Merge remote-tracking branch 'remotes/berrange/tags/pull-qcrypto-2016-07-21-1' into staging

Merge qcrypto-next 2016/07/21 v1

# gpg: Signature made Thu 21 Jul 2016 11:07:36 BST
# gpg:                using RSA key 0xBE86EBB415104FDF
# gpg: Good signature from "Daniel P. Berrange <dan@berrange.com>"
# gpg:                 aka "Daniel P. Berrange <berrange@redhat.com>"
# Primary key fingerprint: DAF3 A6FD B26B 6291 2D0E  8E3F BE86 EBB4 1510 4FDF

* remotes/berrange/tags/pull-qcrypto-2016-07-21-1:
  crypto: don't open-code qcrypto_hash_supports
  crypto: use glib as fallback for hash algorithm
  crypto: use /dev/[u]random as a final fallback random source
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

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 $(CONFIG_GCRYPT),n,y)) += hash-glib.o
 crypto-obj-y += aes.o
 crypto-obj-y += desrfb.o
 crypto-obj-y += cipher.o
@@ -12,6 +13,7 @@ crypto-obj-y += tlssession.o
 crypto-obj-y += secret.o
 crypto-obj-$(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 +30,4 @@ 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

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);

crypto/hash-stub.c → crypto/hash-glib.c

@@ -22,20 +22,76 @@
 #include "qapi/error.h"
 #include "crypto/hash.h"
 
-gboolean qcrypto_hash_supports(QCryptoHashAlgorithm alg G_GNUC_UNUSED)
+
+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 G_GNUC_UNUSED,
-                        size_t niov G_GNUC_UNUSED,
-                        uint8_t **result G_GNUC_UNUSED,
-                        size_t *resultlen G_GNUC_UNUSED,
+                        const struct iovec *iov,
+                        size_t niov,
+                        uint8_t **result,
+                        size_t *resultlen,
                         Error **errp)
 {
-    error_setg(errp,
-               "Hash algorithm %d not supported without GNUTLS",
-               alg);
+    int i, ret;
+    GChecksum *cs;
+
+    if (!qcrypto_hash_supports(alg)) {
+        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;
 }

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);

crypto/random-stub.c → 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;
 }