["aes-gcm", keyid, nonce, data] Encrypts data using the key referenced by keyid (an integer) and a nonce created by aes-gcm-nonce. Returns a byte array. keyid is a 0-indexed reference into the keys array of keys provided by the config. The key must be 16, 24, or 32 bytes in length, hex-encoded.

Examples:

• ["aes-gcm", 0, ["aes-gcm-nonce"], "$number"] ⇒ Some byte array (In a real example you would want to store the result of calling aes-gcm-nonce in an intermediate variable so it can be included in the body of the destination request)

["aes-gcm-nonce"] Returns a byte array filled with 12 random bytes.

Examples:

• ["hex", ["aes-gcm-nonce"]] ⇒ "s8tIW/oPqPkkN1OY"

JSON arrays form the s-expressions of the Forward API DSL. array allows you to create literal arrays.

Examples:

• ["array", "braintree", "payments"] ⇒ ["braintree", "payments"]
• ["array", ["base64", "braintree"], "payments"] ⇒ ["YnJhaW50cmVl", "payments"]

["base64", value] base 64 encodes the result of evaluating value.

Examples:

• ["base64", "braintree"] ⇒ "YnJhaW50cmVl"
• ["base64", ["md5", "braintree"]] ⇒ "cC5vUPvGgxD8+vLvjq7GIQ=="

["encode", charset, input] returns the byte array result of applying the encoding charset to the input. The default charset is UTF-8.

Examples:

• ["base64", ["encode", "UTF-16", "braintree"]]⇒ "/v8AYgByAGEAaQBuAHQAcgBlAGU="
• ["hex", ["encode", "UTF-32", "abc"]] ⇒ "000000610000006200000063"

["execution_time", pattern] returns UTC time now, formatted according to the pattern. Pattern should be in the Joda DateTimeFormat

Examples:

• ["execution_time", "yyyy-MM-dd'T'HH:mm:ss.SSS'Z'"] => "2020-02-21T17:32:28.123Z"

["format_expiration", format_string] the format string may include any combination of the following: %Y, %y, %m, %-m, %%.

Directives:

• %Y - Year with century
• %y - Year modulo 100
• %m - Month of the year, zero-padded (01..12)
• %-m - Month of the year, no padding (1..12)
• %% - Literal "%"

Examples:

• ["format_expiration", "%m/%Y"] ⇒ "10/2015" (assuming an expiration month of October in the year 2015)
• ["format_expiration", "%m/%y"] ⇒ "07/15" (assuming an expiration month of July in the year 2015)

["hex", value] hexadecimal encodes the result of evaluating value.

Examples:

• ["hex", "braintree"] ⇒ "627261696e74726565"
• ["hex", ["md5", "braintree"]] ⇒ "702e6f50fbc68310fcfaf2ef8eaec621"

["hmac-sha1", keyid, data] generates the keyed-hash message authentication code of data using the key referenced by keyid in the (0-indexed) array of keys provided by the config. Returns a byte array; wrap in hex or base64 to make a string.

Examples:

• ["hex", ["hmac-sha1", 0, "The quick brown fox jumps over the lazy dog"]] ⇒ "de7c9b85b8b78aa6bc8a7a36f70a90701c9db4d9", with "keys": ["6b6579"] (the hex encoding of the ASCII string "key").

["hmac-sha256", keyid, data] generates the keyed-hash message authentication code of data using the key referenced by keyid in the (0-indexed) array of keys provided by the config. Returns a byte array; wrap in hex or base64 to make a string.

Examples:

• ["hex", ["hmac-sha256", 0, "The quick brown fox jumps over the lazy dog"]] ⇒ "f7bc83f430538424b13298e6aa6fb143ef4d59a14946175997479dbc2d1a3cd8", with "keys": ["6b6579"] (the hex encoding of the ASCII string "key").

["hmac-sha512", keyid, data] generates the keyed-hash message authentication code of data using the key referenced by keyid in the (0-indexed) array of keys provided by the config. Returns a byte array; wrap in hex or base64 to make a string.

Examples:

• ["hex", ["hmac-sha512", 0, "The quick brown fox jumps over the lazy dog"]] ⇒ "b42af09057bac1e2d41708e48a902e09b5ff7f12ab428a4fe86653c73dd248fb82f948a549f7b791a5b41915ee4d1ec3935357e4e2317250d0372afa2ebeeb3a", with "keys": ["6b6579"] (the hex encoding of the ASCII string "key").

["integer", value] attempts to cast value to an integer. Returns transformation error if string can't be cast.

Examples:

• ["integer", "1"] ⇒ 1

["join", separator, value] returns a string created by converting each element of the evaluated expression value to a string, separated by the result of evaluating separator.

Examples:

• ["join", ":", ["array", "braintree", "payments"]] ⇒ "braintree:payments"

["last_n", n, value] returns the last n characters of the string resulting from evaluating value, or the last n elements if value is an array.

Examples:

• ["last_n", 4, "braintree"] ⇒ "tree"
• ["last_n", 1, ["array", "braintree", "payments"]] ⇒ "payments"

["md5", value] MD5 the result of evaluating value. Returns a byte array; use hex or base64 to make a string.

