Downgraded qmail-dkim from C++ to C. Made DKIMContext opaque.

Added functions DKIMContextNew and DKIMContextFree.
Changed fields of DKIMContext.

1 files changed, 375 insertions, 0 deletions

diff --git a/src/qmail-dkim.c b/src/qmail-dkim.c
new file mode 100644
index 0000000..8b28ab1
--- /dev/null
+++ b/src/qmail-dkim.c
@@ -0,0 +1,375 @@
+/*****************************************************************************
+*  Copyright 2005 Alt-N Technologies, Ltd.
+*
+*  Licensed under the Apache License, Version 2.0 (the "License");
+*  you may not use this file except in compliance with the License.
+*  You may obtain a copy of the License at
+*
+*      http://www.apache.org/licenses/LICENSE-2.0
+*
+*  This code incorporates intellectual property owned by Yahoo! and licensed
+*  pursuant to the Yahoo! DomainKeys Patent License Agreement.
+*
+*  Unless required by applicable law or agreed to in writing, software
+*  distributed under the License is distributed on an "AS IS" BASIS,
+*  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+*  See the License for the specific language governing permissions and
+*  limitations under the License.
+*
+*  Changes done by ¢feh@fehcom.de obeying the above license
+*
+*  Comment: Awful mixture of C and C++ making use of the worst parts of it.
+*           Style: Partial Hungarian notation (see Torvalds comments)
+*           C++: Obsolete classes, allocators, virtual constructors w/o destructors
+*           C: Stdio interface routines
+*           OpenSSL: Brain demaged EVP_Digest calls with memory leaks.
+*           Network: Sigh, exchanged internal DNS routines by fehQlibs resolver
+*
+*****************************************************************************/
+#include <unistd.h>
+
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+
+#include "dkim.h"
+
+// change these to your selector name, domain name, etc
+#define MYRSASELECTOR "default"
+#define MYECCSELECTOR "eddy"
+#define MYDOMAIN      ""  //"bardenhagen.com"
+#define MYIDENTITY    ""  //"dkimtest@bardenhagen.com"
+
+#define strnicmp strncasecmp
+#define FDLOG    stderr /* writing to another FD requires a method */
+
+static int DKIM_CALL SignThisHeader(const char *szHeader)
+{
+  if (strnicmp(szHeader, "X-", 2) == 0) {
+    return 0;
+  }
+  return 1;
+}
+
+static int DKIM_CALL SelectorCallback(const char *szFQDN, char *szBuffer, int nBufLen)
+{
+  return 0;
+}
+
+static void usage()
+{
+  char version[] = "1.4.0";
+  fprintf(FDLOG, "qmail-dkim %s \n", version);
+  fprintf(
+      FDLOG,
+      "Usage: qmail-dkim [-h|-v|-s] [tags] <msgfile> [<RSAkeyfile> <outfile> <Ed25519keyfile>]\n\n");
+  fprintf(FDLOG, "Options:\n\t-h show this help\n");
+  fprintf(FDLOG, "\t-s sign the message \n");
+  fprintf(FDLOG, "\t-v verify the message\n");
+  fprintf(FDLOG, "\t-V verify the message and write result to output file (Pass/Fail)\n\n");
+  fprintf(FDLOG, "These tags are available:\n");
+  fprintf(
+      FDLOG,
+      "\t-c<canonicalization>   - r=relaxed [DEFAULT], s=simple, t=relaxed/simple, u=simple/relaxed\n");
+  fprintf(
+      FDLOG,
+      "\t-d<sdid>               - Signing Domain Identifier (if not provided it will be determined from "
+      "the sender/from header)\n");
+  fprintf(
+      FDLOG,
+      "\t-i<auid>               - Agent User Identifier, usually the sender's email address "
+      "(optional)\n");
+  fprintf(FDLOG, "\t-l                     - include body length tag (optional)\n");
+  fprintf(FDLOG, "\t-q                     - include query method tag\n");
+  fprintf(FDLOG, "\t-t                     - include a timestamp tag (optional)\n");
+  fprintf(
+      FDLOG,
+      "\t-x<expire_time>        - the expire time in seconds since epoch (optional, DEFAULT = current "
+      "time + 604800)\n");
+  fprintf(FDLOG, "\t-y<selector>           - set RSA selector (DEFAULT: default)\n");
+  fprintf(FDLOG, "\t-Y<selector>           - set Ed25519 selector (DEFAULT: default)\n");
+  fprintf(
+      FDLOG,
