Basic Concepts of HUKS
Familiarity with the following concepts is helpful because they are used throughout your development process.
TEE
Trusted Execution Environment (TEE) is a secure area of a main processor of a smartphone, tablet, or a mobile device. Any date in the TEE cannot be read or tampered with by any code outside it. The TEE provides a secure execution environment for trusted applications (TAs) to ensure end-to-end security by features, such as isolated execution, integrity of applications, confidentiality of their assets, and data access permissions.
Key Material Format
HUKS defines a set of key material formats for key pairs, public keys, and private keys of different cryptographic algorithms. The key material formats are used when a key is imported or exported.
Key Pair Material Format
Key pair material = Key pair material header + Key pair material content
For example, an application needs an RSA key in Uint8Array format, the variables are assigned with values based on the structure of the RSA key pair material in the memory.
The following figure illustrates the structure of the RSA key material. For details about the key material formats of other algorithms, see the tables below.
The key algorithm is a value of HuksKeyAlg.
let rsa2048KeyPairMaterial = new Uint8Array([
0x01, 0x00, 0x00, 0x00, // Key algorithm: huks.HuksKeyAlg.HUKS_ALG_RSA = 1
0x00, 0x08, 0x00, 0x00, // Key size (bit): 2048
0x00, 0x01, 0x00, 0x00, // Length of modulus n (byte): 256
0x03, 0x00, 0x00, 0x00, // Length of the public key exponent e (byte): 3
0x00, 0x01, 0x00, 0x00, // Length of the private key exponent d (byte): 256
// Modulus n
0xc5, 0x35, 0x62, 0x48, 0xc4, 0x92, 0x87, 0x73, 0x0d, 0x42, 0x96, 0xfc, 0x7b, 0x11, 0x05, 0x06,
0x0f, 0x8d, 0x66, 0xc1, 0x0e, 0xad, 0x37, 0x44, 0x92, 0x95, 0x2f, 0x6a, 0x55, 0xba, 0xec, 0x1d,
0x54, 0x62, 0x0a, 0x4b, 0xd3, 0xc7, 0x05, 0xe4, 0x07, 0x40, 0xd9, 0xb7, 0xc2, 0x12, 0xcb, 0x9a,
0x90, 0xad, 0xe3, 0x24, 0xe8, 0x5e, 0xa6, 0xf8, 0xd0, 0x6e, 0xbc, 0xd1, 0x69, 0x7f, 0x6b, 0xe4,
0x2b, 0x4e, 0x1a, 0x65, 0xbb, 0x73, 0x88, 0x6b, 0x7c, 0xaf, 0x7e, 0xd0, 0x47, 0x26, 0xeb, 0xa5,
0xbe, 0xd6, 0xe8, 0xee, 0x9c, 0xa5, 0x66, 0xa5, 0xc9, 0xd3, 0x25, 0x13, 0xc4, 0x0e, 0x6c, 0xab,
0x50, 0xb6, 0x50, 0xc9, 0xce, 0x8f, 0x0a, 0x0b, 0xc6, 0x28, 0x69, 0xe9, 0x83, 0x69, 0xde, 0x42,
0x56, 0x79, 0x7f, 0xde, 0x86, 0x24, 0xca, 0xfc, 0xaa, 0xc0, 0xf3, 0xf3, 0x7f, 0x92, 0x8e, 0x8a,
