1 files changed, 312 insertions, 0 deletions
diff --git a/Firebase/Database/Utilities/FValidation.m b/Firebase/Database/Utilities/FValidation.m
new file mode 100644
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+++ b/Firebase/Database/Utilities/FValidation.m
@@ -0,0 +1,312 @@
+/*
+ * Copyright 2017 Google
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#import "FValidation.h"
+#import "FConstants.h"
+#import "FParsedUrl.h"
+#import "FTypedefs.h"
+
+
+// Have to escape:  * ? + [ ( ) { } ^ $ | \ . /
+// See: https://developer.apple.com/library/mac/#documentation/Foundation/Reference/NSRegularExpression_Class/Reference/Reference.html
+
+NSString *const kInvalidPathCharacters = @"[].#$";
+NSString *const kInvalidKeyCharacters =  @"[].#$/";
+
+@implementation FValidation
+
++ (void) validateFrom:(NSString *)fn writablePath:(FPath *)path {
+    if([[path getFront] isEqualToString:kDotInfoPrefix]) {
+        @throw [[NSException alloc] initWithName:@"WritablePathValidation" reason:[NSString stringWithFormat:@"(%@) failed to path %@: Can't modify data under %@", fn, [path description], kDotInfoPrefix] userInfo:nil];
+    }
+}
+
++ (void) validateFrom:(NSString*)fn knownEventType:(FIRDataEventType)event {
+    switch (event) {
+        case FIRDataEventTypeValue:
+        case FIRDataEventTypeChildAdded:
+        case FIRDataEventTypeChildChanged:
+        case FIRDataEventTypeChildMoved:
+        case FIRDataEventTypeChildRemoved:
+            return;
+            break;
+        default:
+            @throw [[NSException alloc] initWithName:@"KnownEventTypeValidation" reason:[NSString stringWithFormat:@"(%@) Unknown event type: %d", fn, (int) event] userInfo:nil];
+            break;
+    }
+}
+
++ (BOOL) isValidPathString:(NSString *)pathString {
+    static dispatch_once_t token;
+    static NSCharacterSet *badPathChars = nil;
+    dispatch_once(&token, ^{
+        badPathChars = [NSCharacterSet characterSetWithCharactersInString:kInvalidPathCharacters];
+    });
+    return pathString != nil && [pathString length] != 0 &&
+            [pathString rangeOfCharacterFromSet:badPathChars].location == NSNotFound;
+}
+
++ (void) validateFrom:(NSString *)fn validPathString:(NSString *)pathString {
+    if(! [self isValidPathString:pathString]) {
+         @throw [[NSException alloc] initWithName:@"InvalidPathValidation" reason:[NSString stringWithFormat:@"(%@) Must be a non-empty string and not contain '.' '#' '$' '[' or ']'", fn] userInfo:nil];
+    }
+}
+
++ (void) validateFrom:(NSString *)fn validRootPathString:(NSString *)pathString {
+    static dispatch_once_t token;
+    static NSRegularExpression *dotInfoRegex = nil;
+    dispatch_once(&token, ^{
+        dotInfoRegex = [NSRegularExpression regularExpressionWithPattern:@"^\\/*\\.info(\\/|$)" options:0 error:nil];
+    });
+
+    NSString *tempPath = pathString;
+    // HACK: Obj-C regex are kinda' slow.  Do a plain string search first before bothering with the regex.
+    if ([pathString rangeOfString:@".info"].location != NSNotFound) {
+        tempPath = [dotInfoRegex stringByReplacingMatchesInString:pathString options:0 range:NSMakeRange(0, pathString.length) withTemplate:@"/"];
+    }
+    [self validateFrom:fn validPathString:tempPath];
+}
+
++ (BOOL) isValidKey:(NSString *)key {
+    static dispatch_once_t token;
+    static NSCharacterSet *badKeyChars = nil;
+    dispatch_once(&token, ^{
+        badKeyChars = [NSCharacterSet characterSetWithCharactersInString:kInvalidKeyCharacters];
+    });
+    return key != nil && key.length > 0 && [key rangeOfCharacterFromSet:badKeyChars].location == NSNotFound;
+}
+
++ (void) validateFrom:(NSString *)fn validKey:(NSString *)key {
+    if (![self isValidKey:key]) {
+        @throw [[NSException alloc] initWithName:@"InvalidKeyValidation" reason:[NSString stringWithFormat:@"(%@) Must be a non-empty string and not contain '/' '.' '#' '$' '[' or ']'", fn] userInfo:nil];
+    }
+}
+
++ (void) validateFrom:(NSString *)fn validURL:(FParsedUrl *)parsedUrl {
+    NSString* pathString = [parsedUrl.path description];
+    [self validateFrom:fn validRootPathString:pathString];
+}
+
+#pragma mark -
+#pragma mark Authentication validation
+
++ (BOOL) stringNonempty:(NSString *)str {
+    return str != nil && ![str isKindOfClass:[NSNull class]] && str.length > 0;
+}
+
++ (void) validateToken:(NSString *)token {
+    if (![FValidation stringNonempty:token]) {
+        [NSException raise:NSInvalidArgumentException format:@"Can't have empty string or nil for custom token"];
+    }
+}
+
+#pragma mark -
+#pragma mark Handling authentication errors
+
+/**
+* This function immediately calls the callback.
