Support AM/PM in MSI token

sdk/identity/azure-identity/src/main/java/com/azure/identity/implementation/MSIToken.java

@@ -13,6 +13,7 @@
 import java.time.ZoneOffset;
 import java.time.format.DateTimeFormatter;
 import java.time.format.DateTimeParseException;
+import java.util.Locale;
 
 /**
  * Type representing response from the local MSI token provider.
@@ -35,15 +36,11 @@ public final class MSIToken extends AccessToken {
      * @param token the token string.
      * @param expiresOn the expiration time.
      */
-    public MSIToken(String token, OffsetDateTime expiresOn) {
-        super(token, expiresOn);
-    }
-
     @JsonCreator
     private MSIToken(
         @JsonProperty(value = "access_token") String token,
         @JsonProperty(value = "expires_on") String expiresOn) {
-        this(token, EPOCH.plusSeconds(parseDateToEpochSeconds(expiresOn)));
+        super(token, EPOCH.plusSeconds(parseDateToEpochSeconds(expiresOn)));
         this.accessToken = token;
         this.expiresOn =  expiresOn;
     }
@@ -53,29 +50,27 @@ public String getToken() {
         return accessToken;
     }
 
-    @Override
-    public OffsetDateTime getExpiresAt() {
-        return EPOCH.plusSeconds(parseDateToEpochSeconds(this.expiresOn));
-    }
-
-    @Override
-    public boolean isExpired() {
-        OffsetDateTime now = OffsetDateTime.now();
-        OffsetDateTime expireOn = EPOCH.plusSeconds(parseDateToEpochSeconds(this.expiresOn));
-        return now.plusMinutes(5).isAfter(expireOn);
-    }
-
     private static Long parseDateToEpochSeconds(String dateTime) {
         ClientLogger logger = new ClientLogger(MSIToken.class);
-        DateTimeFormatter dtf = DateTimeFormatter.ofPattern("MM/dd/yyyy HH:mm:ss XXX");
+        DateTimeFormatter dtf = DateTimeFormatter.ofPattern("M/d/yyyy H:mm:ss XXX", Locale.US);
+        // This is the format for app service on Windows as of API version 2017-09-01.
+        // The format is changed to Unix timestamp in 2019-08-01 but this API version
+        // has not been deployed to Linux app services.
+        DateTimeFormatter dtf_windows = DateTimeFormatter.ofPattern("M/d/yyyy K:mm:ss a XXX", Locale.US);
         try {
             return Long.parseLong(dateTime);
         } catch (NumberFormatException e) {
             logger.error(e.getMessage());
         }
 
         try {
-            return Instant.from(dtf.parse(dateTime)).toEpochMilli() / 1000L;
+            return Instant.from(dtf.parse(dateTime)).getEpochSecond();
+        } catch (DateTimeParseException e) {
+            logger.error(e.getMessage());
+        }
+
+        try {
+            return Instant.from(dtf_windows.parse(dateTime)).getEpochSecond();
         } catch (DateTimeParseException e) {
             logger.error(e.getMessage());
         }

sdk/identity/azure-identity/src/test/java/com/azure/identity/implementation/MSITokenTests.java

@@ -0,0 +1,48 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+package com.azure.identity.implementation;
+
+import com.azure.core.util.serializer.JacksonAdapter;
+import com.azure.core.util.serializer.SerializerEncoding;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.time.OffsetDateTime;
+import java.time.ZoneOffset;
+
+public class MSITokenTests {
+    private JacksonAdapter serializer = new JacksonAdapter();
+    private OffsetDateTime expected = OffsetDateTime.of(2020, 1, 10, 15, 1, 28, 0, ZoneOffset.UTC);
+
+    @Test
+    public void canParseLong() throws Exception {
+        String json = "{\"access_token\":\"fake_token\",\"expires_on\":\"1578668608\"}";
+        MSIToken token = serializer.deserialize(json, MSIToken.class, SerializerEncoding.JSON);
+        Assert.assertEquals(expected.toEpochSecond(), token.getExpiresAt().toEpochSecond());
+    }
+
+    @Test
+    public void canParseDateTime24Hr() throws Exception {
+        String json = "{\"access_token\":\"fake_token\",\"expires_on\":\"01/10/2020 15:03:28 +00:00\"}";
+        MSIToken token = serializer.deserialize(json, MSIToken.class, SerializerEncoding.JSON);
+        Assert.assertEquals(expected.toEpochSecond(), token.getExpiresAt().toEpochSecond());
+    }
+
+    @Test
+    public void canParseDateTime12Hr() throws Exception {
+        String json = "{\"access_token\":\"fake_token\",\"expires_on\":\"1/10/2020 3:03:28 PM +00:00\"}";
+        MSIToken token = serializer.deserialize(json, MSIToken.class, SerializerEncoding.JSON);
+        Assert.assertEquals(expected.toEpochSecond(), token.getExpiresAt().toEpochSecond());
+
+        json = "{\"access_token\":\"fake_token\",\"expires_on\":\"12/20/2019 4:58:20 AM +00:00\"}";
+        token = serializer.deserialize(json, MSIToken.class, SerializerEncoding.JSON);
+        expected = OffsetDateTime.of(2019, 12, 20, 4, 56, 20, 0, ZoneOffset.UTC);
+        Assert.assertEquals(expected.toEpochSecond(), token.getExpiresAt().toEpochSecond());
+
+        json = "{\"access_token\":\"fake_token\",\"expires_on\":\"1/1/2020 0:00:00 PM +00:00\"}";
+        token = serializer.deserialize(json, MSIToken.class, SerializerEncoding.JSON);
+        expected = OffsetDateTime.of(2020, 1, 1, 11, 58, 0, 0, ZoneOffset.UTC);
+        Assert.assertEquals(expected.toEpochSecond(), token.getExpiresAt().toEpochSecond());
+    }
+}