Control: tags -1 +patch
Hi Thijs,
Thijs Kinkhorst <[email protected]> writes:
> Nadhem Alfardan and Kenny Paterson have discovered a weakness in the handling
> of CBC ciphersuites in SSL, TLS and DTLS. Their attack exploits timing
> differences arising during MAC processing. Details of this attack can be
> found at: http://www.isg.rhul.ac.uk/tls/
>
> The issue has been fixed in upstream yaSSL 2.5.0:
> http://www.yassl.com/yaSSL/Docs-cyassl-changelog.html
Currently, MySQL uses yaSSL 2.2.2. yaSSL has released version 2.2.2d
which addresses this problem.
I downloaded yassl-2.2.2.zip from
http://fossies.org/unix/privat/yassl-2.2.2.zip and yassl-2.2.2d.zip from
http://yassl.com/yaSSL/download
I then created a git repo in 2.2.2 and copied over the files from
2.2.2d. The following files differ:
$ git status | grep 'modified' | grep -v '\.in$' | grep -v
'\(INSTALL\|README\|aclocal.m4\|config.guess\|config.sub\|configure\|depcomp\|install-sh\|ltmain.sh\|missing\|mkinstalldirs\)'
# modified: include/openssl/ssl.h
# modified: include/yassl_error.hpp
# modified: include/yassl_types.hpp
# modified: src/handshake.cpp
# modified: src/yassl_error.cpp
# modified: src/yassl_imp.cpp
# modified: taocrypt/include/asn.hpp
# modified: taocrypt/include/sha.hpp
# modified: taocrypt/src/asn.cpp
I then created a patch and modified it so that it (somewhat) applies to
the MySQL source:
git diff include/openssl/ssl.h include/yassl_error.hpp include/yassl_types.hpp
src/handshake.cpp src/yassl_error.cpp src/yassl_imp.cpp
taocrypt/include/asn.hpp taocrypt/include/sha.hpp taocrypt/src/asn.cpp >
yassl.patch
sed -i 's,\([iw]\)/,\1/extra/yassl/,g' yassl.patch
dos2unix yassl.patch
Then, I used quilt to get the patch in shape:
cd /tmp/mysql-5.5-5.5.30+dfsg
export QUILT_PATCHES=debian/patches
quilt import ../yassl-2.2.2/yassl.patch
quilt push -f
# apply 4 hunks of the patch manually
quilt refresh
I attached the result to this email, hopefully that helps.
Note that I didn’t compile and test MySQL.
--
Best regards,
Michael
Index: mysql-5.5-5.5.30+dfsg/extra/yassl/include/openssl/ssl.h
===================================================================
--- mysql-5.5-5.5.30+dfsg.orig/extra/yassl/include/openssl/ssl.h 2013-03-27 10:56:31.000000000 +0100
+++ mysql-5.5-5.5.30+dfsg/extra/yassl/include/openssl/ssl.h 2013-03-27 10:58:30.861636193 +0100
@@ -35,7 +35,7 @@
#include "rsa.h"
-#define YASSL_VERSION "2.2.2"
+#define YASSL_VERSION "2.2.2d"
#if defined(__cplusplus)
Index: mysql-5.5-5.5.30+dfsg/extra/yassl/include/yassl_error.hpp
===================================================================
--- mysql-5.5-5.5.30+dfsg.orig/extra/yassl/include/yassl_error.hpp 2013-03-27 10:56:31.000000000 +0100
+++ mysql-5.5-5.5.30+dfsg/extra/yassl/include/yassl_error.hpp 2013-03-27 10:58:30.861636193 +0100
@@ -53,7 +53,8 @@
badVersion_error = 117,
compress_error = 118,
decompress_error = 119,
- pms_version_error = 120
+ pms_version_error = 120,
+ sanityCipher_error = 121
// !!!! add error message to .cpp !!!!
