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-rw-r--r--tools/rscryutil.c552
1 files changed, 552 insertions, 0 deletions
diff --git a/tools/rscryutil.c b/tools/rscryutil.c
new file mode 100644
index 0000000..6ff0724
--- /dev/null
+++ b/tools/rscryutil.c
@@ -0,0 +1,552 @@
+/* This is a tool for processing rsyslog encrypted log files.
+ *
+ * Copyright 2013-2019 Adiscon GmbH
+ *
+ * This file is part of rsyslog.
+ *
+ * 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
+ * -or-
+ * see COPYING.ASL20 in the source distribution
+ *
+ * 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 exprs or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+#include <stdlib.h>
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <getopt.h>
+#include <fcntl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <gcrypt.h>
+
+#include "rsyslog.h"
+#include "libgcry.h"
+
+
+static enum { MD_DECRYPT, MD_WRITE_KEYFILE
+} mode = MD_DECRYPT;
+static int verbose = 0;
+static gcry_cipher_hd_t gcry_chd;
+static size_t blkLength;
+
+static char *keyfile = NULL;
+static char *keyprog = NULL;
+static int randomKeyLen = -1;
+static char *cry_key = NULL;
+static unsigned cry_keylen = 0;
+static int cry_algo = GCRY_CIPHER_AES128;
+static int cry_mode = GCRY_CIPHER_MODE_CBC;
+static int optionForce = 0;
+
+/* We use some common code which expects rsyslog runtime to be
+ * present, most importantly for debug output. As a stand-alone
+ * tool, we do not really have this. So we do some dummy defines
+ * in order to satisfy the needs of the common code.
+ */
+int Debug = 0;
+#ifndef DEBUGLESS
+void r_dbgprintf(const char *srcname __attribute__((unused)), const char *fmt __attribute__((unused)), ...) {};
+#endif
+void srSleep(int a __attribute__((unused)), int b __attribute__((unused)));
+/* prototype (avoid compiler warning) */
+void srSleep(int a __attribute__((unused)), int b __attribute__((unused))) {}
+/* this is not really needed by any of our code */
+long randomNumber(void);
+/* prototype (avoid compiler warning) */
+long randomNumber(void) {return 0l;}
+/* this is not really needed by any of our code */
+
+/* rectype/value must be EIF_MAX_*_LEN+1 long!
+ * returns 0 on success or something else on error/EOF
+ */
+static int
+eiGetRecord(FILE *eifp, char *rectype, char *value)
+{
+ int r;
+ unsigned short i, j;
+ char buf[EIF_MAX_RECTYPE_LEN+EIF_MAX_VALUE_LEN+128];
+ /* large enough for any valid record */
+
+ if(fgets(buf, sizeof(buf), eifp) == NULL) {
+ r = 1; goto done;
+ }
+
+ for(i = 0 ; i < EIF_MAX_RECTYPE_LEN && buf[i] != ':' ; ++i)
+ if(buf[i] == '\0') {
+ r = 2; goto done;
+ } else
+ rectype[i] = buf[i];
+ rectype[i] = '\0';
+ j = 0;
+ for(++i ; i < EIF_MAX_VALUE_LEN && buf[i] != '\n' ; ++i, ++j)
+ if(buf[i] == '\0') {
+ r = 3; goto done;
+ } else
+ value[j] = buf[i];
+ value[j] = '\0';
+ r = 0;
+done: return r;
+}
+
+static int
+eiCheckFiletype(FILE *eifp)
+{
+ char rectype[EIF_MAX_RECTYPE_LEN+1];
+ char value[EIF_MAX_VALUE_LEN+1];
+ int r;
+
+ if((r = eiGetRecord(eifp, rectype, value)) != 0) goto done;
+ if(strcmp(rectype, "FILETYPE") || strcmp(value, RSGCRY_FILETYPE_NAME)) {
+ fprintf(stderr, "invalid filetype \"cookie\" in encryption "
+ "info file\n");
+ fprintf(stderr, "\trectype: '%s', value: '%s'\n", rectype, value);
+ r = 1; goto done;
