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Fix code scanning alert no. 14: Inefficient regular expression #40

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Merged
tacxou merged 1 commit into from
Nov 22, 2024
Merged

Fix code scanning alert no. 14: Inefficient regular expression #40

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2 changes: 1 addition & 1 deletion src/core/filestorage/_dto/filestorage.dto.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -33,7 +33,7 @@
@IsString()
@IsNotEmpty()
@ApiProperty({ type: String, default: '/' })
@Matches(/^\/(\.?[^\/\0]+\/?)+$/, { message: 'Path must be a valid path' })
@Matches(/^\/(?:\.?[^\/\0]+\/?)+$/, { message: 'Path must be a valid path' })

Check failure

Code scanning / CodeQL

Inefficient regular expression High

This part of the regular expression may cause exponential backtracking on strings starting with '/' and containing many repetitions of '.'.

Copilot Autofix

AI about 1 year ago

To fix the problem, we need to modify the regular expression to remove the ambiguity that causes exponential backtracking. We can achieve this by making the sub-expression more specific and avoiding nested quantifiers. Specifically, we can replace \.?[^\/\0]+\/? with a more precise pattern that matches valid path segments without ambiguity.

The best way to fix the problem is to use a non-capturing group that matches either a single dot or a sequence of characters that are not slashes or null characters. This will eliminate the nested quantifiers and prevent exponential backtracking.

Suggested changeset 1
src/core/filestorage/_dto/filestorage.dto.ts

Autofix patch

Autofix patch
Run the following command in your local git repository to apply this patch
cat << 'EOF' | git apply
diff --git a/src/core/filestorage/_dto/filestorage.dto.ts b/src/core/filestorage/_dto/filestorage.dto.ts
--- a/src/core/filestorage/_dto/filestorage.dto.ts
+++ b/src/core/filestorage/_dto/filestorage.dto.ts
@@ -35,3 +35,3 @@
   @ApiProperty({ type: String, default: '/' })
-  @Matches(/^\/(?:\.?[^\/\0]+\/?)+$/, { message: 'Path must be a valid path' })
+  @Matches(/^\/(?:\.[^\/\0]*|[^\/\0]+\/?)+$/, { message: 'Path must be a valid path' })
   public path: string;
EOF
@@ -35,3 +35,3 @@
@ApiProperty({ type: String, default: '/' })
@Matches(/^\/(?:\.?[^\/\0]+\/?)+$/, { message: 'Path must be a valid path' })
@Matches(/^\/(?:\.[^\/\0]*|[^\/\0]+\/?)+$/, { message: 'Path must be a valid path' })
public path: string;
Copilot is powered by AI and may make mistakes. Always verify output.
public path: string;

@IsOptional()
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