Zcash App
- Zondax API: New API that provides support for shielded and unshielded transactions
General Structure
The general structure of commands and responses is as follows:
| Field | Type | Content | Note |
|---|
| CLA | byte (1) | Application Identifier | 0x85 |
| INS | byte (1) | Instruction ID | |
| P1 | byte (1) | Parameter 1 | |
| P2 | byte (1) | Parameter 2 | |
| L | byte (1) | Bytes in payload | |
| PAYLOAD | byte (L) | Payload | |
Response
| Field | Type | Content | Note |
|---|
| ANSWER | byte (?) | Answer | depends on the command |
| SW1-SW2 | byte (2) | Return code | see list of return codes |
Return codes
| Return code | Description |
|---|
| 0x6400 | Execution Error |
| 0x6400 | Wrong buffer length |
| 0x6982 | Empty buffer |
| 0x6983 | Output buffer too small |
| 0x6984 | Data is invalid |
| 0x6986 | Command not allowed |
| 0x6987 | Tx is not initialized |
| 0x6B00 | P1/P2 are invalid |
| 0x6D00 | INS not supported |
| 0x6E00 | CLA not supported |
| 0x6F00 | Unknown |
| 0x6F01 | Sign / verify error |
| 0x9000 | Success |
New API
GET_DEVICE_INFO
Command
| Field | Type | Content | Expected |
|---|
| CLA | byte (1) | Application Identifier | 0xE0 |
| INS | byte (1) | Instruction ID | 0x01 |
| P1 | byte (1) | Parameter 1 | 0x00 |
| P2 | byte (1) | Parameter 2 | 0x00 |
| L | byte (1) | Bytes in payload | 0x00 |
Response
| Field | Type | Content | Note |
|---|
| TARGET_ID | byte (4) | Target Id | |
| OS_LEN | byte (1) | OS version length | 0..64 |
| OS | byte (?) | OS version | Non terminated string |
| FLAGS_LEN | byte (1) | Flags length | 0 |
| MCU_LEN | byte (1) | MCU version length | 0..64 |
| MCU | byte (?) | MCU version | Non terminated string |
| SW1-SW2 | byte (2) | Return code | see list of return codes |
GET_VERSION
Command
| Field | Type | Content | Expected |
|---|
| CLA | byte (1) | Application Identifier | 0x85 |
| INS | byte (1) | Instruction ID | 0x00 |
| P1 | byte (1) | Parameter 1 | ignored |
| P2 | byte (1) | Parameter 2 | ignored |
| L | byte (1) | Bytes in payload | 0 |
Response
| Field | Type | Content | Note |
|---|
| TEST | byte (1) | Test Mode | 0x01 means test mode is enabled |
| MAJOR | byte (2) | Version Major | 0..65535 |
| MINOR | byte (2) | Version Minor | 0..65535 |
| PATCH | byte (2) | Version Patch | 0..65535 |
| LOCKED | byte (1) | Device is locked | It'll always be 0 |
| TARGET_ID | byte (4) | Target Id | |
| SW1-SW2 | byte (2) | Return code | see list of return codes |
INS_GET_ADDR_SECP256K1
Command
| Field | Type | Content | Expected |
|---|
| CLA | byte (1) | Application Identifier | 0x85 |
| INS | byte (1) | Instruction ID | 0x01 |
| P1 | byte (1) | Request User confirmation | No = 0 |
| P2 | byte (1) | Parameter 2 | ignored |
| L | byte (1) | Bytes in payload | (depends) |
| Path[0] | byte (4) | Derivation Path Data | 0x8000002c |
| Path[1] | byte (4) | Derivation Path Data | 0x80000085 |
| Path[2] | byte (4) | Derivation Path Data | ? |
| Path[3] | byte (4) | Derivation Path Data | ? |
| Path[4] | byte (4) | Derivation Path Data | ? |
Response
| Field | Type | Content | Note |
|---|
| Compressed PK | byte (33) | Public Key | |
