Add tests for invalid GSSAPI per-message tokens

ticket: 7949

5 files changed, 459 insertions, 7 deletions

diff --git a/.gitignore b/.gitignore
index 12aa58e0d..96cf3c357 100644
--- a/.gitignore
+++ b/.gitignore
@@ -293,6 +293,7 @@ testlog
 /src/tests/gssapi/t_gssexts
 /src/tests/gssapi/t_imp_cred
 /src/tests/gssapi/t_imp_name
+/src/tests/gssapi/t_invalid
 /src/tests/gssapi/t_inq_cred
 /src/tests/gssapi/t_inq_mechs_name
 /src/tests/gssapi/t_namingexts
diff --git a/src/lib/gssapi/libgssapi_krb5.exports b/src/lib/gssapi/libgssapi_krb5.exports
index 4929c7101..93c7791a0 100644
--- a/src/lib/gssapi/libgssapi_krb5.exports
+++ b/src/lib/gssapi/libgssapi_krb5.exports
@@ -157,3 +157,4 @@ gss_inquire_name
 gss_acquire_cred_from
 gss_add_cred_from
 gss_store_cred_into
+gssint_g_seqstate_init
diff --git a/src/tests/gssapi/Makefile.in b/src/tests/gssapi/Makefile.in
index ac6a43584..5effd907e 100644
--- a/src/tests/gssapi/Makefile.in
+++ b/src/tests/gssapi/Makefile.in
@@ -12,27 +12,28 @@ SRCS=	$(srcdir)/ccinit.c $(srcdir)/ccrefresh.c $(srcdir)/common.c \
 	$(srcdir)/t_accname.c $(srcdir)/t_ccselect.c $(srcdir)/t_credstore.c \
 	$(srcdir)/t_enctypes.c $(srcdir)/t_err.c $(srcdir)/t_export_cred.c \
 	$(srcdir)/t_export_name.c $(srcdir)/t_gssexts.c \
-	$(srcdir)/t_imp_cred.c $(srcdir)/t_imp_name.c $(srcdir)/t_inq_cred.c \
-	$(srcdir)/t_inq_mechs_name.c $(srcdir)/t_iov.c \
+	$(srcdir)/t_imp_cred.c $(srcdir)/t_imp_name.c $(srcdir)/t_invalid.c \
+	$(srcdir)/t_inq_cred.c $(srcdir)/t_inq_mechs_name.c $(srcdir)/t_iov.c \
 	$(srcdir)/t_namingexts.c $(srcdir)/t_oid.c $(srcdir)/t_prf.c \
 	$(srcdir)/t_s4u.c $(srcdir)/t_s4u2proxy_krb5.c $(srcdir)/t_saslname.c \
 	$(srcdir)/t_spnego.c
 
 OBJS=	ccinit.o ccrefresh.o common.o t_accname.o t_ccselect.o t_credstore.o \
 	t_enctypes.o t_err.o t_export_cred.o t_export_name.o t_gssexts.o \
-	t_imp_cred.o t_imp_name.o t_inq_cred.o t_inq_mechs_name.o t_iov.o \
-	t_namingexts.o t_oid.o t_prf.o t_s4u.o t_s4u2proxy_krb5.o \
+	t_imp_cred.o t_imp_name.o t_invalid.o t_inq_cred.o t_inq_mechs_name.o \
+	t_iov.o t_namingexts.o t_oid.o t_prf.o t_s4u.o t_s4u2proxy_krb5.o \
 	t_saslname.o t_spnego.o
 
 COMMON_DEPS= common.o $(GSS_DEPLIBS) $(KRB5_BASE_DEPLIBS)
 COMMON_LIBS= common.o $(GSS_LIBS) $(KRB5_BASE_LIBS)
 
 all:: ccinit ccrefresh t_accname t_ccselect t_credstore t_enctypes t_err \
-	t_export_cred t_export_name t_gssexts t_imp_cred t_imp_name \
+	t_export_cred t_export_name t_gssexts t_imp_cred t_imp_name t_invalid \
 	t_inq_cred t_inq_mechs_name t_iov t_namingexts t_oid t_prf t_s4u \
 	t_s4u2proxy_krb5 t_saslname t_spnego
 
 check-unix:: t_oid
+	$(RUN_SETUP) $(VALGRIND) ./t_invalid
 	$(RUN_SETUP) $(VALGRIND) ./t_oid
