/* Provenance: openssl/openssl pkey_sm2_decrypt (fixed).
 * repo: openssl/openssl
 * commit: 59f5e75f3bced8fc0e130d72a3f582cf7b480b46
 * parent: 8c74c9d1ade0fbdab5b815ddb747351b8b839641
 * commit_url: https://github.com/openssl/openssl/commit/59f5e75f3bced8fc0e130d72a3f582cf7b480b46
 * cve: CVE-2021-3711
 * license: OpenSSL License
 * function: pkey_sm2_decrypt
 * relpath: crypto/sm2/sm2_pmeth.c
 */

static int pkey_sm2_decrypt(EVP_PKEY_CTX *ctx,
                            unsigned char *out, size_t *outlen,
                            const unsigned char *in, size_t inlen)
{
    EC_KEY *ec = ctx->pkey->pkey.ec;
    SM2_PKEY_CTX *dctx = ctx->data;
    const EVP_MD *md = (dctx->md == NULL) ? EVP_sm3() : dctx->md;

    if (out == NULL) {
        if (!sm2_plaintext_size(in, inlen, outlen))
            return -1;
        else
            return 1;
    }

    return sm2_decrypt(ec, md, in, inlen, out, outlen);
}