diff options
Diffstat (limited to 'runtime/libgcry.c')
| -rw-r--r-- | runtime/libgcry.c | 202 |
1 files changed, 192 insertions, 10 deletions
diff --git a/runtime/libgcry.c b/runtime/libgcry.c index 51c10af4..3fca50ec 100644 --- a/runtime/libgcry.c +++ b/runtime/libgcry.c @@ -49,8 +49,10 @@ #include <errno.h> #include "rsyslog.h" +#include "srUtils.h" #include "libgcry.h" +#define READBUF_SIZE 4096 /* size of the read buffer */ static rsRetVal eiWriteRec(gcryfile gf, char *recHdr, size_t lenRecHdr, char *buf, size_t lenBuf) @@ -90,19 +92,66 @@ finalize_it: RETiRet; } +static rsRetVal +eiRead(gcryfile gf) +{ + ssize_t nRead; + DEFiRet; + + if(gf->readBuf == NULL) { + CHKmalloc(gf->readBuf = malloc(READBUF_SIZE)); + } + + nRead = read(gf->fd, gf->readBuf, READBUF_SIZE); + if(nRead <= 0) { /* TODO: provide specific EOF case? */ + ABORT_FINALIZE(RS_RET_ERR); + } + gf->readBufMaxIdx = (int16_t) nRead; + gf->readBufIdx = 0; + +finalize_it: + RETiRet; +} + + +/* returns EOF on any kind of error */ +static int +eiReadChar(gcryfile gf) +{ + int c; + + if(gf->readBufIdx >= gf->readBufMaxIdx) { + if(eiRead(gf) != RS_RET_OK) { + c = EOF; + goto finalize_it; + } + } + c = gf->readBuf[gf->readBufIdx++]; +finalize_it: + return c; +} + static rsRetVal eiCheckFiletype(gcryfile gf) { char hdrBuf[128]; size_t toRead, didRead; + sbool bNeedClose = 0; DEFiRet; - CHKiRet(eiOpenRead(gf)); + if(gf->fd == -1) { + bNeedClose = 1; + CHKiRet(eiOpenRead(gf)); + } + if(Debug) memset(hdrBuf, 0, sizeof(hdrBuf)); /* for dbgprintf below! */ toRead = sizeof("FILETYPE:")-1 + sizeof(RSGCRY_FILETYPE_NAME)-1 + 1; didRead = read(gf->fd, hdrBuf, toRead); - close(gf->fd); + if(bNeedClose) { + close(gf->fd); + gf->fd = -1; + } DBGPRINTF("eiCheckFiletype read %d bytes: '%s'\n", didRead, hdrBuf); if( didRead != toRead || strncmp(hdrBuf, "FILETYPE:" RSGCRY_FILETYPE_NAME "\n", toRead)) @@ -111,6 +160,79 @@ finalize_it: RETiRet; } +/* rectype/value must be EIF_MAX_*_LEN+1 long! + * returns 0 on success or something else on error/EOF + */ +static rsRetVal +eiGetRecord(gcryfile gf, char *rectype, char *value) +{ + unsigned short i, j; + int c; + DEFiRet; + + for(i = 0 ; i < EIF_MAX_RECTYPE_LEN ; ++i) { + c = eiReadChar(gf); + if(c == ':' || c == EOF) + break; + rectype[i] = c; + } + if(c != ':') { ABORT_FINALIZE(RS_RET_ERR); } + rectype[i] = '\0'; + j = 0; + for(++i ; i < EIF_MAX_VALUE_LEN ; ++i, ++j) { + c = eiReadChar(gf); + if(c == '\n' || c == EOF) + break; + value[j] = c; + } + if(c != '\n') { ABORT_FINALIZE(RS_RET_ERR); } + value[j] = '\0'; +finalize_it: + RETiRet; +} + +static rsRetVal +eiGetIV(gcryfile gf, uchar *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; + unsigned char nibble; + DEFiRet; + + CHKiRet(eiGetRecord(gf, rectype, value)); + if(strcmp(rectype, "IV")) { + DBGPRINTF("no IV record found when expected, record type " + "seen is '%s'\n", rectype); + ABORT_FINALIZE(RS_RET_ERR); + } + valueLen = strlen(value); + if(valueLen/2 != leniv) { + DBGPRINTF("length of IV is %d, expected %d\n", + valueLen/2, leniv); + ABORT_FINALIZE(RS_RET_ERR); + } + + 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 { + DBGPRINTF("invalid IV '%s'\n", value); + ABORT_FINALIZE(RS_RET_ERR); + } + if(i % 2 == 0) + iv[j] = nibble << 4; + else + iv[j++] |= nibble; + } +finalize_it: + RETiRet; +} + + static rsRetVal eiOpenAppend(gcryfile gf) { @@ -180,7 +302,9 @@ eiClose(gcryfile gf, off64_t offsLogfile) /* 2^64 is 20 digits, so the snprintf buffer is large