qemu-devel.nongnu.org archive mirror
 help / color / mirror / Atom feed
* [Qemu-devel] [PULL v1 0/4] Merge qcrypto 2017/05/07
@ 2017-05-09 13:46 Daniel P. Berrange
  2017-05-09 13:46 ` [Qemu-devel] [PULL v1 1/4] Default to GSSAPI (Kerberos) instead of DIGEST-MD5 for SASL Daniel P. Berrange
                   ` (4 more replies)
  0 siblings, 5 replies; 6+ messages in thread
From: Daniel P. Berrange @ 2017-05-09 13:46 UTC (permalink / raw)
  To: qemu-devel; +Cc: Stefan Hajnoczi, Daniel P. Berrange

The following changes since commit dd1559bb267becbb838de41132ef60771d183e5d:

  Merge remote-tracking branch 'elmarco/tags/chr-tests-pull-request' into staging (2017-05-05 17:07:55 +0100)

are available in the git repository at:

  git://github.com/berrange/qemu tags/pull-qcrypto-2017-05-09-1

for you to fetch changes up to a37278169d0d7d33270c6817f4a2e4f7345e1098:

  crypto: qcrypto_random_bytes() now works on windows w/o any other crypto libs (2017-05-09 14:41:47 +0100)

----------------------------------------------------------------
Merge qcrypto 2017/05/09 v1

----------------------------------------------------------------

Daniel P. Berrange (3):
  Default to GSSAPI (Kerberos) instead of DIGEST-MD5 for SASL
  List SASL config file under the cryptography maintainer's realm
  crypto: move 'opaque' parameter to (nearly) the end of parameter list

Geert Martin Ijewski (1):
  crypto: qcrypto_random_bytes() now works on windows w/o any other
    crypto libs

 MAINTAINERS               |  1 +
 block/crypto.c            |  6 +++---
 crypto/block-luks.c       | 13 +++++++-----
 crypto/init.c             |  6 ++++++
 crypto/random-gcrypt.c    |  2 ++
 crypto/random-gnutls.c    |  3 +++
 crypto/random-platform.c  | 45 ++++++++++++++++++++++++++++++++-------
 include/crypto/block.h    |  6 +++---
 include/crypto/random.h   |  9 ++++++++
 qemu-doc.texi             | 50 +++++++++++++++++++++++++------------------
 qemu.sasl                 | 54 +++++++++++++++++++++++++++--------------------
 tests/test-crypto-block.c |  6 +++---
 12 files changed, 135 insertions(+), 66 deletions(-)

-- 
2.9.3

^ permalink raw reply	[flat|nested] 6+ messages in thread

* [Qemu-devel] [PULL v1 1/4] Default to GSSAPI (Kerberos) instead of DIGEST-MD5 for SASL
  2017-05-09 13:46 [Qemu-devel] [PULL v1 0/4] Merge qcrypto 2017/05/07 Daniel P. Berrange
@ 2017-05-09 13:46 ` Daniel P. Berrange
  2017-05-09 13:46 ` [Qemu-devel] [PULL v1 2/4] List SASL config file under the cryptography maintainer's realm Daniel P. Berrange
                   ` (3 subsequent siblings)
  4 siblings, 0 replies; 6+ messages in thread
From: Daniel P. Berrange @ 2017-05-09 13:46 UTC (permalink / raw)
  To: qemu-devel; +Cc: Stefan Hajnoczi, Daniel P. Berrange

RFC 6331 documents a number of serious security weaknesses in
the SASL DIGEST-MD5 mechanism. As such, QEMU should not be
using or recommending it as a default mechanism for VNC auth
with SASL.

