Add support for CDHash rule types

Source/common/BUILD

@@ -427,6 +427,7 @@ objc_library(
     deps = [
         ":SNTCommonEnums",
         ":SNTRule",
+        ":SNTRuleIdentifiers",
         ":SNTStoredEvent",
         ":SNTXPCBundleServiceInterface",
         ":SantaVnode",

Source/common/SNTCachedDecision.h

@@ -40,6 +40,7 @@
 @property NSArray<MOLCertificate *> *certChain;
 @property NSString *teamID;
 @property NSString *signingID;
+@property NSString *cdhash;
 @property NSDictionary *entitlements;
 @property BOOL entitlementsFiltered;
 

Source/common/SNTCommonEnums.h

@@ -46,6 +46,7 @@ typedef NS_ENUM(NSInteger, SNTAction) {
 typedef NS_ENUM(NSInteger, SNTRuleType) {
   SNTRuleTypeUnknown = 0,
 
+  SNTRuleTypeCDHash = 500,
   SNTRuleTypeBinary = 1000,
   SNTRuleTypeSigningID = 2000,
   SNTRuleTypeCertificate = 3000,
@@ -84,6 +85,7 @@ typedef NS_ENUM(uint64_t, SNTEventState) {
   SNTEventStateBlockTeamID = 1ULL << 20,
   SNTEventStateBlockLongPath = 1ULL << 21,
   SNTEventStateBlockSigningID = 1ULL << 22,
+  SNTEventStateBlockCDHash = 1ULL << 23,
 
   // Bits 40-63 store allow decision types
   SNTEventStateAllowUnknown = 1ULL << 40,
@@ -95,6 +97,7 @@ typedef NS_ENUM(uint64_t, SNTEventState) {
   SNTEventStateAllowPendingTransitive = 1ULL << 46,
   SNTEventStateAllowTeamID = 1ULL << 47,
   SNTEventStateAllowSigningID = 1ULL << 48,
+  SNTEventStateAllowCDHash = 1ULL << 49,
 
   // Block and Allow masks
   SNTEventStateBlock = 0xFFFFFFULL << 16,

Source/common/SNTRule.m

@@ -15,6 +15,7 @@
 #import "Source/common/SNTRule.h"
 
 #include <CommonCrypto/CommonCrypto.h>
+#include <Kernel/kern/cs_blobs.h>
 #include <os/base.h>
 
 #import "Source/common/SNTSyncConstants.h"
@@ -103,6 +104,14 @@ - (instancetype)initWithIdentifier:(NSString *)identifier
         break;
       }
 
+      case SNTRuleTypeCDHash: {
+        identifier = [[identifier lowercaseString] stringByTrimmingCharactersInSet:nonHex];
+        if (identifier.length != CS_CDHASH_LEN * 2) {
+          return nil;
+        }
+        break;
+      }
+
       default: {
         break;
       }
@@ -173,6 +182,8 @@ - (instancetype)initWithDictionary:(NSDictionary *)dict {
     type = SNTRuleTypeTeamID;
   } else if ([ruleTypeString isEqual:kRuleTypeSigningID]) {
     type = SNTRuleTypeSigningID;
+  } else if ([ruleTypeString isEqual:kRuleTypeCDHash]) {
+    type = SNTRuleTypeCDHash;
   } else {
     return nil;
   }

Source/common/SNTRuleIdentifiers.h

@@ -26,13 +26,15 @@
 #import <Foundation/Foundation.h>
 
 struct RuleIdentifiers {
+  NSString *cdhash;
   NSString *binarySHA256;
   NSString *signingID;
   NSString *certificateSHA256;
   NSString *teamID;
 };
 
 @interface SNTRuleIdentifiers : NSObject
+@property(readonly) NSString *cdhash;
 @property(readonly) NSString *binarySHA256;
 @property(readonly) NSString *signingID;
 @property(readonly) NSString *certificateSHA256;

Source/common/SNTRuleIdentifiers.m

@@ -19,6 +19,7 @@ @implementation SNTRuleIdentifiers
 - (instancetype)initWithRuleIdentifiers:(struct RuleIdentifiers)identifiers {
   self = [super init];
   if (self) {
+    _cdhash = identifiers.cdhash;
     _binarySHA256 = identifiers.binarySHA256;
     _signingID = identifiers.signingID;
     _certificateSHA256 = identifiers.certificateSHA256;
@@ -28,7 +29,8 @@ - (instancetype)initWithRuleIdentifiers:(struct RuleIdentifiers)identifiers {
 }
 
