[Qemu-devel] [PULL v1 0/3] Merge qcrypto-next 2016/07/21

[Qemu-devel] [PULL v1 0/3] Merge qcrypto-next 2016/07/21

[Daniel P. Berrange]

The following changes since commit e66b05e9ca471715388182613217503160ed7a4d:

  Merge remote-tracking branch 'remotes/ehabkost/tags/x86-pull-request' into staging (2016-07-20 21:32:56 +0100)

are available in the git repository at:

  git://github.com/berrange/qemu tags/pull-qcrypto-2016-07-21-1

for you to fetch changes up to 760328971218bace4ab14b01f619825607fab9c3:

  crypto: don't open-code qcrypto_hash_supports (2016-07-21 10:46:27 +0100)

----------------------------------------------------------------
Merge qcrypto-next 2016/07/21 v1

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

Daniel P. Berrange (3):
  crypto: use /dev/[u]random as a final fallback random source
  crypto: use glib as fallback for hash algorithm
  crypto: don't open-code qcrypto_hash_supports

 crypto/Makefile.objs                        |  4 +-
 crypto/hash-gcrypt.c                        |  3 +-
 crypto/hash-glib.c                          | 97 +++++++++++++++++++++++++++++
 crypto/hash-nettle.c                        |  3 +-
 crypto/hash-stub.c                          | 41 ------------
 crypto/{random-stub.c => random-platform.c} | 37 ++++++++++-
 6 files changed, 136 insertions(+), 49 deletions(-)
 create mode 100644 crypto/hash-glib.c
 delete mode 100644 crypto/hash-stub.c
 rename crypto/{random-stub.c => random-platform.c} (52%)

-- 
2.7.4

[Qemu-devel] [PULL v1 1/3] crypto: use /dev/[u]random as a final fallback random source

[Daniel P. Berrange]

If neither gcrypt or gnutls are available to provide a
cryptographic random number generator, fallback to consuming
bytes directly from /dev/[u]random.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
---
 crypto/Makefile.objs                        |  2 +-
 crypto/{random-stub.c => random-platform.c} | 37 +++++++++++++++++++++++++++--
 2 files changed, 36 insertions(+), 3 deletions(-)
 rename crypto/{random-stub.c => random-platform.c} (52%)

diff --git a/crypto/Makefile.objs b/crypto/Makefile.objs
index 1f86f4f..febffba 100644
--- a/crypto/Makefile.objs
+++ b/crypto/Makefile.objs
@@ -12,6 +12,7 @@ crypto-obj-y += tlssession.o
 crypto-obj-y += secret.o
 crypto-obj-$(CONFIG_GCRYPT) += random-gcrypt.o
 crypto-obj-$(if $(CONFIG_GCRYPT),n,$(CONFIG_GNUTLS_RND)) += random-gnutls.o
+crypto-obj-$(if $(CONFIG_GCRYPT),n,$(if $(CONFIG_GNUTLS_RND),n,y)) += random-platform.o
 crypto-obj-y += pbkdf.o
 crypto-obj-$(CONFIG_NETTLE_KDF) += pbkdf-nettle.o
 crypto-obj-$(if $(CONFIG_NETTLE_KDF),n,$(CONFIG_GCRYPT_KDF)) += pbkdf-gcrypt.o
@@ -28,6 +29,5 @@ crypto-obj-y += block-luks.o
 # Let the userspace emulators avoid linking gnutls/etc
 crypto-aes-obj-y = aes.o
 
-stub-obj-y += random-stub.o
 stub-obj-y += pbkdf-stub.o
 stub-obj-y += hash-stub.o
diff --git a/crypto/random-stub.c b/crypto/random-platform.c
similarity index 52%
rename from crypto/random-stub.c
rename to crypto/random-platform.c
index 63bbf41..82b755a 100644
--- a/crypto/random-stub.c
+++ b/crypto/random-platform.c
@@ -26,6 +26,39 @@ int qcrypto_random_bytes(uint8_t *buf G_GNUC_UNUSED,
                          size_t buflen G_GNUC_UNUSED,
                          Error **errp)
 {
-    error_setg(errp, "No random byte source provided in this build");
-    return -1;
+    int fd;
+    int ret = -1;
+    int got;
+
+    /* TBD perhaps also add support for BSD getentropy / Linux
+     * getrandom syscalls directly */
+    fd = open("/dev/urandom", O_RDONLY);
+    if (fd == -1 && errno == ENOENT) {
+        fd = open("/dev/random", O_RDONLY);
+    }
+
+    if (fd < 0) {
+        error_setg(errp, "No /dev/urandom or /dev/random found");
+        return -1;
+    }
+
+    while (buflen > 0) {
+        got = read(fd, buf, buflen);
+        if (got < 0) {
+            error_setg_errno(errp, errno,
+                             "Unable to read random bytes");
+            goto cleanup;
+        } else if (!got) {
+            error_setg(errp,
+                       "Unexpected EOF reading random bytes");
+            goto cleanup;
+        }
+        buflen -= got;
+        buf += got;
+    }
+
+    ret = 0;
+ cleanup:
+    close(fd);
+    return ret;
 }
-- 
2.7.4