0x12, 0x52, 0xfe, 0x50, 0xb1, 0x5e, 0x8c, 0x01, 0xce, 0xfc, 0x7e, 0xf2, 0x4f, 0x5f, 0x03, 0xfe,
0xa7, 0xcd, 0xa1, 0xfc, 0x94, 0x52, 0x00, 0x8b, 0x9b, 0x7f, 0x09, 0xab, 0xa8, 0xa4, 0xf5, 0xb4,
0xa5, 0xaa, 0xfc, 0x72, 0xeb, 0x17, 0x40, 0xa9, 0xee, 0xbe, 0x8f, 0xc2, 0xd1, 0x80, 0xc2, 0x0d,
0x44, 0xa9, 0x59, 0x44, 0x59, 0x81, 0x3b, 0x5d, 0x4a, 0xde, 0xfb, 0xae, 0x24, 0xfc, 0xa3, 0xd9,
0xbc, 0x57, 0x55, 0xc2, 0x26, 0xbc, 0x19, 0xa7, 0x9a, 0xc5, 0x59, 0xa3, 0xee, 0x5a, 0xef, 0x41,
0x80, 0x7d, 0xf8, 0x5e, 0xc1, 0x1d, 0x32, 0x38, 0x41, 0x5b, 0xb6, 0x92, 0xb8, 0xb7, 0x03, 0x0d,
0x3e, 0x59, 0x0f, 0x1c, 0xb3, 0xe1, 0x2a, 0x95, 0x1a, 0x3b, 0x50, 0x4f, 0xc4, 0x1d, 0xcf, 0x73,
0x7c, 0x14, 0xca, 0xe3, 0x0b, 0xa7, 0xc7, 0x1a, 0x41, 0x4a, 0xee, 0xbe, 0x1f, 0x43, 0xdd, 0xf9,
// Public key exponent e
0x01, 0x00, 0x01,
// Private key exponent d
0x88, 0x4b, 0x82, 0xe7, 0xe3, 0xe3, 0x99, 0x75, 0x6c, 0x9e, 0xaf, 0x17, 0x44, 0x3e, 0xd9, 0x07,
0xfd, 0x4b, 0xae, 0xce, 0x92, 0xc4, 0x28, 0x44, 0x5e, 0x42, 0x79, 0x08, 0xb6, 0xc3, 0x7f, 0x58,
0x2d, 0xef, 0xac, 0x4a, 0x07, 0xcd, 0xaf, 0x46, 0x8f, 0xb4, 0xc4, 0x43, 0xf9, 0xff, 0x5f, 0x74,
0x2d, 0xb5, 0xe0, 0x1c, 0xab, 0xf4, 0x6e, 0xd5, 0xdb, 0xc8, 0x0c, 0xfb, 0x76, 0x3c, 0x38, 0x66,
0xf3, 0x7f, 0x01, 0x43, 0x7a, 0x30, 0x39, 0x02, 0x80, 0xa4, 0x11, 0xb3, 0x04, 0xd9, 0xe3, 0x57,
0x23, 0xf4, 0x07, 0xfc, 0x91, 0x8a, 0xc6, 0xcc, 0xa2, 0x16, 0x29, 0xb3, 0xe5, 0x76, 0x4a, 0xa8,
0x84, 0x19, 0xdc, 0xef, 0xfc, 0xb0, 0x63, 0x33, 0x0b, 0xfa, 0xf6, 0x68, 0x0b, 0x08, 0xea, 0x31,
0x52, 0xee, 0x99, 0xef, 0x43, 0x2a, 0xbe, 0x97, 0xad, 0xb3, 0xb9, 0x66, 0x7a, 0xae, 0xe1, 0x8f,
0x57, 0x86, 0xe5, 0xfe, 0x14, 0x3c, 0x81, 0xd0, 0x64, 0xf8, 0x86, 0x1a, 0x0b, 0x40, 0x58, 0xc9,
0x33, 0x49, 0xb8, 0x99, 0xc6, 0x2e, 0x94, 0x70, 0xee, 0x09, 0x88, 0xe1, 0x5c, 0x4e, 0x6c, 0x22,
0x72, 0xa7, 0x2a, 0x21, 0xdd, 0xd7, 0x1d, 0xfc, 0x63, 0x15, 0x0b, 0xde, 0x06, 0x9c, 0xf3, 0x28,
0xf3, 0xac, 0x4a, 0xa8, 0xb5, 0x50, 0xca, 0x9b, 0xcc, 0x0a, 0x04, 0xfe, 0x3f, 0x98, 0x68, 0x81,
0xac, 0x24, 0x53, 0xea, 0x1f, 0x1c, 0x6e, 0x5e, 0xca, 0xe8, 0x31, 0x0d, 0x08, 0x12, 0xf3, 0x26,
0xf8, 0x5e, 0xeb, 0x10, 0x27, 0xae, 0xaa, 0xc3, 0xad, 0x6c, 0xc1, 0x89, 0xdb, 0x7d, 0x5a, 0x12,
0x55, 0xad, 0x11, 0x19, 0xa1, 0xa9, 0x8f, 0x0b, 0x6d, 0x78, 0x8d, 0x1c, 0xdf, 0xe5, 0x63, 0x82,
0x0b, 0x7d, 0x23, 0x04, 0xb4, 0x75, 0x8c, 0xed, 0x77, 0xfc, 0x1a, 0x85, 0x29, 0x11, 0xe0, 0x61,
]);
- RSA key pair material format