Index: mysql-5.5-5.5.30+dfsg/extra/yassl/include/yassl_types.hpp
===================================================================
--- mysql-5.5-5.5.30+dfsg.orig/extra/yassl/include/yassl_types.hpp 2013-03-27 10:56:31.000000000 +0100
+++ mysql-5.5-5.5.30+dfsg/extra/yassl/include/yassl_types.hpp 2013-03-27 10:58:30.861636193 +0100
@@ -220,7 +220,11 @@
const int MAX_RECORD_SIZE = 16384; // 2^14, max size by standard
const int COMPRESS_EXTRA = 1024; // extra compression possible addition
const int SESSION_FLUSH_COUNT = 256; // when to flush session cache
-
+const int MAX_PAD_SIZE = 256; // max TLS padding size
+const int COMPRESS_CONSTANT = 13; // compression calculation constant
+const int COMPRESS_UPPER = 55; // compression calculation numerator
+const int COMPRESS_LOWER = 64; // compression calculation denominator
+const int COMPRESS_DUMMY_SIZE = 64; // compression dummy round size
typedef uint8 Cipher; // first byte is always 0x00 for SSLv3 & TLS
Index: mysql-5.5-5.5.30+dfsg/extra/yassl/src/handshake.cpp
===================================================================
--- mysql-5.5-5.5.30+dfsg.orig/extra/yassl/src/handshake.cpp 2013-03-27 10:56:31.000000000 +0100
+++ mysql-5.5-5.5.30+dfsg/extra/yassl/src/handshake.cpp 2013-03-27 11:00:12.856176496 +0100
@@ -221,12 +221,45 @@
}
+// sanity checks on encrypted message size
+static int sanity_check_message(SSL& ssl, uint msgSz)
+{
+ uint minSz = 0;
+
+ if (ssl.getSecurity().get_parms().cipher_type_ == block) {
+ uint blockSz = ssl.getCrypto().get_cipher().get_blockSize();
+ if (msgSz % blockSz)
+ return -1;
+
+ minSz = ssl.getSecurity().get_parms().hash_size_ + 1; // pad byte too
+ if (blockSz > minSz)
+ minSz = blockSz;
+
+ if (ssl.isTLSv1_1())
+ minSz += blockSz; // explicit IV
+ }
+ else { // stream
+ minSz = ssl.getSecurity().get_parms().hash_size_;
+ }
+
+ if (msgSz < minSz)
+ return -1;
+
+ return 0;
+}
+
+
// decrypt input message in place, store size in case needed later
void decrypt_message(SSL& ssl, input_buffer& input, uint sz)
{
input_buffer plain(sz);
opaque* cipher = input.get_buffer() + input.get_current();
+ if (sanity_check_message(ssl, sz) != 0) {
+ ssl.SetError(sanityCipher_error);
+ return;
+ }
+
ssl.useCrypto().use_cipher().decrypt(plain.get_buffer(), cipher, sz);
memcpy(cipher, plain.get_buffer(), sz);
ssl.useSecurity().use_parms().encrypt_size_ = sz;
@@ -774,6 +807,8 @@
return 0;
}
decrypt_message(ssl, buffer, hdr.length_);
+ if (ssl.GetError())
+ return 0;
}
mySTL::auto_ptr<Message> msg(mf.CreateObject(hdr.type_));
Index: mysql-5.5-5.5.30+dfsg/extra/yassl/src/yassl_error.cpp
===================================================================
--- mysql-5.5-5.5.30+dfsg.orig/extra/yassl/src/yassl_error.cpp 2013-03-27 10:56:31.000000000 +0100
+++ mysql-5.5-5.5.30+dfsg/extra/yassl/src/yassl_error.cpp 2013-03-27 10:58:30.861636193 +0100
@@ -144,6 +144,10 @@
strncpy(buffer, "bad PreMasterSecret version error", max);
break;
+ case sanityCipher_error :
+ strncpy(buffer, "sanity check on cipher text size error", max);
+ break;