 	$(RUN_SETUP) $(VALGRIND) ./t_prf
 
@@ -70,6 +71,8 @@ t_imp_cred: t_imp_cred.o $(COMMON_DEPS)
 	$(CC_LINK) -o $@ t_imp_cred.o $(COMMON_LIBS)
 t_imp_name: t_imp_name.o $(COMMON_DEPS)
 	$(CC_LINK) -o $@ t_imp_name.o $(COMMON_LIBS)
+t_invalid: t_invalid.o $(COMMON_DEPS)
+	$(CC_LINK) -o $@ t_invalid.o $(COMMON_LIBS)
 t_inq_cred: t_inq_cred.o $(COMMON_DEPS)
 	$(CC_LINK) -o $@ t_inq_cred.o $(COMMON_LIBS)
 t_inq_mechs_name: t_inq_mechs_name.o $(COMMON_DEPS)
@@ -94,5 +97,5 @@ t_spnego: t_spnego.o $(COMMON_DEPS)
 clean::
 	$(RM) ccinit ccrefresh t_accname t_ccselect t_credstore t_enctypes
 	$(RM) t_err t_export_cred t_export_name t_gssexts t_imp_cred t_imp_name
-	$(RM) t_inq_cred t_inq_mechs_name t_iov t_namingexts t_oid t_prf t_s4u
-	$(RM) t_s4u2proxy_krb5 t_saslname t_spnego
+	$(RM) t_invalid t_inq_cred t_inq_mechs_name t_iov t_namingexts t_oid
+	$(RM) t_prf t_s4u t_s4u2proxy_krb5 t_saslname t_spnego
diff --git a/src/tests/gssapi/deps b/src/tests/gssapi/deps
index c76d4ca1a..0a82d5d61 100644
--- a/src/tests/gssapi/deps
+++ b/src/tests/gssapi/deps
@@ -75,6 +75,24 @@ $(OUTPRE)t_imp_name.$(OBJEXT): $(BUILDTOP)/include/gssapi/gssapi.h \
   $(BUILDTOP)/include/gssapi/gssapi_ext.h $(BUILDTOP)/include/gssapi/gssapi_krb5.h \
   $(BUILDTOP)/include/krb5/krb5.h $(COM_ERR_DEPS) $(top_srcdir)/include/krb5.h \
   common.h t_imp_name.c
+$(OUTPRE)t_invalid.$(OBJEXT): $(BUILDTOP)/include/autoconf.h \
+  $(BUILDTOP)/include/gssapi/gssapi.h $(BUILDTOP)/include/gssapi/gssapi_alloc.h \
+  $(BUILDTOP)/include/gssapi/gssapi_ext.h $(BUILDTOP)/include/gssapi/gssapi_krb5.h \
+  $(BUILDTOP)/include/krb5/krb5.h $(BUILDTOP)/include/osconf.h \
+  $(BUILDTOP)/include/profile.h $(BUILDTOP)/lib/gssapi/generic/gssapi_err_generic.h \
+  $(BUILDTOP)/lib/gssapi/krb5/gssapi_err_krb5.h $(COM_ERR_DEPS) \
+  $(srcdir)/../../lib/gssapi/generic/gssapiP_generic.h \
+  $(srcdir)/../../lib/gssapi/generic/gssapi_ext.h $(srcdir)/../../lib/gssapi/generic/gssapi_generic.h \
+  $(srcdir)/../../lib/gssapi/krb5/gssapiP_krb5.h $(srcdir)/../../lib/gssapi/krb5/gssapi_krb5.h \
+  $(srcdir)/../../lib/gssapi/mechglue/mechglue.h $(srcdir)/../../lib/gssapi/mechglue/mglueP.h \
+  $(top_srcdir)/include/k5-buf.h $(top_srcdir)/include/k5-err.h \
+  $(top_srcdir)/include/k5-gmt_mktime.h $(top_srcdir)/include/k5-int-pkinit.h \
+  $(top_srcdir)/include/k5-int.h $(top_srcdir)/include/k5-platform.h \
+  $(top_srcdir)/include/k5-plugin.h $(top_srcdir)/include/k5-thread.h \
+  $(top_srcdir)/include/k5-trace.h $(top_srcdir)/include/krb5.h \
+  $(top_srcdir)/include/krb5/authdata_plugin.h $(top_srcdir)/include/krb5/plugin.h \
+  $(top_srcdir)/include/port-sockets.h $(top_srcdir)/include/socket-utils.h \
