vboot: changes to allow RW_LEGACY hash verification

- Externalize vb2_digest_buffer function to vb2api_digest_buffer.
- Add vb2_context as an argument to VbExLegacy function (so that
  we know whether developer mode is running).

BUG=b:110721285
TEST=make runtests

Change-Id: I2401842cc044949d8cdfeb21edb7b400a3c32426
Reviewed-on: https://chromium-review.googlesource.com/1133598
Tested-by: Joel Kitching <kitching@chromium.org>
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
Commit-Queue: Joel Kitching <kitching@chromium.org>

7 files changed, 41 insertions, 13 deletions

diff --git a/firmware/2lib/2api.c b/firmware/2lib/2api.c
index c12a8051..c5997715 100644
--- a/firmware/2lib/2api.c
+++ b/firmware/2lib/2api.c
@@ -9,6 +9,7 @@
 #include "2sysincludes.h"
 #include "2api.h"
 #include "2common.h"
+#include "2crypto.h"
 #include "2misc.h"
 #include "2nvstorage.h"
 #include "2secdata.h"
@@ -206,3 +207,12 @@ int vb2api_get_pcr_digest(struct vb2_context *ctx,
 
 	return VB2_SUCCESS;
 }
+
+int vb2api_digest_buffer(const uint8_t *buf,
+			 uint32_t size,
+			 enum vb2_hash_algorithm hash_alg,
+			 uint8_t *digest,
+			 uint32_t digest_size)
+{
+	return vb2_digest_buffer(buf, size, hash_alg, digest, digest_size);
+}
diff --git a/firmware/2lib/include/2api.h b/firmware/2lib/include/2api.h
index 21865783..e2100516 100644
--- a/firmware/2lib/include/2api.h
+++ b/firmware/2lib/include/2api.h
@@ -670,4 +670,20 @@ int vb2ex_hwcrypto_digest_extend(const uint8_t *buf, uint32_t size);
  */
 int vb2ex_hwcrypto_digest_finalize(uint8_t *digest, uint32_t digest_size);
 
+/**
+ * Calculate the digest of a buffer and store the result.
+ *
+ * @param buf		Data to hash
+ * @param size		Length of data in bytes
+ * @param hash_alg	Hash algorithm
+ * @param digest	Destination for digest
+ * @param digest_size	Length of digest buffer in bytes.
+ * @return VB2_SUCCESS, or non-zero on error.
+ */
+int vb2api_digest_buffer(const uint8_t *buf,
+			 uint32_t size,
+			 enum vb2_hash_algorithm hash_alg,
+			 uint8_t *digest,
+			 uint32_t digest_size);
+
 #endif  /* VBOOT_2_API_H_ */
diff --git a/firmware/include/vboot_api.h b/firmware/include/vboot_api.h
index 2f88a38a..2e593391 100644
--- a/firmware/include/vboot_api.h
+++ b/firmware/include/vboot_api.h
@@ -26,6 +26,8 @@
 
 #include "gpt.h"
 
+struct vb2_context;
+
 /*****************************************************************************/
 /* Error codes */
 
@@ -1117,7 +1119,7 @@ enum {
 /**
  * Execute legacy boot option.
  */
-int VbExLegacy(void);
+int VbExLegacy(struct vb2_context *ctx);
 
 /* Regions for VbExRegionRead() */
 enum vb_firmware_region {
diff --git a/firmware/lib/vboot_ui.c b/firmware/lib/vboot_ui.c
index 799ffd7c..d037e7fc 100644
--- a/firmware/lib/vboot_ui.c
+++ b/firmware/lib/vboot_ui.c
@@ -50,14 +50,14 @@ static int VbWantShutdown(uint32_t gbb_flags)
 	return !!shutdown_request;
 }
 
-static void VbTryLegacy(int allowed)
+static void VbTryLegacy(struct vb2_context *ctx, int allowed)
 {
 	if (!allowed)
 		VB2_DEBUG("VbBootDeveloper() - Legacy boot is disabled\n");
 	else if (0 != RollbackKernelLock(0))
 		VB2_DEBUG("Error locking kernel versions on legacy boot.\n");
 	else
-		VbExLegacy();	/* will not return if successful */
+		VbExLegacy(ctx);	/* will not return if successful */
 
 	/* If legacy boot fails, beep and return to calling UI loop. */
 	VbExBeep(120, 400);
@@ -237,7 +237,7 @@ VbError_t vb2_alt_os_ui(struct vb2_context *ctx, VbCommonParams *cparams)
 
 	if (boot_alt_os) {
 		/* Will only return on failure */
-		VbTryLegacy(1);
+		VbTryLegacy(ctx, 1);
 	}
 
