SM2 helpers built on top of OTP crypto/public_key capabilities.
SM2 is a Chinese commercial cryptographic algorithm standard, including:
- Key pair generation
- Digital signature helpers using SM3 prehashing and OTP ECDSA primitives
- Encryption/decryption helpers using an internal ECDH + SM3 KDF construction
If the runtime/OpenSSL does not expose SM2 primitives, APIs return
{:error, :unsupported}.
Compatibility
sign/2 and verify/3 currently operate on raw 64-byte ECDSA-style
signatures over an SM3 digest. They do not expose the SM2 user ID/ZA
parameterization used by some interoperable SM2 signature profiles.
encrypt/2 and decrypt/2 use this package's internal ciphertext format:
C1 || C2 || C3, where C1 is a 65-byte ephemeral public key and C3 is an
SM3 MAC. This format is intended for Guomi-to-Guomi round trips and should not
be assumed to interoperate with OpenSSL or other SM2 implementations.
Example
# Key pair generation
{:ok, private_key, public_key} = Guomi.SM2.generate_keypair()
# Sign and verify
{:ok, signature} = Guomi.SM2.sign("message", private_key)
{:ok, true} = Guomi.SM2.verify("message", signature, public_key)
# Encrypt and decrypt
{:ok, ciphertext} = Guomi.SM2.encrypt("secret", public_key)
{:ok, plaintext} = Guomi.SM2.decrypt(ciphertext, private_key)Summary
Functions
Decrypt ciphertext using SM2 decryption algorithm.
Encrypt plaintext using SM2 encryption algorithm.
Types
Functions
@spec decrypt(binary(), binary()) :: {:ok, binary()} | {:error, error_reason()}
Decrypt ciphertext using SM2 decryption algorithm.
Parameters
- ciphertext: The encrypted data
- private_key: The recipient's private key
Returns
{:ok, plaintext}on success{:error, reason}on failure
Example
{:ok, private_key, public_key} = Guomi.SM2.generate_keypair()
{:ok, ciphertext} = Guomi.SM2.encrypt("secret message", public_key)
{:ok, plaintext} = Guomi.SM2.decrypt(ciphertext, private_key)@spec encrypt(binary() | iodata(), binary()) :: {:ok, binary()} | {:error, error_reason()}
Encrypt plaintext using SM2 encryption algorithm.
Parameters
- plaintext: The data to encrypt
- public_key: The recipient's public key
Returns
{:ok, ciphertext}on success{:error, reason}on failure
Example
{:ok, private_key, public_key} = Guomi.SM2.generate_keypair()
{:ok, ciphertext} = Guomi.SM2.encrypt("secret message", public_key)@spec supported?() :: boolean()