| ADDR | byte (??) | address | |
| SW1-SW2 | byte (2) | Return code | see list of return codes |
INS_GET_ADDR_SAPLING
Returns or shows a shielded address with default diversifier (z-address)
Command
| Field | Type | Content | Expected |
|---|
| CLA | byte (1) | Application Identifier | 0x85 |
| INS | byte (1) | Instruction ID | 0x11 |
| P1 | byte (1) | Request User confirmation | No = 0 |
| P2 | byte (1) | Parameter 2 | ignored |
| L | byte (1) | Bytes in payload | always 4 |
| ZIP32-path | byte (4) | Derivation Path Data | u32 Little-Endian |
Response
| Field | Type | Content | Note |
|---|
| ADDR_RAW | byte (43) | Raw address | |
| ADDR_BECH32 | byte (variable) | Bech32 encoding of address | |
| SW1-SW2 | byte (2) | Return code | see list of return codes |
INS_GET_ADDR_SAPLING_DIV
Returns a shielded address using a specific diversifier
Command
| Field | Type | Content | Expected |
|---|
| CLA | byte (1) | Application Identifier | 0x85 |
| INS | byte (1) | Instruction ID | 0x10 |
| P1 | byte (1) | Request User confirmation | No = 0 |
| P2 | byte (1) | Parameter 2 | ignored |
| L | byte (1) | Bytes in payload | always 15 |
| ZIP32-path | byte (4) | Derivation Path Data | u32 Little-Endian |
| DIV | byte (11) | Diversifier | 11-bytes |
Response
| Field | Type | Content | Note |
|---|
| ADDR_RAW | byte (43) | Diversifier (11) + pubkeyDiv(32) | |
| ADDR_BECH32 | byte (43) | Bech32 encoding of raw address | |
| SW1-SW2 | byte (2) | Return code | see list of return codes |
INS_GET_DIV_LIST
On input of a 11-byte starting index, get all valid diversifiers in the 20 indexes after (including starting index). If
a diversifier was not valid, zero-bytes are returned (so always 220 bytes are returned).
Command
| Field | Type | Content | Expected |
|---|
| CLA | byte (1) | Application Identifier | 0x85 |
| INS | byte (1) | Instruction ID | 0x09 |
| P1 | byte (1) | Parameter 1 | ignored |
| P2 | byte (1) | Parameter 2 | ignored |
| L | byte (1) | Bytes in payload | (depends) |
| ZIP32-path | byte (4) | Derivation Path Data | u32 Little-Endian |
| DIV | byte (11) | Starting index search | 11-bytes |
Response
| Field | Type | Content | Note |
|---|
| DIV_LIST_RAW | byte (220) | List of raw diversifiers | 11-bytes each |
| SW1-SW2 | byte (2) | Return code | see list of return codes |
INS_GET_IVK_SAPLING
Returns a sapling incoming viewing key.
Forced user confirmation (So P1 needs to be 0x01).
Also returns the default diversifier (starting from index 0).
Command
| Field | Type | Content | Expected |
|---|
| CLA | byte (1) | Application Identifier | 0x85 |
| INS | byte (1) | Instruction ID | 0xf0 |
| P1 | byte (1) | Request User confirmation | always 1 or error |
| P2 | byte (1) | Parameter 2 | ignored |
| L | byte (1) | Bytes in payload | (depends) |
| ZIP32-path | byte (4) | Derivation Path Data | u32 Little-Endian |
Response
| Field | Type | Content | Note |
|---|
| IVK_RAW | byte (32) | Raw IVK | |
| DIV | byte (11) | Default diversifier | |
| SW1-SW2 | byte (2) | Return code | see list of return codes |
INS_GET_OVK_SAPLING
Returns a sapling outgoing viewing key. Forced user confirmation (So P1 needs to be 0x01).
