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Defining custom patterns for secret scanning

You can extend secret scanning to detect secrets beyond the default patterns.

Secret scanning is available for organization-owned repositories in GitHub Enterprise Server if your enterprise has a license for GitHub Advanced Security. Para más información, consulte "Acerca de GitHub Advanced Security".

About custom patterns for secret scanning

You can define custom patterns to identify secrets that are not detected by the default patterns supported by secret scanning. For example, you might have a secret pattern that is internal to your organization. For details of the supported secrets and service providers, see "Secret scanning patterns."

You can define custom patterns for your enterprise, organization, or repository. Secret scanning supports up to 500 custom patterns for each organization or enterprise account, and up to 100 custom patterns per repository.

Regular expression syntax for custom patterns

You can specify custom patterns for secret scanning as one or more regular expressions.

  • Secret format: an expression that describes the format of the secret itself.
  • Before secret: an expression that describes the characters that come before the secret. By default, this is set to \A|[^0-9A-Za-z] which means that the secret must be at the start of a line or be preceded by a non-alphanumeric character.
  • After secret: an expression that describes the characters that come after the secret. By default, this is set to \z|[^0-9A-Za-z] which means that the secret must be followed by a new line or a non-alphanumeric character.
  • Additional match requirements: one or more optional expressions that the secret itself must or must not match.

For simple tokens you will usually only need to specify a secret format. The other fields provide flexibility so that you can specify more complex secrets without creating complex regular expressions. For an example of a custom pattern, see "Example of a custom pattern specified using additional requirements" below.

Secret scanning uses the Hyperscan library and only supports Hyperscan regex constructs, which are a subset of PCRE syntax. Hyperscan option modifiers are not supported. For more information on Hyperscan pattern constructs, see "Pattern support" in the Hyperscan documentation.

Defining a custom pattern for a repository

Before defining a custom pattern, you must ensure that secret scanning is enabled on your repository. For more information, see "Configuring secret scanning for your repositories."

  1. On your GitHub Enterprise Server instance, navigate to the main page of the repository.

  2. Debajo del nombre del repositorio, haz clic en Configuración. Botón de configuración del repositorio

  3. In the "Security" section of the sidebar, click Code security and analysis.

  4. Debajo de "Seguridad y análisis de código", encuentra "GitHub Advanced Security".

  5. En "Secret scanning", en "Patrones personalizados", haz clic en Nuevo patrón.

  6. Enter the details for your new custom pattern:

    1. You must at least provide the name for your pattern, and a regular expression for the format of your secret pattern.
    2. You can click More options to provide other surrounding content or additional match requirements for the secret format.
    3. Provide a sample test string to make sure your configuration is matching the patterns you expect.

    Create a custom secret scanning pattern form

  7. When you're ready to test your new custom pattern, to identify matches in the repository without creating alerts, click Save and dry run.

  8. Cuando termine el simulacro verás un ejemplo de los resultados (hasta 1000). Revisa los resultados e identifica cualquier falso positivo. Captura de pantalla en la que se muestran los resultados de una simulación

  9. Edita el nuevo patrón personalizado para corregir cualquier problema con los resultados y, después, haz clic en Guardar y realizar simulacro para probar los cambios.

    Nota: Esta característica de simulacro se encuentra en versión beta y está sujeta a cambios.

  10. When you're satisfied with your new custom pattern, click Publish pattern

After your pattern is created, El secret scanning escanea cualquier secreto en el total de tu historial de Git en todas las ramas presentes de tu repositorio de GitHub. For more information on viewing secret scanning alerts, see "Managing alerts from secret scanning."

Example of a custom pattern specified using additional requirements

A company has an internal token with five characteristics. They use the different fields to specify how to identify tokens as follows:

CharacteristicField and regular expression
Length between 5 and 10 charactersSecret format: [$#%@AA-Za-z0-9]{5,10}
Does not end in a .After secret: [^\.]
Contains numbers and uppercase lettersAdditional requirements: secret must match [A-Z] and [0-9]
Does not include more than one lowercase letter in a rowAdditional requirements: secret must not match [a-z]{2,}
Contains one of $%@!Additional requirements: secret must match [$%@!]

These tokens would match the custom pattern described above:

a9@AAfT!         # Secret string match: a9@AAfT
ee95GG@ZA942@aa  # Secret string match: @ZA942@a
a9@AA!ee9        # Secret string match: a9@AA

These strings would not match the custom pattern described above:

a9@AA.!
a@AAAAA
aa9@AA!ee9
aAAAe9

Defining a custom pattern for an organization

Before defining a custom pattern, you must ensure that you enable secret scanning for the repositories that you want to scan in your organization. To enable secret scanning on all repositories in your organization, see "Managing security and analysis settings for your organization."

