--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/nss/lib/softoken/legacydb/dbmshim.c	Tue Aug 05 18:32:02 2014 +0200
@@ -0,0 +1,613 @@
+/* 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;
+    PRFileMap *dbs_mapfile;
+    unsigned char *dbs_addr;
+    PRUint32 dbs_len;
+    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;
+}
+
+
+/*
+ * we need to keep a address map in memory between calls to DBM.
+ * remember what we have mapped can close it when we get another dbm
+ * call. 
+ *
+ * NOTE: Not all platforms support mapped files. This code is designed to
+ * detect this at runtime. If map files aren't supported the OS will indicate
+ * this by failing the PR_Memmap call. In this case we emulate mapped files
+ * by just reading in the file into regular memory. We signal this state by
+ * making dbs_mapfile NULL and dbs_addr non-NULL.
+ */
+
+static void
+dbs_freemap(DBS *dbsp)
+{
+    if (dbsp->dbs_mapfile) {
+	PR_MemUnmap(dbsp->dbs_addr,dbsp->dbs_len);
+	PR_CloseFileMap(dbsp->dbs_mapfile);
+	dbsp->dbs_mapfile = NULL;
+	dbsp->dbs_addr = NULL;
+	dbsp->dbs_len = 0;
+    } else if (dbsp->dbs_addr) {
+	PORT_Free(dbsp->dbs_addr);
+	dbsp->dbs_addr = NULL;
+	dbsp->dbs_len = 0;
+    }
+    return;
+}
+
+static void
+dbs_setmap(DBS *dbsp, PRFileMap *mapfile, unsigned char *addr, PRUint32 len)
+{
+    dbsp->dbs_mapfile = mapfile;
+    dbsp->dbs_addr = addr;
+    dbsp->dbs_len = len;
+}
+
+/*
+ * 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;
+    PRFileMap *mapfile = 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);
+    mapfile = PR_CreateFileMap(filed, len, PR_PROT_READONLY);
+    if (mapfile == NULL) {
+	 /* USE PR_GetError instead of PORT_GetError here
+	  * because we are getting the error from PR_xxx
+	  * function */
+	if (PR_GetError() != PR_NOT_IMPLEMENTED_ERROR) {
+	    goto loser;
+	}
+	addr = dbs_EmulateMap(filed, len);
+    } else {
+	addr = PR_MemMap(mapfile, 0, len);
+    }
+    if (addr == NULL) {
+	goto loser;
+    }
+    PR_Close(filed);
+    dbs_setmap(dbsp,mapfile,addr,len);
+
+    data->data = addr;
+    data->size = len;
+    return 0;
+
+loser:
+    /* preserve the error code */
+    error = PR_GetError();
+    if (mapfile) {
+	PR_CloseFileMap(mapfile);
+    }
+    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;
+    
+
+    dbs_freemap(dbsp);
+    
+    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;
+
+    dbs_freemap(dbsp);
+
+    /* 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;
+    DBS *dbsp = (DBS *)dbs;
+
+    dbs_freemap(dbsp);
+
+    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;
+
+    dbs_freemap(dbsp);
+
+    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;
+    
+    dbs_freemap(dbsp);
+    
+    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;
+
+    dbs_freemap(dbsp);
+    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);
+    dbsp->dbs_mapfile = NULL;
+    dbsp->dbs_addr = NULL;
+    dbsp->dbs_len = 0;
+
+    /* 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) {
+	if (dbsp->blobdir) {
+	    PORT_Free(dbsp->blobdir);
+	}
+	PORT_Free(dbsp);
+    }
+    return NULL;
+}