 	/* Will only return on failure */
@@ -427,7 +427,7 @@ VbError_t vb2_developer_ui(struct vb2_context *ctx, VbCommonParams *cparams)
 		case 0x0c:
 			VB2_DEBUG("VbBootDeveloper() - "
 				  "user pressed Ctrl+L; Try legacy boot\n");
-			VbTryLegacy(allow_legacy);
+			VbTryLegacy(ctx, allow_legacy);
 			break;
 
 		case VB_KEY_CTRL_ENTER:
@@ -482,7 +482,7 @@ VbError_t vb2_developer_ui(struct vb2_context *ctx, VbCommonParams *cparams)
 	/* If defaulting to legacy boot, try that unless Ctrl+D was pressed */
 	if (use_legacy && !ctrl_d_pressed) {
 		VB2_DEBUG("VbBootDeveloper() - defaulting to legacy\n");
-		VbTryLegacy(allow_legacy);
+		VbTryLegacy(ctx, allow_legacy);
 	}
 
 	if ((use_usb && !ctrl_d_pressed) && allow_usb) {
diff --git a/firmware/lib/vboot_ui_menu.c b/firmware/lib/vboot_ui_menu.c
index a481c035..d24cdcfd 100644
--- a/firmware/lib/vboot_ui_menu.c
+++ b/firmware/lib/vboot_ui_menu.c
@@ -53,14 +53,14 @@ static int VbWantShutdownMenu(uint32_t gbb_flags)
 	return !!shutdown_request;
 }
 
-static void VbTryLegacyMenu(int allowed)
+static void VbTryLegacyMenu(struct vb2_context *ctx, int allowed)
 {
 	if (!allowed)
 		VB2_DEBUG("Legacy boot is disabled\n");
 	else if (0 != RollbackKernelLock(0))
 		VB2_DEBUG("Error locking kernel versions on legacy boot.\n");
 	else
-		VbExLegacy();	/* Will not return if successful */
+		VbExLegacy(ctx);	/* Will not return if successful */
 
 	/* If legacy boot fails, beep and return to calling UI loop. */
 	VbExBeep(120, 400);
@@ -724,7 +724,7 @@ VbError_t vb2_developer_menu(struct vb2_context *ctx, VbCommonParams *cparams)
 			break;
 		case 0x0c:
 			VB2_DEBUG("user pressed Ctrl+L; Try legacy boot\n");
-			VbTryLegacyMenu(allow_legacy);
+			VbTryLegacyMenu(ctx, allow_legacy);
 			break;
 		case 0x15:
 			/* Ctrl+U = try USB boot, or beep if failure */
@@ -824,7 +824,7 @@ VbError_t vb2_developer_menu(struct vb2_context *ctx, VbCommonParams *cparams)
 			    current_menu_idx == VB_DEV_LEGACY) {
 				VB2_DEBUG("user pressed Ctrl+L; "
 					  "Try legacy boot\n");
-				VbTryLegacyMenu(allow_legacy);
+				VbTryLegacyMenu(ctx, allow_legacy);
 			}
 
 			/* USB boot, or beep if failure */
@@ -904,7 +904,7 @@ fallout:
 	/* If defaulting to legacy boot, try that unless Ctrl+D was pressed */
 	if (use_legacy && !ctrl_d_pressed) {
 		VB2_DEBUG("defaulting to legacy\n");
-		VbTryLegacyMenu(allow_legacy);
+		VbTryLegacyMenu(ctx, allow_legacy);
 	}
 
 	if ((use_usb && !ctrl_d_pressed) && allow_usb) {
diff --git a/firmware/stub/vboot_api_stub.c b/firmware/stub/vboot_api_stub.c
index 834bff1c..12b69716 100644
--- a/firmware/stub/vboot_api_stub.c
+++ b/firmware/stub/vboot_api_stub.c
@@ -203,7 +203,7 @@ enum VbEcBootMode_t VbGetMode(void)
 	return vboot_mode;
 }
 
-int VbExLegacy(void)
+int VbExLegacy(struct vb2_context *ctx)
 {
 	return 1;
 }
diff --git a/tests/vboot_api_kernel2_tests.c b/tests/vboot_api_kernel2_tests.c
index cbad7827..44c53c92 100644
--- a/tests/vboot_api_kernel2_tests.c
+++ b/tests/vboot_api_kernel2_tests.c
@@ -146,7 +146,7 @@ uint32_t VbExGetSwitches(uint32_t request_mask)
 		return 0;
 }
 
-int VbExLegacy(void)
+int VbExLegacy(struct vb2_context *ctx)
 {
 	vbexlegacy_called++;
 	return 0;