 - (struct RuleIdentifiers)toStruct {
-  return (struct RuleIdentifiers){.binarySHA256 = self.binarySHA256,
+  return (struct RuleIdentifiers){.cdhash = self.cdhash,
+                                  .binarySHA256 = self.binarySHA256,
                                   .signingID = self.signingID,
                                   .certificateSHA256 = self.certificateSHA256,
                                   .teamID = self.teamID};

Source/common/SNTStoredEvent.h

@@ -105,6 +105,11 @@
 ///
 @property NSString *signingID;
 
+///
+/// If the executed file was signed, this is the CDHash of the binary.
+///
+@property NSString *cdhash;
+
 ///
 ///  The user who executed the binary.
 ///

Source/common/SNTStoredEvent.m

@@ -51,6 +51,7 @@ - (void)encodeWithCoder:(NSCoder *)coder {
   ENCODE(self.signingChain, @"signingChain");
   ENCODE(self.teamID, @"teamID");
   ENCODE(self.signingID, @"signingID");
+  ENCODE(self.cdhash, @"cdhash");
 
   ENCODE(self.executingUser, @"executingUser");
   ENCODE(self.occurrenceDate, @"occurrenceDate");
@@ -97,6 +98,7 @@ - (instancetype)initWithCoder:(NSCoder *)decoder {
     _signingChain = DECODEARRAY(MOLCertificate, @"signingChain");
     _teamID = DECODE(NSString, @"teamID");
     _signingID = DECODE(NSString, @"signingID");
+    _cdhash = DECODE(NSString, @"cdhash");
 
     _executingUser = DECODE(NSString, @"executingUser");
     _occurrenceDate = DECODE(NSDate, @"occurrenceDate");

Source/common/SNTSyncConstants.h

@@ -44,6 +44,7 @@ extern NSString *const kCompilerRuleCount;
 extern NSString *const kTransitiveRuleCount;
 extern NSString *const kTeamIDRuleCount;
 extern NSString *const kSigningIDRuleCount;
+extern NSString *const kCDHashRuleCount;
 extern NSString *const kFullSyncInterval;
 extern NSString *const kFCMToken;
 extern NSString *const kFCMFullSyncInterval;
@@ -70,12 +71,14 @@ extern NSString *const kDecisionAllowCertificate;
 extern NSString *const kDecisionAllowScope;
 extern NSString *const kDecisionAllowTeamID;
 extern NSString *const kDecisionAllowSigningID;
+extern NSString *const kDecisionAllowCDHash;
 extern NSString *const kDecisionBlockUnknown;
 extern NSString *const kDecisionBlockBinary;
 extern NSString *const kDecisionBlockCertificate;
 extern NSString *const kDecisionBlockScope;
 extern NSString *const kDecisionBlockTeamID;
 extern NSString *const kDecisionBlockSigningID;
+extern NSString *const kDecisionBlockCDHash;
 extern NSString *const kDecisionUnknown;
 extern NSString *const kDecisionBundleBinary;
 extern NSString *const kLoggedInUsers;
@@ -101,6 +104,7 @@ extern NSString *const kCertValidFrom;
 extern NSString *const kCertValidUntil;
 extern NSString *const kTeamID;
 extern NSString *const kSigningID;
+extern NSString *const kCDHash;
 extern NSString *const kQuarantineDataURL;
 extern NSString *const kQuarantineRefererURL;
 extern NSString *const kQuarantineTimestamp;
@@ -125,6 +129,7 @@ extern NSString *const kRuleTypeBinary;
 extern NSString *const kRuleTypeCertificate;
 extern NSString *const kRuleTypeTeamID;
 extern NSString *const kRuleTypeSigningID;
+extern NSString *const kRuleTypeCDHash;
 extern NSString *const kRuleCustomMsg;
 extern NSString *const kRuleCustomURL;
 extern NSString *const kCursor;

