Re: [PATCH ustream-ssl] ustream-mbedtls: Use getrandom() instead of /dev/urandom
On 1/29/23 15:13, Torsten Duwe wrote:
On Sat, 28 Jan 2023 19:41:13 +0100
Hauke Mehrtens wrote:
Instead of keeping a file descriptor open just use the getrandom syscall
to get random data. This is supported by the musl, glibc and Linux for
some time now.
This also improves the error handling in case this function returns not
as many bytes as expected.
Signed-off-by: Hauke Mehrtens
---
ustream-mbedtls.c | 23 +--
1 file changed, 5 insertions(+), 18 deletions(-)
diff --git a/ustream-mbedtls.c b/ustream-mbedtls.c
index e79e37b..51ba2fa 100644
--- a/ustream-mbedtls.c
+++ b/ustream-mbedtls.c
@@ -17,6 +17,7 @@
*/
#include
+#include
#include
#include
#include
@@ -25,8 +26,6 @@
#include "ustream-ssl.h"
#include "ustream-internal.h"
-static int urandom_fd = -1;
-
static int s_ustream_read(void *ctx, unsigned char *buf, size_t len)
{
struct ustream *s = ctx;
@@ -66,21 +65,12 @@ __hidden void ustream_set_io(struct ustream_ssl_ctx *ctx,
void *ssl, struct ustr
mbedtls_ssl_set_bio(ssl, conn, s_ustream_write, s_ustream_read, NULL);
}
-static bool urandom_init(void)
-{
- if (urandom_fd > -1)
- return true;
-
- urandom_fd = open("/dev/urandom", O_RDONLY);
- if (urandom_fd < 0)
- return false;
-
- return true;
-}
-
static int _urandom(void *ctx, unsigned char *out, size_t len)
{
- if (read(urandom_fd, out, len) < 0)
+ ssize_t ret;
+
+ ret = getrandom(out, len, 0);
+ if (ret < 0 || (size_t)ret != len)
return MBEDTLS_ERR_ENTROPY_SOURCE_FAILED;
[...]
drivers/char/random.c lines 1240- ...
* Reading from /dev/urandom has the same functionality as calling
* getrandom(2) with flags=GRND_INSECURE. Because it does not block
* waiting for the RNG to be ready, it should not be used.
Haven't audited mbedtls, but I assume it reads urandom for "lesser"
entropy when needed. In any case, getrandom(out, len, GRND_INSECURE)
would be the proper replacement.
Torsten
Hi Torsten,
The mapage says this:
> By default, getrandom() draws entropy from the urandom source
> (i.e., the same source as the /dev/urandom device). This
> behavior can be changed via the flags argument.
https://man7.org/linux/man-pages/man2/getrandom.2.html
GRND_INSECURE is also not documented in the man page.
The option was added to the Linux kernel 5.6 here:
https://git.kernel.org/linus/75551dbf112c992bc6c99a972990b3f272247e23
The documentation says
> GRND_INSECURE Return non-cryptographic random bytes
We want to use the random bytes in mbedtls for cryptographic operations.
I think giving no flags is the correct option here.
I think the behavior of /dev/random changed some years ago. This article
described it a bit: https://lwn.net/Articles/808575/
As far as I understood the code, giving no flags will guarantee that the
random pool is initialized (crng_ready() returns true) and otherwise it
is the same as using GRND_INSECURE. As we use it for cryptographic
operations I think we should give no flags.
