On Wed, Jun 22, 2016 at 03:13:04PM +0530, Lokesh Vutla wrote: > > > On Wednesday 22 June 2016 05:26 AM, Tom Rini wrote: > > On Tue, Jun 21, 2016 at 10:01:54AM +0530, Lokesh Vutla wrote: > >> > >> > >> On Tuesday 21 June 2016 09:04 AM, Andreas Dannenberg wrote: > >>> Adds an API that verifies a signature attached to an image (binary > >>> blob). This API is basically a entry to a secure ROM service provided by > >>> the device and accessed via an SMC call, using a particular calling > >>> convention. > >>> > >>> Signed-off-by: Daniel Allred <d-all...@ti.com> > >>> Signed-off-by: Andreas Dannenberg <dannenb...@ti.com> > >>> --- > >>> arch/arm/cpu/armv7/omap-common/sec-common.c | 76 > >>> +++++++++++++++++++++++++++++ > >>> arch/arm/include/asm/omap_common.h | 9 ++++ > >>> 2 files changed, 85 insertions(+) > >>> > >>> diff --git a/arch/arm/cpu/armv7/omap-common/sec-common.c > >>> b/arch/arm/cpu/armv7/omap-common/sec-common.c > >>> index b9c0a42..dbb9078 100644 > >>> --- a/arch/arm/cpu/armv7/omap-common/sec-common.c > >>> +++ b/arch/arm/cpu/armv7/omap-common/sec-common.c > >>> @@ -16,6 +16,9 @@ > >>> #include <asm/arch/sys_proto.h> > >>> #include <asm/omap_common.h> > >>> > >>> +/* Index for signature verify ROM API */ > >>> +#define API_HAL_KM_VERIFYCERTIFICATESIGNATURE_INDEX (0x0000000E) > >>> + > >>> static uint32_t secure_rom_call_args[5] __aligned(ARCH_DMA_MINALIGN); > >>> > >>> u32 secure_rom_call(u32 service, u32 proc_id, u32 flag, ...) > >>> @@ -47,3 +50,76 @@ u32 secure_rom_call(u32 service, u32 proc_id, u32 > >>> flag, ...) > >>> > >>> return omap_smc_sec(service, proc_id, flag, secure_rom_call_args); > >>> } > >>> + > >>> +static u32 find_sig_start(char *image, size_t size) > >>> +{ > >>> + char *image_end = image + size; > >>> + char *sig_start_magic = "CERT_"; > >>> + int magic_str_len = strlen(sig_start_magic); > >>> + char *ch; > >>> + > >>> + while (--image_end > image) { > >>> + if (*image_end == '_') { > >>> + ch = image_end - magic_str_len + 1; > >>> + if (!strncmp(ch, sig_start_magic, magic_str_len)) > >>> + return (u32)ch; > >>> + } > >>> + } > >>> + return 0; > >>> +} > >>> + > >>> +int secure_boot_verify_image(void **image, size_t *size) > >>> +{ > >>> + int result = 1; > >>> + u32 cert_addr, sig_addr; > >>> + size_t cert_size; > >>> + > >>> + /* Perform cache writeback on input buffer */ > >>> + flush_dcache_range( > >>> + (u32)*image, > >>> + (u32)*image + roundup(*size, ARCH_DMA_MINALIGN)); > >>> + > >>> + cert_addr = (uint32_t)*image; > >>> + sig_addr = find_sig_start((char *)*image, *size); > >>> + > >>> + if (sig_addr == 0) { > >>> + printf("No signature found in image.\n"); > >>> + result = 1; > >>> + goto auth_exit; > >>> + } > >>> + > >>> + *size = sig_addr - cert_addr; /* Subtract out the signature size */ > >>> + cert_size = *size; > >>> + > >>> + /* Check if image load address is 32-bit aligned */ > >>> + if (0 != (0x3 & cert_addr)) { > >> > >> if (!IS_ALIGNED(cert_addr, 4)) { ? > >> > >>> + printf("Image is not 4-byte aligned.\n"); > >>> + result = 1; > >>> + goto auth_exit; > >>> + } > >>> + > >>> + /* Image size also should be multiple of 4 */ > >>> + if (0 != (0x3 & cert_size)) { > >> > >> if (!IS_ALIGNED(cert_size, 4)) { ? > >> > >>> + printf("Image size is not 4-byte aligned.\n"); > >>> + result = 1; > >>> + goto auth_exit; > >>> + } > >>> + > >>> + /* Call ROM HAL API to verify certificate signature */ > >>> + debug("%s: load_addr = %x, size = %x, sig_addr = %x\n", __func__, > >>> + cert_addr, cert_size, sig_addr); > >>> + > >>> + result = secure_rom_call( > >>> + API_HAL_KM_VERIFYCERTIFICATESIGNATURE_INDEX, 0, 0, > >>> + 4, cert_addr, cert_size, sig_addr, 0xFFFFFFFF); > >>> +auth_exit: > >>> + if (result != 0) { > >>> + printf("Authentication failed!\n"); > >>> + printf("Return Value = %08X\n", result); > >>> + hang(); > >>> + } > >>> + > >>> + printf("Authentication passed: %s\n", (char *)sig_addr); > >> > >> Uart boot will break because of these prints during the FIT loading. Can > >> you make this as debug? > > > > Are you sure it will break? There's usually a print in between loading > > SPL via UART and then U-Boot itself via UART and Y-MODEM is smart enough > > to re-transmit. > > > > Yes, if the print is in between while Y-MODEM is transferring. The above > print falls in this case.
Tom et al., so if this really breaks stuff I need to do something about it. As said I'd really like to keep the "Authentication passed: <certificate name>" message in the boot log. So if I implement something along the lines what Lokesh suggested: "...you can check if (spl_boot_device() != BOOT_DEVICE_UART) under the config CONFIG_SPL_YMODEM_SUPPORT. Not sure if it is a good way to do..." to selectivly suppress the message in case of UART boot, would this be acceptable? Or is there a better way? Thanks and Regards, Andreas _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot