PasswordSafe database format description version 3.31 ----------------------------------------------------- Copyright (c) 2003-2024 Rony Shapiro . All rights reserved. Use of the code is allowed under the Artistic License terms, as specified in the LICENSE file distributed with this code, or available from http://www.opensource.org/licenses/artistic-license-2.0.php 1. Introduction: This document defines a file format for the secure storage of passwords and related data. The format is designed according to current cryptographic best practices, and is believed to be secure, in the sense that without knowledge of the master passphrase, only a brute-force attack or a flaw in the underlying cryptographic algorithm will result in unauthorized access to the data. 1.1 Design Goals: The PasswordSafe database format is designed to be secure, extensible and platform-independent. 1.2 History: This specification is an evolution of previous formats. The main differences between version 3 of the format and previous versions are: 1.2.1. This version addresses a minor design flaw in previous versions of the PasswordSafe database format. 1.2.3. This version replaces the underlying cryptographic functions with more advanced versions. 1.2.4. This version allows the detection of a truncated or corrupted/tampered database. Meeting these goals is impossible without breaking compatibility: This format is NOT compatible with previous (major) versions. Note, however, that since the data stored in previous versions is a proper subset of the data described here, implementers may read a database written in an older version and store the result in the format described here. 2. Format: A V3 format PasswordSafe is structured as follows: TAG|SALT|ITER|H(P')|B1|B2|B3|B4|IV|HDR|R1|R2|...|Rn|EOF|HMAC Where: 2.1 TAG is the sequence of 4 ASCII characters "PWS3". This is to serve as a quick way for the application to identify the database as a PasswordSafe version 3 file. This tag has no cryptographic value. 2.2 SALT is a 256 bit random value, generated at file creation time. 2.3 P' is the "stretched key" generated from the user's passphrase and the SALT, as defined by the hash-function-based key stretching algorithm in [KEYSTRETCH] (Section 4.1), with SHA-256 [SHA256] as the hash function, and ITER iterations (at least 2048, i.e., t = 11). 2.4 ITER is the number of iterations on the hash function to calculate P', stored as a 32 bit little-endian value. This value is stored here in order to future-proof the file format against increases in processing power. 2.5 H(P') is SHA-256(P'), and is used to verify that the user has the correct passphrase. 2.6 B1 and B2 are two 128-bit blocks encrypted with Twofish [TWOFISH] using P' as the key, in ECB mode. These blocks contain the 256 bit random key K that is used to encrypt the actual records. (This has the property that there is no known or guessable information on the plaintext encrypted with the passphrase-derived key that allows an attacker to mount an attack that bypasses the key stretching algorithm.) 2.7 B3 and B4 are two 128-bit blocks encrypted with Twofish using P' as the key, in ECB mode. These blocks contain the 256 bit random key L that is used to calculate the HMAC (keyed-hash message authentication code) of the encrypted data. See description of EOF field below for more details. Implementation Note: K and L must NOT be related. 2.8 IV is the 128-bit random Initial Value for CBC mode. 2.9 All following records are encrypted using Twofish in CBC mode, with K as the encryption key. 2.9.1 HDR: The database header. The header consists of one or more typed fields (as defined in section 3.2), beginning with the Version type field, and terminated by the 'END' type field. The version number and END fields are mandatory. Aside from these two fields, no order is assumed on the field types. 2.9.2 R1..Rn: The actual database records. Each record consists of one or more typed fields (as defined in Section 3.2), terminated by the 'END' type field. The UUID, Title, and Password fields are mandatory. All non- mandatory fields may either be absent or have zero length. When a field is absent or zero-length, its default value shall be used. Aside from the 'END' field, no order is assumed on the field types. 2.10 EOF: The ASCII characters "PWS3-EOFPWS3-EOF" (note that this is exactly one block long), unencrypted. This is an implementation convenience to inform the application that the following bytes are to be processed differently. 2.11 HMAC: The 256-bit keyed-hash MAC, as described in RFC2104, with SHA- 256 as the underlying hash function. The value is calculated over all of the plaintext fields, that is, over all the data stored in all fields (starting from the version number in the header, ending with the last field of the last record). The key L, as stored in B3 and B4, is used as the hash key value. 3. Fields: Data in PasswordSafe is stored in typed fields. Each field consists of one or more blocks. The blocks are the blocks of the underlying encryption algorithm - 16 bytes long for Twofish. The first block contains the field length in the first 4 bytes (little-endian), followed by a one- byte type identifier. The rest of the block contains up to 11 bytes of record data. If the record has less than 11 bytes of data, the extra bytes are filled with random values. The type of a field also defines the data representation. 3.1 Data representations 3.1.1 UUID The UUID data type is 16 bytes long, as defined in RFC4122. Microsoft Windows has functions for this, and the RFC has a sample implementation. 3.1.2 Text Text is represented in UTF-8 encoding (as defined in RFC3629), with no byte order marker (BOM) and no end-of-string mark (e.g., null byte). Note that the latter isn't necessary since the length of the field is provided explicitly. Note that ALL fields described as "text" are UTF-8 encoded unless explicitly stated otherwise. 3.1.3 Time Timestamps are stored as 32 bit, little endian, unsigned integers, representing the number of seconds since Midnight, January 1, 1970, GMT. (This is equivalent to the time_t type on Windows and POSIX. On the Macintosh, the value needs to be adjusted by the constant value 2082844800 to account for the different epoch of its time_t type.) Note that future versions of this format may allow time to be specified in 64 bits as well. 3.2 Field types for the PasswordSafe database header: Currently Name Value Type Implemented Comments -------------------------------------------------------------------------- Version 0x00 2 bytes Y [1] UUID 0x01 UUID Y [2] Non-default preferences 0x02 Text Y [3] Tree Display Status 0x03 Text Y [4] Timestamp of last save 0x04 time_t Y [5] Who performed last save 0x05 Text Y [DEPRECATED 6] What performed last save 0x06 Text Y [7] Last saved by user 0x07 Text Y [8] Last saved on host 0x08 Text Y [9] Database Name 0x09 Text Y [10] Database Description 0x0a Text Y [11] Database Filters 0x0b Text Y [12] Reserved 0x0c - [13] Reserved 0x0d - [13] Reserved 0x0e - [13] Recently Used Entries 0x0f Text [14] Named Password Policies 0x10 Text [15] Empty Groups 0x11 Text [16] Yubico 0x12 Text [13] Timestamp of last master password change 0x13 time_t Y [5] End of Entry 0xff [empty] Y [17] [1] The version number of the database format. For example, the value 0x0310 is stored in little-endian format, that is, 0x10, 0x03. PasswordSafe V3.01 introduced Format 0x0300 PasswordSafe V3.03 introduced Format 0x0301 PasswordSafe V3.09 introduced Format 0x0302 PasswordSafe V3.12 introduced Format 0x0303 PasswordSafe V3.13 introduced Format 0x0304 PasswordSafe V3.14 introduced Format 0x0305 PasswordSafe V3.19 introduced Format 0x0306 PasswordSafe V3.22 introduced Format 0x0307 PasswordSafe V3.25 introduced Format 0x0308 PasswordSafe V3.26 introduced Format 0x0309 PasswordSafe V3.28 introduced Format 0x030A PasswordSafe V3.29 introduced Format 0x030B PasswordSafe V3.29Y introduced Format 0x030C PasswordSafe V3.30 introduced Format 0x030D PasswordSafe V3.47 introduced Format 0x030E [2] A universally unique identifier is needed in order to synchronize databases across different machine. Representation is described in Section 3.1.1. [3] Non-default preferences are encoded in a string as follows: The string is of the form "X nn vv X nn vv..." Where X=[BIS] for