Arangodump Data Maskings

--maskings path-of-config

This feature allows you to define how sensitive data shall be dumped. It is possible to exclude collections entirely, limit the dump to the structural information of a collection (name, indexes, sharding etc.) or to obfuscate certain fields for a dump. A JSON configuration file is used to define which collections and fields to mask and how.

The general structure of the configuration file looks like this:

{
  "<collection-name-1>": {
    "type": "<masking-type>",
    "maskings": [ // if masking-type is "masked"
      { "path": "<attr1>", "type": "<masking-function>", ... }, // rule 1
      { "path": "<attr2>", "type": "<masking-function>", ... }, // rule 2
      ...
    ]
  },
  "<collection-name-2>": { ... },
  "<collection-name-3>": { ... },
  "*": { ... }
}

At the top level, there is an object with collection names. The masking to be applied to the respective collection is defined by the type sub-attribute. If the type is "masked", then a sibling maskings attribute is available to define rules for obfuscating documents.

Using "*" as collection name defines a default behavior for collections not listed explicitly.

Masking Types

type is a string describing how to mask the given collection. Possible values are:

  • "exclude": the collection is ignored completely and not even the structure data is dumped.

  • "structure": only the collection structure is dumped, but no data at all (the file <collection-name>.data.json or <collection-name>.data.json.gz respectively is still created, but will not contain data).

  • "masked": the collection structure and all data is dumped. However, the data is subject to obfuscation defined in the attribute maskings. It is an array of objects, with one object per masking rule. Each object needs at least a path and a type attribute to define which field to mask and which masking function to apply. Depending on the masking type, there may exist additional attributes to control the masking function behavior.

  • "full": the collection structure and all data is dumped. No masking is applied to this collection at all.

Example

{
  "private": {
    "type": "exclude"
  },

  "temperature": {
    "type": "full"
  },

  "log": {
    "type": "structure"
  },

  "person": {
    "type": "masked",
    "maskings": [
      {
        "path": "name",
        "type": "xifyFront",
        "unmaskedLength": 2
      },
      {
        "path": ".security_id",
        "type": "xifyFront",
        "unmaskedLength": 2
      }
    ]
  }
}
  • The collection called private is completely ignored.
  • Only the structure of the collection log is dumped, but not the data itself.
  • The structure and data of the temperature collection is dumped without any obfuscation of document attributes.
  • The collection person is dumped completely but with maskings applied:
    • The name field is masked if it occurs on the top-level.
    • It also masks fields with the name security_id anywhere in the document.
    • The masking function is of type xifyFront in both cases. The additional setting unmaskedLength is specific so xifyFront.
  • All additional collections that might exist in the targeted database will be ignored (like the collection private), as there is no attribute key "*" to specify a different default type for the remaining collections.

Masking vs. dump-data option

arangodump also supports a very coarse masking with the option --dump-data false, which leaves out all data for the dump.

You can either use --maskings or --dump-data false, but not both.

Masking vs. collection option

arangodump also supports a very coarse masking with the option --collection. This will restrict the collections that are dumped to the ones explicitly listed.

It is possible to combine --maskings and --collection. This will take the intersection of exportable collections.

Path

path defines which field to obfuscate. There can only be a single path per masking, but an unlimited amount of maskings per collection.

{
  "collection1": {
    "type": "masked",
    "maskings": [
      {
        "path": "attr1",
        "type": "random"
      },
      {
        "path": "attr2",
        "type": "randomString"
      },
      ...
    ]
  },
  "collection2": {
    "type": "masked",
    "maskings": [
      {
        "path": "attr3",
        "type": "random"
      }
    ]
  },
  ...
}

Note that the top-level system attributes like _key, _from are never masked.