Command
| Field | Type | Content | Expected |
|---|
| CLA | byte (1) | Application Identifier | 0x85 |
| INS | byte (1) | Instruction ID | 0xf1 |
| P1 | byte (1) | Request User confirmation | always 1 or error |
| P2 | byte (1) | Parameter 2 | ignored |
| L | byte (1) | Bytes in payload | (depends) |
| ZIP32-path | byte (4) | Derivation Path Data | u32 Little-Endian |
Response
| Field | Type | Content | Note |
|---|
| OVK_RAW | byte (32) | Raw OVK | |
| SW1-SW2 | byte (2) | Return code | see list of return codes |
INS_GET_NF_SAPLING
Returns a sapling nullifier. TODO: Forced user confirmation (So P1 needs to be 0x01).
Command
| Field | Type | Content | Expected |
|---|
| CLA | byte (1) | Application Identifier | 0x85 |
| INS | byte (1) | Instruction ID | 0xf2 |
| P1 | byte (1) | Request User confirmation | always 1 or error |
| P2 | byte (1) | Parameter 2 | ignored |
| L | byte (1) | Bytes in payload | (depends) |
| ZIP32-path | byte (4) | Derivation Path Data | u32 Little-Endian |
| POSITION | byte (8) | Note position | uint64 |
| CM | byte(32) | Note commitment Data | 32-bytes |
Response
| Field | Type | Content | Note |
|---|
| NF_RAW | byte (32) | Raw NF | |
| SW1-SW2 | byte (2) | Return code | see list of return codes |
INS_GET_FVK_SAPLING
Returns a sapling full viewing key fvk = (ak, nk, ovk). Forced user confirmation (So P1 needs to be 0x01).
Command
| Field | Type | Content | Expected |
|---|
| CLA | byte (1) | Application Identifier | 0x85 |
| INS | byte (1) | Instruction ID | 0xf3 |
| P1 | byte (1) | Request User confirmation | always 1 or error |
| P2 | byte (1) | Parameter 2 | ignored |
| L | byte (1) | Bytes in payload | (depends) |
| ZIP32-path | byte (4) | Derivation Path Data | u32 Little-Endian |
Response
| Field | Type | Content | Note |
|---|
| AK_RAW | byte (32) | Raw AK | |
| NK_RAW | byte (32) | Raw NK | |
| OVK_RAW | byte (32) | Raw OVK | |
| SW1-SW2 | byte (2) | Return code | see list of return codes |
INS_INIT_TX
Initiates a transaction for sapling. The init_message should have the following format:
| Type | Content | Expected |
|---|
| byte (1) | t_in_len: number of transparent inputs | 0x00 - 0x05 |
| byte (1) | t_out_len: number of transparent outputs | 0x00 - 0x05 |
| byte (1) | s_in_len: number of shielded spends | 0x00 - 0x05 |
| byte (1) | s_out_len: number of shielded outputs | 0x00 - 0x05 |
| byte (variable) | transparent input data = [t_in] | t_in_len * 54 bytes |
| byte (variable) | transparent output data = [t_out] | t_out_len * 34 bytes |
| byte (variable) | shielded spend data = [s_spend] | s_in_len * 55 bytes |
| byte (variable) | shielded output data = [s_out] | s_out_len * 85 bytes |
where
t_in :
| Type | Content | Expected |
|---|
| byte (20) | Derivation path data | 5 times 4 bytes |
| byte (26) | Script of transparent input | |
| byte (8) | transparent input value | u64 |
t_out :
| Type | Content | Expected |
|---|
| byte (26) | Script of transparent output | |
| byte (8) | transparent output value | u64 |
s_spend:
| Type | Content | Expected |
|---|
| byte (4) | ZIP32-path (hardened only) | u32 |
| byte (43) | Shielded spend address | |
| byte (8) | Shielded spend value | u64 |
s_output:
| Type | Content | Expected |
|---|
| byte (43) | Shielded output address | |
| byte (8) | Shielded output value | u64 |
| byte (1) | Shielded output memo type | 0xf6 for default memo |
| byte (32) | Shielded output OVK | 32 zero-bytes for non-OVK |
Command
| Field | Type | Content | Expected |
|---|
| CLA | byte (1) | Application Identifier | 0x85 |
| INS | byte (1) | Instruction ID | 0xa0 |
| P1 | byte (1) | Payload desc | 0 = init |
| | | 1 = add |
| | | 2 = last |
| P2 | byte (1) | ---- | not used |
| L | byte (1) | Bytes in payload | (depends) |
The first packet/chunk includes only the derivation path
All other packets/chunks contain data chunks that are described below
First Packet
Other Chunks/Packets
| Field | Type | Content | Expected |
|---|
| Data | bytes... | Message | |
Data is defined as:
| Field | Type | Content | Expected |
|---|
| Message | bytes.. | init_message bytes as defined above | |
Response
| Field | Type | Content | Note |
|---|
| hash | byte (32) | Hash of init_message | SHA256-hash |
| SW1-SW2 | byte (2) | Return code | see list of return codes |
Returns a proof generating key (PGK) and randomness (rcv and alpha) for a sapling spend.
