/* Provenance: openssl/openssl pkcs7_bio_add_digest (fixed).
 * repo: openssl/openssl
 * commit: 6eebe6c0238178356114a96a7858f36b24172847
 * parent: 7880536fe17c2b5450e279155bedd51771d28c9f
 * commit_url: https://github.com/openssl/openssl/commit/6eebe6c0238178356114a96a7858f36b24172847
 * cve: CVE-2023-0401
 * license: Apache-2.0
 * function: pkcs7_bio_add_digest
 * relpath: crypto/pkcs7/pk7_doit.c
 */

static int pkcs7_bio_add_digest(BIO **pbio, X509_ALGOR *alg,
                                const PKCS7_CTX *ctx)
{
    BIO *btmp;
    char name[OSSL_MAX_NAME_SIZE];
    EVP_MD *fetched = NULL;
    const EVP_MD *md;

    if ((btmp = BIO_new(BIO_f_md())) == NULL) {
        ERR_raise(ERR_LIB_PKCS7, ERR_R_BIO_LIB);
        goto err;
    }

    OBJ_obj2txt(name, sizeof(name), alg->algorithm, 0);

    (void)ERR_set_mark();
    fetched = EVP_MD_fetch(ossl_pkcs7_ctx_get0_libctx(ctx), name,
                           ossl_pkcs7_ctx_get0_propq(ctx));
    if (fetched != NULL)
        md = fetched;
    else
        md = EVP_get_digestbyname(name);

    if (md == NULL) {
        (void)ERR_clear_last_mark();
        ERR_raise(ERR_LIB_PKCS7, PKCS7_R_UNKNOWN_DIGEST_TYPE);
        goto err;
    }
    (void)ERR_pop_to_mark();

    if (BIO_set_md(btmp, md) <= 0) {
        ERR_raise(ERR_LIB_PKCS7, ERR_R_BIO_LIB);
        EVP_MD_free(fetched);
        goto err;
    }
    EVP_MD_free(fetched);
    if (*pbio == NULL)
        *pbio = btmp;
    else if (!BIO_push(*pbio, btmp)) {
        ERR_raise(ERR_LIB_PKCS7, ERR_R_BIO_LIB);
        goto err;
    }
    btmp = NULL;

    return 1;

 err:
    BIO_free(btmp);
    return 0;
}