
+ const EVP_MD *evp_md = EVP_md5();
+ EVP_MD_CTX md;
+
+ if (gss_enc2oid != NULL) {
+ for (i = 0; gss_enc2oid[i].encoded != NULL; i++)
+ xfree(gss_enc2oid[i].encoded);
+ xfree(gss_enc2oid);
+ }
+
+ gss_enc2oid = xmalloc(sizeof(ssh_gss_kex_mapping)*
+ (gss_supported->count + 1));
+
+ buffer_init(&buf);
+
+ oidpos = 0;
+ for (i = 0; i < gss_supported->count; i++) {
+ if (gss_supported->elements[i].length < 128 &&
+ (*check)(NULL, &(gss_supported->elements[i]), data)) {
+ deroid[0] = SSH_GSS_OIDTYPE;
+ deroid[1] = gss_supported->elements[i].length;
+
+ EVP_DigestInit(&md, evp_md);
+ EVP_DigestUpdate(&md, deroid, 2);
+ EVP_DigestUpdate(&md,
+ gss_supported->elements[i].elements,
+ gss_supported->elements[i].length);
+ EVP_DigestFinal(&md, digest, NULL);
+
+ encoded = xmalloc(EVP_MD_size(evp_md) * 2);
+ enclen = __b64_ntop(digest, EVP_MD_size(evp_md),
+ encoded, EVP_MD_size(evp_md) * 2);
+
+ if (oidpos != 0)
+ buffer_put_char(&buf, ',');
+
+ buffer_append(&buf, KEX_GSS_GEX_SHA1_ID,
+ sizeof(KEX_GSS_GEX_SHA1_ID) - 1);
+ buffer_append(&buf, encoded, enclen);
+ buffer_put_char(&buf, ',');
+ buffer_append(&buf, KEX_GSS_GRP1_SHA1_ID,
+ sizeof(KEX_GSS_GRP1_SHA1_ID) - 1);
+ buffer_append(&buf, encoded, enclen);
+ buffer_put_char(&buf, ',');
+ buffer_append(&buf, KEX_GSS_GRP14_SHA1_ID,
+ sizeof(KEX_GSS_GRP14_SHA1_ID) - 1);
+ buffer_append(&buf, encoded, enclen);
+
+ gss_enc2oid[oidpos].oid = &(gss_supported->elements[i]);
+ gss_enc2oid[oidpos].encoded = encoded;
+ oidpos++;
+ }
+ }
+ gss_enc2oid[oidpos].oid = NULL;
+ gss_enc2oid[oidpos].encoded = NULL;
+
+ buffer_put_char(&buf, '\0');
+
+ mechs = xmalloc(buffer_len(&buf));
+ buffer_get(&buf, mechs, buffer_len(&buf));
+ buffer_free(&buf);
+
+ if (strlen(mechs) == 0) {
+ xfree(mechs);
+ mechs = NULL;
+ }
+
+ return (mechs);
+}
+
+gss_OID
+ssh_gssapi_id_kex(Gssctxt *ctx, char *name, int kex_type) {
+ int i = 0;
+
+ switch (kex_type) {
+ case KEX_GSS_GRP1_SHA1:
+ name += sizeof(KEX_GSS_GRP1_SHA1_ID) - 1;
+ break;
+ case KEX_GSS_GRP14_SHA1:
+ name += sizeof(KEX_GSS_GRP14_SHA1_ID) - 1;
+ break;
+ case KEX_GSS_GEX_SHA1:
+ name += sizeof(KEX_GSS_GEX_SHA1_ID) - 1;
+ break;
+ default:
+ return GSS_C_NO_OID;
+ }
+
+ while (gss_enc2oid[i].encoded != NULL &&
+ strcmp(name, gss_enc2oid[i].encoded) != 0)
+ i++;
+
+ if (gss_enc2oid[i].oid != NULL && ctx != NULL)
+ ssh_gssapi_set_oid(ctx, gss_enc2oid[i].oid);
+
+ return gss_enc2oid[i].oid;
+}
+
/* Check that the OID in a data stream matches that in the context */
int
ssh_gssapi_check_oid(Gssctxt *ctx, void *data, size_t len)
/* The GSSAPI error */
do {
gss_display_status(&lmin, ctxt->major,
- GSS_C_GSS_CODE, GSS_C_NULL_OID, &ctx, &msg);
+ GSS_C_GSS_CODE, ctxt->oid, &ctx, &msg);
buffer_append(&b, msg.value, msg.length);
buffer_put_char(&b, '\n');
/* The mechanism specific error */
do {
gss_display_status(&lmin, ctxt->minor,
- GSS_C_MECH_CODE, GSS_C_NULL_OID, &ctx, &msg);
+ GSS_C_MECH_CODE, ctxt->oid, &ctx, &msg);
buffer_append(&b, msg.value, msg.length);
buffer_put_char(&b, '\n');
return (ctx->major);
}
-/* Acquire credentials for a server running on the current host.