+ }
+ r = 0;
+done: return r;
+}
+
+static int
+eiGetIV(FILE *eifp, char *iv, size_t leniv)
+{
+ char rectype[EIF_MAX_RECTYPE_LEN+1];
+ char value[EIF_MAX_VALUE_LEN+1];
+ size_t valueLen;
+ unsigned short i, j;
+ int r;
+ unsigned char nibble;
+
+ if((r = eiGetRecord(eifp, rectype, value)) != 0) goto done;
+ if(strcmp(rectype, "IV")) {
+ fprintf(stderr, "no IV record found when expected, record type "
+ "seen is '%s'\n", rectype);
+ r = 1; goto done;
+ }
+ valueLen = strlen(value);
+ if(valueLen/2 != leniv) {
+ fprintf(stderr, "length of IV is %lld, expected %lld\n",
+ (long long) valueLen/2, (long long) leniv);
+ r = 1; goto done;
+ }
+
+ for(i = j = 0 ; i < valueLen ; ++i) {
+ if(value[i] >= '0' && value[i] <= '9')
+ nibble = value[i] - '0';
+ else if(value[i] >= 'a' && value[i] <= 'f')
+ nibble = value[i] - 'a' + 10;
+ else {
+ fprintf(stderr, "invalid IV '%s'\n", value);
+ r = 1; goto done;
+ }
+ if(i % 2 == 0)
+ iv[j] = nibble << 4;
+ else
+ iv[j++] |= nibble;
+ }
+ r = 0;
+done: return r;
+}
+
+static int
+eiGetEND(FILE *eifp, off64_t *offs)
+{
+ char rectype[EIF_MAX_RECTYPE_LEN+1] = "";
+ char value[EIF_MAX_VALUE_LEN+1];
+ int r;
+
+ if((r = eiGetRecord(eifp, rectype, value)) != 0) goto done;
+ if(strcmp(rectype, "END")) {
+ fprintf(stderr, "no END record found when expected, record type "
+ "seen is '%s'\n", rectype);
+ r = 1; goto done;
+ }
+ *offs = atoll(value);
+ r = 0;
+done: return r;
+}
+
+static int
+initCrypt(FILE *eifp)
+{
+ int r = 0;
+ gcry_error_t gcryError;
+ char iv[4096];
+
+ blkLength = gcry_cipher_get_algo_blklen(cry_algo);
+ if(blkLength > sizeof(iv)) {
+ fprintf(stderr, "internal error[%s:%d]: block length %lld too large for "
+ "iv buffer\n", __FILE__, __LINE__, (long long) blkLength);
+ r = 1; goto done;
+ }
+ if((r = eiGetIV(eifp, iv, blkLength)) != 0) goto done;
+
+ size_t keyLength = gcry_cipher_get_algo_keylen(cry_algo);
+ assert(cry_key != NULL); /* "fix" clang 10 static analyzer false positive */
+ if(strlen(cry_key) != keyLength) {
+ fprintf(stderr, "invalid key length; key is %u characters, but "
+ "exactly %llu characters are required\n", cry_keylen,
+ (long long unsigned) keyLength);
+ r = 1; goto done;
+ }
+
+ gcryError = gcry_cipher_open(&gcry_chd, cry_algo, cry_mode, 0);
+ if (gcryError) {
+ printf("gcry_cipher_open failed: %s/%s\n",
+ gcry_strsource(gcryError),
+ gcry_strerror(gcryError));
+ r = 1; goto done;
+ }
+
+ gcryError = gcry_cipher_setkey(gcry_chd, cry_key, keyLength);
+ if (gcryError) {
+ printf("gcry_cipher_setkey failed: %s/%s\n",
+ gcry_strsource(gcryError),
+ gcry_strerror(gcryError));
+ r = 1; goto done;
+ }
+
+ gcryError = gcry_cipher_setiv(gcry_chd, iv, blkLength);
+ if (gcryError) {
+ printf("gcry_cipher_setiv failed: %s/%s\n",
+ gcry_strsource(gcryError),
+ gcry_strerror(gcryError));
+ r = 1; goto done;
+ }
+done: return r;
+}
+
+static void
+removePadding(char *buf, size_t *plen)
+{
+ unsigned len = (unsigned) *plen;
+ unsigned iSrc, iDst;
+ char *frstNUL;
+
+ frstNUL = memchr(buf, 0x00, *plen);
+ if(frstNUL == NULL)
+ goto done;
+ iDst = iSrc = frstNUL - buf;
+
+ while(iSrc < len) {
+ if(buf[iSrc] != 0x00)
+ buf[iDst++] = buf[iSrc];
+ ++iSrc;
+ }
+
+ *plen = iDst;
+done: return;
+}
+
+static void
+decryptBlock(FILE *fpin, FILE *fpout, off64_t blkEnd, off64_t *pCurrOffs)
