px5g-wolfssl: add package

This package creates certificates and private keys, just like `px5g`
does. Hower it uses WolfSSL rather than MbedTLS.

Signed-off-by: Paul Spooren <mail@aparcar.org>

diff --git a/package/utils/px5g-wolfssl/Makefile b/package/utils/px5g-wolfssl/Makefile
new file mode 100644 (file)
index 0000000..a9f6a09
--- /dev/null
+++ b/package/utils/px5g-wolfssl/Makefile
@@ -0,0 +1,54 @@
+#
+# Copyright (C) 2020 Paul Spooren <mail@aparcar.org>
+#
+# This is free software, licensed under the GNU General Public License v2.
+# See /LICENSE for more information.
+#
+
+include $(TOPDIR)/rules.mk
+
+PKG_NAME:=px5g-wolfssl
+PKG_RELEASE:=1
+PKG_LICENSE:=GPL-2.0-or-later
+
+PKG_USE_MIPS16:=0
+
+PKG_MAINTAINER:=Paul Spooren <mail@aparcar.org>
+
+include $(INCLUDE_DIR)/package.mk
+
+define Package/px5g-wolfssl
+  SECTION:=utils
+  CATEGORY:=Utilities
+  SUBMENU:=Encryption
+  TITLE:=X.509 certificate generator (using wolfssl)
+  DEPENDS:=+libwolfssl
+  PROVIDES:=px5g
+  VARIANT:=wolfssl
+endef
+
+define Package/px5g-wolfssl/description
+ Px5g is a tiny X.509 certificate generator.
+ It suitable to create key files and certificates in DER
+ and PEM format for use with stunnel, uhttpd and others.
+endef
+
+define Build/Prepare
+       mkdir -p $(PKG_BUILD_DIR)
+endef
+
+TARGET_LDFLAGS += -lwolfssl
+
+
+TARGET_CFLAGS += -Wl,--gc-sections
+
+define Build/Compile
+       $(TARGET_CC) $(TARGET_CPPFLAGS) $(TARGET_CFLAGS) -o $(PKG_BUILD_DIR)/px5g px5g-wolfssl.c $(TARGET_LDFLAGS)
+endef
+
+define Package/px5g-wolfssl/install
+       $(INSTALL_DIR) $(1)/usr/sbin
+       $(INSTALL_BIN) $(PKG_BUILD_DIR)/px5g $(1)/usr/sbin/px5g
+endef
+
+$(eval $(call BuildPackage,px5g-wolfssl))

diff --git a/package/utils/px5g-wolfssl/px5g-wolfssl.c b/package/utils/px5g-wolfssl/px5g-wolfssl.c
new file mode 100644 (file)
index 0000000..54ae9bb
--- /dev/null
+++ b/package/utils/px5g-wolfssl/px5g-wolfssl.c
@@ -0,0 +1,350 @@
+#define _GNU_SOURCE
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+#include <wolfssl/options.h>
+#include <wolfssl/wolfcrypt/asn.h>
+#include <wolfssl/wolfcrypt/asn_public.h>
+#include <wolfssl/wolfcrypt/ecc.h>
+#include <wolfssl/wolfcrypt/error-crypt.h>
+#include <wolfssl/wolfcrypt/rsa.h>
+#include <wolfssl/wolfcrypt/settings.h>
+
+#define HEAP_HINT NULL
+#define FOURK_SZ 4096
+#define WOLFSSL_MIN_RSA_BITS 2048
+
+enum {
+  EC_KEY_TYPE = 0,
+  RSA_KEY_TYPE = 1,
+};
+
+int write_file(byte *buf, int bufSz, char *path) {
+  int ret;
+  FILE *file;
+  if (path) {
+    file = fopen(path, "wb");
+    if (file == NULL) {
+      perror("Error opening file");
+      exit(1);
+    }
+  } else {
+    file = stdout;
+  }
+  ret = (int)fwrite(buf, 1, bufSz, file);
+  if (path) {
+    fclose(file);
+  }
+  if (ret > 0) {
+    /* ret > 0 indicates a successful file write, set to zero for return */
+    ret = 0;
+  }
+  return ret;
+}
+
