diff --git a/common/utils.cc b/common/utils.cc
index b06954b..1a8fd53 100644
--- a/common/utils.cc
+++ b/common/utils.cc
@@ -61,6 +61,7 @@
 using base::Time;
 using base::TimeDelta;
 using std::min;
+using std::numeric_limits;
 using std::pair;
 using std::string;
 using std::vector;
@@ -1082,6 +1083,36 @@
   return value;
 }
 
+void ParseRollbackKeyVersion(const string& raw_version,
+                             uint16_t* high_version,
+                             uint16_t* low_version) {
+  DCHECK(high_version);
+  DCHECK(low_version);
+  *high_version = numeric_limits<uint16_t>::max();
+  *low_version = numeric_limits<uint16_t>::max();
+
+  vector<string> parts = base::SplitString(
+      raw_version, ".", base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL);
+  if (parts.size() != 2) {
+    // The version string must have exactly one period.
+    return;
+  }
+
+  int high;
+  int low;
+  if (!(base::StringToInt(parts[0], &high) &&
+        base::StringToInt(parts[1], &low))) {
+    // Both parts of the version could not be parsed correctly.
+    return;
+  }
+
+  if (high >= 0 && high < numeric_limits<uint16_t>::max() && low >= 0 &&
+      low < numeric_limits<uint16_t>::max()) {
+    *high_version = static_cast<uint16_t>(high);
+    *low_version = static_cast<uint16_t>(low);
+  }
+}
+
 }  // namespace utils
 
 }  // namespace chromeos_update_engine
diff --git a/common/utils.h b/common/utils.h
index cbc5eb9..ecb97a3 100644
--- a/common/utils.h
+++ b/common/utils.h
@@ -21,6 +21,7 @@
 #include <unistd.h>
 
 #include <algorithm>
+#include <limits>
 #include <map>
 #include <memory>
 #include <set>
@@ -322,6 +323,13 @@
 // first section of |version| is invalid (e.g. not a number).
 int VersionPrefix(const std::string& version);
 
+// Parses a string in the form high.low, where high and low are 16 bit unsigned
+// integers. If there is more than 1 dot, or if either of the two parts are
+// not valid 16 bit unsigned numbers, then 0xffff is returned for both.
+void ParseRollbackKeyVersion(const std::string& raw_version,
+                             uint16_t* high_version,
+                             uint16_t* low_version);
+
 }  // namespace utils
 
 
diff --git a/common/utils_unittest.cc b/common/utils_unittest.cc
index 16fa481..1590eeb 100644
--- a/common/utils_unittest.cc
+++ b/common/utils_unittest.cc
@@ -22,6 +22,7 @@
 #include <sys/stat.h>
 #include <sys/types.h>
 
+#include <limits>
 #include <string>
 #include <vector>
 
@@ -32,6 +33,7 @@
 
 #include "update_engine/common/test_utils.h"
 
+using std::numeric_limits;
 using std::string;
 using std::vector;
 
@@ -450,6 +452,22 @@
   *ret = true;
 }
 
+static void ExpectParseRollbackKeyVersion(const string& version,
+                                          uint16_t expected_high,
+                                          uint16_t expected_low) {
+  uint16_t actual_high;
+  uint16_t actual_low;
+  utils::ParseRollbackKeyVersion(version, &actual_high, &actual_low);
+  EXPECT_EQ(expected_high, actual_high);
+  EXPECT_EQ(expected_low, actual_low);
+}
+
+static void ExpectInvalidParseRollbackKeyVersion(const string& version) {
+  ExpectParseRollbackKeyVersion(version,
+                                numeric_limits<uint16_t>::max(),
+                                numeric_limits<uint16_t>::max());
+}
+
 TEST(UtilsTest, TestMacros) {
   bool void_test = false;
   VoidMacroTestHelper(&void_test);
@@ -523,4 +541,29 @@
   EXPECT_EQ(-1, utils::VersionPrefix("x.1"));
 }
 
+TEST(UtilsTest, ParseDottedVersion) {
+  // Valid case.
+  ExpectParseRollbackKeyVersion("2.3", 2, 3);
+  ExpectParseRollbackKeyVersion("65535.65535", 65535, 65535);
+
+  // Zero is technically allowed but never actually used.
+  ExpectParseRollbackKeyVersion("0.0", 0, 0);
+
+  // Invalid cases.
+  ExpectInvalidParseRollbackKeyVersion("");
+  ExpectInvalidParseRollbackKeyVersion("2");
+  ExpectInvalidParseRollbackKeyVersion("2.");
+  ExpectInvalidParseRollbackKeyVersion(".2");
+  ExpectInvalidParseRollbackKeyVersion("2.2.");
+  ExpectInvalidParseRollbackKeyVersion("2.2.3");
+  ExpectInvalidParseRollbackKeyVersion(".2.2");
+  ExpectInvalidParseRollbackKeyVersion("a.b");
+  ExpectInvalidParseRollbackKeyVersion("1.b");
+  ExpectInvalidParseRollbackKeyVersion("a.2");
+  ExpectInvalidParseRollbackKeyVersion("65536.65536");
+  ExpectInvalidParseRollbackKeyVersion("99999.99999");
+  ExpectInvalidParseRollbackKeyVersion("99999.1");
+  ExpectInvalidParseRollbackKeyVersion("1.99999");
+}
+
 }  // namespace chromeos_update_engine