GSSAPI (Kerberos) is the only other viable SASL mechanism that
can provide secure session encryption so enable that by defalt
as the replacement. If users have TLS enabled for VNC, they can
optionally decide to use SCRAM-SHA-1 instead of GSSAPI, allowing
plain username and password auth.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
---
 qemu-doc.texi | 50 +++++++++++++++++++++++++++++---------------------
 qemu.sasl     | 54 +++++++++++++++++++++++++++++++-----------------------
 2 files changed, 60 insertions(+), 44 deletions(-)

diff --git a/qemu-doc.texi b/qemu-doc.texi
index 794ab4a..a4be714 100644
--- a/qemu-doc.texi
+++ b/qemu-doc.texi
@@ -1732,37 +1732,45 @@ SASL service config /etc/sasl2/qemu.conf. If running QEMU as an
 unprivileged user, an environment variable SASL_CONF_PATH can be used
 to make it search alternate locations for the service config.
 
-The default configuration might contain
+If the TLS option is enabled for VNC, then it will provide session encryption,
+otherwise the SASL mechanism will have to provide encryption. In the latter
+case the list of possible plugins that can be used is drastically reduced. In
+fact only the GSSAPI SASL mechanism provides an acceptable level of security
+by modern standards. Previous versions of QEMU referred to the DIGEST-MD5
+mechanism, however, it has multiple serious flaws described in detail in
+RFC 6331 and thus should never be used any more. The SCRAM-SHA-1 mechanism
+provides a simple username/password auth facility similar to DIGEST-MD5, but
+does not support session encryption, so can only be used in combination with
+TLS.
+
+When not using TLS the recommended configuration is
 
 @example
-mech_list: digest-md5
-sasldb_path: /etc/qemu/passwd.db
+mech_list: gssapi
+keytab: /etc/qemu/krb5.tab
 @end example
 
-This says to use the 'Digest MD5' mechanism, which is similar to the HTTP
-Digest-MD5 mechanism. The list of valid usernames & passwords is maintained
-in the /etc/qemu/passwd.db file, and can be updated using the saslpasswd2
-command. While this mechanism is easy to configure and use, it is not
-considered secure by modern standards, so only suitable for developers /
-ad-hoc testing.
+This says to use the 'GSSAPI' mechanism with the Kerberos v5 protocol, with
+the server principal stored in /etc/qemu/krb5.tab. For this to work the
+administrator of your KDC must generate a Kerberos principal for the server,
+with a name of 'qemu/somehost.example.com@@EXAMPLE.COM' replacing
+'somehost.example.com' with the fully qualified host name of the machine
+running QEMU, and 'EXAMPLE.COM' with the Kerberos Realm.
 
-A more serious deployment might use Kerberos, which is done with the 'gssapi'
-mechanism
+When using TLS, if username+password authentication is desired, then a
+reasonable configuration is
 
 @example
-mech_list: gssapi
-keytab: /etc/qemu/krb5.tab
+mech_list: scram-sha-1
+sasldb_path: /etc/qemu/passwd.db
 @end example
 
-For this to work the administrator of your KDC must generate a Kerberos
-principal for the server, with a name of  'qemu/somehost.example.com@@EXAMPLE.COM'
-replacing 'somehost.example.com' with the fully qualified host name of the
-machine running QEMU, and 'EXAMPLE.COM' with the Kerberos Realm.
+The saslpasswd2 program can be used to populate the passwd.db file with
+accounts.
 
-Other configurations will be left as an exercise for the reader. It should
-be noted that only Digest-MD5 and GSSAPI provides a SSF layer for data
-encryption. For all other mechanisms, VNC should always be configured to
-use TLS and x509 certificates to protect security credentials from snooping.
+Other SASL configurations will be left as an exercise for the reader. Note that
+all mechanisms except GSSAPI, should be combined with use of TLS to ensure a
+secure data channel.
 