+
// openssl errors
case SSL_ERROR_WANT_READ :
strncpy(buffer, "the read operation would block", max);
Index: mysql-5.5-5.5.30+dfsg/extra/yassl/src/yassl_imp.cpp
===================================================================
--- mysql-5.5-5.5.30+dfsg.orig/extra/yassl/src/yassl_imp.cpp 2013-03-27 10:52:16.000000000 +0100
+++ mysql-5.5-5.5.30+dfsg/extra/yassl/src/yassl_imp.cpp 2013-03-27 11:03:29.017365789 +0100
@@ -972,29 +972,193 @@
}
+// check all bytes for equality
+static int constant_compare(const byte* a, const byte* b, int len)
+{
+ int good = 0;
+ int bad = 0;
+
+ for (int i = 0; i < len; i++) {
+ if (a[i] == b[i])
+ good++;
+ else
+ bad++;
+ }
+
+ if (good == len)
+ return 0;
+ else
+ return 0 - bad; // failure
+}
+
+
+// check bytes for pad value
+static int pad_check(const byte* input, byte pad, int len)
+{
+ int good = 0;
+ int bad = 0;
+
+ for (int i = 0; i < len; i++) {
+ if (input[i] == pad)
+ good++;
+ else
+ bad++;
+ }
+
+ if (good == len)
+ return 0;
+ else
+ return 0 - bad; // failure
+}
+
+
+// get number of compression rounds
+static inline int get_rounds(int pLen, int padLen, int t)
+{
+ int roundL1 = 1; // round ups
+ int roundL2 = 1;
+
+ int L1 = COMPRESS_CONSTANT + pLen - t;
+ int L2 = COMPRESS_CONSTANT + pLen - padLen - 1 - t;
+
+ L1 -= COMPRESS_UPPER;
+ L2 -= COMPRESS_UPPER;
+
+ if ( (L1 % COMPRESS_LOWER) == 0)
+ roundL1 = 0;
+ if ( (L2 % COMPRESS_LOWER) == 0)
+ roundL2 = 0;
+
+ L1 /= COMPRESS_LOWER;
+ L2 /= COMPRESS_LOWER;
+
+ L1 += roundL1;
+ L2 += roundL2;
+
+ return L1 - L2;
+}
+
+
+// do compression rounds on dummy data
+static inline void compress_rounds(SSL& ssl, int rounds, const byte* dummy)
+{
+ if (rounds) {
+ Digest* digest = NULL;
+
+ MACAlgorithm ma = ssl.getSecurity().get_parms().mac_algorithm_;
+ if (ma == sha)
+ digest = NEW_YS SHA;
+ else if (ma == md5)
+ digest = NEW_YS MD5;
+ else if (ma == rmd)
+ digest = NEW_YS RMD;
+ else
+ return;
+
+ for (int i = 0; i < rounds; i++)
+ digest->update(dummy, COMPRESS_LOWER);
+
+ ysDelete(digest);
+ }
+}
+
+
+// timing resistant pad verification
+static int timing_verify(SSL& ssl, const byte* input, int padLen, int t,
+ int pLen)
+{
+ byte verify[SHA_LEN];
+ byte dummy[MAX_PAD_SIZE];
+
+ memset(dummy, 1, sizeof(dummy));
+
+ if ( (t + padLen + 1) > pLen) {
+ pad_check(dummy, (byte)padLen, MAX_PAD_SIZE);
+ if (ssl.isTLS())
+ TLS_hmac(ssl, verify, input, pLen - t, application_data, 1);
+ else
+ hmac(ssl, verify, input, pLen - t, application_data, 1);
+ constant_compare(verify, input + pLen - t, t);
+
+ return -1;
+ }
+
+ if (pad_check(input + pLen - (padLen + 1), (byte)padLen, padLen + 1) != 0) {
+ pad_check(dummy, (byte)padLen, MAX_PAD_SIZE - padLen - 1);
+ if (ssl.isTLS())
+ TLS_hmac(ssl, verify, input, pLen - t, application_data, 1);
+ else
+ hmac(ssl, verify, input, pLen - t, application_data, 1);
+ constant_compare(verify, input + pLen - t, t);
+
+ return -1;
+ }
+
+ pad_check(dummy, (byte)padLen, MAX_PAD_SIZE - padLen - 1);
+ if (ssl.isTLS())
+ TLS_hmac(ssl, verify, input, pLen - padLen - 1 - t, application_data,1);