- This command requires you already called the INS_INIT_TX_SAPLING.
- This command requires that it is needed to extract spendinfo.
Command
| Field | Type | Content | Expected |
|---|
| CLA | byte (1) | Application Identifier | 0x85 |
| INS | byte (1) | Instruction ID | 0xa1 |
| P1 | byte (1) | Parameter 1 | ignored |
| P2 | byte (1) | Parameter 2 | ignored |
| L | byte (1) | Bytes in payload | 0 (empty) |
Response
| Field | Type | Content | Note |
|---|
| PGK_RAW | byte (64) | Raw PGK | 32 byte representations for ak, nsk |
| rcv_RAW | byte (32) | Raw rcv | |
| alpha_RAW | byte (32) | Raw alpha | |
| SW1-SW2 | byte (2) | Return code | see list of return codes |
Returns randomness (rcv and rseed (after ZIP202) and optional Hash_Seed) for a sapling output.
- This command requires you already called the INS_INIT_TX_SAPLING.
- This command requires you already called the correct number of INS_GET_SPENDINFO.
- This command requires that it is needed to extract outputinfo.
Command
| Field | Type | Content | Expected |
|---|
| CLA | byte (1) | Application Identifier | 0x85 |
| INS | byte (1) | Instruction ID | 0xa2 |
| P1 | byte (1) | Parameter 1 | ignored |
| P2 | byte (1) | Parameter 2 | ignored |
| L | byte (1) | Bytes in payload | 0 (empty) |
Response
| Field | Type | Content | Note |
|---|
| - | | | |
| rcv_RAW | byte (32) | Raw rcv | |
| rseed_RAW | byte (32) | Raw rseed | |
| hash_seed | byte (32) | Raw hash_seed | Only returned if OVK=None for this output |
| SW1-SW2 | byte (2) | Return code | see list of return codes |
INS_CHECKANDSIGN
Checks the transaction data and signs if it is correct with the corresponding keys.
- This command requires you already called the INS_INIT_TX
- This command requires you already called the correct number of INS_EXTRACT_SPEND.
- This command requires you already called the correct number of INS_EXTRACT_OUTPUT.
- Due to the complexity of this command, if an error is detected throughout the entire verification process, the response will consist only of the return code.