 @node gdb_usage
 @section GDB usage
diff --git a/qemu.sasl b/qemu.sasl
index 64fdef3..fb8a92b 100644
--- a/qemu.sasl
+++ b/qemu.sasl
@@ -1,36 +1,44 @@
-# If you want to use the non-TLS socket, then you *must* include
-# the GSSAPI or DIGEST-MD5 mechanisms, because they are the only
-# ones that can offer session encryption as well as authentication.
+# If you want to use VNC remotely without TLS, then you *must*
+# pick a mechanism which provides session encryption as well
+# as authentication.
 #
-# If you're only using TLS, then you can turn on any mechanisms
+# If you are only using TLS, then you can turn on any mechanisms
 # you like for authentication, because TLS provides the encryption
 #
-# Default to a simple username+password mechanism
-# NB digest-md5 is no longer considered secure by current standards
-mech_list: digest-md5
+# If you are only using UNIX sockets then encryption is not
+# required at all.
+#
+# NB, previously DIGEST-MD5 was set as the default mechanism for
+# QEMU VNC. Per RFC 6331 this is vulnerable to many serious security
+# flaws as should no longer be used. Thus GSSAPI is now the default.
+#
+# To use GSSAPI requires that a QEMU service principal is
+# added to the Kerberos server for each host running QEMU.
+# This principal needs to be exported to the keytab file listed below
+mech_list: gssapi
 
-# Before you can use GSSAPI, you need a service principle on the
-# KDC server for libvirt, and that to be exported to the keytab
-# file listed below
-#mech_list: gssapi
+# If using TLS with VNC, or a UNIX socket only, it is possible to
+# enable plugins which don't provide session encryption. The
+# 'scram-sha-1' plugin allows plain username/password authentication
+# to be performed
 #
-# You can also list many mechanisms at once, then the user can choose
-# by adding  '?auth=sasl.gssapi' to their libvirt URI, eg
-#   qemu+tcp://hostname/system?auth=sasl.gssapi
-#mech_list: digest-md5 gssapi
+#mech_list: scram-sha-1
+
+# You can also list many mechanisms at once, and the VNC server will
+# negotiate which to use by considering the list enabled on the VNC
+# client.
+#mech_list: scram-sha-1 gssapi
 
 # Some older builds of MIT kerberos on Linux ignore this option &
 # instead need KRB5_KTNAME env var.
 # For modern Linux, and other OS, this should be sufficient
 #
-# There is no default value here, uncomment if you need this
-#keytab: /etc/qemu/krb5.tab
+# This file needs to be populated with the service principal that
+# was created on the Kerberos v5 server. If switching to a non-gssapi
+# mechanism this can be commented out.
+keytab: /etc/qemu/krb5.tab
 
-# If using digest-md5 for username/passwds, then this is the file
+# If using scram-sha-1 for username/passwds, then this is the file
 # containing the passwds. Use 'saslpasswd2 -a qemu [username]'
 # to add entries, and 'sasldblistusers2 -f [sasldb_path]' to browse it
-sasldb_path: /etc/qemu/passwd.db
-
-
-auxprop_plugin: sasldb
-
+#sasldb_path: /etc/qemu/passwd.db
-- 
2.9.3

^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [Qemu-devel] [PULL v1 2/4] List SASL config file under the cryptography maintainer's realm
  2017-05-09 13:46 [Qemu-devel] [PULL v1 0/4] Merge qcrypto 2017/05/07 Daniel P. Berrange
  2017-05-09 13:46 ` [Qemu-devel] [PULL v1 1/4] Default to GSSAPI (Kerberos) instead of DIGEST-MD5 for SASL Daniel P. Berrange
@ 2017-05-09 13:46 ` Daniel P. Berrange
  2017-05-09 13:46 ` [Qemu-devel] [PULL v1 3/4] crypto: move 'opaque' parameter to (nearly) the end of parameter list Daniel P. Berrange
                   ` (2 subsequent siblings)
  4 siblings, 0 replies; 6+ messages in thread
From: Daniel P. Berrange @ 2017-05-09 13:46 UTC (permalink / raw)
  To: qemu-devel; +Cc: Stefan Hajnoczi, Daniel P. Berrange

