diff options
Diffstat (limited to '')
-rw-r--r-- | security/nss/lib/softoken/legacydb/dbmshim.c | 539 |
1 files changed, 539 insertions, 0 deletions
diff --git a/security/nss/lib/softoken/legacydb/dbmshim.c b/security/nss/lib/softoken/legacydb/dbmshim.c new file mode 100644 index 0000000000..cca24bc6be --- /dev/null +++ b/security/nss/lib/softoken/legacydb/dbmshim.c @@ -0,0 +1,539 @@ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +/* + * Berkeley DB 1.85 Shim code to handle blobs. + */ +#include "mcom_db.h" +#include "secitem.h" +#include "nssb64.h" +#include "blapi.h" +#include "secerr.h" + +#include "lgdb.h" + +/* + * Blob block: + * Byte 0 CERTDB Version -+ -+ + * Byte 1 certDBEntryTypeBlob | BLOB_HEAD_LEN | + * Byte 2 flags (always '0'); | | + * Byte 3 reserved (always '0'); -+ | + * Byte 4 LSB length | <--BLOB_LENGTH_START | BLOB_BUF_LEN + * Byte 5 . | | + * Byte 6 . | BLOB_LENGTH_LEN | + * Byte 7 MSB length | | + * Byte 8 blob_filename -+ -+ <-- BLOB_NAME_START | + * Byte 9 . | BLOB_NAME_LEN | + * . . | | + * Byte 37 . -+ -+ + */ +#define DBS_BLOCK_SIZE (16 * 1024) /* 16 k */ +#define DBS_MAX_ENTRY_SIZE (DBS_BLOCK_SIZE - (2048)) /* 14 k */ +#define DBS_CACHE_SIZE DBS_BLOCK_SIZE * 8 +#define ROUNDDIV(x, y) (x + (y - 1)) / y +#define BLOB_HEAD_LEN 4 +#define BLOB_LENGTH_START BLOB_HEAD_LEN +#define BLOB_LENGTH_LEN 4 +#define BLOB_NAME_START BLOB_LENGTH_START + BLOB_LENGTH_LEN +#define BLOB_NAME_LEN 1 + ROUNDDIV(SHA1_LENGTH, 3) * 4 + 1 +#define BLOB_BUF_LEN BLOB_HEAD_LEN + BLOB_LENGTH_LEN + BLOB_NAME_LEN + +/* a Shim data structure. This data structure has a db built into it. */ +typedef struct DBSStr DBS; + +struct DBSStr { + DB db; + char *blobdir; + int mode; + PRBool readOnly; + char staticBlobArea[BLOB_BUF_LEN]; +}; + +/* + * return true if the Datablock contains a blobtype + */ +static PRBool +dbs_IsBlob(DBT *blobData) +{ + unsigned char *addr = (unsigned char *)blobData->data; + if (blobData->size < BLOB_BUF_LEN) { + return PR_FALSE; + } + return addr && ((certDBEntryType)addr[1] == certDBEntryTypeBlob); +} + +/* + * extract the filename in the blob of the real data set. + * This value is not malloced (does not need to be freed by the caller. + */ +static const char * +dbs_getBlobFileName(DBT *blobData) +{ + char *addr = (char *)blobData->data; + + return &addr[BLOB_NAME_START]; +} + +/* + * extract the size of the actual blob from the blob record + */ +static PRUint32 +dbs_getBlobSize(DBT *blobData) +{ + unsigned char *addr = (unsigned char *)blobData->data; + + return (PRUint32)(addr[BLOB_LENGTH_START + 3] << 24) | + (addr[BLOB_LENGTH_START + 2] << 16) | + (addr[BLOB_LENGTH_START + 1] << 8) | + addr[BLOB_LENGTH_START]; +} + +/* We are using base64 data for the filename, but base64 data can include a + * '/' which is interpreted as a path separator on many platforms. Replace it + * with an inocuous '-'. We don't need to convert back because we never actual + * decode the filename. + */ + +static void +dbs_replaceSlash(char *cp, int len) +{ + while (len--) { + if (*cp == '/') + *cp = '-'; + cp++; + } +} + +/* + * create a blob record from a key, data and return it in blobData. + * NOTE: The data element is static data (keeping with the dbm model). + */ +static void +dbs_mkBlob(DBS *dbsp, const DBT *key, const DBT *data, DBT *blobData) +{ + unsigned char sha1_data[SHA1_LENGTH]; + char *b = dbsp->staticBlobArea; + PRUint32 length = data->size; + SECItem sha1Item; + + b[0] = CERT_DB_FILE_VERSION; /* certdb version number */ + b[1] = (char)certDBEntryTypeBlob; /* type */ + b[2] = 0; /* flags */ + b[3] = 0; /* reserved */ + b[BLOB_LENGTH_START] = length & 0xff; + b[BLOB_LENGTH_START + 1] = (length >> 8) & 0xff; + b[BLOB_LENGTH_START + 2] = (length >> 16) & 0xff; + b[BLOB_LENGTH_START + 3] = (length >> 24) & 0xff; + sha1Item.data = sha1_data; + sha1Item.len = SHA1_LENGTH; + SHA1_HashBuf(sha1_data, key->data, key->size); + b[BLOB_NAME_START] = 'b'; /* Make sure we start with a alpha */ + NSSBase64_EncodeItem(NULL, &b[BLOB_NAME_START + 1], BLOB_NAME_LEN - 1, &sha1Item); + b[BLOB_BUF_LEN - 1] = 0; + dbs_replaceSlash(&b[BLOB_NAME_START + 1], BLOB_NAME_LEN - 1); + blobData->data = b; + blobData->size = BLOB_BUF_LEN; + return; +} + +/* + * construct a path to the actual blob. The string returned must be + * freed by the caller with PR_smprintf_free. + * + * Note: this file does lots of consistancy checks on the DBT. The + * routines that call this depend on these checks, so they don't worry + * about them (success of this routine implies a good blobdata record). + */ +static char * +dbs_getBlobFilePath(char *blobdir, DBT *blobData) +{ + const char *name; + + if (blobdir == NULL) { + PR_SetError(SEC_ERROR_BAD_DATABASE, 0); + return NULL; + } + if (!dbs_IsBlob(blobData)) { + PR_SetError(SEC_ERROR_BAD_DATABASE, 0); + return NULL; + } + name = dbs_getBlobFileName(blobData); + if (!name || *name == 0) { + PR_SetError(SEC_ERROR_BAD_DATABASE, 0); + return NULL; + } + return PR_smprintf("%s" PATH_SEPARATOR "%s", blobdir, name); +} + +/* + * Delete a blob file pointed to by the blob record. + */ +static void +dbs_removeBlob(DBS *dbsp, DBT *blobData) +{ + char *file; + + file = dbs_getBlobFilePath(dbsp->blobdir, blobData); + if (!file) { + return; + } + PR_Delete(file); + PR_smprintf_free(file); +} + +/* + * Directory modes are slightly different, the 'x' bit needs to be on to + * access them. Copy all the read bits to 'x' bits + */ +static int +dbs_DirMode(int mode) +{ + int x_bits = (mode >> 2) & 0111; + return mode | x_bits; +} + +/* + * write a data blob to it's file. blobdData is the blob record that will be + * stored in the database. data is the actual data to go out on disk. + */ +static int +dbs_writeBlob(DBS *dbsp, int mode, DBT *blobData, const DBT *data) +{ + char *file = NULL; + PRFileDesc *filed; + PRStatus status; + int len; + int error = 0; + + file = dbs_getBlobFilePath(dbsp->blobdir, blobData); + if (!file) { + goto loser; + } + if (PR_Access(dbsp->blobdir, PR_ACCESS_EXISTS) != PR_SUCCESS) { + status = PR_MkDir(dbsp->blobdir, dbs_DirMode(mode)); + if (status != PR_SUCCESS) { + goto loser; + } + } + filed = PR_OpenFile(file, PR_CREATE_FILE | PR_TRUNCATE | PR_WRONLY, mode); + if (filed == NULL) { + error = PR_GetError(); + goto loser; + } + len = PR_Write(filed, data->data, data->size); + error = PR_GetError(); + PR_Close(filed); + if (len < (int)data->size) { + goto loser; + } + PR_smprintf_free(file); + return 0; + +loser: + if (file) { + PR_Delete(file); + PR_smprintf_free(file); + } + /* don't let close or delete reset the error */ + PR_SetError(error, 0); + return -1; +} + +/* + * platforms that