| Key Algorithm | Key Size | Modulus n Length (Ln) | Public Key Exponent Length (Le) | Private Key Exponent d Length (Ld) | n | e | d |
|---|---|---|---|---|---|---|---|
| 4 bytes | 4 bytes | 4 bytes | 4 bytes | 4 bytes | Ln bytes | Le bytes | Ld bytes |
- ECC key pair material format
| Key Algorithm | Key Size | Coordinate x Length (Lx) | Coordinate y Length (Ly) | Coordinate z Length (Lz) | x | y | z |
|---|---|---|---|---|---|---|---|
| 4 bytes | 4 bytes | 4 bytes | 4 bytes | 4 bytes | Lx bytes | Ly bytes | Lz bytes |
- DSA key pair material format
| Key Algorithm | Key Size | Private Key x Length (Lx) | Public Key y Length (Ly) | Prime p Length (Lp) | Prime Factor q Length (Lq) | g length (Lg) | x | y | p | q | g |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 4 bytes | 4 bytes | 4 bytes | 4 bytes | 4 bytes | 4 bytes | 4 bytes | Lx bytes | Ly bytes | Lp bytes | Lq bytes | Lg bytes |
- DH key pair material format
| Key Algorithm | Key Size | Public Key pk Length (Lpk) | Private Key sk Length (Lsk) | Reserved Field | pk | sk |
|---|---|---|---|---|---|---|
| 4 bytes | 4 bytes | 4 bytes | 4 bytes | 4 bytes | Lpk bytes | Lsk bytes |
- Curve25519 key pair material format
| Key Algorithm | Key Size | Public Key pk Length (Lpk) | Private Key sk Length (Lsk) | Reserved Field | pk | sk |
|---|---|---|---|---|---|---|
| 4 bytes | 4 bytes | 4 bytes | 4 bytes | 4 bytes | Lpk bytes | Lsk bytes |
Public Key Material Format
When a public key is exported or imported, the key material is encapsulated in the DER format defined in X.509.
The following is ECC public key in EDR format:
let eccP256PubKey = new Uint8Array([
0x30, 0x59, 0x30, 0x13, 0x06, 0x07, 0x2a, 0x86, 0x48, 0xce, 0x3d, 0x02, 0x01, 0x06, 0x08, 0x2a,
0x86, 0x48, 0xce, 0x3d, 0x03, 0x01, 0x07, 0x03, 0x42, 0x00, 0x04, 0xc0, 0xfe, 0x1c, 0x67, 0xde,
0x86, 0x0e, 0xfb, 0xaf, 0xb5, 0x85, 0x52, 0xb4, 0x0e, 0x1f, 0x6c, 0x6c, 0xaa, 0xc5, 0xd9, 0xd2,
0x4d, 0xb0, 0x8a, 0x72, 0x24, 0xa1, 0x99, 0xaf, 0xfc, 0x3e, 0x55, 0x5a, 0xac, 0x99, 0x3d, 0xe8,
0x34, 0x72, 0xb9, 0x47, 0x9c, 0xa6, 0xd8, 0xfb, 0x00, 0xa0, 0x1f, 0x9f, 0x7a, 0x41, 0xe5, 0x44,
0x3e, 0xb2, 0x76, 0x08, 0xa2, 0xbd, 0xe9, 0x41, 0xd5, 0x2b, 0x9e
]);
Private Key Material Format
The private key material is in the same format as the key pair material. When the private key material is encapsulated, the public key length in the header of the key pair material is set to 0 and key pair material content and the private key material content are combined.