  1. En la esquina superior derecha de GitHub Enterprise Server, haga clic en la foto de perfil y luego en Your organizations. Opción Your organizations (Sus organizaciones) en el menú del perfil

  2. Junto a la organización, haga clic en Settings. El botón de configuración

  3. In the "Security" section of the sidebar, click Code security and analysis.

  4. Debajo de "Seguridad y análisis de código", encuentra "GitHub Advanced Security".

  5. En "Secret scanning", en "Patrones personalizados", haz clic en Nuevo patrón.

  6. Enter the details for your new custom pattern:

    1. You must at least provide the name for your pattern, and a regular expression for the format of your secret pattern.
    2. You can click More options to provide other surrounding content or additional match requirements for the secret format.
    3. Provide a sample test string to make sure your configuration is matching the patterns you expect.

    Create a custom secret scanning pattern form

  7. When you're ready to test your new custom pattern, to identify matches in select repositories without creating alerts, click Save and dry run.

  8. Busca y selecciona hasta 10 repositorios en los que quieras realizar el simulacro. Captura de pantalla en la que se muestran los repositorios seleccionados para el simulacro

  9. Cuando estés listo para probar el nuevo patrón personalizado, haz clic en Simulacro.

  10. Cuando termine el simulacro verás un ejemplo de los resultados (hasta 1000). Revisa los resultados e identifica cualquier falso positivo. Captura de pantalla en la que se muestran los resultados de una simulación

  11. Edita el nuevo patrón personalizado para corregir cualquier problema con los resultados y, después, haz clic en Guardar y realizar simulacro para probar los cambios.

    Nota: Esta característica de simulacro se encuentra en versión beta y está sujeta a cambios.

  12. When you're satisfied with your new custom pattern, click Publish pattern

After your pattern is created, secret scanning scans for any secrets in repositories in your organization, including their entire Git history on all branches. Organization owners and repository administrators will be alerted to any secrets found and can review the alert in the repository where the secret is found. For more information on viewing secret scanning alerts, see "Managing alerts from secret scanning."

Defining a custom pattern for an enterprise account

Before defining a custom pattern, you must ensure that you enable secret scanning for your enterprise account. For more information, see "Enabling GitHub Advanced Security for your enterprise."

Note: As there is no dry-run functionality, we recommend that you test your custom patterns in a repository before defining them for your entire enterprise. That way, you can avoid creating excess false-positive secret scanning alerts.

  1. En la esquina superior derecha de GitHub Enterprise Server, haga clic en la foto de perfil y luego en Configuración de empresa. "Configuración de empresa" en el menú desplegable de la foto de perfil de GitHub Enterprise Server

  2. En la barra lateral de la empresa, haz clic en Directivas. Pestaña Directivas en la barra lateral de la cuenta de empresa

  3. En Directivas, haga clic en "Seguridad avanzada". Directivas de "Seguridad avanzada" en la barra lateral

  4. En "Seguridad avanzada de GitHub", haga clic en la pestaña Características de seguridad.

  5. Under "Secret scanning custom patterns", click New pattern.

  6. Enter the details for your new custom pattern:

    1. You must at least provide the name for your pattern, and a regular expression for the format of your secret pattern.
    2. You can click More options to provide other surrounding content or additional match requirements for the secret format.
    3. Provide a sample test string to make sure your configuration is matching the patterns you expect.

    Create a custom secret scanning pattern form

  7. When you're satisfied with your new custom pattern, click Publish pattern

After your pattern is created, secret scanning scans for any secrets in repositories within your enterprise's organizations with GitHub Advanced Security enabled, including their entire Git history on all branches. Organization owners and repository administrators will be alerted to any secrets found, and can review the alert in the repository where the secret is found. For more information on viewing secret scanning alerts, see "Managing alerts from secret scanning."

Editing a custom pattern

When you save a change to a custom pattern, this closes all the secret scanning alerts that were created using the previous version of the pattern.

  1. Navigate to where the custom pattern was created. A custom pattern can be created in a repository, organization, or enterprise account.
  2. Under "Secret scanning", to the right of the custom pattern you want to edit, click .
  3. When you have reviewed and tested your changes, click Save changes.

Removing a custom pattern

  1. Navigate to where the custom pattern was created. A custom pattern can be created in a repository, organization, or enterprise account.

  2. To the right of the custom pattern you want to remove, click .

  3. Review the confirmation, and select a method for dealing with any open alerts relating to the custom pattern.

  4. Click Yes, delete this pattern.

    Confirming deletion of a custom secret scanning pattern