bool pem_to_der(const char *pem_file, const char *der_file) {
bool ret = false;
FILE *pf = NULL, *df = NULL;
bool writing = false;
pf = fopen(pem_file, "r");
if (pf == NULL) goto clean;
remove(der_file);
fs_slfs_set_new_file_size(der_file + MG_SSL_IF_SIMPLELINK_SLFS_PREFIX_LEN,
2048);
df = fopen(der_file, "w");
if (df == NULL) goto clean;
while (1) {
char pem_buf[70];
char der_buf[48];
if (!fgets(pem_buf, sizeof(pem_buf), pf)) break;
if (writing) {
if (strstr(pem_buf, "-----END ") != NULL) {
ret = true;
break;
}
int l = 0;
while (!isspace((unsigned int) pem_buf[l])) l++;
int der_len = 0;
cs_base64_decode((const unsigned char *) pem_buf, sizeof(pem_buf),
der_buf, &der_len);
if (der_len <= 0) break;
if (fwrite(der_buf, 1, der_len, df) != der_len) break;
} else if (strstr(pem_buf, "-----BEGIN ") != NULL) {
writing = true;
}
}
clean:
if (pf != NULL) fclose(pf);
if (df != NULL) {
fclose(df);
if (!ret) remove(der_file);
}
return ret;
}
int ns_base64_decode(const unsigned char *s, int len, char *dst) {
return cs_base64_decode(s, len, dst);
}