Private key material = Key pair material header + Private key material content
The following is an example of the RSA private key material.
let rsa2048PrivateKeyMaterial = new Uint8Array([
0x01, 0x00, 0x00, 0x00, // Key algorithm: huks.HuksKeyAlg.HUKS_ALG_RSA = 1
0x00, 0x08, 0x00, 0x00, // Key size (bit): 2048
0x00, 0x01, 0x00, 0x00, // Length of modulus n (byte): 256
0x00, 0x00, 0x00, 0x00, // Length of the public key exponent e (byte): 0
0x00, 0x01, 0x00, 0x00, // Length of the private key exponent d (byte): 256
// Modulus n
0xc5, 0x35, 0x62, 0x48, 0xc4, 0x92, 0x87, 0x73, 0x0d, 0x42, 0x96, 0xfc, 0x7b, 0x11, 0x05, 0x06,
0x0f, 0x8d, 0x66, 0xc1, 0x0e, 0xad, 0x37, 0x44, 0x92, 0x95, 0x2f, 0x6a, 0x55, 0xba, 0xec, 0x1d,
0x54, 0x62, 0x0a, 0x4b, 0xd3, 0xc7, 0x05, 0xe4, 0x07, 0x40, 0xd9, 0xb7, 0xc2, 0x12, 0xcb, 0x9a,
0x90, 0xad, 0xe3, 0x24, 0xe8, 0x5e, 0xa6, 0xf8, 0xd0, 0x6e, 0xbc, 0xd1, 0x69, 0x7f, 0x6b, 0xe4,
0x2b, 0x4e, 0x1a, 0x65, 0xbb, 0x73, 0x88, 0x6b, 0x7c, 0xaf, 0x7e, 0xd0, 0x47, 0x26, 0xeb, 0xa5,
0xbe, 0xd6, 0xe8, 0xee, 0x9c, 0xa5, 0x66, 0xa5, 0xc9, 0xd3, 0x25, 0x13, 0xc4, 0x0e, 0x6c, 0xab,
0x50, 0xb6, 0x50, 0xc9, 0xce, 0x8f, 0x0a, 0x0b, 0xc6, 0x28, 0x69, 0xe9, 0x83, 0x69, 0xde, 0x42,
0x56, 0x79, 0x7f, 0xde, 0x86, 0x24, 0xca, 0xfc, 0xaa, 0xc0, 0xf3, 0xf3, 0x7f, 0x92, 0x8e, 0x8a,
0x12, 0x52, 0xfe, 0x50, 0xb1, 0x5e, 0x8c, 0x01, 0xce, 0xfc, 0x7e, 0xf2, 0x4f, 0x5f, 0x03, 0xfe,
0xa7, 0xcd, 0xa1, 0xfc, 0x94, 0x52, 0x00, 0x8b, 0x9b, 0x7f, 0x09, 0xab, 0xa8, 0xa4, 0xf5, 0xb4,
0xa5, 0xaa, 0xfc, 0x72, 0xeb, 0x17, 0x40, 0xa9, 0xee, 0xbe, 0x8f, 0xc2, 0xd1, 0x80, 0xc2, 0x0d,
0x44, 0xa9, 0x59, 0x44, 0x59, 0x81, 0x3b, 0x5d, 0x4a, 0xde, 0xfb, 0xae, 0x24, 0xfc, 0xa3, 0xd9,
0xbc, 0x57, 0x55, 0xc2, 0x26, 0xbc, 0x19, 0xa7, 0x9a, 0xc5, 0x59, 0xa3, 0xee, 0x5a, 0xef, 0x41,