+  common.h t_invalid.c
 $(OUTPRE)t_inq_cred.$(OBJEXT): $(BUILDTOP)/include/gssapi/gssapi.h \
   $(BUILDTOP)/include/gssapi/gssapi_ext.h $(BUILDTOP)/include/gssapi/gssapi_krb5.h \
   $(BUILDTOP)/include/krb5/krb5.h $(COM_ERR_DEPS) $(top_srcdir)/include/krb5.h \
diff --git a/src/tests/gssapi/t_invalid.c b/src/tests/gssapi/t_invalid.c
new file mode 100644
index 000000000..5c8ddac8d
--- /dev/null
+++ b/src/tests/gssapi/t_invalid.c
@@ -0,0 +1,429 @@
+/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
+/* tests/gssapi/t_invalid.c - Invalid message token regression tests */
+/*
+ * Copyright (C) 2014 by the Massachusetts Institute of Technology.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * * 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 COPYRIGHT HOLDERS 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
+ * COPYRIGHT HOLDER 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.
+ */
+
+/*
+ * This file contains regression tests for some GSSAPI krb5 invalid per-message
+ * token vulnerabilities.
+ *
+ * 1. A pre-CFX wrap or MIC token processed with a CFX-only context causes a
+ *    null pointer dereference.  (The token must use SEAL_ALG_NONE or it will
+ *    be rejected.)
+ *
+ * 2. A pre-CFX wrap or MIC token with fewer than 24 bytes after the ASN.1
+ *    header causes an input buffer overrun, usually leading to either a segv
+ *    or a GSS_S_DEFECTIVE_TOKEN error due to garbage algorithm, filler, or
+ *    sequence number values.
+ *
+ * 3. A pre-CFX wrap token with fewer than 16 + cksumlen bytes after the ASN.1
+ *    header causes an integer underflow when computing the ciphertext length,
+ *    leading to an allocation error on 32-bit platforms or a segv on 64-bit
+ *    platforms.  A pre-CFX MIC token of this size causes an input buffer
+ *    overrun when comparing the checksum, perhaps leading to a segv.
+ *
+ * 4. A pre-CFX wrap token with fewer than conflen + padlen bytes in the
+ *    ciphertext (where padlen is the last byte of the decrypted ciphertext)
+ *    causes an integer underflow when computing the original message length,
+ *    leading to an allocation error.
+ *
+ * Vulnerabilities #1 and #2 also apply to IOV unwrap, although tokens with
+ * fewer than 16 bytes after the ASN.1 header will be rejected.  Vulnerability
+ * #2 can only be robustly detected using a memory-checking environment such as
+ * valgrind.
+ */
+
+#include "k5-int.h"
+#include "common.h"
+#include "mglueP.h"
+#include "gssapiP_krb5.h"
+
+/*
+ * The following samples contain context parameters and otherwise valid seal
+ * tokens where the plain text is padded with byte value 100 instead of the
+ * proper value 1.