cannot map the file need to read it into a temp buffer. + */ +static unsigned char * +dbs_EmulateMap(PRFileDesc *filed, int len) +{ + unsigned char *addr; + PRInt32 dataRead; + + addr = PORT_Alloc(len); + if (addr == NULL) { + return NULL; + } + + dataRead = PR_Read(filed, addr, len); + if (dataRead != len) { + PORT_Free(addr); + if (dataRead > 0) { + /* PR_Read didn't set an error, we need to */ + PR_SetError(SEC_ERROR_BAD_DATABASE, 0); + } + return NULL; + } + + return addr; +} + +/* + * pull a database record off the disk + * data points to the blob record on input and the real record (if we could + * read it) on output. if there is an error data is not modified. + */ +static int +dbs_readBlob(DBS *dbsp, DBT *data) +{ + char *file = NULL; + PRFileDesc *filed = NULL; + unsigned char *addr = NULL; + int error; + int len = -1; + + file = dbs_getBlobFilePath(dbsp->blobdir, data); + if (!file) { + goto loser; + } + filed = PR_OpenFile(file, PR_RDONLY, 0); + PR_smprintf_free(file); + file = NULL; + if (filed == NULL) { + goto loser; + } + + len = dbs_getBlobSize(data); + /* Bug 1323150 + * PR_MemMap fails on Windows for larger certificates. + * https://msdn.microsoft.com/en-us/library/windows/desktop/aa366761(v=vs.85).aspx + * Let's always use the emulated map, i.e. read the file. + */ + addr = dbs_EmulateMap(filed, len); + if (addr == NULL) { + goto loser; + } + PR_Close(filed); + + data->data = addr; + data->size = len; + return 0; + +loser: + /* preserve the error code */ + error = PR_GetError(); + if (filed) { + PR_Close(filed); + } + PR_SetError(error, 0); + return -1; +} + +/* + * actual DBM shims + */ +static int +dbs_get(const DB *dbs, const DBT *key, DBT *data, unsigned int flags) +{ + int ret; + DBS *dbsp = (DBS *)dbs; + DB *db = (DB *)dbs->internal; + + ret = (*db->get)(db, key, data, flags); + if ((ret == 0) && dbs_IsBlob(data)) { + ret = dbs_readBlob(dbsp, data); + } + + return (ret); +} + +static int +dbs_put(const DB *dbs, DBT *key, const DBT *data, unsigned int flags) +{ + DBT blob; + int ret = 0; + DBS *dbsp = (DBS *)dbs; + DB *db = (DB *)dbs->internal; + + /* If the db is readonly, just pass the data down to rdb and let it fail */ + if (!dbsp->readOnly) { + DBT oldData; + int ret1; + + /* make sure the current record is deleted if it's a blob */ + ret1 = (*db->get)(db, key, &oldData, 0); + if ((ret1 == 0) && flags == R_NOOVERWRITE) { + /* let DBM return the error to maintain consistancy */ + return (*db->put)(db, key, data, flags); + } + if ((ret1 == 0) && dbs_IsBlob(&oldData)) { + dbs_removeBlob(dbsp, &oldData); + } + + if (data->size > DBS_MAX_ENTRY_SIZE) { + dbs_mkBlob(dbsp, key, data, &blob); + ret = dbs_writeBlob(dbsp, dbsp->mode, &blob, data); + data = &blob; + } + } + + if (ret == 0) { + ret = (*db->put)(db, key, data, flags); + } + return (ret); +} + +static int +dbs_sync(const DB *dbs, unsigned int flags) +{ + DB *db = (DB *)dbs->internal; + return (*db->sync)(db, flags); +} + +static int +dbs_del(const DB *dbs, const DBT *key, unsigned int flags) +{ + int ret; + DBS *dbsp = (DBS *)dbs; + DB *db = (DB *)dbs->internal; + + if (!dbsp->readOnly) { + DBT oldData; + ret = (*db->get)(db, key, &oldData, 0); + if ((ret == 0) && dbs_IsBlob(&oldData)) { + dbs_removeBlob(dbsp, &oldData); + } + } + + return (*db->del)(db, key, flags); +} + +static