No one is listed as maintainer for qemu.sasl. It is used by the
VNC server for SASL auth, but since it is cryptography related,
list it under the crytography maintainer's realm, rather than
under the UI maintainer.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
---
 MAINTAINERS | 1 +
 1 file changed, 1 insertion(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index efdec47..b4d877b 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1484,6 +1484,7 @@ S: Maintained
 F: crypto/
 F: include/crypto/
 F: tests/test-crypto-*
+F: qemu.sasl
 
 Coroutines
 M: Stefan Hajnoczi <stefanha@redhat.com>
-- 
2.9.3

^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [Qemu-devel] [PULL v1 3/4] crypto: move 'opaque' parameter to (nearly) the end of parameter list
  2017-05-09 13:46 [Qemu-devel] [PULL v1 0/4] Merge qcrypto 2017/05/07 Daniel P. Berrange
  2017-05-09 13:46 ` [Qemu-devel] [PULL v1 1/4] Default to GSSAPI (Kerberos) instead of DIGEST-MD5 for SASL Daniel P. Berrange
  2017-05-09 13:46 ` [Qemu-devel] [PULL v1 2/4] List SASL config file under the cryptography maintainer's realm Daniel P. Berrange
@ 2017-05-09 13:46 ` Daniel P. Berrange
  2017-05-09 13:46 ` [Qemu-devel] [PULL v1 4/4] crypto: qcrypto_random_bytes() now works on windows w/o any other crypto libs Daniel P. Berrange
  2017-05-10 15:26 ` [Qemu-devel] [PULL v1 0/4] Merge qcrypto 2017/05/07 Stefan Hajnoczi
  4 siblings, 0 replies; 6+ messages in thread
From: Daniel P. Berrange @ 2017-05-09 13:46 UTC (permalink / raw)
  To: qemu-devel; +Cc: Stefan Hajnoczi, Daniel P. Berrange

Previous commit moved 'opaque' to be the 2nd parameter in the list:

  commit 375092332eeaa6e47561ce47fd36144cdaf964d0
  Author: Fam Zheng <famz@redhat.com>
  Date:   Fri Apr 21 20:27:02 2017 +0800

    crypto: Make errp the last parameter of functions

    Move opaque to 2nd instead of the 2nd to last, so that compilers help
    check with the conversion.

this puts it back to the 2nd to last position.

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
---
 block/crypto.c            |  6 +++---
 crypto/block-luks.c       | 13 ++++++++-----
 include/crypto/block.h    |  6 +++---
 tests/test-crypto-block.c |  6 +++---
 4 files changed, 17 insertions(+), 14 deletions(-)

diff --git a/block/crypto.c b/block/crypto.c
index 6828180..10e5ddc 100644
--- a/block/crypto.c
+++ b/block/crypto.c
@@ -56,10 +56,10 @@ static int block_crypto_probe_generic(QCryptoBlockFormat format,
 
 
 static ssize_t block_crypto_read_func(QCryptoBlock *block,
-                                      void *opaque,
                                       size_t offset,
                                       uint8_t *buf,
                                       size_t buflen,
+                                      void *opaque,
                                       Error **errp)
 {
     BlockDriverState *bs = opaque;
@@ -83,10 +83,10 @@ struct BlockCryptoCreateData {
 
 
 static ssize_t block_crypto_write_func(QCryptoBlock *block,
-                                       void *opaque,
                                        size_t offset,
                                        const uint8_t *buf,
                                        size_t buflen,
+                                       void *opaque,
                                        Error **errp)
 {
     struct BlockCryptoCreateData *data = opaque;
@@ -102,8 +102,8 @@ static ssize_t block_crypto_write_func(QCryptoBlock *block,
 
 
 static ssize_t block_crypto_init_func(QCryptoBlock *block,
-                                      void *opaque,
                                       size_t headerlen,
+                                      void *opaque,
                                       Error **errp)
 {
     struct BlockCryptoCreateData *data = opaque;
diff --git a/crypto/block-luks.c b/crypto/block-luks.c
index d5a31bb..2b97d89 100644
--- a/crypto/block-luks.c
+++ b/crypto/block-luks.c
@@ -473,9 +473,9 @@ qcrypto_block_luks_load_key(QCryptoBlock *block,
      * then encrypted.
      */
     rv = readfunc(block,
-                  opaque,
                   slot->key_offset * QCRYPTO_BLOCK_LUKS_SECTOR_SIZE,
                   splitkey, splitkeylen,
+                  opaque,
                   errp);
     if (rv < 0) {
         goto cleanup;
@@ -676,9 +676,10 @@ qcrypto_block_luks_open(QCryptoBlock *block,
 