The transaction_blob should have the following format:
| Type | Content | Expected |
|---|
| byte (variable) | transparent data to check | t_in_len * 74 bytes |
| byte (variable) | previous spend data to check | s_in_len* 40 bytes |
| byte (variable) | new spend data to check | s_in_len * 320 bytes |
| byte (variable) | shielded output data to check | s_out_len * 948 bytes |
| byte (220) | sighash | 220 bytes |
where
transparent data to check :
(Some of the below data is already sent in the inittx command, but sending it again is easier for checking purposes)
| Type | Content | Expected |
|---|
| byte (36) | Prevout point | |
| byte (26) | Script | |
| byte (8) | Value | u64 |
| byte (4) | Sequence number | |
previous spend data to check :
| Type | Content | Expected |
|---|
| byte (32) | Rseed of the spent note | |
| byte (8) | Note position of spent note | u64 |
new spend data to check:
NOTE: the values below should have used randomness from INS_GET_SPENDINFO if applicable
| Type | Content | Expected |
|---|
| byte (32) | spend cv | should have used rcv from ledger |
| byte (32) | Anchor | |
| byte (32) | Nullifier | should have used old note Rseed and note position |
| byte (32) | Rk | should have used alpha from ledger |
| byte (192) | zkproof | |
shielded output data to check:
| Type | Content | Expected |
|---|
| byte (32) | output cv | should have used rcv from ledger |
| byte (32) | note commitment | should have used rseed from ledger |
| byte (32) | ephemeral key | should have used rseed from ledger |
| byte (580) | enc_ciphertext | ledger checks correct memo-type too |
| byte (80) | out_ciphertext | |
| byte (192) | zkproof | |
Command
| Field | Type | Content | Expected |
|---|
| CLA | byte (1) | Application Identifier | 0x85 |
| INS | byte (1) | Instruction ID | 0xa3 |
| P1 | byte (1) | Payload desc | 0 = init |
| | | 1 = add |
| | | 2 = last |
| P2 | byte (1) | TxVersion | 4 = Sapling |
| | | 5 = NU5 |
| L | byte (1) | Bytes in payload | (depends) |
The first packet/chunk includes only the derivation path
All other packets/chunks contain data chunks that are described below
First Packet
Other Chunks/Packets
| Field | Type | Content | Expected |
|---|
| Data | bytes... | Message | |
Data is defined as:
| Field | Type | Content | Expected |
|---|
| Message | bytes.. | transaction_blob bytes as defined above | |
Response
| Field | Type | Content | Note |
|---|
| hash | byte (32) | Hash of transaction_blob | SHA256 |
| SW1-SW2 | byte (2) | Return code | see list of return codes |
Error Response
| Field | Type | Content | Note |
|---|
| SW1-SW2 | byte (2) | Return code | see list of return codes |
Returns a SECP256K1 signature for a sapling transparent input if available. Othrewise, it returns only an error code.
- This command requires that you already called INS_CHECKANDSIGN.
It gives the signatures in order of the transaction.
Returns error if all signatures are retrieved.
Command
| Field | Type | Content | Expected |
|---|
| CLA | byte (1) | Application Identifier | 0x85 |
| INS | byte (1) | Instruction ID | 0xa5 |
| P1 | byte (1) | Request User confirmation | always 0 |
| P2 | byte (1) | Parameter 2 | ignored |
| L | byte (1) | Bytes in payload | != 0 |
Response
| Field | Type | Content | Note |
|---|
| SECP256K1 | byte (64) | R/S signature | |
| SW1-SW2 | byte (2) | Return code | see list of return codes |
Error Response
| Field | Type | Content | Note |
|---|
| SW1-SW2 | byte (2) | Return code | see list of return codes |
Returns a spend signature for a sapling shielded spend input if available. Othrewise, it returns only an error code.
- This command requires that you already called INS_CHECKANDSIGN.
Command
| Field | Type | Content | Expected |
|---|
| CLA | byte (1) | Application Identifier | 0x85 |
| INS | byte (1) | Instruction ID | 0xa4 |
| P1 | byte (1) | Request User confirmation | No = 0 |
| P2 | byte (1) | Parameter 2 | ignored |
| L | byte (1) | Bytes in payload | 0 (empty) |
Response
| Field | Type | Content | Note |
|---|
| RedJubjub signature | byte (64) | R/S signature | |
| SW1-SW2 | byte (2) | Return code | see list of return codes |
Error Response
| Field | Type | Content | Note |
|---|
| SW1-SW2 | byte (2) | Return code | see list of return codes |
INS_SIGN_SECP256K1
THIS COMMAND HAS BEEN DEPRECATED
INS_SIGN_SAPLING
THIS COMMAND HAS BEEN DEPRECATED
