svn rev #23651: branches/krb5-1-7/src/lib/crypto/ arcfour/ dk/ enc_provider/ ...
tlyu@MIT.EDU
tlyu at MIT.EDU
Tue Jan 12 16:32:00 EST 2010
http://src.mit.edu/fisheye/changelog/krb5/?cs=23651
Commit By: tlyu
Log Message:
ticket: 6637
target_version: 1.7.1
version_fixed: 1.7.1
status: resolved
subject: MITKRB5-SA-2009-004 [CVE-2009-4212] integer underflow in AES and RC4 decryption
Fix integer underflow in AES and RC4 decryption.
[MITKRB5-SA-2009-004, CVE-2009-4212]
Changed Files:
U branches/krb5-1-7/src/lib/crypto/Makefile.in
U branches/krb5-1-7/src/lib/crypto/arcfour/arcfour.c
U branches/krb5-1-7/src/lib/crypto/deps
U branches/krb5-1-7/src/lib/crypto/dk/dk_aead.c
U branches/krb5-1-7/src/lib/crypto/dk/dk_decrypt.c
U branches/krb5-1-7/src/lib/crypto/enc_provider/aes.c
U branches/krb5-1-7/src/lib/crypto/old/old_decrypt.c
U branches/krb5-1-7/src/lib/crypto/raw/raw_decrypt.c
A branches/krb5-1-7/src/lib/crypto/t_short.c
Modified: branches/krb5-1-7/src/lib/crypto/Makefile.in
===================================================================
--- branches/krb5-1-7/src/lib/crypto/Makefile.in 2010-01-12 05:37:06 UTC (rev 23650)
+++ branches/krb5-1-7/src/lib/crypto/Makefile.in 2010-01-12 21:31:59 UTC (rev 23651)
@@ -18,6 +18,7 @@
$(srcdir)/t_nfold.c \
$(srcdir)/t_cf2.c \
$(srcdir)/t_encrypt.c \
+ $(srcdir)/t_short.c \
$(srcdir)/t_prf.c \
$(srcdir)/t_prng.c \
$(srcdir)/t_hmac.c \
@@ -206,7 +207,7 @@
clean-unix:: clean-liblinks clean-libs clean-libobjs
-check-unix:: t_nfold t_encrypt t_prf t_prng t_hmac t_pkcs5 t_cf2
+check-unix:: t_nfold t_encrypt t_prf t_prng t_hmac t_pkcs5 t_cf2 t_short
$(RUN_SETUP) $(VALGRIND) ./t_nfold
$(RUN_SETUP) $(VALGRIND) ./t_encrypt
$(RUN_SETUP) $(VALGRIND) ./t_prng <$(srcdir)/t_prng.seed >t_prng.output && \
@@ -216,6 +217,7 @@
diff t_prf.output $(srcdir)/t_prf.expected
$(RUN_SETUP) $(VALGRIND) ./t_cf2 <$(srcdir)/t_cf2.in >t_cf2.output
diff t_cf2.output $(srcdir)/t_cf2.expected
+ $(RUN_SETUP) $(VALGRIND) ./t_short
# $(RUN_SETUP) $(VALGRIND) ./t_pkcs5
@@ -249,10 +251,15 @@
$(CC_LINK) -o $@ t_cts.$(OBJEXT) \
$(K5CRYPTO_LIB) $(COM_ERR_LIB) $(SUPPORT_LIB)
+t_short$(EXEEXT): t_short.$(OBJEXT) $(CRYPTO_DEPLIB) $(SUPPORT_DEPLIB)
+ $(CC_LINK) -o $@ t_short.$(OBJEXT) \
+ $(K5CRYPTO_LIB) $(COM_ERR_LIB) $(SUPPORT_LIB)
+
clean::
$(RM) t_nfold.o t_nfold t_encrypt t_encrypt.o t_prng.o t_prng \
- t_hmac.o t_hmac t_pkcs5.o t_pkcs5 pbkdf2.o t_prf t_prf.o t_cf2 t_cf2.o
+ t_hmac.o t_hmac t_pkcs5.o t_pkcs5 pbkdf2.o t_prf t_prf.o \
+ t_cf2 t_cf2.o t_short t_short.o
-$(RM) t_prng.output
all-windows::
Modified: branches/krb5-1-7/src/lib/crypto/arcfour/arcfour.c
===================================================================
--- branches/krb5-1-7/src/lib/crypto/arcfour/arcfour.c 2010-01-12 05:37:06 UTC (rev 23650)
+++ branches/krb5-1-7/src/lib/crypto/arcfour/arcfour.c 2010-01-12 21:31:59 UTC (rev 23651)
@@ -199,6 +199,12 @@
keylength = enc->keylength;
hashsize = hash->hashsize;
+ /* Verify input and output lengths. */
+ if (input->length < hashsize + CONFOUNDERLENGTH)
+ return KRB5_BAD_MSIZE;
+ if (output->length < input->length - hashsize - CONFOUNDERLENGTH)
+ return KRB5_BAD_MSIZE;
+
d1.length=keybytes;
d1.data=malloc(d1.length);
if (d1.data == NULL)
Modified: branches/krb5-1-7/src/lib/crypto/deps
===================================================================
--- branches/krb5-1-7/src/lib/crypto/deps 2010-01-12 05:37:06 UTC (rev 23650)