     /* Read the entire LUKS header, minus the key material from
      * the underlying device */
-    rv = readfunc(block, opaque, 0,
+    rv = readfunc(block, 0,
                   (uint8_t *)&luks->header,
                   sizeof(luks->header),
+                  opaque,
                   errp);
     if (rv < 0) {
         ret = rv;
@@ -1245,7 +1246,7 @@ qcrypto_block_luks_create(QCryptoBlock *block,
         QCRYPTO_BLOCK_LUKS_SECTOR_SIZE;
 
     /* Reserve header space to match payload offset */
-    initfunc(block, opaque, block->payload_offset, &local_err);
+    initfunc(block, block->payload_offset, opaque, &local_err);
     if (local_err) {
         error_propagate(errp, local_err);
         goto error;
@@ -1267,9 +1268,10 @@ qcrypto_block_luks_create(QCryptoBlock *block,
 
 
     /* Write out the partition header and key slot headers */
-    writefunc(block, opaque, 0,
+    writefunc(block, 0,
               (const uint8_t *)&luks->header,
               sizeof(luks->header),
+              opaque,
               &local_err);
 
     /* Delay checking local_err until we've byte-swapped */
@@ -1295,10 +1297,11 @@ qcrypto_block_luks_create(QCryptoBlock *block,
 
     /* Write out the master key material, starting at the
      * sector immediately following the partition header. */
-    if (writefunc(block, opaque,
+    if (writefunc(block,
                   luks->header.key_slots[0].key_offset *
                   QCRYPTO_BLOCK_LUKS_SECTOR_SIZE,
                   splitkey, splitkeylen,
+                  opaque,
                   errp) != splitkeylen) {
         goto error;
     }
diff --git a/include/crypto/block.h b/include/crypto/block.h
index 4a053a3..013a435 100644
--- a/include/crypto/block.h
+++ b/include/crypto/block.h
@@ -30,22 +30,22 @@ typedef struct QCryptoBlock QCryptoBlock;
  * and QCryptoBlockOpenOptions in qapi/crypto.json */
 
 typedef ssize_t (*QCryptoBlockReadFunc)(QCryptoBlock *block,
-                                        void *opaque,
                                         size_t offset,
                                         uint8_t *buf,
                                         size_t buflen,
+                                        void *opaque,
                                         Error **errp);
 
 typedef ssize_t (*QCryptoBlockInitFunc)(QCryptoBlock *block,
-                                        void *opaque,
                                         size_t headerlen,
+                                        void *opaque,
                                         Error **errp);
 
 typedef ssize_t (*QCryptoBlockWriteFunc)(QCryptoBlock *block,
-                                         void *opaque,
                                          size_t offset,
                                          const uint8_t *buf,
                                          size_t buflen,
+                                         void *opaque,
                                          Error **errp);
 