To mask a top-level attribute value, the path is simply the attribute name, for instance "name" to mask the value "foobar":

{
  "_key": "1234",
  "name": "foobar"
}

The path to a nested attribute name with a top-level attribute person as its parent is "person.name" (here: "foobar"):

{
  "_key": "1234",
  "person": {
    "name": "foobar"
  }
}

Example masking definition:

{
  "<collection-name>": {
    "type": "masked",
    "maskings": [
      {
        "path": "person.name",
        "type": "<masking-function>"
      }
    ]
}

If the path starts with a . then it matches any path ending in name. For example, .name will match the field name of all leaf attributes in the document. Leaf attributes are attributes whose value is null, true, false, or of data type string, number or array. That means, it matches name at the top level as well as at any nested level (e.g. foo.bar.name), but not nested objects themselves.

On the other hand, name will only match leaf attributes at top level. person.name will match the attribute name of a leaf in the top-level object person. If person was itself an object, then the masking settings for this path would be ignored, because it is not a leaf attribute.

If the attribute value is an array then the masking is applied to all array elements individually.

If you have an attribute key that contains a dot or a top-level attribute with a single asterisk as full name ("*": ...) then you need to quote the name in ticks or backticks to escape it. For example:

"path": "´name.with.dots´"

or

"path": "`name.with.dots`"

Example

The following configuration will replace the value of the name attribute with an “xxxx”-masked string:

{
  "type": "xifyFront",
  "path": ".name",
  "unmaskedLength": 2
}

The document:

{
  "name": "top-level-name",
  "age": 42,
  "nicknames" : [ { "name": "hugo" }, "egon" ],
  "other": {
    "name": [ "emil", { "secret": "superman" } ]
  }
}

… will be changed as follows:

{
  "name": "xxxxxxxxxxxxme",
  "age": 42,
  "nicknames" : [ { "name": "xxgo" }, "egon" ],
  "other": {
    "name": [ "xxil", { "secret": "superman" } ]
  }
}

The values "egon" and "superman" are not replaced, because they are not contained in an attribute value of which the attribute name is name.

Nested objects and arrays

If you specify a path and the attribute value is an array then the masking decision is applied to each element of the array as if this was the value of the attribute. This applies to arrays inside the array too.

If the attribute value is an object, then it is ignored and the attribute does not get masked. To mask nested fields, specify the full path for each leaf attribute.

If some documents have an attribute mail with a string as value, but other documents store a nested object under the same attribute name, then make sure to set up proper masking for the latter case, in which sub-attributes will not get masked if there is only a masking configured for the attribute mail but not its nested attributes.

You can use the special path "*" to match all leaf attributes in the document.

Examples

Masking mail with the Xify Front function:

{
  "<collection>": {
    "type": "masked",
    "maskings": [
      {
        "path": "mail",
        "type": "xifyFront"
      }
    ]
  }
}

… will convert this document:

{
  "mail" : "mail address"
}

… into:

{
  "mail" : "xxil xxxxxxss"
}

because mail is a leaf attribute. The document:

{
  "mail" : [
    "address one",
    "address two",
    [
      "address three"
    ]
  ]
}

… will be converted into:

{
  "mail" : [
    "xxxxxss xne",
    "xxxxxss xwo",
    [
      "xxxxxss xxxee"
    ]
  ]
}

… because the masking is applied to each array element individually including the elements of the sub-array. The document:

{
  "mail" : {
    "address" : "mail address"
  }
}

… will not be masked because mail is not a leaf attribute. To mask the mail address, you could use the paths mail.address or .address in the masking definition:

{
  "<collection>": {
    "type": "masked",
    "maskings": [
      {
        "path": ".address",
        "type": "xifyFront"
      }
    ]
  }
}

A catch-all "path": "*" would apply to the nested address attribute too, but it would mask all other string attributes as well, which may not be what you want. A syntax "path": "mail.* to only match the sub-attributes of the top-level mail attribute is not supported.

Rule precedence

Masking rules may overlap, for instance if you specify the same path multiple times, or if you define a rule for a specific field but also one which matches all leaf attributes of the same name.

The precedence is determined by the order in which the rules are defined in the masking configuration file in such cases, giving priority to the first matching rule (i.e. the rule above the other ambiguous ones).

