On Thu, Aug 20, 2009 at 08:18:13PM +0200, Miloslav Trma?? wrote:
If the <encryption format='qcow'> element does not specify a secret during volume creation, generate a suitable secret and add it to the <encryption> tag. The caller can view the updated <encryption> tag using virStorageVolGetXMLDesc().
Similarly, when <encryption format='default'/> is specified while creating a qcow or qcow2-formatted volume, change the format to "qcow" and generate a secret as described above.
Changes since the third submission: - Add "flags" parameter to virSecretDefineXML(), virSecretGetXMLDesc(), virSecretGetValue(), virSecretSetValue(), and all derived interfaces. --- src/storage_backend.c | 127 +++++++++++++++++++++++++++++++++++++++++++++++- 1 files changed, 124 insertions(+), 3 deletions(-)
diff --git a/src/storage_backend.c b/src/storage_backend.c index c818142..5fa0035 100644 --- a/src/storage_backend.c +++ b/src/storage_backend.c @@ -43,6 +43,7 @@ #include <selinux/selinux.h> #endif
+#include "datatypes.h" #include "virterror_internal.h" #include "util.h" #include "memory.h" @@ -331,6 +332,118 @@ cleanup: }
static int +virStorageGenerateQcowEncryption(virConnectPtr conn, + virStorageVolDefPtr vol) +{ + virBuffer buf = VIR_BUFFER_INITIALIZER; + virStorageEncryptionPtr enc; + virStorageEncryptionSecretPtr enc_secret = NULL; + virSecretPtr secret = NULL; + char *uuid = NULL, *xml; + unsigned char value[16]; + int ret = -1, fd = -1; + size_t i; + + if (conn->secretDriver == NULL || conn->secretDriver->defineXML == NULL || + conn->secretDriver->setValue == NULL) { + virStorageReportError(conn, VIR_ERR_NO_SUPPORT, "%s", + _("secret storage not supported")); + goto cleanup; + } + + enc = vol->target.encryption; + if (enc->nsecrets != 0) { + virStorageReportError(conn, VIR_ERR_INTERNAL_ERROR, "%s", + _("secrets already defined")); + goto cleanup; + } + + if (VIR_ALLOC(enc_secret) < 0 || VIR_REALLOC_N(enc->secrets, 1) < 0) { + virReportOOMError(conn); + goto cleanup; + } + + virBufferAddLit(&buf, "<secret ephemeral='no' private='no'>"); + /* <uuid/> is chosen by the secret driver */ + virBufferEscapeString(&buf, + "<description>qcow passphrase for %s</description>", + vol->target.path); + virBufferEscapeString(&buf, "<volume>%s</volume>", vol->target.path); + virBufferAddLit(&buf, "</secret>"); + if (virBufferError(&buf)) { + virReportOOMError(conn); + goto cleanup; + } + xml = virBufferContentAndReset(&buf);
This is the first place where we should be just calling into an internal secret_conf.h API for formatting XML from a struct, rather than duplicating the XML formatting.
+ /* A qcow passphrase is up to 16 bytes, with any data following a NUL + ignored. Prohibit control and non-ASCII characters to avoid possible + unpleasant surprises with the qemu monitor input mechanism. */ + fd = open("/dev/urandom", O_RDONLY); + if (fd < 0) { + virStorageReportError(conn, VIR_ERR_INTERNAL_ERROR, "%s", + _("Cannot open /dev/urandom")); + goto cleanup; + } + i = 0; + while (i < sizeof (value)) { + ssize_t r; + + while ((r = read(fd, value + i, 1)) == -1 && errno == EINTR) + ; + if (r <= 0) { + virStorageReportError(conn, VIR_ERR_INTERNAL_ERROR, "%s", + _("Cannot read from /dev/urandom")); + goto cleanup; + } + if (value[i] >= 0x20 && value[i] <= 0x7E) + i++; /* Got an acceptable character */ + } + close(fd);
I reckon this snippet of code could usefully be put into the util.h file as virFileGenerateRandomkey(), or alternatively perhaps secret_conf.h, as virSecretGenerateRandomKey(unsigned char *buf, size_t buflen); Regards, Daniel -- |: Red Hat, Engineering, London -o- http://people.redhat.com/berrange/ :| |: http://libvirt.org -o- http://virt-manager.org -o- http://ovirt.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: GnuPG: 7D3B9505 -o- F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 :|