[Qemu-devel] [PULL v1 2/3] crypto: use glib as fallback for hash algorithm

[Daniel P. Berrange]

GLib >= 2.16 provides GChecksum API which is good enough
for md5, sha1, sha256 and sha512. Use this as a final
fallback if neither nettle or gcrypt are available. This
lets us remove the stub hash impl, and so callers can
be sure those 4 algs are always available at compile
time. They may still be disabled at runtime, so a check
for qcrypto_hash_supports() is still best practice to
report good error messages.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
---
 crypto/Makefile.objs |  2 +-
 crypto/hash-glib.c   | 98 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 crypto/hash-stub.c   | 41 ----------------------
 3 files changed, 99 insertions(+), 42 deletions(-)
 create mode 100644 crypto/hash-glib.c
 delete mode 100644 crypto/hash-stub.c

diff --git a/crypto/Makefile.objs b/crypto/Makefile.objs
index febffba..a36d2d9 100644
--- a/crypto/Makefile.objs
+++ b/crypto/Makefile.objs
@@ -2,6 +2,7 @@ crypto-obj-y = init.o
 crypto-obj-y += hash.o
 crypto-obj-$(CONFIG_NETTLE) += hash-nettle.o
 crypto-obj-$(if $(CONFIG_NETTLE),n,$(CONFIG_GCRYPT)) += hash-gcrypt.o
+crypto-obj-$(if $(CONFIG_NETTLE),n,$(if $(CONFIG_GCRYPT),n,y)) += hash-glib.o
 crypto-obj-y += aes.o
 crypto-obj-y += desrfb.o
 crypto-obj-y += cipher.o
@@ -30,4 +31,3 @@ crypto-obj-y += block-luks.o
 crypto-aes-obj-y = aes.o
 
 stub-obj-y += pbkdf-stub.o
-stub-obj-y += hash-stub.o
diff --git a/crypto/hash-glib.c b/crypto/hash-glib.c
new file mode 100644
index 0000000..cb68a3b
--- /dev/null
+++ b/crypto/hash-glib.c
@@ -0,0 +1,98 @@
+/*
+ * QEMU Crypto hash algorithms
+ *
+ * Copyright (c) 2016 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "crypto/hash.h"
+
+
+static int qcrypto_hash_alg_map[QCRYPTO_HASH_ALG__MAX] = {
+    [QCRYPTO_HASH_ALG_MD5] = G_CHECKSUM_MD5,
+    [QCRYPTO_HASH_ALG_SHA1] = G_CHECKSUM_SHA1,
+    [QCRYPTO_HASH_ALG_SHA224] = -1,
+    [QCRYPTO_HASH_ALG_SHA256] = G_CHECKSUM_SHA256,
+    [QCRYPTO_HASH_ALG_SHA384] = -1,
+#if GLIB_CHECK_VERSION(2, 36, 0)
+    [QCRYPTO_HASH_ALG_SHA512] = G_CHECKSUM_SHA512,
+#else
+    [QCRYPTO_HASH_ALG_SHA512] = -1,
+#endif
+    [QCRYPTO_HASH_ALG_RIPEMD160] = -1,
+};
+
+gboolean qcrypto_hash_supports(QCryptoHashAlgorithm alg)
+{
+    if (alg < G_N_ELEMENTS(qcrypto_hash_alg_map) &&
+        qcrypto_hash_alg_map[alg] != -1) {
+        return true;
+    }
+    return false;
+}
+
+
+int qcrypto_hash_bytesv(QCryptoHashAlgorithm alg,
+                        const struct iovec *iov,
+                        size_t niov,
+                        uint8_t **result,
+                        size_t *resultlen,
+                        Error **errp)
+{
+    int i, ret;
+    GChecksum *cs;
+
+    if (alg >= G_N_ELEMENTS(qcrypto_hash_alg_map) ||
+        qcrypto_hash_alg_map[alg] == -1) {
+        error_setg(errp,
+                   "Unknown hash algorithm %d",
+                   alg);
+        return -1;
+    }
+
+    cs = g_checksum_new(qcrypto_hash_alg_map[alg]);
+
+    for (i = 0; i < niov; i++) {
+        g_checksum_update(cs, iov[i].iov_base, iov[i].iov_len);
+    }
+
+    ret = g_checksum_type_get_length(qcrypto_hash_alg_map[alg]);
+    if (ret < 0) {
+        error_setg(errp, "%s",
+                   "Unable to get hash length");
+        goto error;
+    }
+    if (*resultlen == 0) {
+        *resultlen = ret;
+        *result = g_new0(uint8_t, *resultlen);
+    } else if (*resultlen != ret) {
+        error_setg(errp,
+                   "Result buffer size %zu is smaller than hash %d",
+                   *resultlen, ret);
+        goto error;
+    }
+
+    g_checksum_get_digest(cs, *result, resultlen);
+
+    g_checksum_free(cs);
+    return 0;
+
+ error:
+    g_checksum_free(cs);
+    return -1;
+}
diff --git a/crypto/hash-stub.c b/crypto/hash-stub.c
deleted file mode 100644
index 8a9b8d4..0000000
--- a/crypto/hash-stub.c
+++ /dev/null
@@ -1,41 +0,0 @@
-/*
- * QEMU Crypto hash algorithms
- *
- * Copyright (c) 2016 Red Hat, Inc.
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, see <http://www.gnu.org/licenses/>.
- *
- */
-
-#include "qemu/osdep.h"
-#include "qapi/error.h"
-#include "crypto/hash.h"
-
-gboolean qcrypto_hash_supports(QCryptoHashAlgorithm alg G_GNUC_UNUSED)
-{
-    return false;
-}
-
-int qcrypto_hash_bytesv(QCryptoHashAlgorithm alg,
-                        const struct iovec *iov G_GNUC_UNUSED,
-                        size_t niov G_GNUC_UNUSED,
-                        uint8_t **result G_GNUC_UNUSED,
-                        size_t *resultlen G_GNUC_UNUSED,
-                        Error **errp)
-{
-    error_setg(errp,
-               "Hash algorithm %d not supported without GNUTLS",
-               alg);
-    return -1;
-}
-- 
2.7.4