Source/common/SNTSyncConstants.m

@@ -44,6 +44,7 @@
 NSString *const kTransitiveRuleCount = @"transitive_rule_count";
 NSString *const kTeamIDRuleCount = @"teamid_rule_count";
 NSString *const kSigningIDRuleCount = @"signingid_rule_count";
+NSString *const kCDHashRuleCount = @"cdhash_rule_count";
 NSString *const kFullSyncInterval = @"full_sync_interval";
 NSString *const kFCMToken = @"fcm_token";
 NSString *const kFCMFullSyncInterval = @"fcm_full_sync_interval";
@@ -71,12 +72,14 @@
 NSString *const kDecisionAllowScope = @"ALLOW_SCOPE";
 NSString *const kDecisionAllowTeamID = @"ALLOW_TEAMID";
 NSString *const kDecisionAllowSigningID = @"ALLOW_SIGNINGID";
+NSString *const kDecisionAllowCDHash = @"ALLOW_CDHASH";
 NSString *const kDecisionBlockUnknown = @"BLOCK_UNKNOWN";
 NSString *const kDecisionBlockBinary = @"BLOCK_BINARY";
 NSString *const kDecisionBlockCertificate = @"BLOCK_CERTIFICATE";
 NSString *const kDecisionBlockScope = @"BLOCK_SCOPE";
 NSString *const kDecisionBlockTeamID = @"BLOCK_TEAMID";
 NSString *const kDecisionBlockSigningID = @"BLOCK_SIGNINGID";
+NSString *const kDecisionBlockCDHash = @"BLOCK_CDHASH";
 NSString *const kDecisionUnknown = @"UNKNOWN";
 NSString *const kDecisionBundleBinary = @"BUNDLE_BINARY";
 NSString *const kLoggedInUsers = @"logged_in_users";
@@ -102,6 +105,7 @@
 NSString *const kCertValidUntil = @"valid_until";
 NSString *const kTeamID = @"team_id";
 NSString *const kSigningID = @"signing_id";
+NSString *const kCDHash = @"cdhash";
 NSString *const kQuarantineDataURL = @"quarantine_data_url";
 NSString *const kQuarantineRefererURL = @"quarantine_referer_url";
 NSString *const kQuarantineTimestamp = @"quarantine_timestamp";
@@ -126,6 +130,7 @@
 NSString *const kRuleTypeCertificate = @"CERTIFICATE";
 NSString *const kRuleTypeTeamID = @"TEAMID";
 NSString *const kRuleTypeSigningID = @"SIGNINGID";
+NSString *const kRuleTypeCDHash = @"CDHASH";
 NSString *const kRuleCustomMsg = @"custom_msg";
 NSString *const kRuleCustomURL = @"custom_url";
 NSString *const kCursor = @"cursor";

Source/common/SNTXPCUnprivilegedControlInterface.h

@@ -16,6 +16,7 @@
 #import <MOLCertificate/MOLCertificate.h>
 
 #import "Source/common/SNTCommonEnums.h"
+#import "Source/common/SNTRuleIdentifiers.h"
 #import "Source/common/SantaVnode.h"
 
 @class SNTRule;
@@ -29,6 +30,7 @@ struct RuleCounts {
   int64_t transitive;
   int64_t teamID;
   int64_t signingID;
+  int64_t cdhash;
 };
 
 ///
@@ -55,17 +57,10 @@ struct RuleCounts {
 
 ///
 ///  @param filePath A Path to the file, can be nil.
-///  @param fileSHA256 The pre-calculated SHA256 hash for the file, can be nil. If nil the hash will
-///                    be calculated by this method from the filePath.
-///  @param certificateSHA256 A SHA256 hash of the signing certificate, can be nil.
-///  @note If fileInfo and signingCertificate are both passed in, the most specific rule will be
-///        returned. Binary rules take precedence over cert rules.
+///  @param identifiers The various identifiers to be used when making a decision.
 ///
 - (void)decisionForFilePath:(NSString *)filePath
-                 fileSHA256:(NSString *)fileSHA256
-          certificateSHA256:(NSString *)certificateSHA256
-                     teamID:(NSString *)teamID
-                  signingID:(NSString *)signingID
+                identifiers:(SNTRuleIdentifiers *)identifiers
                       reply:(void (^)(SNTEventState))reply;
 
 ///

Source/common/santa.proto

@@ -284,6 +284,7 @@ message Execution {
     REASON_LONG_PATH = 9;
     REASON_NOT_RUNNING = 10;
     REASON_SIGNING_ID = 11;
+    REASON_CDHASH = 12;
   }
   optional Reason reason = 10;
 

Source/santactl/Commands/SNTCommandFileInfo.m

@@ -22,6 +22,7 @@
 #import "Source/common/SNTFileInfo.h"
 #import "Source/common/SNTLogging.h"
 #import "Source/common/SNTRule.h"
+#import "Source/common/SNTRuleIdentifiers.h"
 #import "Source/common/SNTStoredEvent.h"
 #import "Source/common/SNTXPCBundleServiceInterface.h"
 #import "Source/common/SNTXPCControlInterface.h"
@@ -45,6 +46,7 @@
 static NSString *const kUniversalSigningChain = @"Universal Signing Chain";
 static NSString *const kTeamID = @"Team ID";
 static NSString *const kSigningID = @"Signing ID";
+static NSString *const kCDHash = @"CDHash";
 
