Struct tss_esapi::abstraction::transient::TransientKeyContext

pub struct TransientKeyContext { /* private fields */ }

Structure offering an abstracted programming experience.

The TransientKeyContext makes use of a root key from which the other, client-controlled keyes are derived.

Currently, only functionality necessary for RSA key creation and usage (for signing, verifying signatures, encryption and decryption) is implemented. The RSA SSA asymmetric scheme with SHA256 is used for all created and imported signing keys. The RSA OAEP asymmetric scheme with SHA256 is used for all created and imported signing/encryption/decryption keys.

Implementations

impl TransientKeyContext

pub fn create_key(
    &mut self,
    key_params: KeyParams,
    auth_size: usize
) -> Result<(TpmsContext, Option<Auth>)>

Create a new key.

A key is created as a descendant of the context root key, with the given parameters.

If successful, the result contains the saved context of the key and a vector of bytes forming the authentication value for said key.

Constraints

• auth_size must be at most 32

Errors

• if the authentication size is larger than 32 a WrongParamSize wrapper error is returned
• for RSA keys, if the specified key size is not one of 1024, 2048, 3072 or 4096, WrongParamSize is returned
• if the key_params is not for an RSA key, InvalidParam is returned
• if the key_params does not have an AnySig scheme, InvalidParam is returned
• errors are returned if any method calls return an error: Context::get_random, TransientKeyContext::set_session_attrs, Context::create, Context::load, Context::context_save, Context::context_flush

pub fn load_external_rsa_public_key(
    &mut self,
    public_key: &[u8]
) -> Result<TpmsContext>

Load a previously generated RSA public key.

Returns the key context.

Constraints

• public_key must be 128, 256, 384 or 512 bytes (i.e. slice elements) long, corresponding to 1024, 2048, 3072 or 4096 bits

Errors

• if the public key length is different than 128, 256, 384 or 512 bytes, a WrongParamSize wrapper error is returned
• errors are returned if any method calls return an error: TransientKeyContext::set_session_attrs, Context::load_external_public, Context::context_save, Context::flush_context`

pub fn load_external_rsa(
    &mut self,
    key_prime: &[u8],
    public_modulus: &[u8],
    public_exponent: RsaExponent
) -> Result<TpmsContext>

Load a previously generated RSA keypair. Currently only supports signing keys for RSA PKCS 1v5 with SHA256.

Returns the key context.

Constraints

• public_modulus must be 128, 256, 384 or 512 bytes (i.e. slice elements) long, corresponding to 1024, 2048, 3072 or 4096 bits
• key_prime’s length must coincide with that of the public key. Namely, key_prime should be 64, 128, 192, or 256 bytes (i.e. slice elements) long for public keys of length 128, 256, 384 or 512 respectively (which in turn correspond to 512/1024/1536/2048 bits for key_prime).

Errors

• errors are returned if any method calls return an error. TransientKeyContext::set_session_attrs, Context::load_external, Context::context_save, Context::flush_context`

pub fn read_public_key(&mut self, key_context: TpmsContext) -> Result<PublicKey>

Read the public part from a previously generated key.

The method takes the key as a parameter and returns its public part.

Errors

• errors are returned if any method calls return an error: Context::context_load, Context::read_public, Context::flush_context, TransientKeyContext::set_session_attrs

pub fn rsa_encrypt(
    &mut self,
    key_context: TpmsContext,
    key_auth: Option<Auth>,
    message: PublicKeyRSA,
    scheme: AsymSchemeUnion,
    label: Option<Data>
) -> Result<PublicKeyRSA>

Encrypt a message with an existing key.

Takes the key as a parameter, encrypts the message and returns the ciphertext. A label (i.e. nonce) can also be provided.

Errors

• errors are returned if any method calls return an error: Context::context_load, Context::rsa_encrypt, Context::flush_context, TransientKeyContext::set_session_attrs Context::set_handle_auth

pub fn rsa_decrypt(
    &mut self,
    key_context: TpmsContext,
    key_auth: Option<Auth>,
    ciphertext: PublicKeyRSA,
    scheme: AsymSchemeUnion,
    label: Option<Data>
) -> Result<PublicKeyRSA>

Decrypt ciphertext with an existing key.

Takes the key as a parameter, decrypts the ciphertext and returns the plaintext. A label (i.e. nonce) can also be provided.

Errors

• errors are returned if any method calls return an error: Context::context_load, Context::rsa_decrypt, Context::flush_context, TransientKeyContext::set_session_attrs Context::set_handle_auth

pub fn sign(
    &mut self,
    key_context: TpmsContext,
    key_auth: Option<Auth>,
    digest: Digest
) -> Result<Signature>

Sign a digest with an existing key.

Takes the key as a parameter, signs and returns the signature.

Errors

• errors are returned if any method calls return an error: Context::context_load, Context::sign, Context::flush_context, TransientKeyContext::set_session_attrs Context::set_handle_auth

pub fn verify_signature(
    &mut self,
    key_context: TpmsContext,
    digest: Digest,
    signature: Signature
) -> Result<VerifiedTicket>

Verify a signature against a digest.

Given a digest, a key and a signature, this method returns a Verified ticket if the verification was successful.

Errors

• if the verification fails (i.e. the signature is invalid), a TPM error is returned
• errors are returned if any method calls return an error: Context::context_load, Context::verify_signature, Context::flush_context, TransientKeyContext::set_session_attrs

Trait Implementations

impl Debug for TransientKeyContext

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.