+int write_key(ecc_key *ecKey, RsaKey *rsaKey, int type, int keySz, char *fName,
+              bool write_pem) {
+  int ret;
+  byte der[FOURK_SZ] = {};
+  byte pem[FOURK_SZ] = {};
+  int derSz, pemSz;
+  if (type == EC_KEY_TYPE) {
+    ret = wc_EccKeyToDer(ecKey, der, sizeof(der));
+  } else {
+    ret = wc_RsaKeyToDer(rsaKey, der, sizeof(der));
+  }
+  if (ret <= 0) {
+    fprintf(stderr, "Key To DER failed: %d\n", ret);
+  }
+  derSz = ret;
+
+  if (write_pem) {
+    if (type == EC_KEY_TYPE) {
+      ret = wc_DerToPem(der, derSz, pem, sizeof(pem), ECC_PRIVATEKEY_TYPE);
+    } else {
+      ret = wc_DerToPem(der, derSz, pem, sizeof(pem), PRIVATEKEY_TYPE);
+    }
+    if (ret <= 0) {
+      fprintf(stderr, "DER to PEM failed: %d\n", ret);
+    }
+    pemSz = ret;
+    ret = write_file(pem, pemSz, fName);
+  } else {
+    ret = write_file(der, derSz, fName);
+  }
+  return ret;
+}
+
+int gen_key(WC_RNG *rng, ecc_key *ecKey, RsaKey *rsaKey, int type, int keySz,
+            long exp, int curve) {
+  int ret;
+
+  if (type == EC_KEY_TYPE) {
+    ret = wc_ecc_init(ecKey);
+    (void)rsaKey;
+  } else {
+    ret = wc_InitRsaKey(rsaKey, NULL);
+    (void)ecKey;
+  }
+  if (ret != 0) {
+    fprintf(stderr, "Key initialization failed: %d\n", ret);
+    return ret;
+  }
+
+  if (type == EC_KEY_TYPE) {
+    fprintf(stderr, "Generating EC private key\n");
+    ret = wc_ecc_make_key_ex(rng, 32, ecKey, curve);
+  } else {
+    fprintf(stderr, "Generating RSA private key, %i bit long modulus\n", keySz);
+    ret = wc_MakeRsaKey(rsaKey, keySz, WC_RSA_EXPONENT, rng);
+  }
+  if (ret != 0) {
+    fprintf(stderr, "Key generation failed: %d\n", ret);
+  }
+  return ret;
+}
+
+int selfsigned(WC_RNG *rng, char **arg) {
+  ecc_key ecKey;
+  RsaKey rsaKey;
+  int ret;
+  char *subject = "";
+  int keySz = WOLFSSL_MIN_RSA_BITS;
+  int type = EC_KEY_TYPE;
+  int exp = WC_RSA_EXPONENT;
+  int curve = ECC_SECP256R1;
+  unsigned int days = 3653; // 10 years
+  char *keypath = NULL, *certpath = NULL;
+  char fstr[20], tstr[20];
+  bool pem = true;
+  Cert newCert;
+#ifdef __USE_TIME_BITS64
+  time_t to, from = time(NULL);
+#else
+  unsigned long to, from = time(NULL);
+#endif
+  byte derBuf[FOURK_SZ] = {};
+  byte pemBuf[FOURK_SZ] = {};
+  int pemSz = -1;
+  int derSz = -1;
+  char *key, *val, *tmp;
+
+  ret = wc_InitCert(&newCert);
+  if (ret != 0) {
+    fprintf(stderr, "Init Cert failed: %d\n", ret);
+    return ret;
+  }
+  newCert.isCA = 0;
+
+  while (*arg && **arg == '-') {
+    if (!strncmp(*arg, "-der", 4)) {
+      pem = false;
+    } else if (!strncmp(*arg, "-newkey", 6) && arg[1]) {
+      if (!strncmp(arg[1], "rsa:", 4)) {
+        type = RSA_KEY_TYPE;
+        keySz = (unsigned int)atoi(arg[1] + 4);
+      } else if (!strncmp(arg[1], "ec", 2)) {
+        type = EC_KEY_TYPE;
+      } else {
+        fprintf(stderr, "error: invalid algorithm\n");
+        return 1;
