/**

* Provides abstract classes representing generic concepts such as file system

* access or system command execution, for which individual framework libraries

* provide concrete subclasses.

*/

import go

import semmle.go.dataflow.FunctionInputsAndOutputs

import semmle.go.concepts.HTTP

import semmle.go.concepts.GeneratedFile

/**

* A data-flow node that executes an operating system command,

* for instance by spawning a new process.

*

* Extend this class to refine existing API models. If you want to model new APIs,

* extend `SystemCommandExecution::Range` instead.

*/

class SystemCommandExecution extends DataFlow::Node instanceof SystemCommandExecution::Range {

/** Gets the argument that specifies the command to be executed. */

DataFlow::Node getCommandName() { result = super.getCommandName() }

/** Holds if this node is sanitized whenever it follows `--` in an argument list. */

predicate doubleDashIsSanitizing() { super.doubleDashIsSanitizing() }

}

/** Provides a class for modeling new system-command execution APIs. */

module SystemCommandExecution {

/**

* A data-flow node that executes an operating system command,

* for instance by spawning a new process.

*

* Extend this class to model new APIs. If you want to refine existing API models,

* extend `SystemCommandExecution` instead.

*/

abstract class Range extends DataFlow::Node {

/** Gets the argument that specifies the command to be executed. */

abstract DataFlow::Node getCommandName();

/** Holds if this node is sanitized whenever it follows `--` in an argument list. */

predicate doubleDashIsSanitizing() { none() }

}

}

/**

* An instantiation of a template; that is, a call which fills out a template with data.

*

* Extend this class to refine existing API models. If you want to model new APIs,

* extend `TemplateInstantiation::Range` instead.

*/

class TemplateInstantiation extends DataFlow::Node instanceof TemplateInstantiation::Range {

/**

* Gets the argument to this template instantiation that is the template being

* instantiated.

*/

DataFlow::Node getTemplateArgument() { result = super.getTemplateArgument() }

/**

* Gets an argument to this template instantiation that is data being inserted

* into the template.

*/

DataFlow::Node getADataArgument() { result = super.getADataArgument() }

}

/** Provides a class for modeling new template-instantiation APIs. */

module TemplateInstantiation {

/**

* An instantiation of a template; that is, a call which fills out a template with data.

*

* Extend this class to model new APIs. If you want to refine existing API models,

* extend `TemplateInstantiation` instead.

*/

abstract class Range extends DataFlow::Node {

/**

* Gets the argument to this template instantiation that is the template being

* instantiated.

*/

abstract DataFlow::Node getTemplateArgument();

/**

* Gets an argument to this template instantiation that is data being inserted

* into the template.

*/

abstract DataFlow::Node getADataArgument();

}

}

/**

* A data-flow node that performs a file system access, including reading and writing data,

* creating and deleting files and folders, checking and updating permissions, and so on.

*

* Extend this class to refine existing API models. If you want to model new APIs,

* extend `FileSystemAccess::Range` instead.

*/

class FileSystemAccess extends DataFlow::Node instanceof FileSystemAccess::Range {

/** Gets an argument to this file system access that is interpreted as a path. */

DataFlow::Node getAPathArgument() { result = super.getAPathArgument() }

}

/** Provides a class for modeling new file-system access APIs. */

module FileSystemAccess {

/**

* A data-flow node that performs a file system access, including reading and writing data,

* creating and deleting files and folders, checking and updating permissions, and so on.

*

* Extend this class to model new APIs. If you want to refine existing API models,

* extend `FileSystemAccess` instead.

*/

abstract class Range extends DataFlow::Node {

/** Gets an argument to this file system access that is interpreted as a path. */

abstract DataFlow::Node getAPathArgument();

}

}

private class DefaultFileSystemAccess extends FileSystemAccess::Range, DataFlow::CallNode {

DataFlow::ArgumentNode pathArgument;

DefaultFileSystemAccess() {

sinkNode(pathArgument, "path-injection") and

this = pathArgument.getCall()

}

override DataFlow::Node getAPathArgument() {

result = pathArgument.getACorrespondingSyntacticArgument()

}

}

/** A function that escapes meta-characters to prevent injection attacks. */

class EscapeFunction extends Function instanceof EscapeFunction::Range {

/**

* Gets the context that this function escapes for.

*

* Currently, this can be "js", "html", or "url".

*/

string kind() { result = super.kind() }

}

/** Provides a class for modeling new escape-function APIs. */

module EscapeFunction {

/**

* A function that escapes meta-characters to prevent injection attacks.

*

* Extend this class to model new APIs. If you want to refine existing API models,

* extend `EscapeFunction' instead.

*/

abstract class Range extends Function {

/**

* Gets the context that this function escapes for.

*

* Currently, this can be `js', `html', or `url'.

*/

abstract string kind();

}

}

/**

* A function that escapes a string so it can be safely included in a

* JavaScript string literal.

*/

class JsEscapeFunction extends EscapeFunction {

JsEscapeFunction() { super.kind() = "js" }

}

/**

* A function that escapes a string so it can be safely included in an

* the body of an HTML element, for example, replacing `{}` in

* `<p>{}</p>`.

