Struct KdfAlgorithmBuilder

pub struct KdfAlgorithmBuilder;

Builder for constructing KDF algorithm instances.

用于构建 KDF 算法实例的构建器。

Design Pattern | 设计模式

This builder separates key-based and password-based derivation functions, ensuring that the appropriate algorithm is chosen for the input entropy level.

此构建器分离基于密钥和基于密码的派生函数， 确保为输入熵级别选择适当的算法。

Security Guidance | 安全指导

• Use .key() for high-entropy inputs (≥128 bits of entropy)

• Use .passwd() for low-entropy inputs (user passwords, PINs)

• 对高熵输入使用 .key()（≥128 位熵）

• 对低熵输入使用 .passwd()（用户密码、PIN）

Implementations

impl KdfAlgorithmBuilder

pub fn key(self) -> KdfKeyAlgorithmBuilder

Creates a key-based KDF algorithm builder.

创建基于密钥的 KDF 算法构建器。

Use Cases | 使用场景

• Deriving multiple keys from a master key

• Key expansion in cryptographic protocols

• Deriving keys from shared secrets (ECDH, etc.)

• Creating domain-separated keys

• 从主密钥派生多个密钥

• 密码协议中的密钥扩展

• 从共享密钥派生密钥（ECDH 等）

• 创建域分离的密钥

Available Algorithms | 可用算法

• HKDF-SHA256: Fast, widely supported
• HKDF-SHA384: Higher security margin
• HKDF-SHA512: Maximum security

Examples | 示例

use seal_crypto_wrapper::algorithms::kdf::KdfAlgorithm;

let hkdf = KdfAlgorithm::build().key().hkdf_sha256();

pub fn passwd(self) -> KdfPasswordAlgorithmBuilder

Creates a password-based KDF algorithm builder.

创建基于密码的 KDF 算法构建器。

Use Cases | 使用场景

• Deriving encryption keys from user passwords

• Password-based authentication

• Secure password storage

• Key derivation for encrypted storage

• 从用户密码派生加密密钥

• 基于密码的认证

• 安全密码存储

• 加密存储的密钥派生

Available Algorithms | 可用算法

• PBKDF2: Widely supported, configurable iterations
• Argon2: Memory-hard, resistant to specialized attacks

Security Note | 安全注意

Always use sufficient iteration counts and random salts to protect against brute-force and rainbow table attacks.

始终使用足够的迭代次数和随机盐来防止暴力攻击和彩虹表攻击。

Examples | 示例

use seal_crypto_wrapper::algorithms::kdf::KdfAlgorithm;

// PBKDF2 with 100,000 iterations
let pbkdf2 = KdfAlgorithm::build().passwd().pbkdf2_sha256_with_params(100000);

// Argon2 with memory cost, time cost, and parallelism
let argon2 = KdfAlgorithm::build().passwd().argon2_with_params(65536, 3, 4);