boolean, integer and string respectively, nn is the numeric value of the enum, and vv is the value, {1 or 0} for bool, unsigned integer for int, and a delimited string for String. Only non-default values are stored. See PWSprefs.cpp for more details. Note: normally strings are delimited by the doublequote character. However, if this character is in the string value, an arbitrary character will be chosen to delimit the string. Version 0x0309 added database wide special symbols to the Non-default preferences (0x02). [4] If requested to be saved, this is a string of 1s and 0s indicating the expanded state of the tree display when the database was saved. This can be applied at database open time, if the user wishes, so that the tree is displayed as it was. Alternatively, it can be ignored and the tree displayed completely expanded or collapsed. Note that the mapping of the string to the display state is implementation-specific. Introduced in format 0x0301. [5] Representation is as described in Section 3.1.3. Note that prior to PasswordSafe 3.09, this field was mistakenly represented as an eight-byte hexadecimal ASCII string. Implementations SHOULD attempt to parse 8-byte long timestamps as a hexadecimal ASCII string representation of the timestamp value. [6] Text saved in the format: nnnnu..uh..h, where: nnnn = 4 hexadecimal digits giving length of following user name field u..u = user name h..h = host computer name Note: As of format 0x0302, this field is deprecated, and should be replaced by fields 0x07 and 0x08. In databases prior to format 0x0302, this field should be maintained. 0x0302 and later may either maintain this field in addition to fields 0x07 and 0x08, for backwards compatability, or not write this field. If both this field and 0x07, 0x08 exist, they MUST represent the same values. [7] Free form text giving the application that saved the database. For example, the Windows PasswordSafe application will use the text "Password Safe Vnn.mm", where nn and mm are the major and minor version numbers. The major version will contain only the significant digits whereas the minor version will be padded to the left with zeroes e.g. "Password Safe V3.02". [8] Text containing the username (e.g., login, userid, etc.) of the user who last saved the database, as determined by the appropriate operating-system dependent function. This field was introduced in format version 0x0302, as a replacement for field 0x05. See Comment [6]. [9] Text containing the hostname (e.g., machine name, hostid, etc.) of the machine on which the database was last saved, as determined by the appropriate operating-system dependent function. This field was introduced in format version 0x0302, as a replacement for field 0x05. See Comment [6]. [10] Database name. A logical name for a database which can be used by applications in place of the possibly lengthy filepath notion. Note that this field SHOULD be limited to what can be displayed in a single line. This field was introduced in format version 0x0302. [11] Database Description. A purely informative description concerning the purpose or other practical use of the database. This field was introduced in format version 0x0302. [12] Specific filters for this database. This is the text equivalent to the XML export of the filters as defined by the filter schema. The text 'image' has no 'print formatting' e.g. tabs and carriage return/line feeds, since XML processing does not require this. This field was introduced in format version 0x0305. [13] Values marked 'Reserved' are know to have been used by customized versions of PasswordSafe. To ensure compatability between versions, use of these values should be avoided. [14] A list of the UUIDs (32 hex character representation of the 16 byte field) of the recently used entries, prefixed by a 2 hex character representation of the number of these entries (right justified and left filled with zeroes). The size of the number of entries field gives a maximum number of entries of 255, however the GUI may impose further restrictions e.g. Windows MFC UI limits this to 25. The first entry is the most recent entry accessed. This field was introduced