+ else
+ hmac(ssl, verify, input, pLen - padLen - 1 - t, application_data, 1);
+
+ compress_rounds(ssl, get_rounds(pLen, padLen, t), dummy);
+
+ if (constant_compare(verify, input + (pLen - padLen - 1 - t), t) != 0)
+ return -1;
+
+ return 0;
+}
+
+
// Process handler for Data
void Data::Process(input_buffer& input, SSL& ssl)
{
int msgSz = ssl.getSecurity().get_parms().encrypt_size_;
int pad = 0, padSz = 0;
int ivExtra = 0;
+ int digestSz = ssl.getCrypto().get_digest().get_digestSize();
+ const byte* rawData = input.get_buffer() + input.get_current();
+ opaque verify[SHA_LEN];
if (ssl.getSecurity().get_parms().cipher_type_ == block) {
if (ssl.isTLSv1_1()) // IV
ivExtra = ssl.getCrypto().get_cipher().get_blockSize();
pad = *(input.get_buffer() + input.get_current() + msgSz -ivExtra - 1);
padSz = 1;
+
+ if (ssl.isTLS()) {
+ if (timing_verify(ssl, rawData, pad,digestSz, msgSz-ivExtra) != 0) {
+ ssl.SetError(verify_error);
+ return;
+ }
+ }
+ else { // SSLv3, some don't do this padding right
+ int sz3 = msgSz - digestSz - pad - 1;
+ hmac(ssl, verify, rawData, sz3, application_data, true);
+ if (constant_compare(verify, rawData + sz3, digestSz) != 0) {
+ ssl.SetError(verify_error);
+ return;
+ }
+ }
}
- int digestSz = ssl.getCrypto().get_digest().get_digestSize();
+ else { // stream
+ int streamSz = msgSz - digestSz;
+ if (ssl.isTLS())
+ TLS_hmac(ssl, verify, rawData, streamSz, application_data, true);
+ else
+ hmac(ssl, verify, rawData, streamSz, application_data, true);
+ if (constant_compare(verify, rawData + streamSz, digestSz) != 0) {
+ ssl.SetError(verify_error);
+ return;
+ }
+ }
+
int dataSz = msgSz - ivExtra - digestSz - pad - padSz;
- opaque verify[SHA_LEN];
if (dataSz < 0) {
ssl.SetError(bad_input);
return;
}
- const byte* rawData = input.get_buffer() + input.get_current();
// read data
if (dataSz) { // could be compressed
@@ -1013,27 +1177,10 @@
input.read(data->get_buffer(), dataSz);
data->add_size(dataSz);
}
-
- if (ssl.isTLS())
- TLS_hmac(ssl, verify, rawData, dataSz, application_data, true);
- else
- hmac(ssl, verify, rawData, dataSz, application_data, true);
}
- // read mac and skip fill
- opaque mac[SHA_LEN];
- input.read(mac, digestSz);
- input.set_current(input.get_current() + pad + padSz);
-
- // verify
- if (dataSz) {
- if (memcmp(mac, verify, digestSz)) {
- ssl.SetError(verify_error);
- return;
- }
- }
- else
- ssl.get_SEQIncrement(true); // even though no data, increment verify
+ // advance past mac and fill
+ input.set_current(input.get_current() + digestSz + pad + padByte);
}
Index: mysql-5.5-5.5.30+dfsg/extra/yassl/taocrypt/include/asn.hpp
===================================================================
--- mysql-5.5-5.5.30+dfsg.orig/extra/yassl/taocrypt/include/asn.hpp 2013-03-27 10:56:31.000000000 +0100
+++ mysql-5.5-5.5.30+dfsg/extra/yassl/taocrypt/include/asn.hpp 2013-03-27 10:58:30.865636136 +0100
@@ -112,7 +112,7 @@
MAX_LENGTH_SZ = 5,
MAX_SEQ_SZ = 5, // enum(seq|con) + length(4)
MAX_ALGO_SIZE = 9,
- MAX_DIGEST_SZ = 25, // SHA + enum(Bit or Octet) + length(4)