 /**
diff --git a/tests/test-crypto-block.c b/tests/test-crypto-block.c
index 85e6603..95c4bd5 100644
--- a/tests/test-crypto-block.c
+++ b/tests/test-crypto-block.c
@@ -187,10 +187,10 @@ static struct QCryptoBlockTestData {
 
 
 static ssize_t test_block_read_func(QCryptoBlock *block,
-                                    void *opaque,
                                     size_t offset,
                                     uint8_t *buf,
                                     size_t buflen,
+                                    void *opaque,
                                     Error **errp)
 {
     Buffer *header = opaque;
@@ -204,8 +204,8 @@ static ssize_t test_block_read_func(QCryptoBlock *block,
 
 
 static ssize_t test_block_init_func(QCryptoBlock *block,
-                                    void *opaque,
                                     size_t headerlen,
+                                    void *opaque,
                                     Error **errp)
 {
     Buffer *header = opaque;
@@ -219,10 +219,10 @@ static ssize_t test_block_init_func(QCryptoBlock *block,
 
 
 static ssize_t test_block_write_func(QCryptoBlock *block,
-                                     void *opaque,
                                      size_t offset,
                                      const uint8_t *buf,
                                      size_t buflen,
+                                     void *opaque,
                                      Error **errp)
 {
     Buffer *header = opaque;
-- 
2.9.3

^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [Qemu-devel] [PULL v1 4/4] crypto: qcrypto_random_bytes() now works on windows w/o any other crypto libs
  2017-05-09 13:46 [Qemu-devel] [PULL v1 0/4] Merge qcrypto 2017/05/07 Daniel P. Berrange
                   ` (2 preceding siblings ...)
  2017-05-09 13:46 ` [Qemu-devel] [PULL v1 3/4] crypto: move 'opaque' parameter to (nearly) the end of parameter list Daniel P. Berrange
@ 2017-05-09 13:46 ` Daniel P. Berrange
  2017-05-10 15:26 ` [Qemu-devel] [PULL v1 0/4] Merge qcrypto 2017/05/07 Stefan Hajnoczi
  4 siblings, 0 replies; 6+ messages in thread
From: Daniel P. Berrange @ 2017-05-09 13:46 UTC (permalink / raw)
  To: qemu-devel; +Cc: Stefan Hajnoczi, Geert Martin Ijewski, Daniel P . Berrange

From: Geert Martin Ijewski <gm.ijewski@web.de>

If no crypto library is included in the build, QEMU uses
qcrypto_random_bytes() to generate random data. That function tried to open
/dev/urandom or /dev/random and if opening both files failed it errored out.

Those files obviously do not exist on windows, so there the code uses
CryptGenRandom().

Furthermore there was some refactoring and a new function
qcrypto_random_init() was introduced. If a proper crypto library (gnutls or
libgcrypt) is included in the build, this function does nothing. If neither
is included it initializes the (platform specific) handles that are used by
qcrypto_random_bytes().
Either:
* a handle to /dev/urandom | /dev/random on unix like systems
* a handle to a cryptographic service provider on windows

Signed-off-by: Geert Martin Ijewski <gm.ijewski@web.de>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
---
 crypto/init.c            |  6 ++++++
 crypto/random-gcrypt.c   |  2 ++
 crypto/random-gnutls.c   |  3 +++
 crypto/random-platform.c | 45 +++++++++++++++++++++++++++++++++++++--------
 include/crypto/random.h  |  9 +++++++++
 5 files changed, 57 insertions(+), 8 deletions(-)

diff --git a/crypto/init.c b/crypto/init.c
index f65207e..f131c42 100644
--- a/crypto/init.c
+++ b/crypto/init.c
@@ -32,6 +32,8 @@
 #include <gcrypt.h>
 #endif
 
+#include "crypto/random.h"
+
 /* #define DEBUG_GNUTLS */
 
 /*
@@ -146,5 +148,9 @@ int qcrypto_init(Error **errp)
     gcry_control(GCRYCTL_INITIALIZATION_FINISHED, 0);
 #endif
 
