Stateless, mbedTLS-backed primitives (AES / SHA / bignum are hardware-accelerated on the ESP32-C6). The heavy crypto code lives in the firmware, so an app can implement transport crypto such as MTProto without carrying its own AES/bignum in the 64 KB app pool.

jpp_crypto_sha256¶

jpp_crypto_sha1¶

One-shot digests.

jpp_crypto_status_t jpp_crypto_sha256(const uint8_t *msg, size_t len, uint8_t out[32]);
jpp_crypto_status_t jpp_crypto_sha1(const uint8_t *msg, size_t len, uint8_t out[20]);

jpp_crypto_aes256_ige_encrypt / jpp_crypto_aes256_ige_decrypt¶

AES-256 in IGE mode (the mode MTProto uses). length must be a non-zero multiple of 16. iv is 32 bytes (two blocks) and is read-only. out may alias in for in-place operation.

jpp_crypto_status_t jpp_crypto_aes256_ige_encrypt(
    const uint8_t *in, size_t length,
    const uint8_t key[32], const uint8_t iv[32], uint8_t *out);
jpp_crypto_status_t jpp_crypto_aes256_ige_decrypt(
    const uint8_t *in, size_t length,
    const uint8_t key[32], const uint8_t iv[32], uint8_t *out);

jpp_crypto_modexp¶

Big-integer modular exponentiation out = base^exp mod modulus. All operands are unsigned big-endian byte strings. out receives modulus_len bytes, big-endian, left-padded with zeros.

jpp_crypto_status_t jpp_crypto_modexp(
    const uint8_t *base, size_t base_len,
    const uint8_t *exp, size_t exp_len,
    const uint8_t *modulus, size_t modulus_len,
    uint8_t *out, size_t *out_len);

jpp_crypto_rsa_encrypt¶

jpp_crypto_dh_compute¶

Thin, clarity-only wrappers over modexp: rsa_encrypt computes data^exponent mod modulus (the RSA public-key operation); dh_compute computes base^exp mod prime (a Diffie-Hellman step). The math is identical to modexp.

jpp_crypto_status_t jpp_crypto_rsa_encrypt(
    const uint8_t *data, size_t data_len,
    const uint8_t *modulus, size_t modulus_len,
    const uint8_t *exponent, size_t exponent_len,
    uint8_t *out, size_t *out_len);
jpp_crypto_status_t jpp_crypto_dh_compute(
    const uint8_t *base, size_t base_len,
    const uint8_t *exp, size_t exp_len,
    const uint8_t *prime, size_t prime_len,
    uint8_t *out, size_t *out_len);

Returns (all): JPP_CRYPTO_OK, JPP_CRYPTO_ERR_INVALID_ARG (NULL/zero-length operand, non-block-multiple AES length, or zero modulus), or JPP_CRYPTO_ERR_INTERNAL.