+ MAX_DIGEST_SZ = 69, // SHA512 + enum(Bit or Octet) + length(4)
DSA_SIG_SZ = 40,
ASN_NAME_MAX = 512 // max total of all included names
};
@@ -258,8 +258,11 @@
enum ContentType { HUH = 651 };
-enum SigType { SHAwDSA = 517, MD2wRSA = 646, MD5wRSA = 648, SHAwRSA =649};
-enum HashType { MD2h = 646, MD5h = 649, SHAh = 88 };
+enum SigType { SHAwDSA = 517, MD2wRSA = 646, MD5wRSA = 648, SHAwRSA = 649,
+ SHA256wRSA = 655, SHA384wRSA = 656, SHA512wRSA = 657,
+ SHA256wDSA = 416 };
+enum HashType { MD2h = 646, MD5h = 649, SHAh = 88, SHA256h = 414, SHA384h = 415,
+ SHA512h = 416 };
enum KeyType { DSAk = 515, RSAk = 645 }; // sums of algo OID
Index: mysql-5.5-5.5.30+dfsg/extra/yassl/taocrypt/include/sha.hpp
===================================================================
--- mysql-5.5-5.5.30+dfsg.orig/extra/yassl/taocrypt/include/sha.hpp 2013-03-27 10:56:31.000000000 +0100
+++ mysql-5.5-5.5.30+dfsg/extra/yassl/taocrypt/include/sha.hpp 2013-03-27 10:58:30.865636136 +0100
@@ -158,6 +158,12 @@
void Transform();
};
+enum { MAX_SHA2_DIGEST_SIZE = 64 }; // SHA512
+
+#else
+
+enum { MAX_SHA2_DIGEST_SIZE = 32 }; // SHA256
+
#endif // WORD64_AVAILABLE
Index: mysql-5.5-5.5.30+dfsg/extra/yassl/taocrypt/src/asn.cpp
===================================================================
--- mysql-5.5-5.5.30+dfsg.orig/extra/yassl/taocrypt/src/asn.cpp 2013-03-27 10:56:31.000000000 +0100
+++ mysql-5.5-5.5.30+dfsg/extra/yassl/taocrypt/src/asn.cpp 2013-03-27 10:58:30.865636136 +0100
@@ -972,12 +972,26 @@
hasher.reset(NEW_TC SHA);
ht = SHAh;
}
+ else if (signatureOID_ == SHA256wRSA || signatureOID_ == SHA256wDSA) {
+ hasher.reset(NEW_TC SHA256);
+ ht = SHA256h;
+ }
+#ifdef WORD64_AVAILABLE
+ else if (signatureOID_ == SHA384wRSA) {
+ hasher.reset(NEW_TC SHA384);
+ ht = SHA384h;
+ }
+ else if (signatureOID_ == SHA512wRSA) {
+ hasher.reset(NEW_TC SHA512);
+ ht = SHA512h;
+ }
+#endif
else {
source_.SetError(UNKOWN_SIG_E);
return false;
}
- byte digest[SHA::DIGEST_SIZE]; // largest size
+ byte digest[MAX_SHA2_DIGEST_SIZE]; // largest size
hasher->Update(source_.get_buffer() + certBegin_, sigIndex_ - certBegin_);
hasher->Final(digest);
@@ -1050,6 +1064,12 @@
0x02, 0x05, 0x05, 0x00 };
static const byte md2AlgoID[] = { 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d,
0x02, 0x02, 0x05, 0x00};
+ static const byte sha256AlgoID[] = { 0x60, 0x86, 0x48, 0x01, 0x65, 0x03,
+ 0x04, 0x02, 0x01, 0x05, 0x00 };
+ static const byte sha384AlgoID[] = { 0x60, 0x86, 0x48, 0x01, 0x65, 0x03,
+ 0x04, 0x02, 0x02, 0x05, 0x00 };
+ static const byte sha512AlgoID[] = { 0x60, 0x86, 0x48, 0x01, 0x65, 0x03,
+ 0x04, 0x02, 0x03, 0x05, 0x00 };
int algoSz = 0;
const byte* algoName = 0;
@@ -1060,6 +1080,21 @@
algoName = shaAlgoID;
break;
+ case SHA256h:
+ algoSz = sizeof(sha256AlgoID);
+ algoName = sha256AlgoID;
+ break;
+
+ case SHA384h:
+ algoSz = sizeof(sha384AlgoID);
+ algoName = sha384AlgoID;
+ break;
+
+ case SHA512h:
+ algoSz = sizeof(sha512AlgoID);
+ algoName = sha512AlgoID;
+ break;
+
case MD2h:
algoSz = sizeof(md2AlgoID);
algoName = md2AlgoID;
