util_keylet

Compute a serialized keylet of a given type

Concepts

• Slots and Keylets

📘Tip

Not every Keylet type is supported by this utility function. If you need another Keylet type you can derive it yourself using util_sha512h and by checking the required fields here. A further Keylet tool may assist you.

Behaviour

• Compute a keylet of the specified keylet_type according to the parameters a through f depending on type.

• Write the serialized 34 byte keylet into write_ptr

Definition

C

int64_t util_keylet (
    uint32_t write_ptr,
    uint32_t write_len,
    uint32_t keylet_type,
    uint32_t a,
    uint32_t b,
    uint32_t c,
    uint32_t d,
    uint32_t e,
    uint32_t f
);

Javascript

function util_keylet(
    keylet_type: number,
    accountid: ByteArray | HexString,
    statekey: ByteArray | HexString,
    namespace: ByteArray | HexString
  ): ErrorCode | ByteArray

Example

C

uint8_t keylet[34];
if (util_keylet(keylet, 34, KEYLET_LINE,
              hook_accid, 20,
              account_field, 20,
              currency_code, 20) != 34)
	rollback("Keylet Failed.", 14, 1);

Javascript

if (util_keylet(
        KEYLET_LINE, hook_accid, account_field, currency_code
        ).length < 34) 
    rollback("Keylet Failed.", 1)

Parameters

C

Name	Type	Description
write_ptr	uint32_t	Pointer to a buffer the serialized keylet will be written to
write_len	uint32_t	Length of output buffer, should be at least 34.
keylet_type	uint32_t	One of the keylet types as defined in hookapi.h e.g. KEYLET_LINE for a trustline.
a	uint32_t	See keylet table below
b	uint32_t	See keylet table below
c	uint32_t	See keylet table below
d	uint32_t	See keylet table below
e	uint32_t	See keylet table below
f	uint32_t	See keylet table below

Javascript

Name	Type	Description
keylet_type		The type of the keylet to create
accountid		(Optional) First piece of data for the keylet, can be an array of numbers, a string, or a number.
statekey		(Optional) Second piece of data for the keylet, can be an array of numbers, a string, or a number.
namespace		(Optional) Third piece of data for the keylet, can be an array of numbers, a string, or a number.

Keylet Table

C

Keylet Type	Parameters
KEYLET_HOOK_STATE	a points to an Account ID b is the length of the Account ID (should be 20) c points to a hook state key d is the length of the key (should be 32) e points to a hook state namespace f is the length of the namespace (should be 32)
KEYLET_AMENDMENTS KEYLET_FEES KEYLET_NEGATIVE_UNL KEYLET_EMITTED_DIR	a, b, c, d, e, f must all be zero
KEYLET_SKIP	Either: a, b, c, d, e, f all zero Or: a is a LedgerIndex b is 1 c, d, e, f must all ​be zero
KEYLET_LINE	a points to the High Account ID b is the length of the above (should be 20) c points to the Low Account ID d is the length of the above (should be 20) e points to the Currency Code f is the length of the above (should be 20)
KEYLET_QUALITY	a points to a serialized keylet b is the length of the above (should be 34) c is the high 32 bits of the uint64 to pass d is the low 32 bits of the uint64 to pass e, f must all be zero
KEYLET_DEPOSIT_PREAUTH	a points to an Account ID b is the length (should be 20) c points to an Account ID d is the length (should be 20) e, f must all be zero
KEYLET_UNCHECKED KEYLET_CHILD KEYLET_EMITTED_TXN	a points to a key. b is the length of the key (should be 32.) c, d, e, f must both ​be zero
KEYLET_OWNER_DIR KEYLET_SIGNERS KEYLET_ACCOUNT KEYLET_HOOK	a points to an Account ID. b is the length (should be 20.) c, d, e, f must all be zero.
KEYLET_PAGE	a points to a key. b is the length of the key (should be 32.) c is the high 32 bits of the uint64 to pass d is the low 32 bits of the uint64 to pass e, f must both ​be zero
KEYLET_OFFER KEYLET_CHECK KEYLET_ESCROW KEYLET_NFT_OFFER	a points to an Account ID. b is the length (should be 20.) And Either: c is a 32bit unsigned integer (sequence) d is 0 Or: c points to a 32 byte key d is the length of the key (32). In both cases: e and f must be 0.
KEYLET_PAYCHAN	a points to an Account ID b is the length (should be 20) c points to an Account ID d is the length (should be 20) And Either: e 32bit unsigned int to pass f is zero Or: e points to a 32 byte key f is the length of the key (32)

Javascript

Return Code

C

Type	Description
int64_t	The number of bytes written, should always be 34. If negative, an error: OUT_OF_BOUNDS - pointers/lengths specified outside of hook memory. INVALID_ARGUMENT - Call didn't comply with the above table. TOO_SMALL - Writing buffer was smaller than 34 bytes.

Javascript

Type	Description
number	ErrorCode if there is an error in creating the keylet, otherwise returns the generated keylet as an array of numbers.