+    if (qcrypto_random_init(errp) < 0) {
+        return -1;
+    }
+
     return 0;
 }
diff --git a/crypto/random-gcrypt.c b/crypto/random-gcrypt.c
index 0de9a09..9f1c9ee 100644
--- a/crypto/random-gcrypt.c
+++ b/crypto/random-gcrypt.c
@@ -31,3 +31,5 @@ int qcrypto_random_bytes(uint8_t *buf,
     gcry_randomize(buf, buflen, GCRY_STRONG_RANDOM);
     return 0;
 }
+
+int qcrypto_random_init(Error **errp G_GNUC_UNUSED) { return 0; }
diff --git a/crypto/random-gnutls.c b/crypto/random-gnutls.c
index 04b45a8..5350003 100644
--- a/crypto/random-gnutls.c
+++ b/crypto/random-gnutls.c
@@ -41,3 +41,6 @@ int qcrypto_random_bytes(uint8_t *buf,
 
     return 0;
 }
+
+
+int qcrypto_random_init(Error **errp G_GNUC_UNUSED) { return 0; }
diff --git a/crypto/random-platform.c b/crypto/random-platform.c
index 82b755a..0eddb91 100644
--- a/crypto/random-platform.c
+++ b/crypto/random-platform.c
@@ -22,14 +22,16 @@
 
 #include "crypto/random.h"
 
-int qcrypto_random_bytes(uint8_t *buf G_GNUC_UNUSED,
-                         size_t buflen G_GNUC_UNUSED,
-                         Error **errp)
-{
-    int fd;
-    int ret = -1;
-    int got;
+#ifdef _WIN32
+#include <Wincrypt.h>
+static HCRYPTPROV hCryptProv;
+#else
+static int fd; /* a file handle to either /dev/urandom or /dev/random */
+#endif
 
+int qcrypto_random_init(Error **errp)
+{
+#ifndef _WIN32
     /* TBD perhaps also add support for BSD getentropy / Linux
      * getrandom syscalls directly */
     fd = open("/dev/urandom", O_RDONLY);
@@ -41,6 +43,25 @@ int qcrypto_random_bytes(uint8_t *buf G_GNUC_UNUSED,
         error_setg(errp, "No /dev/urandom or /dev/random found");
         return -1;
     }
+#else
+    if (!CryptAcquireContext(&hCryptProv, NULL, NULL, PROV_RSA_FULL,
+                             CRYPT_SILENT | CRYPT_VERIFYCONTEXT)) {
+        error_setg_win32(errp, GetLastError(),
+                         "Unable to create cryptographic provider");
+        return -1;
+    }
+#endif
+
+    return 0;
+}
+
+int qcrypto_random_bytes(uint8_t *buf G_GNUC_UNUSED,
+                         size_t buflen G_GNUC_UNUSED,
+                         Error **errp)
+{
+#ifndef _WIN32
+    int ret = -1;
+    int got;
 
     while (buflen > 0) {
         got = read(fd, buf, buflen);
@@ -59,6 +80,14 @@ int qcrypto_random_bytes(uint8_t *buf G_GNUC_UNUSED,
 
     ret = 0;
  cleanup:
-    close(fd);
     return ret;
+#else
+    if (!CryptGenRandom(hCryptProv, buflen, buf)) {
+        error_setg_win32(errp, GetLastError(),
+                         "Unable to read random bytes");
+        return -1;
+    }
+
+    return 0;
+#endif
 }
diff --git a/include/crypto/random.h b/include/crypto/random.h
index a101353..a07229c 100644
--- a/include/crypto/random.h
+++ b/include/crypto/random.h
@@ -40,5 +40,14 @@ int qcrypto_random_bytes(uint8_t *buf,
                          size_t buflen,
                          Error **errp);
 
+/**
+ * qcrypto_random_init:
+ * @errp: pointer to a NULL-initialized error object
+ *
+ * Initializes the handles used by qcrypto_random_bytes
+ *
+ * Returns 0 on success, -1 on error
+ */
+int qcrypto_random_init(Error **errp);
 