Examples:

• ["hex", ["md5", "braintree"]] "702e6f50fbc68310fcfaf2ef8eaec621"

["percent-encode", value] returns the result of applying percent-encoding replacements on the specified value.

Examples:

• ["percent-encode", "braintree payments"] ⇒ "braintree%20payments"

["replace", replacement_map_index, value] returns the result of applying the string replacements specified by the (0-indexed) config's replacement_map.

Examples with replacement_maps: [{"a": "@", "e": "$!"}, {"e": "3"}]:

* `["replace", 0, "braintree"]` ⇒ "br@intr$!$!"
* `["replace", 1, "braintree"]` ⇒ "braintr33"

["rsa-pkcs1", ["rsa-public-key", "$PEM_encoded_public_key"], "value to encrypt"] encrypts the specified value using a given RSA public key, with PKCS1 padding. Returns a byte array; wrap in hex or base64 to make a string.

Examples:

• ["base64", ["rsa-pkcs1", ["rsa-public-key", "$public_key"], "value to encrypt"]] ⇒ "dA0KkYFXykS5L2bPPecFBmXuEMxst+E6gQ6/i+w2+PYxCBserUIc21gW5eCXcca6kjhevo5371OfOivy+pIoY0HOgThB3DTQV+cEqxN9tb0U7ZJXXsMOVuIKXzkGofKeAI1CJVzwVh6lK5Cy7EDtYd8dUPLt+QuozWGtm7zaWfn6HWycRS0WG7GMbON2A+BiWv+fehv1jFB4nArHMiXbR1tdY10hLXsNrXHhwuft99LyCx0sIE7R6fdXi/WckdTeyVDeCmBiSX41CEjjgqGFj0KibjMYkzSNY+XO4k5Amvge4ha0YLv5bx38GhooshU0QqjzKRiz6dbJVP1ikzd49w=="Using the example RSA public key

["rsa-pkcs15-sha256", keyid, data] encrypts the SHA256 digest using a given (PEM encoded) RSA private key in the config's keys array, with PKCS1 v1.5 padding. Returns a byte array; wrap in hex or base64 to make a string.

Examples:

• ["base64", ["rsa-pkcs16-sha256", 0, "Data to digest and encrypt"]] ⇒ "zyhOjvWCcTxf1CtBVK2BdS1Djfv8FReCuRhQ7WPd3qUp2Hw89A2oj1oQr43THGcD+i0dWiVlcObEshPwKEXqns0bNRbKoBRVKNWCFUfmoJuNLuqOBDQMMeRxFwf91zbeYSAz6x3FwY7BcD713422jYRvTcawezKCB8QKGP9LUs4nJNZ9B5VGC0L9fTzsWJbv6ra7KNSQRGPYug9kK1/Y5dcTozaTiBJvYj22TBd2L4Gfr7pazQgGjiLzAA+qAg4/YPLHGv9EL39yJQZ2FM5Uuds6PhJAT3KjzKmqGkZr/QK0tIlax/3SZ3pnQ/LSHWRnczMdBC/FN0gVFl/FcxNlxw=="Using the example RSA private key

["sha1", value] SHA1 the result of evaluating value. Returns a byte array; use hex or base64 to make a string.

Examples:

• ["hex", ["sha1", "braintree"]] ⇒ "984214838d0fc4b1eab0dbca61160867c9878041"
• ["base64", ["sha1", "braintree"]] ⇒ "mEIUg40PxLHqsNvKYRYIZ8mHgEE="

["sha256", value] SHA256 the result of evaluating value. Returns a byte array; use hex or base64 to make a string.

Examples:

• ["hex", ["sha256", "braintree"]] ⇒ "e2d67f41fee239d12faf598242412e25b357740b9a20a5b14c9795dcae320bf5"
• ["base64", ["sha256", "braintree"]] ⇒ "4tZ/Qf7iOdEvr1mCQkEuJbNXdAuaIKWxTJeV3K4yC/U="

["sha512", value] SHA512 the result of evaluating value. Returns a byte array; use hex or base64 to make a string.

Examples:

• ["hex", ["sha512", "braintree"]] ⇒ "4bdd950f340870714a8c6b58209e2a3b2b7df78c995835e34a66e7de2c213040a1ba0ad5d7e0342db8411467b3051a1470ec9ac13569cd5b8a47e7030b60d63b"
• ["base64", ["sha512", "braintree"]] ⇒ ""S92VDzQIcHFKjGtYIJ4qOyt994yZWDXjSmbn3iwhMEChugrV1+A0LbhBFGezBRoUcOyawTVpzVuKR+cDC2DWOw=="

["substring", start, end, value] returns the substring of the value, inclusive of the start-index and exclusive of the end-index. Index starts at zero. For values of unknown length, see last_n function. Examples:

• ["substring", 0, 5, "Happy Birthday To You"] => "Happy"
• ["substring", 6, 14, "Happy Birthday To You"] => "Birthday"