+++ branches/krb5-1-7/src/lib/crypto/deps 2010-01-12 21:31:59 UTC (rev 23651)
@@ -463,6 +463,16 @@
$(SRCTOP)/include/krb5.h $(SRCTOP)/include/krb5/locate_plugin.h \
$(SRCTOP)/include/krb5/preauth_plugin.h $(SRCTOP)/include/port-sockets.h \
$(SRCTOP)/include/socket-utils.h etypes.h t_encrypt.c
+t_short.so t_short.po $(OUTPRE)t_short.$(OBJEXT): $(BUILDTOP)/include/autoconf.h \
+ $(BUILDTOP)/include/krb5/krb5.h $(BUILDTOP)/include/osconf.h \
+ $(BUILDTOP)/include/profile.h $(COM_ERR_DEPS) $(SRCTOP)/include/k5-buf.h \
+ $(SRCTOP)/include/k5-err.h $(SRCTOP)/include/k5-gmt_mktime.h \
+ $(SRCTOP)/include/k5-int-pkinit.h $(SRCTOP)/include/k5-int.h \
+ $(SRCTOP)/include/k5-platform.h $(SRCTOP)/include/k5-plugin.h \
+ $(SRCTOP)/include/k5-thread.h $(SRCTOP)/include/krb5.h \
+ $(SRCTOP)/include/krb5/locate_plugin.h $(SRCTOP)/include/krb5/preauth_plugin.h \
+ $(SRCTOP)/include/port-sockets.h $(SRCTOP)/include/socket-utils.h \
+ t_short.c
t_prf.so t_prf.po $(OUTPRE)t_prf.$(OBJEXT): $(BUILDTOP)/include/autoconf.h \
$(BUILDTOP)/include/krb5/krb5.h $(BUILDTOP)/include/osconf.h \
$(BUILDTOP)/include/profile.h $(COM_ERR_DEPS) $(SRCTOP)/include/k5-buf.h \
Modified: branches/krb5-1-7/src/lib/crypto/dk/dk_aead.c
===================================================================
--- branches/krb5-1-7/src/lib/crypto/dk/dk_aead.c 2010-01-12 05:37:06 UTC (rev 23650)
+++ branches/krb5-1-7/src/lib/crypto/dk/dk_aead.c 2010-01-12 21:31:59 UTC (rev 23651)
@@ -250,7 +250,7 @@
for (i = 0; i < num_data; i++) {
const krb5_crypto_iov *iov = &data[i];
- if (ENCRYPT_DATA_IOV(iov))
+ if (ENCRYPT_IOV(iov))
cipherlen += iov->data.length;
}
if (cipherlen % blocksize != 0)
Modified: branches/krb5-1-7/src/lib/crypto/dk/dk_decrypt.c
===================================================================
--- branches/krb5-1-7/src/lib/crypto/dk/dk_decrypt.c 2010-01-12 05:37:06 UTC (rev 23650)
+++ branches/krb5-1-7/src/lib/crypto/dk/dk_decrypt.c 2010-01-12 21:31:59 UTC (rev 23651)
@@ -89,6 +89,12 @@
else if (hmacsize > hashsize)
return KRB5KRB_AP_ERR_BAD_INTEGRITY;
+ /* Verify input and output lengths. */
+ if (input->length < blocksize + hmacsize)
+ return KRB5_BAD_MSIZE;
+ if (output->length < input->length - blocksize - hmacsize)
+ return KRB5_BAD_MSIZE;
+
enclen = input->length - hmacsize;
if ((kedata = (unsigned char *) malloc(keylength)) == NULL)
Modified: branches/krb5-1-7/src/lib/crypto/enc_provider/aes.c
===================================================================
--- branches/krb5-1-7/src/lib/crypto/enc_provider/aes.c 2010-01-12 05:37:06 UTC (rev 23650)
+++ branches/krb5-1-7/src/lib/crypto/enc_provider/aes.c 2010-01-12 21:31:59 UTC (rev 23651)
@@ -105,9 +105,11 @@
nblocks = (input->length + BLOCK_SIZE - 1) / BLOCK_SIZE;
if (nblocks == 1) {
- /* XXX Used for DK function. */
+ /* Used when deriving keys. */
+ if (input->length < BLOCK_SIZE)
+ return KRB5_BAD_MSIZE;
enc(output->data, input->data, &ctx);
- } else {
+ } else if (nblocks > 1) {
unsigned int nleft;
for (blockno = 0; blockno < nblocks - 2; blockno++) {
@@ -160,9 +162,9 @@
if (nblocks == 1) {
if (input->length < BLOCK_SIZE)
- abort();
+ return KRB5_BAD_MSIZE;
dec(output->data, input->data, &ctx);
- } else {
+ } else if (nblocks > 1) {
for (blockno = 0; blockno < nblocks - 2; blockno++) {
dec(tmp2, input->data + blockno * BLOCK_SIZE, &ctx);
@@ -208,6 +210,7 @@
char tmp[BLOCK_SIZE], tmp2[BLOCK_SIZE];
int nblocks = 0, blockno;
size_t input_length, i;
+ struct iov_block_state input_pos, output_pos;