+{
+ gcry_error_t gcryError;
+ size_t nRead, nWritten;
+ size_t toRead;
+ size_t leftTillBlkEnd;
+ char buf[64*1024];
+
+ leftTillBlkEnd = blkEnd - *pCurrOffs;
+ while(1) {
+ toRead = sizeof(buf) <= leftTillBlkEnd ? sizeof(buf) : leftTillBlkEnd;
+ toRead = toRead - toRead % blkLength;
+ nRead = fread(buf, 1, toRead, fpin);
+ if(nRead == 0)
+ break;
+ leftTillBlkEnd -= nRead, *pCurrOffs += nRead;
+ gcryError = gcry_cipher_decrypt(
+ gcry_chd, // gcry_cipher_hd_t
+ buf, // void *
+ nRead, // size_t
+ NULL, // const void *
+ 0); // size_t
+ if (gcryError) {
+ fprintf(stderr, "gcry_cipher_decrypt failed: %s/%s\n",
+ gcry_strsource(gcryError),
+ gcry_strerror(gcryError));
+ return;
+ }
+ removePadding(buf, &nRead);
+ nWritten = fwrite(buf, 1, nRead, fpout);
+ if(nWritten != nRead) {
+ perror("fpout");
+ return;
+ }
+ }
+}
+
+
+static int
+doDecrypt(FILE *logfp, FILE *eifp, FILE *outfp)
+{
+ off64_t blkEnd;
+ off64_t currOffs = 0;
+ int r = 1;
+ int fd;
+ struct stat buf;
+
+ while(1) {
+ /* process block */
+ if(initCrypt(eifp) != 0)
+ goto done;
+ /* set blkEnd to size of logfp and proceed. */
+ if((fd = fileno(logfp)) == -1) {
+ r = -1;
+ goto done;
+ }
+ if((r = fstat(fd, &buf)) != 0) goto done;
+ blkEnd = buf.st_size;
+ r = eiGetEND(eifp, &blkEnd);
+ if(r != 0 && r != 1) goto done;
+ decryptBlock(logfp, outfp, blkEnd, &currOffs);
+ gcry_cipher_close(gcry_chd);
+ }
+ r = 0;
+done: return r;
+}
+
+static void
+decrypt(const char *name)
+{
+ FILE *logfp = NULL, *eifp = NULL;
+ int r = 0;
+ char eifname[4096];
+
+ if(!strcmp(name, "-")) {
+ fprintf(stderr, "decrypt mode cannot work on stdin\n");
+ goto err;
+ } else {
+ if((logfp = fopen(name, "r")) == NULL) {
+ perror(name);
+ goto err;
+ }
+ snprintf(eifname, sizeof(eifname), "%s%s", name, ENCINFO_SUFFIX);
+ eifname[sizeof(eifname)-1] = '\0';
+ if((eifp = fopen(eifname, "r")) == NULL) {
+ perror(eifname);
+ goto err;
+ }
+ if(eiCheckFiletype(eifp) != 0)
+ goto err;
+ }
+
+ if((r = doDecrypt(logfp, eifp, stdout)) != 0)
+ goto err;
+
+ fclose(logfp); logfp = NULL;
+ fclose(eifp); eifp = NULL;
+ return;
+
+err:
+ fprintf(stderr, "error %d processing file %s\n", r, name);
+ if(eifp != NULL)
+ fclose(eifp);
+ if(logfp != NULL)
+ fclose(logfp);
+}
+
+static void
+write_keyfile(char *fn)
+{
+ int fd;
+ int r;
+ mode_t fmode;
+
+ fmode = O_WRONLY|O_CREAT;
+ if(!optionForce)
+ fmode |= O_EXCL;
+ if(fn == NULL) {
+ fprintf(stderr, "program error: keyfile is NULL");
+ exit(1);
+ }
+ if((fd = open(fn, fmode, S_IRUSR)) == -1) {
+ fprintf(stderr, "error opening keyfile ");
+ perror(fn);
+ exit(1);
+ }
+ if((r = write(fd, cry_key, cry_keylen)) != (ssize_t)cry_keylen) {
+ fprintf(stderr, "error writing keyfile (ret=%d) ", r);
+ perror(fn);
+ exit(1);
+ }
+ close(fd);
+}
+
+static void
+getKeyFromFile(const char *fn)
+{
+ const int r = gcryGetKeyFromFile(fn, &cry_key, &cry_keylen);
+ if(r != 0) {
+ perror(fn);
+ exit(1);
+ }
+}
+
+static void
+getRandomKey(void)
+{
+ int fd;
+ cry_keylen = randomKeyLen;
+ cry_key = malloc(randomKeyLen); /* do NOT zero-out! */
+ /* if we cannot obtain data from /dev/urandom, we use whatever
+ * is present at the current memory location as random data. Of
+ * course, this is very weak and we should consider a different
+ * option, especially when not running under Linux (for Linux,