Hauke
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Re: [PATCH v2] tplink-safeloader: Add support for Deco M4R V4
Hi Mark, On Sun, 2023-01-29 at 15:28 +0100, Mark Ceeha wrote: > Software version: > soft_ver:1.0.0 Build 20211202 Rel. 69482 > > Partition table: > 0004 fs-uboot > 0004 0040 os-image > 0044 00b6 file-system > 00fa 0300 default-mac > 00fa0300 0100 device-id > 00fa0400 fc00 product-info > 00fb 4000 group-info > 00fb4000 c000 user-config > 00fc 0001 device-config > 00fd 0001 default-config > 00fe 0800 partition-table > 00fe0800 0100 soft-version > 00fe0900 0200 support-list > 00fe0b00 3000 profile > 00fe3b00 0100 extra-para > 00ff 0001 radio > > `os-image` and `file-system` have been merged into `firmware`. > > Signed-off-by: Mark Ceeha > --- > v2: > - Change `soft_ver` to 1.0.0; while the TP-Link stock firmware cares > about the version and if it's not older than the current `soft_ver`, > it will not allow you to flash OpenWrt anyway as the image is not signed. > U-Boot accepts unsigned images, and does not care about the `soft_ver`, > so we'll just make it consistent with the initial firmware release > this partition table was checked against. > - Fix style issues pointed out by Sander. Thanks for the update. I applied this v2 to the firmware-utils repository. Best, Sander ___ openwrt-devel mailing list openwrt-devel@lists.openwrt.org https://lists.openwrt.org/mailman/listinfo/openwrt-devel
[sdwalker/sdwalker.github.io] 08303c: This week's update
The sender domain has a DMARC Reject/Quarantine policy which disallows sending mailing list messages using the original "From" header. To mitigate this problem, the original message has been wrapped automatically by the mailing list software.--- Begin Message --- Branch: refs/heads/master Home: https://github.com/sdwalker/sdwalker.github.io Commit: 08303c4be9c8f7bea7c7a30ff57287d406a94ba1 https://github.com/sdwalker/sdwalker.github.io/commit/08303c4be9c8f7bea7c7a30ff57287d406a94ba1 Author: Stephen Walker Date: 2023-01-29 (Sun, 29 Jan 2023) Changed paths: M uscan/index-21.02.html M uscan/index-22.03.html M uscan/index.html Log Message: --- This week's update --- End Message --- ___ openwrt-devel mailing list openwrt-devel@lists.openwrt.org https://lists.openwrt.org/mailman/listinfo/openwrt-devel
[PATCH v2] tplink-safeloader: Add support for Deco M4R V4
The sender domain has a DMARC Reject/Quarantine policy which disallows
sending mailing list messages using the original "From" header.
To mitigate this problem, the original message has been wrapped
automatically by the mailing list software.--- Begin Message ---
Software version:
soft_ver:1.0.0 Build 20211202 Rel. 69482
Partition table:
0004 fs-uboot
0004 0040 os-image
0044 00b6 file-system
00fa 0300 default-mac
00fa0300 0100 device-id
00fa0400 fc00 product-info
00fb 4000 group-info
00fb4000 c000 user-config
00fc 0001 device-config
00fd 0001 default-config
00fe 0800 partition-table
00fe0800 0100 soft-version
00fe0900 0200 support-list
00fe0b00 3000 profile
00fe3b00 0100 extra-para
00ff 0001 radio
`os-image` and `file-system` have been merged into `firmware`.
Signed-off-by: Mark Ceeha
---
v2:
- Change `soft_ver` to 1.0.0; while the TP-Link stock firmware cares
about the version and if it's not older than the current `soft_ver`,
it will not allow you to flash OpenWrt anyway as the image is not signed.
U-Boot accepts unsigned images, and does not care about the `soft_ver`,
so we'll just make it consistent with the initial firmware release
this partition table was checked against.
- Fix style issues pointed out by Sander.