[Qemu-devel] [PULL v1 3/3] crypto: don't open-code qcrypto_hash_supports

[Daniel P. Berrange]

Call the existing qcrypto_hash_supports method from
qcrypto_hash_bytesv instead of open-coding it again.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
---
 crypto/hash-gcrypt.c | 3 +--
 crypto/hash-glib.c   | 3 +--
 crypto/hash-nettle.c | 3 +--
 3 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/crypto/hash-gcrypt.c b/crypto/hash-gcrypt.c
index ed6f842..7690690 100644
--- a/crypto/hash-gcrypt.c
+++ b/crypto/hash-gcrypt.c
@@ -55,8 +55,7 @@ int qcrypto_hash_bytesv(QCryptoHashAlgorithm alg,
     gcry_md_hd_t md;
     unsigned char *digest;
 
-    if (alg >= G_N_ELEMENTS(qcrypto_hash_alg_map) ||
-        qcrypto_hash_alg_map[alg] == GCRY_MD_NONE) {
+    if (!qcrypto_hash_supports(alg)) {
         error_setg(errp,
                    "Unknown hash algorithm %d",
                    alg);
diff --git a/crypto/hash-glib.c b/crypto/hash-glib.c
index cb68a3b..ec99ac9 100644
--- a/crypto/hash-glib.c
+++ b/crypto/hash-glib.c
@@ -57,8 +57,7 @@ int qcrypto_hash_bytesv(QCryptoHashAlgorithm alg,
     int i, ret;
     GChecksum *cs;
 
-    if (alg >= G_N_ELEMENTS(qcrypto_hash_alg_map) ||
-        qcrypto_hash_alg_map[alg] == -1) {
+    if (!qcrypto_hash_supports(alg)) {
         error_setg(errp,
                    "Unknown hash algorithm %d",
                    alg);
diff --git a/crypto/hash-nettle.c b/crypto/hash-nettle.c
index 4c6f50b..6a206dc 100644
--- a/crypto/hash-nettle.c
+++ b/crypto/hash-nettle.c
@@ -113,8 +113,7 @@ int qcrypto_hash_bytesv(QCryptoHashAlgorithm alg,
     int i;
     union qcrypto_hash_ctx ctx;
 
-    if (alg >= G_N_ELEMENTS(qcrypto_hash_alg_map) ||
-        qcrypto_hash_alg_map[alg].init == NULL) {
+    if (!qcrypto_hash_supports(alg)) {
         error_setg(errp,
                    "Unknown hash algorithm %d",
                    alg);
-- 
2.7.4

Re: [Qemu-devel] [PULL v1 0/3] Merge qcrypto-next 2016/07/21

[Peter Maydell]

On 21 July 2016 at 11:09, Daniel P. Berrange <berrange@redhat.com> wrote:
> The following changes since commit e66b05e9ca471715388182613217503160ed7a4d:
>
>   Merge remote-tracking branch 'remotes/ehabkost/tags/x86-pull-request' into staging (2016-07-20 21:32:56 +0100)
>
> are available in the git repository at:
>
>   git://github.com/berrange/qemu tags/pull-qcrypto-2016-07-21-1
>
> for you to fetch changes up to 760328971218bace4ab14b01f619825607fab9c3:
>
>   crypto: don't open-code qcrypto_hash_supports (2016-07-21 10:46:27 +0100)
>
> ----------------------------------------------------------------
> Merge qcrypto-next 2016/07/21 v1
>
> ----------------------------------------------------------------

Applied, thanks.

-- PMM