+ */
+struct test {
+    krb5_enctype enctype;
+    krb5_enctype encseq_enctype;
+    int sealalg;
+    int signalg;
+    size_t cksum_size;
+    size_t keylen;
+    const char *keydata;
+    size_t toklen;
+    const char *token;
+} tests[] = {
+    {
+        ENCTYPE_DES_CBC_CRC, ENCTYPE_DES_CBC_RAW,
+        SEAL_ALG_DES, SGN_ALG_DES_MAC_MD5, 8,
+        8,
+        "\x26\xEC\xBA\xB6\xFE\xBA\x91\xCE",
+        53,
+        "\x60\x33\x06\x09\x2A\x86\x48\x86\xF7\x12\x01\x02\x02\x02\x01\x00"
+        "\x00\x00\x00\xFF\xFF\xF0\x0B\x90\x7B\xC4\xFC\xEB\xF4\x84\x9C\x5A"
+        "\xA8\x56\x41\x3E\xE1\x62\xEE\x38\xD1\x34\x9A\xE3\xFB\xC9\xFD\x0A"
+        "\xDC\x83\xE1\x4A\xE4"
+    },
+    {
+        ENCTYPE_DES3_CBC_SHA1, ENCTYPE_DES3_CBC_RAW,
+        SEAL_ALG_DES3KD, SGN_ALG_HMAC_SHA1_DES3_KD, 20,
+        24,
+        "\x4F\xEA\x19\x19\x5E\x0E\x10\xDF\x3D\x29\xB5\x13\x8F\x01\xC7\xA7"
+        "\x92\x3D\x38\xF7\x26\x73\x0D\x6D",
+        65,
+        "\x60\x3F\x06\x09\x2A\x86\x48\x86\xF7\x12\x01\x02\x02\x02\x01\x04"
+        "\x00\x02\x00\xFF\xFF\xEB\xF3\x9A\x89\x24\x57\xB8\x63\x95\x25\xE8"
+        "\x6E\x8E\x79\xE6\x2E\xCA\xD3\xFF\x57\x9F\x8C\xAB\xEF\xDD\x28\x10"
+        "\x2F\x93\x21\x2E\xF2\x52\xB6\x6F\xA8\xBB\x8A\x6D\xAA\x6F\xB7\xF4\xD4"
+    },
+    {
+        ENCTYPE_ARCFOUR_HMAC, ENCTYPE_ARCFOUR_HMAC,
+        SEAL_ALG_MICROSOFT_RC4, SGN_ALG_HMAC_MD5, 8,
+        16,
+        "\x66\x64\x41\x64\x55\x78\x21\xD0\xD0\xFD\x05\x6A\xFF\x6F\xE8\x09",
+        53,
+        "\x60\x33\x06\x09\x2A\x86\x48\x86\xF7\x12\x01\x02\x02\x02\x01\x11"
+        "\x00\x10\x00\xFF\xFF\x35\xD4\x79\xF3\x8C\x47\x8F\x6E\x23\x6F\x3E"
+        "\xCC\x5E\x57\x5C\x6A\x89\xF0\xA2\x03\x4F\x0B\x51\x11\xEE\x89\x7E"
+        "\xD6\xF6\xB5\xD6\x51"
+    }
+};
+
+/* Fake up enough of a CFX GSS context for gss_unwrap, using an AES key. */
+static gss_ctx_id_t
+make_fake_cfx_context()
+{
+    gss_union_ctx_id_t uctx;
+    krb5_gss_ctx_id_t kgctx;
+    krb5_keyblock kb;
+
+    kgctx = calloc(1, sizeof(*kgctx));
+    if (kgctx == NULL)
+        abort();
+    kgctx->established = 1;
+    kgctx->proto = 1;
+    if (g_seqstate_init(&kgctx->seqstate, 0, 0, 0, 0) != 0)
+        abort();
+    kgctx->mech_used = &mech_krb5;
+    kgctx->sealalg = -1;
+    kgctx->signalg = -1;
+
+    kb.enctype = ENCTYPE_AES128_CTS_HMAC_SHA1_96;
+    kb.length = 16;
+    kb.contents = (unsigned char *)"1234567887654321";
+    if (krb5_k_create_key(NULL, &kb, &kgctx->subkey) != 0)
+        abort();
+
+    uctx = calloc(1, sizeof(*uctx));
+    if (uctx == NULL)
+        abort();
+    uctx->mech_type = &mech_krb5;
+    uctx->internal_ctx_id = (gss_ctx_id_t)kgctx;
+    return (gss_ctx_id_t)uctx;
+}
+
+/* Fake up enough of a GSS context for gss_unwrap, using keys from test. */
+static gss_ctx_id_t
+make_fake_context(const struct test *test)
+{
+    gss_union_ctx_id_t uctx;