{
  "<collection>": {
    "type": "masked",
    "maskings": [
      {
        "path": "address",
        "type": "xifyFront"
      },
      {
        "path": ".address",
        "type": "random"
      }
    ]
  }
}

Above masking definition will obfuscate the top-level attribute address with the xifyFront function, whereas all nested attributes with name address will use the random masking function. If the rules are defined in reverse order however, then all attributes called address will be obfuscated using random. The second, overlapping rule is effectively ignored:

{
  "<collection>": {
    "type": "masked",
    "maskings": [
      {
        "path": ".address",
        "type": "random"
      },
      {
        "path": "address",
        "type": "xifyFront"
      }
    ]
  }
}

This behavior also applies to the catch-all path "*", which means it should generally be placed below all other rules for a collection so that it is used for all unspecified attribute paths. Otherwise all document attributes will be processed by a single masking function, ignoring any other rules below it.

{
  "<collection>": {
    "type": "masked",
    "maskings": [
      {
        "path": "address",
        "type": "random"
      },
      {
        "path": ".address",
        "type": "xifyFront"
      },
      {
        "path": "*",
        "type": "email"
      }
    ]
  }
}

Masking Functions

The following masking functions are only available in the Enterprise Edition, also available in the ArangoDB Cloud.

The masking functions:

… are available in the Community Edition as well as the Enterprise Edition.

Random String

This masking type will replace all values of attributes whose values are strings with key name with an anonymized string. It is not guaranteed that the string will be of the same length. Attribute whose values are not strings are not modified.

A hash of the original string is computed. If the original string is shorter then the hash will be used. This will result in a longer replacement string. If the string is longer than the hash then characters will be repeated as many times as needed to reach the full original string length.

Masking settings:

  • path (string): which field to mask
  • type (string): masking function name "randomString"

Example

{
  "path": ".name",
  "type": "randomString"
}

Above masking setting applies to all leaf attributes with name .name. A document like:

{
  "_key" : "1234",
  "name" : [
    "My Name",
    {
      "other" : "Hallo Name"
    },
    [
      "Name One",
      "Name Two"
    ],
    true,
    false,
    null,
    1.0,
    1234,
    "This is a very long name"
  ],
  "deeply": {
    "nested": {
      "name": "John Doe",
      "not-a-name": "Pizza"
    }
  }
}

… will be converted to:

{
  "_key": "1234",
  "name": [
    "+y5OQiYmp/o=",
    {
      "other": "Hallo Name"
    },
    [
      "ihCTrlsKKdk=",
      "yo/55hfla0U="
    ],
    true,
    false,
    null,
    1.0,
    1234,
    "hwjAfNe5BGw=hwjAfNe5BGw="
  ],
  "deeply": {
    "nested": {
      "name": "55fHctEM/wY=",
      "not-a-name": "Pizza"
    }
  }
}

Random

This masking type substitutes leaf attribute values of all data types with random values of the same kind:

  • Strings are replaced with random strings.
  • Numbers are replaced with random integer or decimal numbers, depending on the original value (but not keeping sign or scientific notation). The generated numbers are between -1000 and 1000.
  • Booleans are randomly replaced with true or false.
  • null values remain null.

Masking settings:

  • path (string): which field to mask
  • type (string): masking function name "random"

Examples

{
  "collection": {
    "type": "masked",
    "maskings": [
      {
        "path": "*",
        "type": "random"
      }
    ]
  }
}

Using above masking configuration, all leaf attributes of the documents in collection would be randomized. A possible input document:

{
  "_key" : "1121535",
  "_id" : "coll/1121535",
  "_rev" : "_Z3AKGjW--_",
  "nullValue" : null,
  "bool" : true,
  "int" : 1,
  "decimal" : 2.34,
  "string" : "hello",
  "array" : [
    null,
    false,
    true,
    0,
    -123,
    0.45,
    6e7,
    -0.8e-3,
    "nine",
    "Lorem ipsum sit dolor amet.",
    [
      false,
      false
    ],
    {
      "obj" : "nested"
    }
  ]
}