 #endif /* QCRYPTO_RANDOM_H */
-- 
2.9.3

^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [Qemu-devel] [PULL v1 0/4] Merge qcrypto 2017/05/07
  2017-05-09 13:46 [Qemu-devel] [PULL v1 0/4] Merge qcrypto 2017/05/07 Daniel P. Berrange
                   ` (3 preceding siblings ...)
  2017-05-09 13:46 ` [Qemu-devel] [PULL v1 4/4] crypto: qcrypto_random_bytes() now works on windows w/o any other crypto libs Daniel P. Berrange
@ 2017-05-10 15:26 ` Stefan Hajnoczi
  4 siblings, 0 replies; 6+ messages in thread
From: Stefan Hajnoczi @ 2017-05-10 15:26 UTC (permalink / raw)
  To: Daniel P. Berrange; +Cc: qemu-devel, Stefan Hajnoczi

[-- Attachment #1: Type: text/plain, Size: 1916 bytes --]

On Tue, May 09, 2017 at 02:46:19PM +0100, Daniel P. Berrange wrote:
> The following changes since commit dd1559bb267becbb838de41132ef60771d183e5d:
> 
>   Merge remote-tracking branch 'elmarco/tags/chr-tests-pull-request' into staging (2017-05-05 17:07:55 +0100)
> 
> are available in the git repository at:
> 
>   git://github.com/berrange/qemu tags/pull-qcrypto-2017-05-09-1
> 
> for you to fetch changes up to a37278169d0d7d33270c6817f4a2e4f7345e1098:
> 
>   crypto: qcrypto_random_bytes() now works on windows w/o any other crypto libs (2017-05-09 14:41:47 +0100)
> 
> ----------------------------------------------------------------
> Merge qcrypto 2017/05/09 v1
> 
> ----------------------------------------------------------------
> 
> Daniel P. Berrange (3):
>   Default to GSSAPI (Kerberos) instead of DIGEST-MD5 for SASL
>   List SASL config file under the cryptography maintainer's realm
>   crypto: move 'opaque' parameter to (nearly) the end of parameter list
> 
> Geert Martin Ijewski (1):
>   crypto: qcrypto_random_bytes() now works on windows w/o any other
>     crypto libs
> 
>  MAINTAINERS               |  1 +
>  block/crypto.c            |  6 +++---
>  crypto/block-luks.c       | 13 +++++++-----
>  crypto/init.c             |  6 ++++++
>  crypto/random-gcrypt.c    |  2 ++
>  crypto/random-gnutls.c    |  3 +++
>  crypto/random-platform.c  | 45 ++++++++++++++++++++++++++++++++-------
>  include/crypto/block.h    |  6 +++---
>  include/crypto/random.h   |  9 ++++++++
>  qemu-doc.texi             | 50 +++++++++++++++++++++++++------------------
>  qemu.sasl                 | 54 +++++++++++++++++++++++++++--------------------
>  tests/test-crypto-block.c |  6 +++---
>  12 files changed, 135 insertions(+), 66 deletions(-)
> 
> -- 
> 2.9.3
> 
> 

Thanks, applied to my staging tree:
https://github.com/stefanha/qemu/commits/staging

Stefan

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 455 bytes --]

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2017-05-10 15:27 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2017-05-09 13:46 [Qemu-devel] [PULL v1 0/4] Merge qcrypto 2017/05/07 Daniel P. Berrange
2017-05-09 13:46 ` [Qemu-devel] [PULL v1 1/4] Default to GSSAPI (Kerberos) instead of DIGEST-MD5 for SASL Daniel P. Berrange
2017-05-09 13:46 ` [Qemu-devel] [PULL v1 2/4] List SASL config file under the cryptography maintainer's realm Daniel P. Berrange
2017-05-09 13:46 ` [Qemu-devel] [PULL v1 3/4] crypto: move 'opaque' parameter to (nearly) the end of parameter list Daniel P. Berrange
2017-05-09 13:46 ` [Qemu-devel] [PULL v1 4/4] crypto: qcrypto_random_bytes() now works on windows w/o any other crypto libs Daniel P. Berrange
2017-05-10 15:26 ` [Qemu-devel] [PULL v1 0/4] Merge qcrypto 2017/05/07 Stefan Hajnoczi

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).