add example to generate smime

Author: JacobBarthelmeh

pkcs7/smime.c

@@ -0,0 +1,195 @@
+/* smime.c
+ *
+ * Copyright (C) 2006-2020 wolfSSL Inc.
+ *
+ * This file is part of wolfSSL. (formerly known as CyaSSL)
+ *
+ * wolfSSL is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * wolfSSL is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
+ */
+
+#include <wolfssl/options.h>
+#include <wolfssl/wolfcrypt/settings.h>
+#include <wolfssl/ssl.h>
+#include <wolfssl/wolfcrypt/pkcs7.h>
+#include <wolfssl/wolfcrypt/error-crypt.h>
+#include <wolfssl/wolfcrypt/logging.h>
+
+
+#ifdef HAVE_SMIME
+
+/* Create an SMIME bundle, uses steps similar to PKCS7_sign() but this is
+ * with native PKCS7 API allowing for control over the devID set */
+static int Create(byte* smime, int* smimeSz, byte* key, int keySz,
+    byte* signer, int signerSz, byte* content, int contentSz, int detatched)
+{
+    WOLFSSL_BIO *out, *in;
+    WOLFSSL_PKCS7* pkcs7Compat;
+    PKCS7* pkcs7;
+    int ret = 0;
+
+    out = wolfSSL_BIO_new(wolfSSL_BIO_s_mem());
+    in  = wolfSSL_BIO_new(wolfSSL_BIO_s_mem());
+    if (out == NULL || in == NULL) {
+        printf("Failed to create bio's\n");
+        return -1;
+    }
+
+    pkcs7Compat = (WOLFSSL_PKCS7*)wolfSSL_PKCS7_new();
+    if (pkcs7Compat == NULL) {
+        ret = MEMORY_E;
+    }
+    else {
+        pkcs7 = &(pkcs7Compat->pkcs7);
+
+        /* can change devID here and set signer */
+        ret = wc_PKCS7_Init(pkcs7, NULL, INVALID_DEVID);
+    }
+
+    if (ret == 0) {
+        ret = wc_PKCS7_InitWithCert(pkcs7, signer, signerSz);
+    }
+
+    if (ret == 0) {
+        /* set signer private key, data types, defaults */
+        pkcs7->privateKey   = key;
+        pkcs7->privateKeySz = keySz;
+        pkcs7->contentOID   = DATA;  /* inner content default is DATA */
+        pkcs7->hashOID      = SHA256h;  /* default to SHA-256 hash type */
+
+        /* type of SMIME */
+        pkcs7Compat->type = SIGNED_DATA;
+
+        /* add additional chain certs if provided */
+        /* wc_PKCS7_AddCertificate(pkcs7, additionalCert, additionalCertSz); */
+
+        /* set detached flag */
+        if (detatched & PKCS7_DETACHED) {
+            ret = wc_PKCS7_SetDetached(pkcs7, 1);
+        }
+
+        /* setup content to sign */
+        if (ret == 0) {
+            if (wolfSSL_BIO_write(in, content, contentSz) != contentSz) {
+                ret = -1;
+            }
+        }
+
+        if (ret == 0) {
+            if (wolfSSL_SMIME_write_PKCS7(out, (PKCS7*)pkcs7Compat, in,
+                    detatched) != WOLFSSL_SUCCESS) {
+                printf("SMIME write failed!\n");
+                ret = -1;
+            }
+        }
+    }
+
+    if (ret == 0) {
+        ret = wolfSSL_BIO_read(out, smime, *smimeSz);
+        if (ret > 0) {
+            *smimeSz = ret;
+            ret = 0;
+        }
+        else {
+            ret = -1;
+        }
+    }
+
+    wolfSSL_BIO_free(in);
+    wolfSSL_BIO_free(out);
+    wolfSSL_PKCS7_free((PKCS7*)pkcs7Compat);
+    return ret;
+}
+
+
+/* read private key and signer certificate in DER format */
+static int ReadKeyAndCert(char* keyFile, char* certFile, byte* key, int* keySz,
+    byte* cert, int* certSz)
+{
+    int ret;
+    XFILE f;
+
+    f = XFOPEN(keyFile, "rb");
+    if (f == NULL) {
+        printf("Error opening file %s\n", keyFile);
+        return -1;
+    }
+    else {
+        ret = XFREAD(key, 1, *keySz, f);
+        if (ret >= 0) {
+            *keySz = ret;
+            ret = 0;
+            XFCLOSE(f);
+        }
+    }
+
+    f = XFOPEN(certFile, "rb");
+    if (f == NULL) {
+        printf("Error opening file %s\n", certFile);
+        return -1;
+    }
+    else {
+        ret = XFREAD(cert, 1, *certSz, f);
+        if (ret >= 0) {
+            *certSz = ret;
+            ret = 0;
+            XFCLOSE(f);
+        }
+    }
+
+    return ret;
+}
+
+int main(int argc, char** argv)
+{
+    byte key[2048];
+    int keySz = 2048;
+
+    byte cert[2048];
+    int certSz = 2048;
+
+    byte smime[3072];
+    int smimeSz = 3072;
+
+    byte content[] = "Test content to sign";
+    int contentSz = sizeof(content);
+
+    int ret;
+    int i;
+
+    if (argc != 3) {
+        printf("Use ./smime <der key file> <der cert file>\n");
+        return -1;
+    }
+
+    ret = ReadKeyAndCert(argv[1], argv[2], key, &keySz, cert, &certSz);
+    if (ret == 0)
+        ret = Create(smime, &smimeSz, key, keySz, cert, certSz,
+                content, contentSz, 0);
+    if (ret == 0) {
+        printf("Generated SMIME : ");
+        for (i = 0; i < smimeSz; i++)
+            printf("%02X", smime[i]);
+        printf("\n");
+    }
+
+    return ret;
+}
+#else
+int main()
+{
+    printf("wolfSSL was compiled with out HAVE_SMIME support\n");
+    return 0;
+}
+#endif