*/

class HtmlEscapeFunction extends EscapeFunction {

HtmlEscapeFunction() { super.kind() = "html" }

}

/**

* A function that escapes a string so it can be safely included as part

* of a URL.

*/

class UrlEscapeFunction extends EscapeFunction {

UrlEscapeFunction() { super.kind() = "url" }

}

/**

* A node whose value is interpreted as a part of a regular expression.

*

* Extend this class to refine existing API models. If you want to model new APIs,

* extend `RegexpPattern::Range` instead.

*/

class RegexpPattern extends DataFlow::Node instanceof RegexpPattern::Range {

/**

* Gets the node where this pattern is parsed as a part of a regular

* expression.

*/

DataFlow::Node getAParse() { result = super.getAParse() }

/**

* Gets this regexp pattern as a string.

*/

string getPattern() { result = super.getPattern() }

/**

* Gets a use of this pattern, either as itself in an argument to a function or as a compiled

* regexp object.

*/

DataFlow::Node getAUse() { result = super.getAUse() }

}

/** Provides a class for modeling new regular-expression APIs. */

module RegexpPattern {

/**

* A node whose value is interpreted as a part of a regular expression.

*

* Extend this class to model new APIs. If you want to refine existing API models,

* extend `RegexpPattern' instead.

*/

abstract class Range extends DataFlow::Node {

/**

* Gets a node where the pattern of this node is parsed as a part of

* a regular expression.

*/

abstract DataFlow::Node getAParse();

/**

* Gets this regexp pattern as a string.

*/

abstract string getPattern();

/**

* Gets a use of this pattern, either as itself in an argument to a function or as a compiled

* regexp object.

*/

abstract DataFlow::Node getAUse();

}

}

/**

* A function that matches a regexp with a string or byte slice.

*

* Extend this class to refine existing API models. If you want to model new APIs,

* extend `RegexpMatchFunction::Range` instead.

*/

class RegexpMatchFunction extends Function instanceof RegexpMatchFunction::Range {

/**

* Gets the function input that is the regexp being matched.

*/

FunctionInput getRegexpArg() { result = super.getRegexpArg() }

/**

* Gets the regexp pattern that is used in the call to this function `call`.

*/

RegexpPattern getRegexp(DataFlow::CallNode call) {

result.getAUse() = this.getRegexpArg().getNode(call)

}

/**

* Gets the function input that is the string being matched against.

*/

FunctionInput getValue() { result = super.getValue() }

/**

* Gets the function output that is the Boolean result of the match function.

*/

FunctionOutput getResult() { result = super.getResult() }

}

/** Provides a class for modeling new regular-expression matcher APIs. */

module RegexpMatchFunction {

/**

* A function that matches a regexp with a string or byte slice.

*

* Extend this class to model new APIs. If you want to refine existing API models,

* extend `RegexpPattern' instead.

*/

abstract class Range extends Function {

/**

* Gets the function input that is the regexp being matched.

*/

abstract FunctionInput getRegexpArg();

/**

* Gets the function input that is the string being matched against.

*/

abstract FunctionInput getValue();

/**

* Gets the Boolean result of the match function.

*/

abstract FunctionOutput getResult();

}

}

/**

* A function that uses a regexp to replace parts of a string or byte slice.

*

* Extend this class to refine existing API models. If you want to model new APIs,

* extend `RegexpReplaceFunction::Range` instead.

*/

class RegexpReplaceFunction extends Function instanceof RegexpReplaceFunction::Range {

/**

* Gets the function input that is the regexp that matches text to replace.

*/

FunctionInput getRegexpArg() { result = super.getRegexpArg() }

/**

* Gets the regexp pattern that is used to match patterns to replace in the call to this function

* `call`.

*/

RegexpPattern getRegexp(DataFlow::CallNode call) {

result.getAUse() = call.(DataFlow::MethodCallNode).getReceiver()

}

/**

* Gets the function input corresponding to the source value, that is, the value that is having

* its contents replaced.

*/

FunctionInput getSource() { result = super.getSource() }

/**

* Gets the function output corresponding to the result, that is, the value after replacement has

* occurred.

*/

FunctionOutput getResult() { result = super.getResult() }

}

/** Provides a class for modeling new regular-expression replacer APIs. */

module RegexpReplaceFunction {

/**

* A function that uses a regexp to replace parts of a string or byte slice.

*

* Extend this class to model new APIs. If you want to refine existing API models,

* extend `RegexpReplaceFunction' instead.

*/

abstract class Range extends Function {

/**

* Gets the function input that is the regexp that matches text to replace.

*/

abstract FunctionInput getRegexpArg();

/**

* Gets the function input corresponding to the source value, that is, the value that is having

* its contents replaced.

*/

abstract FunctionInput getSource();

/**

* Gets the function output corresponding to the result, that is, the value after replacement

* has occurred.

*/

abstract FunctionOutput getResult();

}

}

/**

* A call to a logging mechanism.

