C.Mask – Data Masking Methods

C.Mask.CC()

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C.Mask.CC(value: string, unmasked: number = -4, maskChar: string='X'): string

Checks whether a value could be a valid credit card number, and masks a subset of the value. By default, all digits except the last 4 will be replaced with X.

Examples

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Let’s assume your parsed data contains a creditCard field. You can mask this number by using a Mask Function. Apply it to the cardNumber field and create the following masking rule:

To control how the masking is performed, you can specify how many digit should be unmasked and what masking character to use:

C.Mask.crc32()

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C.Mask.crc32(value: string): string

Generates a CRC32 hash of given value.

C.Mask.IMEI()

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C.Mask.IMEI(value: string, unmasked: number = -4, maskChar: string='X'): string

Checks whether a value could be a valid IMEI number, and masks a subset of the value. By default, all digits except the last 4 will be replaced with X.

Examples

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Let’s assume your parsed data contains an imei field. You can mask this number by using a Mask Function. Apply it to the imei field and create the following masking rule:

To control how the masking is performed, you can specify how many digit should be unmasked and what masking character to use:

C.Mask.isCC()

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C.Mask.isCC(value: string): boolean

Checks whether the given value could be a valid credit card number, by computing the string’s Luhn’s checksum modulo 10 == 0.

Examples

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The following example expression uses isCC() to check whether the cardNumber field actually contains a credit card number. If it does, the card number is replaced with the REDACTED string, otherwise, en empty string is returned.

C.Mask.isCC(cardNumber) ? C.Mask.REDACTED : ""

C.Mask.isIMEI()

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C.Mask.isIMEI(value: string): boolean

Checks whether the given value could be a valid IMEI number, by computing the string’s Luhn’s checksum modulo 10 == 0.

Examples

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The following example expression uses isCC() to check whether the imei field actually contains ab IMEI number number. If it does, the IMEI number is replaced with the REDACTED string, otherwise, en empty string is returned.

C.Mask.isIMEI(imei) ? C.Mask.REDACTED : ""

C.Mask.luhn()

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C.Mask.luhn(value: string, unmasked: number = -4, maskChar: string='X'): string

Checks that value Luhn’s checksum mod 10 is 0, and masks a subset of the value. By default, all digits except the last 4 will be replaced with X. If the value’s Luhn’s checksum mod 10 is not 0, then the value is returned unmodified.

C.Mask.luhnChecksum()

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C.Mask.luhnChecksum(value: string, mod: number=10): number

Generates the Luhn checksum (used to validate certain credit card numbers, IMEIs, etc.). By default, the mod 10 of the checksum is returned. Pass mod = 0 to get the actual checksum.

C.Mask.md5()

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C.Mask.md5(value: string, len?: string | number, encoding?: BufferEncoding): string

Generates an MD5 hash of a given value.

C.Mask.md5() doesn’t work when Cribl Stream is running in FIPS mode.

Examples

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To hash the contents of a username field with the MD5 algorithm, run:

C.Mask.md5(username)

To hash the contents of an authToken field, where the value of the field is a base64-encoded string, with the MD5 algorithm, run:

C.Mask.md5(authToken, undefined, 'base64')

C.Mask.random

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C.Mask.random(len?: string | number): string

Generates a random alphanumeric string.

Examples

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Assuming you have some identifying user information in a username field, you can replace it with a random string of the same length with:

C.Mask.random(username)

C.Mask.repeat()

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C.Mask.repeat(len?: number | string, char: string = 'X'): string

Generates a repeating char/string pattern, e.g., XXXX.

Examples

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The following example will repeat the GOAT string as many time as there are characters in the first parameter, goat, so four times:

C.Mask.repeat("goat", "GOAT")

C.Mask.sha1(), C.Mask.sha256(), C.Mask.sha512()

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C.Mask.sha1(value: string, len?: string | number, encoding?: BufferEncoding): string
C.Mask.sha256(value: string, len?: string | number, encoding?: BufferEncoding): string
C.Mask.sha512(value: string, len?: string | number, encoding?: BufferEncoding): string

Generates an SHA1, SHA256, or SHA512 hash of given value.

Examples

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To hash the contents of a secret field with the SHA256 algorithm, run:

C.Mask.sha256(secret)

To hash the contents of an authToken field, where the value of the field is a base64-encoded string, with the SHA256 algorithm, run:

C.Mask.sha256(authToken, undefined, 'base64')

C.Mask.REDACTED

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C.Mask.REDACTED: string

The literal 'REDACTED'.