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
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