/* Provenance: openssl/openssl X509_issuer_and_serial_hash (fixed).
 * repo: openssl/openssl
 * commit: 122a19ab48091c657f7cb1fb3af9fc07bd557bbf
 * parent: c8c6e7438c03b2fc24e7ead460feeaef04911fb4
 * commit_url: https://github.com/openssl/openssl/commit/122a19ab48091c657f7cb1fb3af9fc07bd557bbf
 * cve: CVE-2021-23841
 * license: OpenSSL License
 * function: X509_issuer_and_serial_hash
 * relpath: crypto/x509/x509_cmp.c
 */

unsigned long X509_issuer_and_serial_hash(X509 *a)
{
    unsigned long ret = 0;
    EVP_MD_CTX *ctx = EVP_MD_CTX_new();
    unsigned char md[16];
    char *f;

    if (ctx == NULL)
        goto err;
    f = X509_NAME_oneline(a->cert_info.issuer, NULL, 0);
    if (f == NULL)
        goto err;
    if (!EVP_DigestInit_ex(ctx, EVP_md5(), NULL))
        goto err;
    if (!EVP_DigestUpdate(ctx, (unsigned char *)f, strlen(f)))
        goto err;
    OPENSSL_free(f);
    if (!EVP_DigestUpdate
        (ctx, (unsigned char *)a->cert_info.serialNumber.data,
         (unsigned long)a->cert_info.serialNumber.length))
        goto err;
    if (!EVP_DigestFinal_ex(ctx, &(md[0]), NULL))
        goto err;
    ret = (((unsigned long)md[0]) | ((unsigned long)md[1] << 8L) |
           ((unsigned long)md[2] << 16L) | ((unsigned long)md[3] << 24L)
        ) & 0xffffffffL;
 err:
    EVP_MD_CTX_free(ctx);
    return ret;
}