+* It assumes that it is not on FirebaseWorker thread.
+* It assumes it's on a user-controlled thread.
+*/
++ (void) handleError:(NSError *)error withUserCallback:(fbt_void_nserror_id)userCallback {
+    if (userCallback) {
+        userCallback(error, nil);
+    }
+}
+
+/**
+* This function immediately calls the callback.
+* It assumes that it is not on FirebaseWorker thread.
+* It assumes it's on a user-controlled thread.
+*/
++ (void) handleError:(NSError *)error withSuccessCallback:(fbt_void_nserror)userCallback {
+    if (userCallback) {
+        userCallback(error);
+    }
+}
+
+#pragma mark -
+#pragma mark Snapshot validation
+
++ (BOOL) validateFrom:(NSString*)fn isValidLeafValue:(id)value withPath:(NSArray*)path {
+    if ([value isKindOfClass:[NSString class]]) {
+        // Try to avoid conversion to bytes if possible
+        NSString* theString = value;
+        if ([theString maximumLengthOfBytesUsingEncoding:NSUTF8StringEncoding] > kFirebaseMaxLeafSize &&
+                   [theString lengthOfBytesUsingEncoding:NSUTF8StringEncoding] > kFirebaseMaxLeafSize) {
+            NSRange range;
+            range.location = 0;
+            range.length = MIN(path.count, 50);
+            NSString* pathString = [[path subarrayWithRange:range] componentsJoinedByString:@"."];
+            @throw [[NSException alloc] initWithName:@"InvalidFirebaseData" reason:[NSString stringWithFormat:@"(%@) String exceeds max size of %u utf8 bytes: %@", fn, (int)kFirebaseMaxLeafSize, pathString] userInfo:nil];
+        }
+        return YES;
+    }
+
+    else if ([value isKindOfClass:[NSNumber class]]) {
+        // Cannot store NaN, but otherwise can store NSNumbers.
+        if ([[NSDecimalNumber notANumber] isEqualToNumber:value]) {
+            NSRange range;
+            range.location = 0;
+            range.length = MIN(path.count, 50);
+            NSString* pathString = [[path subarrayWithRange:range] componentsJoinedByString:@"."];
+            @throw [[NSException alloc] initWithName:@"InvalidFirebaseData" reason:[NSString stringWithFormat:@"(%@) Cannot store NaN at path: %@.", fn, pathString] userInfo:nil];
+        }
+        return YES;
+    }
+
+    else if ([value isKindOfClass:[NSDictionary class]]) {
+        NSDictionary* dval = value;
+        if (dval[kServerValueSubKey] != nil) {
+            if ([dval count] > 1) {
+                NSRange range;
+                range.location = 0;
+                range.length = MIN(path.count, 50);
+                NSString* pathString = [[path subarrayWithRange:range] componentsJoinedByString:@"."];
+                @throw [[NSException alloc] initWithName:@"InvalidFirebaseData" reason:[NSString stringWithFormat:@"(%@) Cannot store other keys with server value keys.%@.", fn, pathString] userInfo:nil];
+            }
+            return YES;
+        }
+        return NO;
+    }
+
+    else if (value == [NSNull null] || value == nil) {
+        // Null is valid type to store at leaf
+        return YES;
+    }
+
+    return NO;
+}
+
++ (NSString*) parseAndValidateKey:(id)keyId fromFunction:(NSString*)fn path:(NSArray*)path {
+    if (![keyId isKindOfClass:[NSString class]]) {
+        NSRange range;
+        range.location = 0;
+        range.length = MIN(path.count, 50);
+        NSString* pathString = [[path subarrayWithRange:range] componentsJoinedByString:@"."];
+        @throw [[NSException alloc] initWithName:@"InvalidFirebaseData" reason:[NSString stringWithFormat:@"(%@) Non-string keys are not allowed in object at path: %@", fn, pathString] userInfo:nil];
+    }
+    return (NSString*)keyId;
+}
+
++ (void) validateFrom:(NSString*)fn validDictionaryKey:(id)keyId withPath:(NSArray*)path {
+    NSString *key = [self parseAndValidateKey:keyId fromFunction:fn path:path];
+    if (![key isEqualToString:kPayloadPriority] && ![key isEqualToString:kPayloadValue] && ![key isEqualToString:kServerValueSubKey] && ![FValidation isValidKey:key]) {
+        NSRange range;
+        range.location = 0;
+        range.length = MIN(path.count, 50);
+        NSString *pathString = [[path subarrayWithRange:range] componentsJoinedByString:@"."];
+        @throw [[NSException alloc] initWithName:@"InvalidFirebaseData" reason:[NSString stringWithFormat:@"(%@) Invalid key in object at path: %@. Keys must be non-empty and cannot contain '/' '.' '#' '$' '[' or ']'", fn, pathString] userInfo:nil];
+    }
+}
+
++ (void) validateFrom:(NSString*)fn validUpdateDictionaryKey:(id)keyId withValue:(id)value {
+    FPath *path = [FPath pathWithString:[self parseAndValidateKey:keyId fromFunction:fn path:@[]]];
+    __block NSInteger keyNum = 0;
+    [path enumerateComponentsUsingBlock:^void (NSString *key, BOOL *stop) {
+        if ([key isEqualToString:kPayloadPriority] && keyNum == [path length] - 1) {
+            [self validateFrom:fn isValidPriorityValue:value withPath:@[]];
+        } else {
+          keyNum++;
+        
+          if (![FValidation isValidKey:key]) {
+              @throw [[NSException alloc] initWithName:@"InvalidFirebaseData" reason:[NSString stringWithFormat:@"(%@) Invalid key in object. Keys must be non-empty and cannot contain '.' '#' '$' '[' or ']'", fn] userInfo:nil];
+          }
+        }
+    }];
+}
+
++ (void) validateFrom:(NSString*)fn isValidPriorityValue:(id)value withPath:(NSArray*)path {
+    [self validateFrom:fn isValidPriorityValue:value withPath:path throwError:YES];
+}
+
+/**
+* Returns YES if priority is valid.