---
src/tplink-safeloader.c | 37 +
1 file changed, 37 insertions(+)
diff --git a/src/tplink-safeloader.c b/src/tplink-safeloader.c
index ddb5dff..d9e1605 100644
--- a/src/tplink-safeloader.c
+++ b/src/tplink-safeloader.c
@@ -1612,6 +1612,42 @@ static struct device_info boards[] = {
.last_sysupgrade_partition = "file-system",
},
+ /** Firmware layout for the Deco M4R v4 */
+ {
+ .id = "DECO-M4R-V4",
+ .vendor = "",
+ .support_list =
+ "SupportList:\n"
+
"{product_name:M4R,product_ver:4.0.0,special_id:5553}\n"
+
"{product_name:M4R,product_ver:4.0.0,special_id:4555}\n"
+
"{product_name:M4R,product_ver:4.0.0,special_id:4A50}\n"
+
"{product_name:M4R,product_ver:4.0.0,special_id:4234}\n"
+
"{product_name:M4R,product_ver:4.0.0,special_id:5A47}\n",
+ .part_trail = 0x00,
+ .soft_ver = SOFT_VER_TEXT("soft_ver:1.0.0\n"),
+
+ .partitions = {
+ {"fs-uboot", 0x0, 0x4},
+ {"firmware", 0x4, 0xf6},
+ {"default-mac", 0xfa, 0x00300},
+ {"device-id", 0xfa0300, 0x00100},
+ {"product-info", 0xfa0400, 0x0fc00},
+ {"group-info", 0xfb, 0x04000},
+ {"user-config", 0xfb4000, 0x0c000},
+ {"device-config", 0xfc, 0x1},
+ {"default-config", 0xfd, 0x1},
+ {"partition-table", 0xfe, 0x00800},
+ {"soft-version", 0xfe0800, 0x00100},
+ {"support-list", 0xfe0900, 0x00200},
+ {"profile", 0xfe0b00, 0x03000},
+ {"extra-para", 0xfe3b00, 0x00100},
+ {"radio", 0xff, 0x1},
+ {NULL, 0, 0}
+ },
+ .first_sysupgrade_partition = "os-image",
+ .last_sysupgrade_partition = "file-system",
+ },
+
/** Firmware layout for the Deco S4 v2 */
{
.id = "DECO-S4-V2",
@@ -3525,6 +3561,7 @@ static void build_image(const char *output,
strcasecmp(info->id, "ARCHER-C60-V3") == 0 ||
strcasecmp(info->id, "ARCHER-C6U-V1") == 0 ||
strcasecmp(info->id, "ARCHER-C6-V3") == 0 ||
+ strcasecmp(info->id, "DECO-M4R-V4") == 0 ||
strcasecmp(info->id, "MR70X") == 0 ||
strcasecmp(info->id, "TLWR1043NV5") == 0) {
const uint8_t extra_para[2] = {0x01, 0x00};
--
2.39.0
--- End Message ---
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Re: [PATCH ustream-ssl] ustream-mbedtls: Use getrandom() instead of /dev/urandom
On Sat, 28 Jan 2023 19:41:13 +0100
Hauke Mehrtens wrote:
> Instead of keeping a file descriptor open just use the getrandom syscall
> to get random data. This is supported by the musl, glibc and Linux for
> some time now.
>
> This also improves the error handling in case this function returns not
> as many bytes as expected.
>
> Signed-off-by: Hauke Mehrtens
> ---
> ustream-mbedtls.c | 23 +--
> 1 file changed, 5 insertions(+), 18 deletions(-)
>
> diff --git a/ustream-mbedtls.c b/ustream-mbedtls.c
> index e79e37b..51ba2fa 100644
> --- a/ustream-mbedtls.c
> +++ b/ustream-mbedtls.c
> @@ -17,6 +17,7 @@
> */
>
> #include
> +#include
> #include
> #include
> #include
> @@ -25,8 +26,6 @@
> #include "ustream-ssl.h"
> #include "ustream-internal.h"
>
> -static int urandom_fd = -1;
> -
> static int s_ustream_read(void *ctx, unsigned char *buf, size_t len)
> {
> struct ustream *s = ctx;
> @@ -66,21 +65,12 @@ __hidden void ustream_set_io(struct ustream_ssl_ctx *ctx,
> void *ssl, struct ustr
> mbedtls_ssl_set_bio(ssl, conn, s_ustream_write, s_ustream_read, NULL);
> }
>
> -static bool urandom_init(void)
> -{
> - if (urandom_fd > -1)
> - return true;
> -
> - urandom_fd = open("/dev/urandom", O_RDONLY);
> - if (urandom_fd < 0)
> - return false;
> -
> - return true;
> -}
> -
> static int _urandom(void *ctx, unsigned char *out, size_t len)
> {
> - if (read(urandom_fd, out, len) < 0)
> + ssize_t ret;
> +
> + ret = getrandom(out, len, 0);
> + if (ret < 0 || (size_t)ret != len)
> return MBEDTLS_ERR_ENTROPY_SOURCE_FAILED;
[...]
drivers/char/random.c lines 1240- ...
* Reading from /dev/urandom has the same functionality as calling
* getrandom(2) with flags=GRND_INSECURE. Because it does not block
* waiting for the RNG to be ready, it should not be used.
Haven't audited mbedtls, but I assume it reads urandom for "lesser"
entropy when needed. In any case, getrandom(out, len, GRND_INSECURE)
would be the proper replacement.
Torsten
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