Metadata-Version: 2.1
Name: semgrep
Version: 0.10.0
Summary: Fast and syntax-aware semantic code pattern search for many languages: like grep but for code
Home-page: https://github.com/returntocorp/semgrep
Author: Return To Corporation
Author-email: support@r2c.dev
License: UNKNOWN
Platform: UNKNOWN
Classifier: Programming Language :: Python :: 3
Classifier: License :: OSI Approved :: GNU Lesser General Public License v2 (LGPLv2)
Classifier: Operating System :: OS Independent
Requires-Python: >=3.6
Description-Content-Type: text/markdown
Requires-Dist: colorama (>=0.4.3)
Requires-Dist: ruamel.yaml (==0.16.10)
Requires-Dist: requests (>=2.22.0)
Requires-Dist: attrs (>=19.3.0)

# Semgrep

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`semgrep` is a tool for easily detecting and preventing bugs and anti-patterns in
your codebase. It combines the convenience of `grep` with the correctness of
syntactical and semantic search. Developers, DevOps engineers, and security engineers
use `semgrep` to write code with confidence.

**Try it now:** [https://semgrep.live](https://semgrep.live/)

## Overview

Language support:

| **Python** | **Javascript** | **Go &nbsp; &nbsp; &nbsp;** | **Java &nbsp;** | **C &nbsp; &nbsp; &nbsp; &nbsp;** | **Typescript** | **PHP &nbsp; &nbsp;** |
|:-----------|:---------------|:----------------------------|:----------------|:----------------------------------|:---------------|:----------------------|
| ✅          | ✅              | ✅                           | ✅               | ✅                                 | Coming...      | Coming...             |

Example patterns:

| **Pattern**                                                        | **Matches**                                                |
|:-------------------------------------------------------------------|:-----------------------------------------------------------|
| [`$X == $X`](https://semgrep.live/20B)                             | `if (node.id == node.id): ...`                             |
| [`requests.get(..., verify=False, ...)`](https://semgrep.live/jqn) | `requests.get(url, timeout=3, verify=False)`               |
| [`os.system(...)`](https://semgrep.live/1W5)                       | `from os import system; system('echo semgrep')`            |
| [`$ELEMENT.innerHTML`](https://semgrep.live/9ze)                   | ``el.innerHTML = "<img src='x' onerror='alert(`XSS`)'>";`` |
| [`$TOKEN.SignedString([]byte("..."))`](https://semgrep.live/rXW)   | `ss, err := token.SignedString([]byte("HARDCODED KEY"))`   |

→ [see more example patterns in the live registry viewer](https://semgrep.live/registry)

## Installation

On macOS, binaries are available via [Homebrew](https://formulae.brew.sh/formula/semgrep):

```bash
brew install returntocorp/semgrep/semgrep
```

On Ubuntu, an install script is available on each release [here](https://github.com/returntocorp/semgrep/releases/download/v0.10.0/semgrep-v0.10.0-ubuntu-generic.sh)
```bash
./semgrep-v0.10.0-ubuntu-generic.sh
```

To try `semgrep` without installation, you can also run it via [Docker](https://docs.docker.com/install/):

```
docker run --rm -v "${PWD}:/home/repo" returntocorp/semgrep --help
```

## Usage

### Example Usage

Here is a simple Python example, `test.py`. We want to retrieve an object by ID:

```python3
def get_node(node_id, nodes):
    for node in nodes:
        if node.id == node.id:  # Oops, supposed to be 'node_id'
            return node
    return None
```

This is a bug. Let's use `semgrep` to find bugs like it, using a simple search pattern: `$X == $X`. It will find all places in our code where the left- and right-hand sides of a comparison are the same expression:

```
$ semgrep --lang python --pattern '$X == $X' test.py
test.py
3:        if node.id == node.id:  # Oops, supposed to be 'node_id'
```

## Configuration

For simple patterns use the `--lang` and `--pattern` flags. This mode of
operation is useful for quickly iterating on a pattern on a single file or
folder:

```bash
semgrep --lang javascript --pattern 'eval(...)' path/to/file.js
```

### Configuration Files

For advanced configuration use the `--config` flag. This flag automagically
handles a multitude of input configuration types:

* `--config <file|folder|yaml_url|tarball_url|registy_name>`

In the absence of this flag, a default configuration is loaded from `.semgrep.yml`
or multiple files matching `.semgrep/**/*.yml`.

### Registry

As mentioned above, you may also specify a `registry_name` as configuration.
[r2c](https://r2c.dev) provides a [registry](https://semgrep.live/r)
of rules. These rules have been tuned on thousands of repositories
using our [analysis platform](https://app.r2c.dev).