+*/
++ (BOOL)validatePriorityValue:value {
+    return [self validateFrom:nil isValidPriorityValue:value withPath:nil throwError:NO];
+}
+
+/**
+* Helper for validating priorities.  If passed YES for throwError, it'll throw descriptive errors on validation
+* problems.  Else, it'll just return YES/NO.
+*/
++ (BOOL) validateFrom:(NSString*)fn isValidPriorityValue:(id)value withPath:(NSArray*)path throwError:(BOOL)throwError {
+    if ([value isKindOfClass:[NSNumber class]]) {
+        if ([[NSDecimalNumber notANumber] isEqualToNumber:value]) {
+            if (throwError) {
+                NSRange range;
+                range.location = 0;
+                range.length = MIN(path.count, 50);
+                NSString *pathString = [[path subarrayWithRange:range] componentsJoinedByString:@"."];
+                @throw [[NSException alloc] initWithName:@"InvalidFirebaseData" reason:[NSString stringWithFormat:@"(%@) Cannot store NaN as priority at path: %@.", fn, pathString] userInfo:nil];
+            } else {
+                return NO;
+            }
+        } else if (value == (id) kCFBooleanFalse || value == (id) kCFBooleanTrue) {
+            if (throwError) {
+                NSRange range;
+                range.location = 0;
+                range.length = MIN(path.count, 50);
+                NSString *pathString = [[path subarrayWithRange:range] componentsJoinedByString:@"."];
+                @throw [[NSException alloc] initWithName:@"InvalidFirebaseData" reason:[NSString stringWithFormat:@"(%@) Cannot store true/false as priority at path: %@.", fn, pathString] userInfo:nil];
+            } else {
+                return NO;
+            }
+        }
+    }
+    else if ([value isKindOfClass:[NSDictionary class]]) {
+        NSDictionary *dval = value;
+        if (dval[kServerValueSubKey] != nil) {
+            if ([dval count] > 1) {
+                if (throwError) {
+                    NSRange range;
+                    range.location = 0;
+                    range.length = MIN(path.count, 50);
+                    NSString *pathString = [[path subarrayWithRange:range] componentsJoinedByString:@"."];
+                    @throw [[NSException alloc] initWithName:@"InvalidFirebaseData" reason:[NSString stringWithFormat:@"(%@) Cannot store other keys with server value keys as priority at path: %@.", fn, pathString] userInfo:nil];
+                } else {
+                    return NO;
+                }
+            }
+        } else {
+            if (throwError) {
+                NSRange range;
+                range.location = 0;
+                range.length = MIN(path.count, 50);
+                NSString *pathString = [[path subarrayWithRange:range] componentsJoinedByString:@"."];
+                @throw [[NSException alloc] initWithName:@"InvalidFirebaseData" reason:[NSString stringWithFormat:@"(%@) Cannot store an NSDictionary as priority at path: %@.", fn, pathString] userInfo:nil];
+            } else {
+                return NO;
+            }
+        }
+    }
+    else if ([value isKindOfClass:[NSArray class]]) {
+        if (throwError) {
+            NSRange range;
+            range.location = 0;
+            range.length = MIN(path.count, 50);
+            NSString *pathString = [[path subarrayWithRange:range] componentsJoinedByString:@"."];
+            @throw [[NSException alloc] initWithName:@"InvalidFirebaseData" reason:[NSString stringWithFormat:@"(%@) Cannot store an NSArray as priority at path: %@.", fn, pathString] userInfo:nil];
+        } else {
+            return NO;
+        }
+    }
+
+    // It's valid!
+    return YES;
+}
+@end