+      "\t-z<hash>               - set signature algorithm type (1=rsa-sha1, 2=rsa-sha256, 3=both, "
+      "4=ed25519, 5=hybrid)\n");
+}
+
+int main(int argc, char *argv[])
+{
+  int n;
+  const char *RSAKeyFile = "rsa.pem";
+  const char *ECCKeyFile = "ed25519.pem";
+  const char *MsgFile = "test.msg";
+  const char *OutFile = "signed.msg";
+  int nKeyLen;
+  char RSAPrivKey[4196];  // storge for private key FILE including header and DER envelope
+  char ECCPrivKey[128];
+  char Buffer[1000];
+  int BufLen;
+  char szSignature[8192];
+  time_t t;
+  struct DKIMContext *ctxt = DKIMContextNew();
+  DKIMSignOptions opts = {0};
+
+  opts.nHash = DKIM_HASH_SHA256;  // default
+
+  time(&t);
+
+  opts.nCanon = DKIM_SIGN_RELAXED;
+  opts.nIncludeBodyLengthTag = 0;
+  opts.nIncludeQueryMethod = 0;
+  opts.nIncludeTimeStamp = 0;
+  opts.expireTime = t + 604800;  // expires in 1 week
+  strcpy(opts.szSelector, MYRSASELECTOR);
+  strcpy(opts.szSelectorE, MYECCSELECTOR);
+  strcpy(opts.szDomain, MYDOMAIN);
+  strcpy(opts.szIdentity, MYIDENTITY);
+  opts.pfnHeaderCallback = SignThisHeader;
+  strcpy(opts.szRequiredHeaders, "NonExistant");
+  opts.nIncludeCopiedHeaders = 0;
+
+  int nArgParseState = 0;
+  bool bSign = true;
+  bool bRes = false;
+
+  if (argc < 2) {
+    usage();
+    exit(1);
+  }
+
+  for (n = 1; n < argc; n++) {
+    if (argv[n][0] == '-' && strlen(argv[n]) > 1) {
+      switch (argv[n][1]) {
+        case 'c':  // canonicalization
+          if (argv[n][2] == 'r') {
+            opts.nCanon = DKIM_SIGN_RELAXED;
+          } else if (argv[n][2] == 's') {
+            opts.nCanon = DKIM_SIGN_SIMPLE;
+          } else if (argv[n][2] == 't') {
+            opts.nCanon = DKIM_SIGN_RELAXED_SIMPLE;
+          } else if (argv[n][2] == 'u') {
+            opts.nCanon = DKIM_SIGN_SIMPLE_RELAXED;
+          }
+          break;
+        case 'd': strncpy(opts.szDomain, (const char *)(argv[n] + 2), sizeof(opts.szDomain) - 1); break;
+        case 'l':  // body length tag
+          opts.nIncludeBodyLengthTag = 1;
+          break;
+        case 'h': usage(); return 0;
+        case 'i':  // identity
+          if (argv[n][2] == '-') {
+            opts.szIdentity[0] = '\0';
+          } else {
+            strncpy(opts.szIdentity, argv[n] + 2, sizeof(opts.szIdentity) - 1);
+          }
+          break;
+        case 'q':  // query method tag
+          opts.nIncludeQueryMethod = 1;
+          break;
+        case 's':  // sign with and use potentially Ed25519 private key
+          bSign = true;
+          break;
+        case 't':  // timestamp tag
+          opts.nIncludeTimeStamp = 1;
+          break;
+        case 'v':  // verify
+          bSign = false;
+          break;
+        case 'V':  // verify and write result to OutFile
+          bSign = false;
+          bRes = true;
+          break;
+        case 'x':  // expire time
+          if (argv[n][2] == '-') {
+            opts.expireTime = 0;
+          } else {
+            opts.expireTime = t + atoi(argv[n] + 2);
+          }
+          break;
+        case 'y': strncpy(opts.szSelector, argv[n] + 2, sizeof(opts.szSelector) - 1); break;
+        case 'Y': strncpy(opts.szSelectorE, argv[n] + 2, sizeof(opts.szSelectorE) - 1); break;
+        case 'z':  // sign w/ sha1, sha256, both, ed25519, hybrid
+          opts.nHash = atoi(&argv[n][2]);
+      }
+    } else {
+      switch (nArgParseState) {
+        case 0: MsgFile = argv[n]; break;
+        case 1: RSAKeyFile = argv[n]; break;
+        case 2: OutFile = argv[n]; break;
+        case 3: ECCKeyFile = argv[n]; break;
+      }
+      nArgParseState++;
+    }
+  }
+
+  /** Go for DKIM signing ... **/
+
+  if (bSign) {
+    if (opts.nHash != 4) {
+      FILE *RSAPrivKeyFP = fopen(RSAKeyFile, "r");
+      if (RSAPrivKeyFP == NULL) {
+#ifdef SHOWLOG
+        fprintf(FDLOG, " qmail-dkim: can't open private key file (%s) \n", RSAKeyFile);
+#endif
+        exit(1);
+      }
+      nKeyLen = fread(
+          RSAPrivKey,
+          1,
+          sizeof(RSAPrivKey),