+    krb5_gss_ctx_id_t kgctx;
+    krb5_keyblock kb;
+    unsigned char encbuf[8];
+    size_t i;
+
+    kgctx = calloc(1, sizeof(*kgctx));
+    if (kgctx == NULL)
+        abort();
+    kgctx->established = 1;
+    if (g_seqstate_init(&kgctx->seqstate, 0, 0, 0, 0) != 0)
+        abort();
+    kgctx->mech_used = &mech_krb5;
+    kgctx->sealalg = test->sealalg;
+    kgctx->signalg = test->signalg;
+    kgctx->cksum_size = test->cksum_size;
+
+    kb.enctype = test->enctype;
+    kb.length = test->keylen;
+    kb.contents = (unsigned char *)test->keydata;
+    if (krb5_k_create_key(NULL, &kb, &kgctx->subkey) != 0)
+        abort();
+
+    kb.enctype = test->encseq_enctype;
+    if (krb5_k_create_key(NULL, &kb, &kgctx->seq) != 0)
+        abort();
+
+    if (kb.enctype == ENCTYPE_DES_CBC_RAW) {
+        for (i = 0; i < 8; i++)
+            encbuf[i] = kb.contents[i] ^ 0xF0;
+        kb.contents = encbuf;
+    }
+    if (krb5_k_create_key(NULL, &kb, &kgctx->enc) != 0)
+        abort();
+
+    uctx = calloc(1, sizeof(*uctx));
+    if (uctx == NULL)
+        abort();
+    uctx->mech_type = &mech_krb5;
+    uctx->internal_ctx_id = (gss_ctx_id_t)kgctx;
+    return (gss_ctx_id_t)uctx;
+}
+
+/* Free a context created by make_fake_context. */
+static void
+free_fake_context(gss_ctx_id_t ctx)
+{
+    gss_union_ctx_id_t uctx = (gss_union_ctx_id_t)ctx;
+    krb5_gss_ctx_id_t kgctx = (krb5_gss_ctx_id_t)uctx->internal_ctx_id;
+
+    free(kgctx->seqstate);
+    krb5_k_free_key(NULL, kgctx->subkey);
+    krb5_k_free_key(NULL, kgctx->seq);
+    krb5_k_free_key(NULL, kgctx->enc);
+    free(kgctx);
+    free(uctx);
+}
+
+/* Prefix a token (starting at the two-byte ID) with an ASN.1 header and return
+ * it in an allocated block to facilitate checking by valgrind or similar. */
+static void
+make_token(unsigned char *token, size_t len, gss_buffer_t out)
+{
+    char *wrapped;
+
+    assert(mech_krb5.length == 9);
+    assert(len + 11 < 128);
+    wrapped = malloc(len + 13);
+    if (wrapped == NULL)
+        abort();
+    wrapped[0] = 0x60;
+    wrapped[1] = len + 11;
+    wrapped[2] = 0x06;
+    wrapped[3] = 9;
+    memcpy(wrapped + 4, mech_krb5.elements, 9);
+    memcpy(wrapped + 13, token, len);
+    out->length = len + 13;
+    out->value = wrapped;
+}
+
+/* Unwrap a superficially valid RFC 1964 token with a CFX-only context, with
+ * regular and IOV unwrap. */
+static void
+test_bogus_1964_token(gss_ctx_id_t ctx)
+{
+    OM_uint32 minor, major;
+    unsigned char tokbuf[128];
+    gss_buffer_desc in, out;
+    gss_iov_buffer_desc iov;
+
+    store_16_be(KG_TOK_SIGN_MSG, tokbuf);
+    store_16_le(SGN_ALG_DES_MAC_MD5, tokbuf + 2);
+    store_16_le(SEAL_ALG_NONE, tokbuf + 4);
+    store_16_le(0xFFFF, tokbuf + 6);
+    memset(tokbuf + 8, 0, 16);
+    make_token(tokbuf, 24, &in);
+
