gatekeeper: fix

com.android.cts.devicepolicy.DeviceOwnerTest#testKeyManagement [1/2]

PD# 158086

Soft gatekeeper should calculate valid hmac based on default key
Signed-off-by: Matthew Shyu <matthew.shyu@amlogic.com>

Change-Id: I5d796d611f2871c2d054122170e91b54c61f1b1d

1 files changed, 10 insertions, 1 deletions

diff --git a/soft/SoftGateKeeper.h b/soft/SoftGateKeeper.h
index f646f70..ddd0cff 100644
--- a/soft/SoftGateKeeper.h
+++ b/soft/SoftGateKeeper.h
@@ -21,6 +21,7 @@
 extern "C" {
 #include <openssl/rand.h>
 #include <openssl/sha.h>
+#include <openssl/hmac.h>
 
 #include <crypto_scrypt.h>
 }
@@ -32,6 +33,8 @@ extern "C" {
 #include <unordered_map>
 #include <memory>
 
+#define HMAC_SHA_256_KEY_SIZE 32
+
 namespace gatekeeper {
 
 struct fast_hash_t {
@@ -92,9 +95,15 @@ public:
     }
 
     virtual void ComputeSignature(uint8_t *signature, uint32_t signature_length,
-            const uint8_t *, uint32_t, const uint8_t *, const uint32_t) const {
+            const uint8_t *key, uint32_t key_length, const uint8_t *message, const uint32_t length) const {
         if (signature == NULL) return;
+        uint8_t buf[HMAC_SHA_256_KEY_SIZE];
+        size_t buf_len;
+        HMAC(EVP_sha256(), key, key_length, message, length, buf, (unsigned int *)&buf_len);
+        size_t to_write = buf_len;
+        if (buf_len > signature_length) to_write = signature_length;
         memset(signature, 0, signature_length);
+        memcpy(signature, buf, to_write);
     }
 
     virtual uint64_t GetMillisecondsSinceBoot() const {