You can browse the registry at [semgrep.live/r](https://semgrep.live/r). To run a set of rules, use a rule ID or namespace.

```bash
# Run a specific rule
semgrep --config=https://semgrep.live/c/r/java.spring.security.audit.cookie-missing-samesite

# Run a set of rules
semgrep --config=https://semgrep.live/c/r/java.spring.security
```

The registry features rules for many programming errors, including security issues and correctness bugs. Security rules are annotated with CWE and OWASP metadata when applicable. OWASP rule coverage per language is displayed below.

<p align="center">
    <img width="600" src="https://web-assets.r2c.dev/semgrep-rules-owasp-coverage-20200520.png" style="max-width:100%;" />
</p>


#### Pattern Features

`semgrep` patterns make use of two primary features:

* **Metavariables like `$X`, `$WIDGET`, or `$USERS_2`.** Metavariable names can
only contain uppercase characters, or `_`, or digits, and must start with
an uppercase character or `_`. Names like `$x` or `$some_value` are
invalid.  Metavariables are used to track a variable across a specific code
scope.
* **The `...` (ellipsis) operator.** The ellipsis operator abstracts away
sequences of zero or more arguments, statements, characters, [and more](docs/pattern-features.md).

For example,
```yaml
$FILE = open(...)
```
will find all occurrences in your code where the result of an `open()` call with zero or more arguments is assigned
to a variable.

#### Composing Patterns

You can also construct rules by composing multiple patterns together.

Let's consider an example:

```yaml
rules:
  - id: open-never-closed
    patterns:
      - pattern: $FILE = open(...)
      - pattern-not-inside: |
          $FILE = open(...)
          ...
          $FILE.close()
    message: "file object opened without corresponding close"
    languages: [python]
    severity: ERROR
```

This rule looks for files that are opened but never closed. It accomplishes
this by looking for the `open(...)` pattern _and not_ a following `close()`
pattern. The `$FILE` metavariable ensures that the same variable name is used
in the `open` and `close` calls. The ellipsis operator allows for any arguments
to be passed to `open` and any sequence of code statements in-between the `open`
and `close` calls. We don't care how `open` is called or what happens up to
a `close` call, we just need to make sure `close` is called.

**For more information on rule fields like `patterns` and `pattern-not-inside`
see the [configuration documentation](docs/configuration-files.md).**

#### Equivalences

Equivalences are another key concept in `semgrep`. `semgrep` automatically searches
for code that is semantically equivalent. For example, the following patterns
are semantically equivalent. The pattern `subprocess.Popen(...)` will fire on both.

```python
subprocess.Popen("ls")
```

```python
from subprocess import Popen as sub_popen

result = sub_popen("ls")
```

For a full list of `semgrep` feature support by language see the
[language matrix](docs/matrix.md).

### Programmatic Usage

To integrate semgrep's results with other tools,
you can get results in machine-readable JSON format with the `--json` option,
or formatted according to the
[SARIF standard](https://docs.oasis-open.org/sarif/sarif/v2.1.0/cs01/sarif-v2.1.0-cs01.html)
with the `--sarif` flag.

See our [output documentation](docs/output.md) for details.

## Resources

* [Semgrep presentation](https://www.youtube.com/watch?v=pul1bRIOYc8) and [slides](https://web-assets.r2c.dev/presentations/r2c-semgrep-OWASP-BayArea-21-May-2020.pdf) at Bay Area OWASP meetup. Check out the [r2c YouTube channel](https://www.youtube.com/channel/UC5ahcFBorwzUTqPipFhjkWg) for more videos.
* [Documentation](/docs)
  * [Pattern Features](docs/pattern-features.md)
  * [Configuration Files](docs/configuration-files.md)
  * [Integrations](docs/integrations.md)
  * [Output](docs/output.md)
  * [Development](docs/development.md)
* [Bug reports](https://github.com/returntocorp/semgrep/issues)

## Contribution

`semgrep` is LGPL-licensed, feel free to help out: [CONTRIBUTING](https://github.com/returntocorp/semgrep/blob/develop/CONTRIBUTING.md).

`semgrep` is a frontend to a larger program analysis library named [`pfff`](https://github.com/returntocorp/pfff/). `pfff` began and was open-sourced at [Facebook](https://github.com/facebookarchive/pfff) but is now archived. The primary maintainer now works at [r2c](https://r2c.dev). `semgrep` was originally named `sgrep` and was renamed to avoid collisons with existing projects.

## Commercial Support

`semgrep` is proudly supported by [r2c](https://r2c.dev). We're hiring!

Interested in a fully-supported, hosted version of semgrep? [Drop your email](https://forms.gle/dpUUvSo1WtELL8DW6) and we'll ping you!