+          RSAPrivKeyFP);  // we read sizeof(RSAPrivKey) members with size of 1 byte each; sigh
+#ifdef SHOWLOG
+      fprintf(FDLOG, " qmail-dkim: private key file (%s) - length %i \n", RSAKeyFile, nKeyLen);
+#endif
+      if (nKeyLen >= sizeof(RSAPrivKey)) { /* (TC9) on return, we get the number of members read!  */
+#ifdef SHOWLOG
+        fprintf(
+            FDLOG,
+            " qmail-dkim: private key buffer isn't big enough for private key length %i \n",
+            nKeyLen);
+#endif
+        exit(1);
+      }
+      RSAPrivKey[nKeyLen] = '\0';
+      fclose(RSAPrivKeyFP);
+    }
+
+    /** Ed25519 signing **/
+
+    if (opts.nHash == 4 || opts.nHash == 5) {
+      FILE *ECCPrivKeyFP = fopen(ECCKeyFile, "r");
+      if (ECCPrivKeyFP == NULL) {
+#ifdef SHOWLOG
+        fprintf(FDLOG, " qmail-dkim: can't open Ed25519 private key file (%s) \n", ECCKeyFile);
+#endif
+        exit(1);
+      }
+      nKeyLen = fread(ECCPrivKey, 1, sizeof(ECCPrivKey), ECCPrivKeyFP);
+#ifdef SHOWLOG
+      fprintf(FDLOG, " qmail-dkim: Ed25519 private key file (%s) - length %i \n", ECCKeyFile, nKeyLen);
+#endif
+      if (nKeyLen >= sizeof(ECCPrivKey)) {
+#ifdef SHOWLOG
+        fprintf(
+            FDLOG,
+            " qmail-dkim: ECC private key buffer isn't big enough for ECC private key length %i \n",
+            nKeyLen);
+#endif
+        exit(1);
+      }
+      ECCPrivKey[nKeyLen] = '\0';
+      fclose(ECCPrivKeyFP);
+    }
+
+    /** Input message for signing **/
+
+    FILE *MsgFP = fopen(MsgFile, "rb");
+    if (MsgFP == NULL) {
+#ifdef SHOWLOG
+      fprintf(FDLOG, " qmail-dkim: can't open msg file (%s) \n", MsgFile);
+#endif
+      exit(1);
+    }
+
+    n = DKIMSignInit(ctxt, &opts);
+
+    while (1) {
+      BufLen = fread(Buffer, 1, sizeof(Buffer), MsgFP);
+      if (BufLen > 0) {
+        DKIMSignProcess(ctxt, Buffer, BufLen);
+      } else {
+        break;
+      }
+    }
+    fclose(MsgFP);
+
+    char *pSig = NULL;
+
+    /** Do the actual signing **/
+
+    n = DKIMSignGetSig2(ctxt, RSAPrivKey, ECCPrivKey, &pSig);
+
+    strcpy(szSignature, pSig);
+
+    DKIMSignFree(ctxt);
+
+    FILE *in = fopen(MsgFile, "rb");
+    FILE *out = fopen(OutFile, "wb+");
+
+#ifdef SHOWLOG
+    fprintf(FDLOG, " outfile written %s \n", OutFile);
+#endif
+
+    fwrite(szSignature, 1, strlen(szSignature), out);
+    fwrite("\r\n", 1, 2, out);
+
+    while (1) {
+      BufLen = fread(Buffer, 1, sizeof(Buffer), in);
+      if (BufLen > 0) {
+        fwrite(Buffer, 1, BufLen, out);
+      } else {
+        break;
+      }
+    }
+    fclose(in);
+
+  }
+
+  /** Now go for verification **/
+
+  else
+  {
+    FILE *in = fopen(MsgFile, "rb");
+    if (in == NULL) {
+      //#ifdef SHOWLOG
+      fprintf(FDLOG, " qmail-dkim: can't open input file\n");
+      //#endif
+      return 0;  // bad option --  no CTX set up yet
+    }
+
+    DKIMVerifyOptions vopts = {0};
+    vopts.pfnSelectorCallback = NULL;  //SelectorCallback;
+
+    n = DKIMVerifyInit(ctxt, &vopts);
+
+    while (1) {
+      BufLen = fread(Buffer, 1, sizeof(Buffer), in);
+      if (BufLen > 0) {
+        DKIMVerifyProcess(ctxt, Buffer, BufLen);
+      } else {
+        break;
+      }
+    }
+
+    n = DKIMVerifyResults(ctxt);
+
+    int nSigCount = 0;
+    DKIMVerifyDetails *pDetails;
+    char szPolicy[512];
+
+    n = DKIMVerifyGetDetails(ctxt, &nSigCount, &pDetails, szPolicy);
+
+    for (int i = 0; i < nSigCount; i++) {
+      const char s[] = "pass";
+      const char f[] = "fail";
+      const char *error = DKIM_ErrorResult(pDetails[i].nResult);
+      if (!bRes) fprintf(FDLOG, " Signature #%d: ", i + 1);
+      if (pDetails[i].nResult >= 0) {
+        if (bRes) {
+          _DKIM_ReportResult(OutFile, s, 0);
+        } else
+          printf(" Pass\n");
+      } else {  // fail
+        if (bRes) {
+          _DKIM_ReportResult(OutFile, f, error);
+        } else
+          printf(" Fail %s \n", error);
+      }
+    }
+    DKIMVerifyFree(ctxt);
+  }
+  DKIMContextFree(ctxt);
+  return 0;
+}