Add copy endpoint to ArchiveController

Co-authored-by: Jonathan Klabunde Tomer <125505367+jkt-signal@users.noreply.github.com>
Co-authored-by: Chris Eager <79161849+eager-signal@users.noreply.github.com>

service/src/main/java/org/whispersystems/textsecuregcm/configuration/ClientCdnConfiguration.java

@@ -0,0 +1,53 @@
+package org.whispersystems.textsecuregcm.configuration;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+import javax.validation.constraints.NotBlank;
+import javax.validation.constraints.NotEmpty;
+import javax.validation.constraints.NotNull;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Configuration used to interact with a cdn via HTTP
+ */
+public class ClientCdnConfiguration {
+
+  /**
+   * Map from cdn number to the base url for attachments.
+   * <p>
+   * For example, if an attachment with the id 'abc' can be retrieved from cdn 2 at https://example.org/attachments/abc,
+   * the attachment url for 2 should https://example.org/attachments
+   */
+  @JsonProperty
+  @NotNull
+  Map<Integer, @NotBlank String> attachmentUrls;
+
+  @JsonProperty
+  @NotNull
+  @NotEmpty List<@NotBlank String> caCertificates = new ArrayList<>();
+
+  @JsonProperty
+  @NotNull
+  CircuitBreakerConfiguration circuitBreaker = new CircuitBreakerConfiguration();
+
+  @JsonProperty
+  @NotNull
+  RetryConfiguration retry = new RetryConfiguration();
+
+  public List<String> getCaCertificates() {
+    return caCertificates;
+  }
+
+  public CircuitBreakerConfiguration getCircuitBreaker() {
+    return circuitBreaker;
+  }
+
+  public RetryConfiguration getRetry() {
+    return retry;
+  }
+
+  public Map<Integer, String> getAttachmentUrls() {
+    return attachmentUrls;
+  }
+}

service/src/main/java/org/whispersystems/textsecuregcm/configuration/DynamoDbTables.java

@@ -49,6 +49,7 @@ public class DynamoDbTables {
   private final AccountsTableConfiguration accounts;
 
   private final Table backups;
+  private final Table backupMedia;
   private final Table clientReleases;
   private final Table deletedAccounts;
   private final Table deletedAccountsLock;
@@ -71,6 +72,7 @@ public class DynamoDbTables {
   public DynamoDbTables(
       @JsonProperty("accounts") final AccountsTableConfiguration accounts,
       @JsonProperty("backups") final Table backups,
+      @JsonProperty("backupMedia") final Table backupMedia,
       @JsonProperty("clientReleases") final Table clientReleases,
       @JsonProperty("deletedAccounts") final Table deletedAccounts,
       @JsonProperty("deletedAccountsLock") final Table deletedAccountsLock,
@@ -92,6 +94,7 @@ public class DynamoDbTables {
 
     this.accounts = accounts;
     this.backups = backups;
+    this.backupMedia = backupMedia;
     this.clientReleases = clientReleases;
     this.deletedAccounts = deletedAccounts;
     this.deletedAccountsLock = deletedAccountsLock;
@@ -124,6 +127,12 @@ public class DynamoDbTables {
     return backups;
   }
 
+  @NotNull
+  @Valid
+  public Table getBackupMedia() {
+    return backupMedia;
+  }
+
   @NotNull
   @Valid
   public Table getClientReleases() {