kyn_vdf/
error.rs

1//! Error types for VDF verification and Class Group arithmetic.
2//!
3//! All public functions in `kyn-vdf` return [`KynVdfError`] on failure rather than
4//! panicking, ensuring the library is safe for use in WASM, `no_std`, and adversarial
5//! input environments.
6
7use thiserror::Error;
8
9/// Domain-specific errors returned during Class Group operations and Wesolowski VDF verification.
10///
11/// Every variant carries a human-readable message describing the exact failure point.
12/// Callers should treat [`KynVdfError::VerificationFailed`] as a clean "proof rejected"
13/// signal, and all other variants as malformed or invalid inputs.
14#[derive(Debug, Error, Clone, PartialEq, Eq)]
15pub enum KynVdfError {
16    /// The proof byte slice is shorter than the required minimum.
17    ///
18    /// Chia-format proofs must be exactly 200 bytes (`y || π`, each 100 bytes).
19    #[error("Invalid proof length: expected {expected} bytes, got {actual}")]
20    InvalidProofLength { expected: usize, actual: usize },
21
22    /// The challenge seed passed to [`crate::create_discriminant`] was empty or invalid.
23    ///
24    /// Seeds must be non-empty byte slices. Longer seeds (≥32 bytes) are recommended
25    /// for security.
26    #[error("Invalid seed: {0}")]
27    InvalidSeed(String),
28
29    /// The discriminant bit-size is zero, not a multiple of 8, or otherwise unsupported.
30    ///
31    /// Valid values are multiples of 8 (e.g. `512`, `1024`, `2048`).
32    #[error("Invalid discriminant size: {0} bits (must be a non-zero multiple of 8)")]
33    InvalidDiscriminantSize(usize),
34
35    /// Discriminant generation or prime hashing failed unexpectedly.
36    #[error("Failed to generate discriminant: {0}")]
37    DiscriminantError(String),
38
39    /// A quadratic form could not be serialized or deserialized from the Chia BQFC format.
40    ///
41    /// This typically means the proof bytes are corrupted, truncated, or were produced
42    /// by an incompatible implementation.
43    #[error("Quadratic form (de)serialization failed: {0}")]
44    FormDeserializationError(String),
45
46    /// The deserialized or constructed quadratic form does not satisfy the fundamental
47    /// discriminant identity $b^2 - 4ac = D$.
48    ///
49    /// Indicates a corrupted proof or an incorrect discriminant was used for verification.
50    #[error("Invalid quadratic form: discriminant identity b² - 4ac = D does not hold")]
51    InvalidDiscriminantIdentity,
52
53    /// An extended GCD, modular inverse, or other class group arithmetic step failed.
54    #[error("Class group arithmetic error: {0}")]
55    ArithmeticError(String),
56
57    /// The iteration count passed to verify is zero.
58    ///
59    /// A VDF with zero iterations is undefined — the minimum meaningful value is 1.
60    #[error("Invalid iteration count: {0} (must be ≥ 1)")]
61    InvalidIterations(u64),
62
63    /// Verification completed without error but the proof equation does not hold:
64    /// `π^B · x^r ≠ y`.
65    ///
66    /// This is the expected error when a valid but incorrect proof is presented.
67    #[error("VDF proof rejected: π^B · x^r ≠ y (proof does not verify)")]
68    VerificationFailed,
69}
kyn_vdf/error.rs

kyn_vdf/
error.rs