+    major = gss_unwrap(&minor, ctx, &in, &out, NULL, NULL);
+    if (major != GSS_S_DEFECTIVE_TOKEN)
+        abort();
+    (void)gss_release_buffer(&minor, &out);
+
+    iov.type = GSS_IOV_BUFFER_TYPE_HEADER;
+    iov.buffer = in;
+    major = gss_unwrap_iov(&minor, ctx, NULL, NULL, &iov, 1);
+    if (major != GSS_S_DEFECTIVE_TOKEN)
+        abort();
+
+    free(in.value);
+}
+
+/* Process wrap and MIC tokens with incomplete headers. */
+static void
+test_short_header(gss_ctx_id_t ctx)
+{
+    OM_uint32 minor, major;
+    unsigned char tokbuf[128];
+    gss_buffer_desc in, out, empty = GSS_C_EMPTY_BUFFER;
+
+    /* Seal token, 2-24 bytes */
+    store_16_be(KG_TOK_SEAL_MSG, tokbuf);
+    make_token(tokbuf, 2, &in);
+    major = gss_unwrap(&minor, ctx, &in, &out, NULL, NULL);
+    if (major != GSS_S_DEFECTIVE_TOKEN)
+        abort();
+    free(in.value);
+    (void)gss_release_buffer(&minor, &out);
+
+    /* Sign token, 2-24 bytes */
+    store_16_be(KG_TOK_SIGN_MSG, tokbuf);
+    make_token(tokbuf, 2, &in);
+    major = gss_unwrap(&minor, ctx, &in, &out, NULL, NULL);
+    if (major != GSS_S_DEFECTIVE_TOKEN)
+        abort();
+    free(in.value);
+    (void)gss_release_buffer(&minor, &out);
+
+    /* MIC token, 2-24 bytes */
+    store_16_be(KG_TOK_MIC_MSG, tokbuf);
+    make_token(tokbuf, 2, &in);
+    major = gss_verify_mic(&minor, ctx, &empty, &in, NULL);
+    if (major != GSS_S_DEFECTIVE_TOKEN)
+        abort();
+    free(in.value);
+}
+
+/* Process wrap and MIC tokens with incomplete headers. */
+static void
+test_short_header_iov(gss_ctx_id_t ctx, const struct test *test)
+{
+    OM_uint32 minor, major;
+    unsigned char tokbuf[128];
+    gss_iov_buffer_desc iov;
+
+    /* IOV seal token, 16-23 bytes */
+    store_16_be(KG_TOK_SEAL_MSG, tokbuf);
+    store_16_le(test->signalg, tokbuf + 2);
+    store_16_le(test->sealalg, tokbuf + 4);
+    store_16_be(0xFFFF, tokbuf + 6);
+    memset(tokbuf + 8, 0, 8);
+    iov.type = GSS_IOV_BUFFER_TYPE_HEADER;
+    make_token(tokbuf, 16, &iov.buffer);
+    major = gss_unwrap_iov(&minor, ctx, NULL, NULL, &iov, 1);
+    if (major != GSS_S_DEFECTIVE_TOKEN)
+        abort();
+    free(iov.buffer.value);
+
+    /* IOV sign token, 16-23 bytes */
+    store_16_be(KG_TOK_SIGN_MSG, tokbuf);
+    store_16_le(test->signalg, tokbuf + 2);
+    store_16_le(SEAL_ALG_NONE, tokbuf + 4);
+    store_16_le(0xFFFF, tokbuf + 6);
+    memset(tokbuf + 8, 0, 8);
+    iov.type = GSS_IOV_BUFFER_TYPE_HEADER;
+    make_token(tokbuf, 16, &iov.buffer);
+    major = gss_unwrap_iov(&minor, ctx, NULL, NULL, &iov, 1);
+    if (major != GSS_S_DEFECTIVE_TOKEN)
+        abort();
+    free(iov.buffer.value);
+
+    /* IOV MIC token, 16-23 bytes */
+    store_16_be(KG_TOK_MIC_MSG, tokbuf);
+    store_16_be(test->signalg, tokbuf + 2);
+    store_16_le(SEAL_ALG_NONE, tokbuf + 4);
+    store_16_le(0xFFFF, tokbuf + 6);