if (aes_enc_key(key->contents, key->length, &ctx) != aes_good)
abort();
@@ -224,18 +227,20 @@
input_length += iov->data.length;
}
+ IOV_BLOCK_STATE_INIT(&input_pos);
+ IOV_BLOCK_STATE_INIT(&output_pos);
+
nblocks = (input_length + BLOCK_SIZE - 1) / BLOCK_SIZE;
-
- assert(nblocks > 1);
-
- {
+ if (nblocks == 1) {
+ krb5int_c_iov_get_block((unsigned char *)tmp, BLOCK_SIZE,
+ data, num_data, &input_pos);
+ enc(tmp2, tmp, &ctx);
+ krb5int_c_iov_put_block(data, num_data, (unsigned char *)tmp2,
+ BLOCK_SIZE, &output_pos);
+ } else if (nblocks > 1) {
char blockN2[BLOCK_SIZE]; /* second last */
char blockN1[BLOCK_SIZE]; /* last block */
- struct iov_block_state input_pos, output_pos;
- IOV_BLOCK_STATE_INIT(&input_pos);
- IOV_BLOCK_STATE_INIT(&output_pos);
-
for (blockno = 0; blockno < nblocks - 2; blockno++) {
char blockN[BLOCK_SIZE];
@@ -288,6 +293,7 @@
char tmp[BLOCK_SIZE], tmp2[BLOCK_SIZE], tmp3[BLOCK_SIZE];
int nblocks = 0, blockno, i;
size_t input_length;
+ struct iov_block_state input_pos, output_pos;
CHECK_SIZES;
@@ -306,18 +312,20 @@
input_length += iov->data.length;
}
+ IOV_BLOCK_STATE_INIT(&input_pos);
+ IOV_BLOCK_STATE_INIT(&output_pos);
+
nblocks = (input_length + BLOCK_SIZE - 1) / BLOCK_SIZE;
-
- assert(nblocks > 1);
-
- {
+ if (nblocks == 1) {
+ krb5int_c_iov_get_block((unsigned char *)tmp, BLOCK_SIZE,
+ data, num_data, &input_pos);
+ dec(tmp2, tmp, &ctx);
+ krb5int_c_iov_put_block(data, num_data, (unsigned char *)tmp2,
+ BLOCK_SIZE, &output_pos);
+ } else if (nblocks > 1) {
char blockN2[BLOCK_SIZE]; /* second last */
char blockN1[BLOCK_SIZE]; /* last block */
- struct iov_block_state input_pos, output_pos;
- IOV_BLOCK_STATE_INIT(&input_pos);
- IOV_BLOCK_STATE_INIT(&output_pos);
-
for (blockno = 0; blockno < nblocks - 2; blockno++) {
char blockN[BLOCK_SIZE];
Modified: branches/krb5-1-7/src/lib/crypto/old/old_decrypt.c
===================================================================
--- branches/krb5-1-7/src/lib/crypto/old/old_decrypt.c 2010-01-12 05:37:06 UTC (rev 23650)
+++ branches/krb5-1-7/src/lib/crypto/old/old_decrypt.c 2010-01-12 21:31:59 UTC (rev 23651)
@@ -45,8 +45,10 @@
blocksize = enc->block_size;
hashsize = hash->hashsize;
+ /* Verify input and output lengths. */
+ if (input->length < blocksize + hashsize || input->length % blocksize != 0)
+ return(KRB5_BAD_MSIZE);
plainsize = input->length - blocksize - hashsize;
-
if (arg_output->length < plainsize)
return(KRB5_BAD_MSIZE);
Modified: branches/krb5-1-7/src/lib/crypto/raw/raw_decrypt.c
===================================================================
--- branches/krb5-1-7/src/lib/crypto/raw/raw_decrypt.c 2010-01-12 05:37:06 UTC (rev 23650)
+++ branches/krb5-1-7/src/lib/crypto/raw/raw_decrypt.c 2010-01-12 21:31:59 UTC (rev 23651)
@@ -34,5 +34,7 @@
const krb5_data *ivec, const krb5_data *input,
krb5_data *output)
{
+ if (output->length < input->length)
+ return KRB5_BAD_MSIZE;
return((*(enc->decrypt))(key, ivec, input, output));
}
Added: branches/krb5-1-7/src/lib/crypto/t_short.c
===================================================================
--- branches/krb5-1-7/src/lib/crypto/t_short.c (rev 0)
+++ branches/krb5-1-7/src/lib/crypto/t_short.c 2010-01-12 21:31:59 UTC (rev 23651)
@@ -0,0 +1,126 @@
+/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
+/*
+ * lib/crypto/crypto_tests/t_short.c
+ *
+ * Copyright (C) 2009 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.