- * Requires that the context structure contains a valid OID
- */
-
-/* Returns a GSSAPI error code */
OM_uint32
-ssh_gssapi_acquire_cred(Gssctxt *ctx)
+ssh_gssapi_sign(Gssctxt *ctx, gss_buffer_t buffer, gss_buffer_t hash)
{
- OM_uint32 status;
- char lname[MAXHOSTNAMELEN];
- gss_OID_set oidset;
-
- gss_create_empty_oid_set(&status, &oidset);
- gss_add_oid_set_member(&status, ctx->oid, &oidset);
-
- if (gethostname(lname, MAXHOSTNAMELEN)) {
- gss_release_oid_set(&status, &oidset);
- return (-1);
- }
+ if (ctx == NULL)
+ return -1;
- if (GSS_ERROR(ssh_gssapi_import_name(ctx, lname))) {
- gss_release_oid_set(&status, &oidset);
- return (ctx->major);
- }
-
- if ((ctx->major = gss_acquire_cred(&ctx->minor,
- ctx->name, 0, oidset, GSS_C_ACCEPT, &ctx->creds, NULL, NULL)))
+ if ((ctx->major = gss_get_mic(&ctx->minor, ctx->context,
+ GSS_C_QOP_DEFAULT, buffer, hash)))
ssh_gssapi_error(ctx);
- gss_release_oid_set(&status, &oidset);
return (ctx->major);
}
+/* Priviledged when used by server */
OM_uint32
-ssh_gssapi_sign(Gssctxt *ctx, gss_buffer_t buffer, gss_buffer_t hash)
+ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic)
{
- if ((ctx->major = gss_get_mic(&ctx->minor, ctx->context,
- GSS_C_QOP_DEFAULT, buffer, hash)))
- ssh_gssapi_error(ctx);
+ if (ctx == NULL)
+ return -1;
+
+ ctx->major = gss_verify_mic(&ctx->minor, ctx->context,
+ gssbuf, gssmic, NULL);
return (ctx->major);
}
buffer_put_cstring(b, context);
}
-OM_uint32
-ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID oid)
-{
- if (*ctx)
- ssh_gssapi_delete_ctx(ctx);
- ssh_gssapi_build_ctx(ctx);
- ssh_gssapi_set_oid(*ctx, oid);
- return (ssh_gssapi_acquire_cred(*ctx));
-}
-
int
ssh_gssapi_check_mechanism(Gssctxt **ctx, gss_OID oid, const char *host)
{
gss_buffer_desc token = GSS_C_EMPTY_BUFFER;
OM_uint32 major, minor;
gss_OID_desc spnego_oid = {6, (void *)"\x2B\x06\x01\x05\x05\x02"};
+ Gssctxt *intctx = NULL;
+
+ if (ctx == NULL)
+ ctx = &intctx;
/* RFC 4462 says we MUST NOT do SPNEGO */
if (oid->length == spnego_oid.length &&
GSS_C_NO_BUFFER);
}
- if (GSS_ERROR(major))
+ if (GSS_ERROR(major) || intctx != NULL)
ssh_gssapi_delete_ctx(ctx);
return (!GSS_ERROR(major));
andersk / gssapi-openssh.git / blobdiff