… could result in an output like this:

{
  "_key": "1121535",
  "_id": "coll/1121535",
  "_rev": "_Z3AKGjW--_",
  "nullValue": null,
  "bool": false,
  "int": -900,
  "decimal": -4.27,
  "string": "etxfOC+K0HM=",
  "array": [
    null,
    true,
    false,
    754,
    -692,
    2.64,
    834,
    1.69,
    "NGf7NKGrMYw=",
    "G0czIlvaGw4=G0czIlvaGw4=G0c",
    [
      false,
      true
    ],
    {
      "obj": "eCGe36xiRho="
    }
  ]
}

Xify Front

This masking type replaces the front characters with x and blanks. Alphanumeric characters, _ and - are replaced by x, everything else is replaced by a blank.

Masking settings:

  • path (string): which field to mask
  • type (string): masking function name "xifyFront"
  • unmaskedLength (number, default: 2): how many characters to leave as-is on the right-hand side of each word as integer value
  • hash (bool, default: false): whether to append a hash value to the masked string to avoid possible unique constraint violations caused by the obfuscation
  • seed (integer, default: 0): used as secret for computing the hash. A value of 0 means a random seed

Examples

{
  "<collection>": {
    "type": "masked",
    "maskings": [
      {
        "path": ".name",
        "type": "xifyFront",
        "unmaskedLength": 2
      }
    ]
  }
}

This will affect attributes with key "name" at any level by masking all alphanumeric characters of a word except the last two characters. Words of length 1 and 2 remain unmasked. If the attribute value is not a string but boolean or numeric, then the result will be "xxxx" (fixed length). null values remain null.

{
  "name": "This is a test!Do you agree?",
  "bool": true,
  "number": 1.23,
  "null": null
}

… will become:

{
  "name": "xxis is a xxst Do xou xxxee ",
  "bool": "xxxx",
  "number": "xxxx",
  "null": null
}

There is a catch. If you have an index on the attribute the masking might distort the index efficiency or even cause errors in case of a unique index.

{
  "path": ".name",
  "type": "xifyFront",
  "unmaskedLength": 2,
  "hash": true
}

This will add a hash at the end of the string.

"This is a test!Do you agree?"

… will become

"xxis is a xxst Do xou xxxee  NAATm8c9hVQ="

Note that the hash is based on a random secret that is different for each run. This avoids dictionary attacks which could be used to guess values based pre-computations on dictionaries.

If you need reproducible results, i.e. hashes that do not change between different runs of arangodump, you need to specify a secret as seed, a number which must not be 0.

{
  "path": ".name",
  "type": "xifyFront",
  "unmaskedLength": 2,
  "hash": true,
  "seed": 246781478647
}

Zip

This masking type replaces a zip code with a random one. It uses the following rules:

  • If a character of the original zip code is a digit it will be replaced by a random digit.
  • If a character of the original zip code is a letter it will be replaced by a random letter keeping the case.
  • If the attribute value is not a string then the default value is used.

Note that this will generate random zip codes. Therefore there is a chance that the same zip code value is generated multiple times, which can cause unique constraint violations if a unique index is or will be used on the zip code attribute.

Masking settings:

  • path (string): which field to mask
  • type (string): masking function name "zip"
  • default (string, default: "12345"): if the input field is not of data type string, then this value is used

Examples

{
  "path": ".code",
  "type": "zip",
}

This replaces real zip codes stored in fields called code at any level with random ones. "12345" is used as fallback value.

{
  "path": ".code",
  "type": "zip",
  "default": "abcdef"
}

If the original zip code is:

50674

… it will be replaced by e.g.:

98146

If the original zip code is:

SA34-EA

… it will be replaced by e.g.:

OW91-JI

If the original zip code is null, true, false or a number, then the user-defined default value of "abcdef" will be used.

Datetime

This masking type replaces the value of the attribute with a random date between two configured dates in a customizable format.