+ *
+ * Tests the outcome of decrypting overly short tokens. This program can be
+ * run under a tool like valgrind to detect bad memory accesses; when run
+ * normally by the test suite, it verifies that each operation returns
+ * KRB5_BAD_MSIZE.
+ */
+
+#include "k5-int.h"
+
+krb5_enctype interesting_enctypes[] = {
+ ENCTYPE_DES_CBC_CRC,
+ ENCTYPE_DES_CBC_MD4,
+ ENCTYPE_DES_CBC_MD5,
+ ENCTYPE_DES3_CBC_SHA1,
+ ENCTYPE_ARCFOUR_HMAC,
+ ENCTYPE_ARCFOUR_HMAC_EXP,
+ ENCTYPE_AES256_CTS_HMAC_SHA1_96,
+ ENCTYPE_AES128_CTS_HMAC_SHA1_96,
+ 0
+};
+
+/* Abort if an operation unexpectedly fails. */
+static void
+x(krb5_error_code code)
+{
+ if (code != 0)
+ abort();
+}
+
+/* Abort if a decrypt operation doesn't have the expected result. */
+static void
+check_decrypt_result(krb5_error_code code, size_t len, size_t min_len)
+{
+ if (len < min_len) {
+ /* Undersized tokens should always result in BAD_MSIZE. */
+ if (code != KRB5_BAD_MSIZE)
+ abort();
+ } else {
+ /* Min-size tokens should succeed or fail the integrity check. */
+ if (code != 0 && code != KRB5KRB_AP_ERR_BAD_INTEGRITY)
+ abort();
+ }
+}
+
+static void
+test_enctype(krb5_enctype enctype)
+{
+ krb5_error_code ret;
+ krb5_keyblock keyblock;
+ krb5_enc_data input;
+ krb5_data output;
+ krb5_crypto_iov iov[2];
+ unsigned int dummy;
+ size_t min_len, len;
+
+ printf("Testing enctype %d\n", (int) enctype);
+ x(krb5_c_encrypt_length(NULL, enctype, 0, &min_len));
+ x(krb5_c_make_random_key(NULL, enctype, &keyblock));
+ input.enctype = enctype;
+
+ /* Try each length up to the minimum length. */
+ for (len = 0; len <= min_len; len++) {
+ input.ciphertext.data = calloc(len, 1);
+ input.ciphertext.length = len;
+ output.data = calloc(len, 1);
+ output.length = len;
+
+ /* Attempt a normal decryption. */
+ ret = krb5_c_decrypt(NULL, &keyblock, 0, NULL, &input, &output);
+ check_decrypt_result(ret, len, min_len);
+
+ if (krb5_c_crypto_length(NULL, enctype, KRB5_CRYPTO_TYPE_HEADER,
+ &dummy) == 0) {
+ /* Attempt an IOV stream decryption. */
+ iov[0].flags = KRB5_CRYPTO_TYPE_STREAM;
+ iov[0].data = input.ciphertext;
+ iov[1].flags = KRB5_CRYPTO_TYPE_DATA;
+ iov[1].data.data = NULL;
+ iov[1].data.length = 0;
+ ret = krb5_c_decrypt_iov(NULL, &keyblock, 0, NULL, iov, 2);
+ check_decrypt_result(ret, len, min_len);
+ }
+
+ free(input.ciphertext.data);
+ free(output.data);
+ }
+}
+
+int
+main(int argc, char **argv)
+{
+ int i;
+ krb5_data notrandom;
+
+ notrandom.data = "notrandom";
+ notrandom.length = 9;
+ krb5_c_random_seed(NULL, ¬random);
+ for (i = 0; interesting_enctypes[i]; i++)
+ test_enctype(interesting_enctypes[i]);
+ return 0;
+}
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