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Diffstat (limited to 'src/qmail-dkim.c')
| -rw-r--r-- | src/qmail-dkim.c | 375 |
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; +} |