+      }
+      arg++;
+    } else if (!strncmp(*arg, "-days", 5) && arg[1]) {
+      days = (unsigned int)atoi(arg[1]);
+      arg++;
+    } else if (!strncmp(*arg, "-pkeyopt", 8) && arg[1]) {
+      if (strncmp(arg[1], "ec_paramgen_curve:", 18)) {
+        fprintf(stderr, "error: invalid pkey option: %s\n", arg[1]);
+        return 1;
+      }
+      if (!strncmp(arg[1] + 18, "P-256:", 5)) {
+        curve = ECC_SECP256R1;
+      } else if (!strncmp(arg[1] + 18, "P-384:", 5)) {
+        curve = ECC_SECP384R1;
+      } else if (!strncmp(arg[1] + 18, "P-521:", 5)) {
+        curve = ECC_SECP521R1;
+      } else {
+        fprintf(stderr, "error: invalid curve name: %s\n", arg[1] + 18);
+        return 1;
+      }
+      arg++;
+    } else if (!strncmp(*arg, "-keyout", 7) && arg[1]) {
+      keypath = arg[1];
+      arg++;
+    } else if (!strncmp(*arg, "-out", 4) && arg[1]) {
+      certpath = arg[1];
+      arg++;
+    } else if (!strcmp(*arg, "-subj") && arg[1]) {
+      subject = strdupa(arg[1]);
+      key = arg[1];
+      do {
+        tmp = strchr(key, '/');
+        if (tmp)
+          *tmp = '\0';
+
+        val = strchr(key, '=');
+        if (val) {
+          *val = '\0';
+          ++val;
+
+          if (!strcmp(key, "C"))
+            strncpy(newCert.subject.country, val, CTC_NAME_SIZE);
+          else if (!strcmp(key, "ST"))
+            strncpy(newCert.subject.state, val, CTC_NAME_SIZE);
+          else if (!strcmp(key, "L"))
+            strncpy(newCert.subject.locality, val, CTC_NAME_SIZE);
+          else if (!strcmp(key, "O"))
+            strncpy(newCert.subject.org, val, CTC_NAME_SIZE);
+          else if (!strcmp(key, "OU"))
+            strncpy(newCert.subject.unit, val, CTC_NAME_SIZE);
+          else if (!strcmp(key, "CN"))
+            strncpy(newCert.subject.commonName, val, CTC_NAME_SIZE);
+          else if (!strcmp(key, "EMAIL"))
+            strncpy(newCert.subject.email, val, CTC_NAME_SIZE);
+          else
+            printf("warning: unknown attribute %s=%s\n", key, val);
+        }
+      } while (tmp && (key = ++tmp));
+    }
+    arg++;
+  }
+  newCert.daysValid = days;
+
+  gen_key(rng, &ecKey, &rsaKey, type, keySz, exp, curve);
+  write_key(&ecKey, &rsaKey, type, keySz, keypath, pem);
+
+  from = (from < 1000000000) ? 1000000000 : from;
+  strftime(fstr, sizeof(fstr), "%Y%m%d%H%M%S", gmtime(&from));
+  to = from + 60 * 60 * 24 * days;
+  if (to < from)
+    to = INT_MAX;
+  strftime(tstr, sizeof(tstr), "%Y%m%d%H%M%S", gmtime(&to));
+
+  fprintf(stderr,
+          "Generating selfsigned certificate with subject '%s'"
+          " and validity %s-%s\n",
+          subject, fstr, tstr);
+
+  if (type == EC_KEY_TYPE) {
+    ret = wc_MakeCert(&newCert, derBuf, sizeof(derBuf), NULL, &ecKey, rng);
+  } else {
+    ret = wc_MakeCert(&newCert, derBuf, sizeof(derBuf), &rsaKey, NULL, rng);
+  }