+ * unavailability of /dev/urandom is just a theoretic thing, it
+ * will always work...). -- TODO -- rgerhards, 2013-03-06
+ */
+ if((fd = open("/dev/urandom", O_RDONLY)) >= 0) {
+ if(read(fd, cry_key, randomKeyLen) != randomKeyLen) {
+ fprintf(stderr, "warning: could not read sufficient data "
+ "from /dev/urandom - key may be weak\n");
+ };
+ close(fd);
+ }
+}
+
+
+static void
+setKey(void)
+{
+ if(randomKeyLen != -1)
+ getRandomKey();
+ else if(keyfile != NULL)
+ getKeyFromFile(keyfile);
+ else if(keyprog != NULL)
+ gcryGetKeyFromProg(keyprog, &cry_key, &cry_keylen);
+ if(cry_key == NULL) {
+ fprintf(stderr, "ERROR: key must be set via some method\n");
+ exit(1);
+ }
+}
+
+static struct option long_options[] =
+{
+ {"verbose", no_argument, NULL, 'v'},
+ {"version", no_argument, NULL, 'V'},
+ {"decrypt", no_argument, NULL, 'd'},
+ {"force", no_argument, NULL, 'f'},
+ {"write-keyfile", required_argument, NULL, 'W'},
+ {"key", required_argument, NULL, 'K'},
+ {"generate-random-key", required_argument, NULL, 'r'},
+ {"keyfile", required_argument, NULL, 'k'},
+ {"key-program", required_argument, NULL, 'p'},
+ {"algo", required_argument, NULL, 'a'},
+ {"mode", required_argument, NULL, 'm'},
+ {NULL, 0, NULL, 0}
+};
+
+int
+main(int argc, char *argv[])
+{
+ int i;
+ int opt;
+ int temp;
+ char *newKeyFile = NULL;
+
+ while(1) {
+ opt = getopt_long(argc, argv, "a:dfk:K:m:p:r:vVW:", long_options, NULL);
+ if(opt == -1)
+ break;
+ switch(opt) {
+ case 'd':
+ mode = MD_DECRYPT;
+ break;
+ case 'W':
+ mode = MD_WRITE_KEYFILE;
+ newKeyFile = optarg;
+ break;
+ case 'k':
+ keyfile = optarg;
+ break;
+ case 'p':
+ keyprog = optarg;
+ break;
+ case 'f':
+ optionForce = 1;
+ break;
+ case 'r':
+ randomKeyLen = atoi(optarg);
+ if(randomKeyLen > 64*1024) {
+ fprintf(stderr, "ERROR: keys larger than 64KiB are "
+ "not supported\n");
+ exit(1);
+ }
+ break;
+ case 'K':
+ fprintf(stderr, "WARNING: specifying the actual key "
+ "via the command line is highly insecure\n"
+ "Do NOT use this for PRODUCTION use.\n");
+ cry_key = optarg;
+ cry_keylen = strlen(cry_key);
+ break;
+ case 'a':
+ temp = rsgcryAlgoname2Algo(optarg);
+ if(temp == GCRY_CIPHER_NONE) {
+ fprintf(stderr, "ERROR: algorithm \"%s\" is not "
+ "kown/supported\n", optarg);
+ exit(1);
+ }
+ cry_algo = temp;
+ break;
+ case 'm':
+ temp = rsgcryModename2Mode(optarg);
+ if(temp == GCRY_CIPHER_MODE_NONE) {
+ fprintf(stderr, "ERROR: cipher mode \"%s\" is not "
+ "kown/supported\n", optarg);
+ exit(1);
+ }
+ cry_mode = temp;
+ break;
+ case 'v':
+ verbose = 1;
+ break;
+ case 'V':
+ fprintf(stderr, "rsgtutil " VERSION "\n");
+ exit(0);
+ break;
+ case '?':
+ break;
+ default:fprintf(stderr, "getopt_long() returns unknown value %d\n", opt);
+ return 1;
+ }
+ }
+
+ setKey();
+ assert(cry_key != NULL);
+
+ if(mode == MD_WRITE_KEYFILE) {
+ if(optind != argc) {
+ fprintf(stderr, "ERROR: no file parameters permitted in "
+ "--write-keyfile mode\n");
+ exit(1);
+ }
+ write_keyfile(newKeyFile);
+ } else {
+ if(optind == argc)
+ decrypt("-");
+ else {
+ for(i = optind ; i < argc ; ++i)
+ decrypt(argv[i]);
+ }
+ }
+
+ assert(cry_key != NULL);
+ memset(cry_key, 0, cry_keylen); /* zero-out key store */
+ cry_keylen = 0;
+ return 0;
+}
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