Masking settings:

  • path (string): which field to mask
  • type (string): masking function name "datetime"
  • begin (string, default: "1970-01-01T00:00:00.000"): earliest point in time to return. Date time string in ISO 8601 format.
  • end (string, default: now): latest point in time to return. Date time string in ISO 8601 format. In case a partial date time string is provided (e.g. 2010-06 without day and time) the earliest date and time is assumed (2010-06-01T00:00:00.000). The default value is the current system date and time.
  • format (string, default: ""): the formatting string format is described in DATE_FORMAT(). If no format is specified, then the result will be an empty string.

Example

{
  "path": "eventDate",
  "type": "datetime",
  "begin" : "2019-01-01",
  "end": "2019-12-31",
  "format": "%yyyy-%mm-%dd",
}

Above example masks the field eventDate by returning a random date time string in the range of January 1st and December 31st in 2019 using a format like 2019-06-17.

Integer Number

This masking type replaces the value of the attribute with a random integer number. It will replace the value even if it is a string, Boolean, or null.

Masking settings:

  • path (string): which field to mask
  • type (string): masking function name "integer"
  • lower (number, default: -100): smallest integer value to return
  • upper (number, default: 100): largest integer value to return

Example

{
  "path": "count",
  "type": "integer",
  "lower" : -100,
  "upper": 100
}

This masks the field count with a random number between -100 and 100 (inclusive).

Decimal Number

This masking type replaces the value of the attribute with a random floating point number. It will replace the value even if it is a string, Boolean, or null.

Masking settings:

  • path (string): which field to mask
  • type (string): masking function name "decimal"
  • lower (number, default: -1): smallest floating point value to return
  • upper (number, default: 1): largest floating point value to return
  • scale (number, default: 2): maximal amount of digits in the decimal fraction part

Examples

{
  "path": "rating",
  "type": "decimal",
  "lower" : -0.3,
  "upper": 0.3
}

This masks the field rating with a random floating point number between -0.3 and +0.3 (inclusive). By default, the decimal has a scale of 2. That means, it has at most 2 digits after the dot.

The configuration:

{
  "path": "rating",
  "type": "decimal",
  "lower" : -0.3,
  "upper": 0.3,
  "scale": 3
}

… will generate numbers with at most 3 decimal digits.

Credit Card Number

This masking type replaces the value of the attribute with a random credit card number (as integer number). See Luhn algorithm for details.

Masking settings:

  • path (string): which field to mask
  • type (string): masking function name "creditCard"

Example

{
  "path": "ccNumber",
  "type": "creditCard"
}

This generates a random credit card number to mask field ccNumber, e.g. 4111111414443302.

Phone Number

This masking type replaces a phone number with a random one. It uses the following rule:

  • If a character of the original number is a digit it will be replaced by a random digit.
  • If it is a letter it is replaced by a random letter.
  • All other characters are left unchanged.
  • If the attribute value is not a string it is replaced by the default value.

Masking settings:

  • path (string): which field to mask
  • type (string): masking function name "phone"
  • default (string, default: "+1234567890"): if the input field is not of data type string, then this value is used

Examples

{
  "path": "phone.landline",
  "type": "phone"
}

This will replace an existing phone number with a random one, for instance "+31 66-77-88-xx" might get substituted by "+75 10-79-52-sb".

{
  "path": "phone.landline",
  "type": "phone",
  "default": "+49 12345 123456789"
}

This masks a phone number as before, but falls back to a different default phone number in case the input value is not a string.

Email Address

This masking type takes an email address, computes a hash value and splits it into three equal parts AAAA, BBBB, and CCCC. The resulting email address is in the format AAAA.BBBB@CCCC.invalid. The hash is based on a random secret that is different for each run.

Masking settings:

  • path (string): which field to mask
  • type (string): masking function name "email"

Example

{
  "path": ".email",
  "type": "email"
}

This masks every leaf attribute email with a random email address similar to "EHwG.3AOg@hGU=.invalid".