feature/1114 implement account interface (#1167)

- **refactor: move session-related code to middleware package**
- **refactor: update PKL build process and adjust related
configurations**
- **feat: integrate base.cosmos.v1 Genesis module**
- **refactor: pass session context to modal rendering functions**
- **refactor: move nebula package to app directory and update templ
version**
- **refactor: Move home section video view to dedicated directory**
- **refactor: remove unused views file**
- **refactor: move styles and UI components to global scope**
- **refactor: Rename images.go to cdn.go**
- **feat: Add Empty State Illustrations**
- **refactor: Consolidate Vault Index Logic**
- **fix: References to App.wasm and remove Vault Directory embedded CDN
files**
- **refactor: Move CDN types to Models**
- **fix: Correct line numbers in templ error messages for
arch_templ.go**
- **refactor: use common types for peer roles**
- **refactor: move common types and ORM to a shared package**
- **fix: Config import dwn**
- **refactor: move nebula directory to app**
- **feat: Rebuild nebula**
- **fix: correct file paths in panels templates**
- **feat: Remove duplicate types**
- **refactor: Move dwn to pkg/core**
- **refactor: Binary Structure**
- **feat: Introduce Crypto Pkg**
- **fix: Broken Process Start**
- **feat: Update pkg/* structure**
- **feat: Refactor PKL Structure**
- **build: update pkl build process**
- **chore: Remove Empty Files**
- **refactor: remove unused macaroon package**
- **feat: Add WebAwesome Components**
- **refactor: consolidate build and generation tasks into a single
taskfile, remove redundant makefile targets**
- **refactor: refactor server and move components to pkg/core/dwn**
- **build: update go modules**
- **refactor: move gateway logic into dedicated hway command**
- **feat: Add KSS (Krawczyk-Song-Song) MPC cryptography module**
- **feat: Implement MPC-based JWT signing and UCAN token generation**
- **feat: add support for MPC-based JWT signing**
- **feat: Implement MPC-based UCAN capabilities for smart accounts**
- **feat: add address field to keyshareSource**
- **feat: Add comprehensive MPC test suite for keyshares, UCAN tokens,
and token attenuations**
- **refactor: improve MPC keyshare management and signing process**
- **feat: enhance MPC capability hierarchy documentation**
- **refactor: rename GenerateKeyshares function to NewKeyshareSource for
clarity**
- **refactor: remove unused Ethereum address computation**
- **feat: Add HasHandle and IsAuthenticated methods to HTTPContext**
- **refactor: Add context.Context support to session HTTPContext**
- **refactor: Resolve context interface conflicts in HTTPContext**
- **feat: Add session ID context key and helper functions**
- **feat: Update WebApp Page Rendering**
- **refactor: Simplify context management by using single HTTPContext
key**
- **refactor: Simplify HTTPContext creation and context management in
session middleware**
- **refactor: refactor session middleware to use a single data
structure**
- **refactor: Simplify HTTPContext implementation and session data
handling**
- **refactor: Improve session context handling and prevent nil pointer
errors**
- **refactor: Improve session context handling with nil safety and type
support**
- **refactor: improve session data injection**
- **feat: add full-screen modal component and update registration flow**
- **chore: add .air.toml to .gitignore**
- **feat: add Air to devbox and update dependencies**

pkg/crypto/core/commit.go

@@ -0,0 +1,115 @@
+//
+// Copyright Coinbase, Inc. All Rights Reserved.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+package core
+
+import (
+	"crypto/hmac"
+	crand "crypto/rand"
+	"crypto/sha256"
+	"crypto/subtle"
+	"encoding/json"
+	"fmt"
+	"hash"
+)
+
+// Size of random values and hash outputs are determined by our hash function
+const Size = sha256.Size
+
+type (
+	// Commitment to a given message which can be later revealed.
+	// This is sent to and held by a verifier until the corresponding
+	// witness is provided.
+	Commitment []byte
+
+	// Witness is sent to and opened by the verifier. This proves that
+	// committed message hasn't been altered by later information.
+	Witness struct {
+		Msg []byte
+		r   [Size]byte
+	}
+
+	// witnessJSON is used for un/marshaling.
+	witnessJSON struct {
+		Msg []byte
+		R   [Size]byte
+	}
+)
+
+// MarshalJSON encodes Witness in JSON
+func (w Witness) MarshalJSON() ([]byte, error) {
+	return json.Marshal(witnessJSON{w.Msg, w.r})
+}
+
+// UnmarshalJSON decodes JSON into a Witness struct
+func (w *Witness) UnmarshalJSON(data []byte) error {
+	witness := &witnessJSON{}
+	err := json.Unmarshal(data, witness)
+	if err != nil {
+		return err
+	}
+	w.Msg = witness.Msg
+	w.r = witness.R
+	return nil
+}
+
+// Commit to a given message. Uses SHA256 as the hash function.
+func Commit(msg []byte) (Commitment, *Witness, error) {
+	// Initialize our decommitment
+	d := Witness{msg, [Size]byte{}}
+
+	// Generate a random nonce of the required length
+	n, err := crand.Read(d.r[:])
+	// Ensure no errors retrieving nonce
+	if err != nil {
+		return nil, nil, err
+	}
+
+	// Ensure we read all the bytes expected
+	if n != Size {
+		return nil, nil, fmt.Errorf("failed to read %v bytes from crypto/rand: received %v bytes", Size, n)
+	}
+	// Compute the commitment: HMAC(Sha2, msg, key)
+	c, err := ComputeHMAC(sha256.New, msg, d.r[:])
+	if err != nil {
+		return nil, nil, err
+	}
+	return c, &d, nil
+}
+
+// Open a commitment and return true if the commitment/decommitment pair are valid.
+// reference: spec.§2.4: Commitment Scheme
+func Open(c Commitment, d Witness) (bool, error) {
+	// Ensure commitment is well-formed.
+	if len(c) != Size {
+		return false, fmt.Errorf("invalid commitment, wrong length. %v != %v", len(c), Size)
+	}
+
+	// Re-compute the commitment: HMAC(Sha2, msg, key)
+	cʹ, err := ComputeHMAC(sha256.New, d.Msg, d.r[:])
+	if err != nil {
+		return false, err
+	}
+	return subtle.ConstantTimeCompare(cʹ, c) == 1, nil
+}
+
+// ComputeHMAC computes HMAC(hash_fn, msg, key)
+// Takes in a hash function to use for HMAC
+func ComputeHMAC(f func() hash.Hash, msg []byte, k []byte) ([]byte, error) {
+	if f == nil {
+		return nil, fmt.Errorf("hash function cannot be nil")
+	}
+
+	mac := hmac.New(f, k)
+	w, err := mac.Write(msg)
+
+	if w != len(msg) {
+		return nil, fmt.Errorf("bytes written to hash doesn't match expected: %v != %v", w, len(msg))
+	} else if err != nil {
+		return nil, err
+	}
+	return mac.Sum(nil), nil
+}