add PKCS#7/CMS example for CompressedData content type

pkcs7/Makefile

@@ -42,4 +42,5 @@ clean:
         envelopedDataKTRI.der envelopedDataKARI.der \
         envelopedDataPWRI.der envelopedDataORI.der \
         authEnvelopedDataKARI.der authEnvelopedDataKTRI.der \
-        authEnvelopedDataORI.der authEnvelopedDataPWRI.der encryptedData.der
+        authEnvelopedDataORI.der authEnvelopedDataPWRI.der encryptedData.der \
+        compressedData.der

pkcs7/README.md

@@ -126,6 +126,25 @@ of the bundle will be printed out to the terminal window.
 Successfully encoded EncryptedData bundle (encryptedData.der)
 ```
 
+### CompressedData
+
+Example file: `compressedData.c`
+Generated bundle file: `compressedData.der`
+
+This example creates a PKCS#7/CMS CompressedData bundle. After creating the
+bundle, it decodes, uncompresses, and verifies the bundle.
+
+The generated CompressedData bundle is written out to a file for analysis and
+additional debugging.
+
+If wolfSSL has been configured and compiled with debug support, the bytes
+of the bundle will be printed out to the terminal window.
+
+```
+./compressedData
+Successfully encoded CompressedData bundle (compressedData.der)
+```
+
 ### EnvelopedData using KTRI RecipientInfo
 
 Example file: `envelopedData-ktri.c`

pkcs7/compressedData.c

@@ -0,0 +1,155 @@
+/* compressedData.c
+ *
+ * Copyright (C) 2006-2018 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/wolfcrypt/pkcs7.h>
+#include <wolfssl/wolfcrypt/error-crypt.h>
+#include <wolfssl/wolfcrypt/logging.h>
+
+#define compressedFile "compressedData.der"
+
+static const byte data[] = { /* Hello World */
+    0x48,0x65,0x6c,0x6c,0x6f,0x20,0x57,0x6f,
+    0x72,0x6c,0x64
+};
+
+static int write_file_buffer(const char* fileName, byte* in, word32 inSz)
+{
+    int ret;
+    FILE* file;
+
+    file = fopen(fileName, "wb");
+    if (file == NULL) {
+        printf("ERROR: opening file for writing: %s\n", fileName);
+        return -1;
+    }
+
+    ret = (int)fwrite(in, 1, inSz, file);
+    if (ret == 0) {
+        printf("ERROR: writing buffer to output file\n");
+        return -1;
+    }
+    fclose(file);
+
+    return 0;
+}
+
+static int compressedData_encode(byte* out, word32 outSz)
+{
+    int ret;
+    PKCS7* pkcs7;
+
+    pkcs7 = wc_PKCS7_New(NULL, 0);
+    if (pkcs7 == NULL)
+        return -1;
+
+    pkcs7->content              = (byte*)data;
+    pkcs7->contentSz            = sizeof(data);
+    pkcs7->contentOID           = DATA;
+
+    /* encode compressedData, returns size */
+    ret = wc_PKCS7_EncodeCompressedData(pkcs7, out, outSz);
+    if (ret <= 0) {
+        wc_PKCS7_Free(pkcs7);
+        return -1;
+    } else {
+        printf("Successfully encoded CompressedData bundle (%s)\n",
+               compressedFile);
+
+        if (write_file_buffer(compressedFile, out, ret) != 0) {
+            printf("ERROR: error writing encoded to output file\n");
+            return -1;
+        }
+    }
+
+    wc_PKCS7_Free(pkcs7);
+
+    return ret;
+}
+
+static int compressedData_decode(byte* in, word32 inSz, byte* out, word32 outSz)
+{
+    int ret;
+    PKCS7* pkcs7;
+
+    pkcs7 = wc_PKCS7_New(NULL, 0);
+    if (pkcs7 == NULL)
+        return -1;
+
+    /* decode compressedData, returns size */
+    ret = wc_PKCS7_DecodeCompressedData(pkcs7, in, inSz, out, outSz);
+    if (ret <= 0) {
+        wc_PKCS7_Free(pkcs7);
+        return -1;
+    }
+
+    wc_PKCS7_Free(pkcs7);
+
+    return ret;
+}
+
+#ifdef HAVE_PKCS7
+
+int main(int argc, char** argv)
+{
+    int compressedSz, decodedSz;
+    byte compressed[1024];
+    byte decoded[1024];
+
+#ifdef DEBUG_WOLFSSL
+    wolfSSL_Debugging_ON();
+#endif
+
+    compressedSz = compressedData_encode(compressed, sizeof(compressed));
+    if (compressedSz < 0)
+        return -1;
+
+#ifdef DEBUG_WOLFSSL
+    printf("CompressedData DER (%d bytes):\n", compressedSz);
+    WOLFSSL_BUFFER(compressed, compressedSz);
+#endif
+
+    decodedSz = compressedData_decode(compressed, compressedSz,
+                                      decoded, sizeof(decoded));
+    if (decodedSz < 0)
+        return -1;
+
+#ifdef DEBUG_WOLFSSL
+    printf("Decoded Data DER (%d bytes):\n", decodedSz);
+    WOLFSSL_BUFFER(decoded, decodedSz);
+#endif
+
+    (void)argc;
+    (void)argv;
+
+    return 0;
+}
+
+#else
+
+int main(int argc, char** argv)
+{
+    printf("Must build wolfSSL using ./configure --enable-pkcs7\n");
+    return 0;
+}
+
+#endif
+