0x80, 0x7d, 0xf8, 0x5e, 0xc1, 0x1d, 0x32, 0x38, 0x41, 0x5b, 0xb6, 0x92, 0xb8, 0xb7, 0x03, 0x0d,
0x3e, 0x59, 0x0f, 0x1c, 0xb3, 0xe1, 0x2a, 0x95, 0x1a, 0x3b, 0x50, 0x4f, 0xc4, 0x1d, 0xcf, 0x73,
0x7c, 0x14, 0xca, 0xe3, 0x0b, 0xa7, 0xc7, 0x1a, 0x41, 0x4a, 0xee, 0xbe, 0x1f, 0x43, 0xdd, 0xf9,
// Private key exponent d
0x88, 0x4b, 0x82, 0xe7, 0xe3, 0xe3, 0x99, 0x75, 0x6c, 0x9e, 0xaf, 0x17, 0x44, 0x3e, 0xd9, 0x07,
0xfd, 0x4b, 0xae, 0xce, 0x92, 0xc4, 0x28, 0x44, 0x5e, 0x42, 0x79, 0x08, 0xb6, 0xc3, 0x7f, 0x58,
0x2d, 0xef, 0xac, 0x4a, 0x07, 0xcd, 0xaf, 0x46, 0x8f, 0xb4, 0xc4, 0x43, 0xf9, 0xff, 0x5f, 0x74,
0x2d, 0xb5, 0xe0, 0x1c, 0xab, 0xf4, 0x6e, 0xd5, 0xdb, 0xc8, 0x0c, 0xfb, 0x76, 0x3c, 0x38, 0x66,
0xf3, 0x7f, 0x01, 0x43, 0x7a, 0x30, 0x39, 0x02, 0x80, 0xa4, 0x11, 0xb3, 0x04, 0xd9, 0xe3, 0x57,
0x23, 0xf4, 0x07, 0xfc, 0x91, 0x8a, 0xc6, 0xcc, 0xa2, 0x16, 0x29, 0xb3, 0xe5, 0x76, 0x4a, 0xa8,
0x84, 0x19, 0xdc, 0xef, 0xfc, 0xb0, 0x63, 0x33, 0x0b, 0xfa, 0xf6, 0x68, 0x0b, 0x08, 0xea, 0x31,
0x52, 0xee, 0x99, 0xef, 0x43, 0x2a, 0xbe, 0x97, 0xad, 0xb3, 0xb9, 0x66, 0x7a, 0xae, 0xe1, 0x8f,
0x57, 0x86, 0xe5, 0xfe, 0x14, 0x3c, 0x81, 0xd0, 0x64, 0xf8, 0x86, 0x1a, 0x0b, 0x40, 0x58, 0xc9,
0x33, 0x49, 0xb8, 0x99, 0xc6, 0x2e, 0x94, 0x70, 0xee, 0x09, 0x88, 0xe1, 0x5c, 0x4e, 0x6c, 0x22,
0x72, 0xa7, 0x2a, 0x21, 0xdd, 0xd7, 0x1d, 0xfc, 0x63, 0x15, 0x0b, 0xde, 0x06, 0x9c, 0xf3, 0x28,
0xf3, 0xac, 0x4a, 0xa8, 0xb5, 0x50, 0xca, 0x9b, 0xcc, 0x0a, 0x04, 0xfe, 0x3f, 0x98, 0x68, 0x81,
0xac, 0x24, 0x53, 0xea, 0x1f, 0x1c, 0x6e, 0x5e, 0xca, 0xe8, 0x31, 0x0d, 0x08, 0x12, 0xf3, 0x26,
0xf8, 0x5e, 0xeb, 0x10, 0x27, 0xae, 0xaa, 0xc3, 0xad, 0x6c, 0xc1, 0x89, 0xdb, 0x7d, 0x5a, 0x12,
0x55, 0xad, 0x11, 0x19, 0xa1, 0xa9, 0x8f, 0x0b, 0x6d, 0x78, 0x8d, 0x1c, 0xdf, 0xe5, 0x63, 0x82,
0x0b, 0x7d, 0x23, 0x04, 0xb4, 0x75, 0x8c, 0xed, 0x77, 0xfc, 0x1a, 0x85, 0x29, 0x11, 0xe0, 0x61,
]);