wolfssl-ra.c

#include <assert.h>
#include <stdint.h>

#include <wolfssl/options.h>
#include <wolfssl/wolfcrypt/asn_public.h>
#include <wolfssl/wolfcrypt/rsa.h>
#include "wolfssl-ra.h"

void sha256_rsa_pubkey
(
    unsigned char hash[SHA256_DIGEST_SIZE],
    RsaKey* key
)
{
    // Expect a 2048 bit RSA key.
    assert(key->n.used == 32);

    uint8_t buf[1024];
    /* SetRsaPublicKey() only exports n and e without wrapping them in
       additional ASN.1 (PKCS#1). */
    int pub_rsa_key_der_len = SetRsaPublicKey(buf, key, sizeof(buf), 0);
    assert(pub_rsa_key_der_len == 270);
    
    Sha256 sha;
    wc_InitSha256(&sha);
    wc_Sha256Update(&sha, buf, pub_rsa_key_der_len);
    wc_Sha256Final(&sha, hash);
}

/* This function only exists to make edger8r happy. There must be at
   least one trusted (ECALL) function. */
void dummy(void) {
}