+  if (ret <= 0) {
+    fprintf(stderr, "Make Cert failed: %d\n", ret);
+    return ret;
+  }
+
+  if (type == EC_KEY_TYPE) {
+    newCert.sigType = CTC_SHA256wECDSA;
+    ret = wc_SignCert(newCert.bodySz, newCert.sigType, derBuf, sizeof(derBuf),
+                      NULL, &ecKey, rng);
+  } else {
+    newCert.sigType = CTC_SHA256wRSA;
+    ret = wc_SignCert(newCert.bodySz, newCert.sigType, derBuf, sizeof(derBuf),
+                      &rsaKey, NULL, rng);
+  }
+  if (ret <= 0) {
+    fprintf(stderr, "Sign Cert failed: %d\n", ret);
+    return ret;
+  }
+  derSz = ret;
+
+  ret = wc_DerToPem(derBuf, derSz, pemBuf, sizeof(pemBuf), CERT_TYPE);
+  if (ret <= 0) {
+    fprintf(stderr, "DER to PEM failed: %d\n", ret);
+    return ret;
+  }
+  pemSz = ret;
+
+  ret = write_file(pemBuf, pemSz, certpath);
+  if (ret != 0) {
+    fprintf(stderr, "Write Cert failed: %d\n", ret);
+    return ret;
+  }
+
+  if (type == EC_KEY_TYPE) {
+    wc_ecc_free(&ecKey);
+  } else {
+    wc_FreeRsaKey(&rsaKey);
+  }
+  return 0;
+}
+
+int dokey(WC_RNG *rng, int type, char **arg) {
+  ecc_key ecKey;
+  RsaKey rsaKey;
+  int ret;
+  int curve = ECC_SECP256R1;
+  int keySz = WOLFSSL_MIN_RSA_BITS;
+  int exp = WC_RSA_EXPONENT;
+  char *path = NULL;
+  bool pem = true;
+
+  while (*arg && **arg == '-') {
+    if (!strncmp(*arg, "-out", 4) && arg[1]) {
+      path = arg[1];
+      arg++;
+    } else if (!strncmp(*arg, "-3", 2)) {
+      exp = 3;
+    } else if (!strncmp(*arg, "-der", 4)) {
+      pem = false;
+    }
+    arg++;
+  }
+
+  if (*arg && type == RSA_KEY_TYPE) {
+    keySz = (unsigned int)atoi(*arg);
+  } else if (*arg) {
+    if (!strncmp(*arg, "P-256", 5)) {
+      curve = ECC_SECP256R1;
+    } else if (!strncmp(*arg, "P-384", 5)) {
+      curve = ECC_SECP384R1;
+    } else if (!strncmp(*arg, "P-521", 5)) {
+      curve = ECC_SECP521R1;
+    } else {
+      fprintf(stderr, "Invalid Curve Name: %s\n", *arg);
+      return 1;
+    }
+  }
+
+  ret = gen_key(rng, &ecKey, &rsaKey, type, keySz, exp, curve);
+  if (ret != 0)
+    return ret;
+
+  ret = write_key(&ecKey, &rsaKey, type, keySz, path, pem);
+
+  if (type == EC_KEY_TYPE) {
+    wc_ecc_free(&ecKey);
+  } else {
+    wc_FreeRsaKey(&rsaKey);
+  }
+  return ret;
+}
+
+int main(int argc, char *argv[]) {
+  int ret;
+  WC_RNG rng;
+  ret = wc_InitRng(&rng);
+  if (ret != 0) {
+    fprintf(stderr, "Init Rng failed: %d\n", ret);
+    return ret;
+  }
+
+  if (argv[1]) {
+    if (!strncmp(argv[1], "eckey", 5))
+      return dokey(&rng, EC_KEY_TYPE, argv + 2);
+
+    if (!strncmp(argv[1], "rsakey", 5))
+      return dokey(&rng, RSA_KEY_TYPE, argv + 2);
+
+    if (!strncmp(argv[1], "selfsigned", 10))
+      return selfsigned(&rng, argv + 2);
+  }
+
+  fprintf(stderr, "PX5G X.509 Certificate Generator Utilit using WolfSSL\n\n");
+  fprintf(stderr, "Usage: [eckey|rsakey|selfsigned]\n");
+  return 1;
+}