 // signing chain keys
 static NSString *const kCommonName = @"Common Name";
@@ -123,6 +125,7 @@ @interface SNTCommandFileInfo : SNTCommand <SNTCommandProtocol>
 @property(readonly, copy, nonatomic) SNTAttributeBlock downloadAgent;
 @property(readonly, copy, nonatomic) SNTAttributeBlock teamID;
 @property(readonly, copy, nonatomic) SNTAttributeBlock signingID;
+@property(readonly, copy, nonatomic) SNTAttributeBlock cdhash;
 @property(readonly, copy, nonatomic) SNTAttributeBlock type;
 @property(readonly, copy, nonatomic) SNTAttributeBlock pageZero;
 @property(readonly, copy, nonatomic) SNTAttributeBlock codeSigned;
@@ -201,8 +204,8 @@ + (NSString *)longHelpText {
 + (NSArray<NSString *> *)fileInfoKeys {
   return @[
     kPath, kSHA256, kSHA1, kBundleName, kBundleVersion, kBundleVersionStr, kDownloadReferrerURL,
-    kDownloadURL, kDownloadTimestamp, kDownloadAgent, kTeamID, kSigningID, kType, kPageZero,
-    kCodeSigned, kRule, kSigningChain, kUniversalSigningChain
+    kDownloadURL, kDownloadTimestamp, kDownloadAgent, kTeamID, kSigningID, kCDHash, kType,
+    kPageZero, kCodeSigned, kRule, kSigningChain, kUniversalSigningChain
   ];
 }
 
@@ -236,6 +239,7 @@ - (instancetype)initWithDaemonConnection:(MOLXPCConnection *)daemonConn {
       kUniversalSigningChain : self.universalSigningChain,
       kTeamID : self.teamID,
       kSigningID : self.signingID,
+      kCDHash : self.cdhash,
     };
 
     _printQueue = dispatch_queue_create("com.google.santactl.print_queue", DISPATCH_QUEUE_SERIAL);
@@ -376,6 +380,8 @@ - (SNTAttributeBlock)rule {
     NSError *err;
     MOLCodesignChecker *csc = [fileInfo codesignCheckerWithError:&err];
 
+    NSString *cdhash =
+      [csc.signingInformation objectForKey:(__bridge NSString *)kSecCodeInfoUnique];
     NSString *teamID =
       [csc.signingInformation objectForKey:(__bridge NSString *)kSecCodeInfoTeamIdentifier];
     NSString *identifier =
@@ -394,15 +400,21 @@ - (SNTAttributeBlock)rule {
       }
     }
 
-    [[cmd.daemonConn remoteObjectProxy] decisionForFilePath:fileInfo.path
-                                                 fileSHA256:fileInfo.SHA256
-                                          certificateSHA256:err ? nil : csc.leafCertificate.SHA256
-                                                     teamID:teamID
-                                                  signingID:signingID
-                                                      reply:^(SNTEventState s) {
-                                                        state = s;
-                                                        dispatch_semaphore_signal(sema);
-                                                      }];
+    struct RuleIdentifiers identifiers = {
+      .cdhash = cdhash,
+      .binarySHA256 = fileInfo.SHA256,
+      .signingID = signingID,
+      .certificateSHA256 = err ? nil : csc.leafCertificate.SHA256,
+      .teamID = teamID,
+    };
+
+    [[cmd.daemonConn remoteObjectProxy]
+      decisionForFilePath:fileInfo.path
+              identifiers:[[SNTRuleIdentifiers alloc] initWithRuleIdentifiers:identifiers]
+                    reply:^(SNTEventState s) {
+                      state = s;
+                      dispatch_semaphore_signal(sema);
+                    }];
     if (dispatch_semaphore_wait(sema, dispatch_time(DISPATCH_TIME_NOW, 5 * NSEC_PER_SEC))) {
       cmd.daemonUnavailable = YES;
       return kCommunicationErrorMsg;
@@ -420,6 +432,8 @@ - (SNTAttributeBlock)rule {
         case SNTEventStateBlockTeamID: [output appendString:@" (TeamID)"]; break;
         case SNTEventStateAllowSigningID:
         case SNTEventStateBlockSigningID: [output appendString:@" (SigningID)"]; break;
+        case SNTEventStateAllowCDHash:
+        case SNTEventStateBlockCDHash: [output appendString:@" (CDHash)"]; break;
         case SNTEventStateAllowScope:
         case SNTEventStateBlockScope: [output appendString:@" (Scope)"]; break;
         case SNTEventStateAllowCompiler: [output appendString:@" (Compiler)"]; break;
@@ -519,6 +533,13 @@ - (SNTAttributeBlock)signingID {
   };
 }
 
+- (SNTAttributeBlock)cdhash {
+  return ^id(SNTCommandFileInfo *cmd, SNTFileInfo *fileInfo) {
+    MOLCodesignChecker *csc = [fileInfo codesignCheckerWithError:NULL];
+    return [csc.signingInformation objectForKey:(__bridge NSString *)kSecCodeInfoUnique];
+  };
+}
+
 #pragma mark -
 
 // Entry point for the command.