int +dbs_seq(const DB *dbs, DBT *key, DBT *data, unsigned int flags) +{ + int ret; + DBS *dbsp = (DBS *)dbs; + DB *db = (DB *)dbs->internal; + + ret = (*db->seq)(db, key, data, flags); + if ((ret == 0) && dbs_IsBlob(data)) { + /* don't return a blob read as an error so traversals keep going */ + (void)dbs_readBlob(dbsp, data); + } + + return (ret); +} + +static int +dbs_close(DB *dbs) +{ + DBS *dbsp = (DBS *)dbs; + DB *db = (DB *)dbs->internal; + int ret; + + ret = (*db->close)(db); + PORT_Free(dbsp->blobdir); + PORT_Free(dbsp); + return ret; +} + +static int +dbs_fd(const DB *dbs) +{ + DB *db = (DB *)dbs->internal; + + return (*db->fd)(db); +} + +/* + * the naming convention we use is + * change the .xxx into .dir. (for nss it's always .db); + * if no .extension exists or is equal to .dir, add a .dir + * the returned data must be freed. + */ +#define DIRSUFFIX ".dir" +static char * +dbs_mkBlobDirName(const char *dbname) +{ + int dbname_len = PORT_Strlen(dbname); + int dbname_end = dbname_len; + const char *cp; + char *blobDir = NULL; + + /* scan back from the end looking for either a directory separator, a '.', + * or the end of the string. NOTE: Windows should check for both separators + * here. For now this is safe because we know NSS always uses a '.' + */ + for (cp = &dbname[dbname_len]; + (cp > dbname) && (*cp != '.') && (*cp != *PATH_SEPARATOR); + cp--) + /* Empty */; + if (*cp == '.') { + dbname_end = cp - dbname; + if (PORT_Strcmp(cp, DIRSUFFIX) == 0) { + dbname_end = dbname_len; + } + } + blobDir = PORT_ZAlloc(dbname_end + sizeof(DIRSUFFIX)); + if (blobDir == NULL) { + return NULL; + } + PORT_Memcpy(blobDir, dbname, dbname_end); + PORT_Memcpy(&blobDir[dbname_end], DIRSUFFIX, sizeof(DIRSUFFIX)); + return blobDir; +} + +#define DBM_DEFAULT 0 +static const HASHINFO dbs_hashInfo = { + DBS_BLOCK_SIZE, /* bucket size, must be greater than = to + * or maximum entry size (+ header) + * we allow before blobing */ + DBM_DEFAULT, /* Fill Factor */ + DBM_DEFAULT, /* number of elements */ + DBS_CACHE_SIZE, /* cache size */ + DBM_DEFAULT, /* hash function */ + DBM_DEFAULT, /* byte order */ +}; + +/* + * the open function. NOTE: this is the only exposed function in this file. + * everything else is called through the function table pointer. + */ +DB * +dbsopen(const char *dbname, int flags, int mode, DBTYPE type, + const void *userData) +{ + DB *db = NULL, *dbs = NULL; + DBS *dbsp = NULL; + + /* NOTE: we are overriding userData with dbs_hashInfo. since all known + * callers pass 0, this is ok, otherwise we should merge the two */ + + dbsp = (DBS *)PORT_ZAlloc(sizeof(DBS)); + if (!dbsp) { + return NULL; + } + dbs = &dbsp->db; + + dbsp->blobdir = dbs_mkBlobDirName(dbname); + if (dbsp->blobdir == NULL) { + goto loser; + } + dbsp->mode = mode; + dbsp->readOnly = (PRBool)(flags == NO_RDONLY); + + /* the real dbm call */ + db = dbopen(dbname, flags, mode, type, &dbs_hashInfo); + if (db == NULL) { + goto loser; + } + dbs->internal = (void *)db; + dbs->type = type; + dbs->close = dbs_close; + dbs->get = dbs_get; + dbs->del = dbs_del; + dbs->put = dbs_put; + dbs->seq = dbs_seq; + dbs->sync = dbs_sync; + dbs->fd = dbs_fd; + + return dbs; +loser: + if (db) { + (*db->close)(db); + } + if (dbsp->blobdir) { + PORT_Free(dbsp->blobdir); + } + PORT_Free(dbsp); + return NULL; +} |