+    memset(tokbuf + 8, 0, 8);
+    iov.type = GSS_IOV_BUFFER_TYPE_MIC_TOKEN;
+    make_token(tokbuf, 16, &iov.buffer);
+    major = gss_verify_mic_iov(&minor, ctx, NULL, &iov, 1);
+    if (major != GSS_S_DEFECTIVE_TOKEN)
+        abort();
+    free(iov.buffer.value);
+}
+
+/* Process wrap and MIC tokens with incomplete checksums. */
+static void
+test_short_checksum(gss_ctx_id_t ctx, const struct test *test)
+{
+    OM_uint32 minor, major;
+    unsigned char tokbuf[128];
+    gss_buffer_desc in, out, empty = GSS_C_EMPTY_BUFFER;
+
+    /* Can only do this with the DES3 checksum, as we can't easily get past
+     * retrieving the sequence number when the checksum is only eight bytes. */
+    if (test->cksum_size <= 8)
+        return;
+    /* Seal token, fewer than 16 + cksum_size bytes.  Use the token from the
+     * test data to get a valid sequence number. */
+    make_token((unsigned char *)test->token + 13, 24, &in);
+    major = gss_unwrap(&minor, ctx, &in, &out, NULL, NULL);
+    if (major != GSS_S_DEFECTIVE_TOKEN)
+        abort();
+    free(in.value);
+    (void)gss_release_buffer(&minor, &out);
+
+    /* Sign token, fewer than 16 + cksum_size bytes. */
+    memcpy(tokbuf, test->token + 13, 24);
+    store_16_be(KG_TOK_SIGN_MSG, tokbuf);
+    store_16_le(SEAL_ALG_NONE, tokbuf + 4);
+    make_token(tokbuf, 24, &in);
+    major = gss_unwrap(&minor, ctx, &in, &out, NULL, NULL);
+    if (major != GSS_S_DEFECTIVE_TOKEN)
+        abort();
+    free(in.value);
+    (void)gss_release_buffer(&minor, &out);
+
+    /* MIC token, fewer than 16 + cksum_size bytes. */
+    memcpy(tokbuf, test->token + 13, 24);
+    store_16_be(KG_TOK_MIC_MSG, tokbuf);
+    store_16_le(SEAL_ALG_NONE, tokbuf + 4);
+    make_token(tokbuf, 24, &in);
+    major = gss_verify_mic(&minor, ctx, &empty, &in, NULL);
+    if (major != GSS_S_DEFECTIVE_TOKEN)
+        abort();
+    free(in.value);
+}
+
+/* Unwrap a token with a bogus padding byte in the decrypted ciphertext. */
+static void
+test_bad_pad(gss_ctx_id_t ctx, const struct test *test)
+{
+    OM_uint32 minor, major;
+    gss_buffer_desc in, out;
+
+    in.length = test->toklen;
+    in.value = (char *)test->token;
+    major = gss_unwrap(&minor, ctx, &in, &out, NULL, NULL);
+    if (major != GSS_S_BAD_SIG)
+        abort();
+    (void)gss_release_buffer(&minor, &out);
+}
+
+int
+main(int argc, char **argv)
+{
+    gss_ctx_id_t ctx;
+    size_t i;
+
+    ctx = make_fake_cfx_context();
+    test_bogus_1964_token(ctx);
+    free_fake_context(ctx);
+
+    for (i = 0; i < sizeof(tests) / sizeof(*tests); i++) {
+        ctx = make_fake_context(&tests[i]);
+        test_short_header(ctx);
+        test_short_header_iov(ctx, &tests[i]);
+        test_short_checksum(ctx, &tests[i]);
+        test_bad_pad(ctx, &tests[i]);
+        free_fake_context(ctx);
+    }
+
+    return 0;
+}