enough */ len = snprintf(offs, sizeof(offs), "%lld", offsLogfile); eiWriteRec(gf, "END:", 4, offs, len); + free(gf->readBuf); close(gf->fd); + gf->fd = -1; DBGPRINTF("encryption info file %s: closed\n", gf->eiName); } @@ -193,6 +317,7 @@ gcryfileConstruct(gcryctx ctx, gcryfile *pgf, uchar *logfn) CHKmalloc(gf = calloc(1, sizeof(struct gcryfile_s))); gf->ctx = ctx; + gf->fd = -1; snprintf(fn, sizeof(fn), "%s%s", logfn, ENCINFO_SUFFIX); fn[MAXFNAME] = '\0'; /* be on save side */ gf->eiName = (uchar*) strdup(fn); @@ -246,13 +371,13 @@ addPadding(gcryfile pF, uchar *buf, size_t *plen) } static inline void -removePadding(char *buf, size_t *plen) +removePadding(uchar *buf, size_t *plen) { unsigned len = (unsigned) *plen; unsigned iSrc, iDst; - char *frstNUL; + uchar *frstNUL; - frstNUL = strchr(buf, 0x00); + frstNUL = (uchar*)strchr((char*)buf, 0x00); if(frstNUL == NULL) goto done; iDst = iSrc = frstNUL - buf; @@ -343,8 +468,31 @@ seedIV(gcryfile gf, uchar **iv) } } +static inline rsRetVal +readIV(gcryfile gf, uchar **iv) +{ + rsRetVal localRet; + DEFiRet; + + do { + localRet = eiOpenRead(gf); + if(localRet == RS_RET_EI_NO_EXISTS) { + /* wait until it is created */ + srSleep(0, 10000); + } else { + CHKiRet(localRet); + } + } while(localRet != RS_RET_OK); + CHKiRet(eiCheckFiletype(gf)); + *iv = malloc(gf->blkLength); /* do NOT zero-out! */ + CHKiRet(eiGetIV(gf, *iv, (size_t) gf->blkLength)); +dbgprintf("DDDD: read %d bytes of IV\n", (int) gf->blkLength); +finalize_it: + RETiRet; +} + rsRetVal -rsgcryInitCrypt(gcryctx ctx, gcryfile *pgf, uchar *fname) +rsgcryInitCrypt(gcryctx ctx, gcryfile *pgf, uchar *fname, char openMode) { gcry_error_t gcryError; gcryfile gf = NULL; @@ -352,6 +500,7 @@ rsgcryInitCrypt(gcryctx ctx, gcryfile *pgf, uchar *fname) DEFiRet; CHKiRet(gcryfileConstruct(ctx, &gf, fname)); + gf->mode = openMode; gf->blkLength = gcry_cipher_get_algo_blklen(ctx->algo); @@ -371,7 +520,12 @@ rsgcryInitCrypt(gcryctx ctx, gcryfile *pgf, uchar *fname) ABORT_FINALIZE(RS_RET_ERR); } - seedIV(gf, &iv); + if(openMode == 'r') { + readIV(gf, &iv); + } else { + seedIV(gf, &iv); + } + gcryError = gcry_cipher_setiv(gf->chd, iv, gf->blkLength); if (gcryError) { dbgprintf("gcry_cipher_setiv failed: %s/%s\n", @@ -379,8 +533,10 @@ rsgcryInitCrypt(gcryctx ctx, gcryfile *pgf, uchar *fname) gcry_strerror(gcryError)); ABORT_FINALIZE(RS_RET_ERR); } - CHKiRet(eiOpenAppend(gf)); - CHKiRet(eiWriteIV(gf, iv)); + if(openMode == 'w') { + CHKiRet(eiOpenAppend(gf)); + CHKiRet(eiWriteIV(gf, iv)); + } *pgf = gf; finalize_it: free(iv); @@ -389,7 +545,7 @@ finalize_it: RETiRet; } -int +rsRetVal rsgcryEncrypt(gcryfile pF, uchar *buf, size_t *len) { int gcryError; @@ -410,6 +566,32 @@ finalize_it: RETiRet; } +/* TODO: handle multiple blocks + * test-read END record; if present, store offset, else unbounded (current active block) + * when decrypting, check if bound is reached. If yes, split into two blocks, get new IV for + * second one. + */ +rsRetVal +rsgcryDecrypt(gcryfile pF, uchar *buf, size_t *len) +{ + gcry_error_t gcryError; + DEFiRet; + + gcryError = gcry_cipher_decrypt(pF->chd, buf, *len, NULL, 0); + if(gcryError) { + DBGPRINTF("gcry_cipher_decrypt failed: %s/%s\n", + gcry_strsource(gcryError), + gcry_strerror(gcryError)); + ABORT_FINALIZE(RS_RET_ERR); + } + removePadding(buf, len); +dbgprintf("DDDD: decrypted, buffer is now '%50.50s'\n", buf); + +finalize_it: + RETiRet; +} + + /* module-init dummy for potential later use */ int |