A denial-of-service vulnerability exists in the SM2 public-key encryption (PKE) implementation: the decrypt() path performs unchecked slice::split_at operations on input buffers derived from untrusted ciphertext. An attacker can submit short/undersized ciphertext or carefully-crafted DER-encoded structures to trigger bounds-check panics (Rust unwinding) which crash the calling thread or process.
A denial-of-service vulnerability exists in the SM2 PKE decryption path where an invalid elliptic-curve point (C1) is decoded and the resulting value is unwrapped without checking. Specifically, AffinePoint::from_encoded_point(&encoded_c1) may return a None/CtOption::None when the supplied coordinates are syntactically valid but do not lie on the SM2 curve. The calling code previously used .unwrap(), causing a panic when presented with such input.
A critical vulnerability exists in the SM2 Public Key Encryption (PKE) implementation where the ephemeral nonce k is generated with severely reduced entropy. A unit mismatch error causes the nonce generation function to request only 32 bits of randomness instead of the expected 256 bits. This reduces the security of the encryption from a 128-bit level to a trivial 16-bit level, allowing a practical attack to recover the nonce k …