Copy HexString to libbinder

Bug: 302723053
Test: mma
Change-Id: I5c7a71a91b7dc95bfa0cd653eabe554bdd3f7812

1 files changed, 19 insertions, 0 deletions

diff --git a/libs/binder/Utils.cpp b/libs/binder/Utils.cpp
index 0314b0fea7..47fd17dcb1 100644
--- a/libs/binder/Utils.cpp
+++ b/libs/binder/Utils.cpp
@@ -16,6 +16,7 @@
 
 #include "Utils.h"
 
+#include <android-base/logging.h>
 #include <string.h>
 
 namespace android {
@@ -24,4 +25,22 @@ void zeroMemory(uint8_t* data, size_t size) {
     memset(data, 0, size);
 }
 
+std::string HexString(const void* bytes, size_t len) {
+    CHECK(bytes != nullptr || len == 0) << bytes << " " << len;
+
+    // b/132916539: Doing this the 'C way', std::setfill triggers ubsan implicit conversion
+    const uint8_t* bytes8 = static_cast<const uint8_t*>(bytes);
+    const char chars[] = "0123456789abcdef";
+    std::string result;
+    result.resize(len * 2);
+
+    for (size_t i = 0; i < len; i++) {
+        const auto c = bytes8[i];
+        result[2 * i] = chars[c >> 4];
+        result[2 * i + 1] = chars[c & 0xf];
+    }
+
+    return result;
+}
+
 } // namespace android