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
);

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);

Parameters

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

Keylet Table

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)

Return Code

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.