*

* Extend this class to refine existing API models. If you want to model new APIs,

* extend `LoggerCall::Range` instead.

*/

class LoggerCall extends DataFlow::Node instanceof LoggerCall::Range {

/** Gets a node that is a part of the logged message. */

DataFlow::Node getAMessageComponent() { result = super.getAMessageComponent() }

/**

* Gets a node whose value is a part of the logged message.

*

* Components corresponding to the format specifier "%T" are excluded as

* their type is logged rather than their value.

*/

DataFlow::Node getAValueFormattedMessageComponent() {

result = this.getAMessageComponent() and

not exists(string formatSpecifier |

result = this.(StringOps::Formatting::StringFormatCall).getOperand(_, formatSpecifier) and

// We already know that `formatSpecifier` starts with `%`, so we check

// that it ends with `T` to confirm that it is `%T` or possibly some

// variation on it.

formatSpecifier.matches("%T")

)

}

}

/** Provides a class for modeling new logging APIs. */

module LoggerCall {

/**

* A call to a logging mechanism.

*

* Extend this class to model new APIs. If you want to refine existing API models,

* extend `LoggerCall` instead.

*/

abstract class Range extends DataFlow::Node {

/** Gets a node that is a part of the logged message. */

abstract DataFlow::Node getAMessageComponent();

}

}

private class DefaultLoggerCall extends LoggerCall::Range, DataFlow::CallNode {

DataFlow::ArgumentNode messageComponent;

DefaultLoggerCall() {

sinkNode(messageComponent, "log-injection") and

this = messageComponent.getCall()

}

override DataFlow::Node getAMessageComponent() {

not messageComponent instanceof DataFlow::ImplicitVarargsSlice and

result = messageComponent

or

messageComponent instanceof DataFlow::ImplicitVarargsSlice and

result = this.getAnImplicitVarargsArgument()

}

}

/**

* A call to an interface that looks like a logger. It is common to use a

* locally-defined interface for logging to make it easy to changing logging

* library.

*/

private class HeuristicLoggerCall extends LoggerCall::Range, DataFlow::CallNode {

HeuristicLoggerCall() {

exists(Method m, string tp, string logFunctionPrefix, string name |

m = this.getTarget() and

m.hasQualifiedName(_, tp, name) and

m.getReceiverBaseType().getUnderlyingType() instanceof InterfaceType

|

tp.regexpMatch(".*[lL]ogger") and

logFunctionPrefix =

[

"Debug", "Error", "Fatal", "Info", "Log", "Output", "Panic", "Print", "Trace", "Warn",

"With"

] and

name.matches(logFunctionPrefix + "%")

)

}

override DataFlow::Node getAMessageComponent() { result = this.getASyntacticArgument() }

}

/**

* A function that encodes data into a binary or textual format.

*

* Extend this class to refine existing API models. If you want to model new APIs,

* extend `MarshalingFunction::Range` instead.

*/

class MarshalingFunction extends Function instanceof MarshalingFunction::Range {

/** Gets an input that is encoded by this function. */

FunctionInput getAnInput() { result = super.getAnInput() }

/** Gets the output that contains the encoded data produced by this function. */

FunctionOutput getOutput() { result = super.getOutput() }

/** Gets an identifier for the format this function encodes into, such as "JSON". */

string getFormat() { result = super.getFormat() }

}

/** Provides a class for modeling new marshaling APIs. */

module MarshalingFunction {

/**

* A function that encodes data into a binary or textual format.

*

* Extend this class to model new APIs. If you want to refine existing API models,

* extend `MarshalingFunction` instead.

*/

abstract class Range extends Function {

/** Gets an input that is encoded by this function. */

abstract FunctionInput getAnInput();

/** Gets the output that contains the encoded data produced by this function. */

abstract FunctionOutput getOutput();

/** Gets an identifier for the format this function encodes into, such as "JSON". */

abstract string getFormat();

}

}

/**

* A function that decodes data from a binary or textual format.

*

* Extend this class to refine existing API models. If you want to model new APIs,

* extend `UnmarshalingFunction::Range` instead.

*/

class UnmarshalingFunction extends Function instanceof UnmarshalingFunction::Range {

/** Gets an input that is decoded by this function. */

FunctionInput getAnInput() { result = super.getAnInput() }

/** Gets the output that contains the decoded data produced by this function. */

FunctionOutput getOutput() { result = super.getOutput() }

/** Gets an identifier for the format this function decodes from, such as "JSON". */

string getFormat() { result = super.getFormat() }

}

/** Provides a class for modeling new unmarshaling APIs. */

module UnmarshalingFunction {

/**

* A function that decodes data from a binary or textual format.

*

* Extend this class to model new APIs. If you want to refine existing API models,

* extend `UnmarshalingFunction` instead.

*/

abstract class Range extends Function {

/** Gets an input that is decoded by this function. */

abstract FunctionInput getAnInput();

/** Gets the output that contains the decoded data produced by this function. */

abstract FunctionOutput getOutput();

/** Gets an identifier for the format this function decodes from, such as "JSON". */

abstract string getFormat();

}

}