in format version 0x0307. [15] This field allows multiple Password Policies per database. The format is: "NN{LLxxx...xxxffffnnnllluuudddsssMMSSS...SSS}" where: NN = 2 hexadecimal digits giving number of password policies in field (max. 255). Each entry is of the form: LL = 2 hexadecimal digits giving length of the policy name in bytes xxx...xxx = The policy name (maximum 255 bytes) ffff = 4 hexadecimal digits representing the following flags UseLowercase 0x8000 UseUppercase 0x4000 UseDigits 0x2000 UseSymbols 0x1000 UseHexDigits 0x0800 (if set, then no other flags can be set) UseEasyVision 0x0400 MakePronounceable 0x0200 Unused 0x01ff nnn = 3 hexadecimal digits password total length lll = 3 hexadecimal digits password minimum number of lowercase characters uuu = 3 hexadecimal digits password minimum number of uppercase characters ddd = 3 hexadecimal digits password minimum number of digit characters sss = 3 hexadecimal digits password minimum number of symbol characters MM = 2 hexadecimal digits giving the length in bytes of allowed special symbols, or zero to specify the database default special symbol set. SSS...SSS = List of allowed symbols in this policy (maximum 255 bytes) This field was introduced in format version 0x030A. [16] This fields contains the name of an empty group that cannot be constructed from entries within the database. Unlike other header fields, this field can appear multiple times. This field was introduced in format version 0x030B. [17] An explicit end of entry field is useful for supporting new fields without breaking backwards compatability. 3.3 Field types for database Records: Currently Name Value Type Implemented Comments -------------------------------------------------------------------------- UUID 0x01 UUID Y [1] Group 0x02 Text Y [2] Title 0x03 Text Y Username 0x04 Text Y Notes 0x05 Text Y Password 0x06 Text Y [3,4,21] Creation Time 0x07 time_t Y [5] Password Modification Time 0x08 time_t Y [5] Last Access Time 0x09 time_t Y [5,6] Password Expiry Time 0x0a time_t Y [5,7] *RESERVED* 0x0b 4 bytes - [8] Last Modification Time 0x0c time_t Y [5,9] URL 0x0d Text Y [10] Autotype 0x0e Text Y [11] Password History 0x0f Text Y [12] Password Policy 0x10 Text Y [13] Password Expiry Interval 0x11 4 bytes Y [14] Run Command 0x12 Text Y Double-Click Action 0x13 2 bytes Y [15] EMail address 0x14 Text Y [16] Protected Entry 0x15 1 byte Y [17] Own symbols for password 0x16 Text Y [18] Shift Double-Click Action 0x17 2 bytes Y [15] Password Policy Name 0x18 Text Y [19] Entry keyboard shortcut 0x19 4 bytes Y [20] *RESERVED* 0x1a UUID - [22] Two-Factor Key 0x1b Binary N [23] Credit Card Number 0x1c Text N [24] Credit Card Expiration 0x1d Text N [24] Credit Card Verif. Value 0x1e Text N [24] Credit Card PIN 0x1f Text N [24] QR Code 0x20 Text N [25] TOTP Config 0x21 1 byte N [29] TOTP Length 0x22 1 byte N [29] TOTP Time Step 0x23 1 byte N [29] TOTP Start Time 0x24 time_t N [29] Unknown (testing) 0xdf - N [26] Implementation-specific 0xe0-0xfe - N [27] End of Entry 0xff [empty] Y [28] [1] Per-record UUID to assist in sync, merge, etc. Representation is as described in Section 3.1.1. [2] The "Group" supports displaying the entries in a tree-like manner. Groups can be hierarchical, with elements separated by a period, supporting groups such as "Finance.credit cards.Visa", "Finance.credit cards.Mastercard", Finance.bank.web access", etc. Dots entered by the user should be "escaped" by the application. [3] If the entry is an alias, the password will be saved in a special form of "[[uuidstr]]", where "uuidstr" is a 32-character representation of the alias' associated base entry's UUID (field type 0x01). This representation is the same as the standard 36-character string representation as defined in RFC4122 but with the four hyphens removed. If an entry with this UUID is not in the database, this is treated just as an 'unusual' password. The alias will only use its base's password entry when copying it to the clipboard or during Autotype. [4] If the entry is a shortcut, the password will be saved in a special form of "[~uuidstr~]", where "uuidstr" is a 32-character representation of the shortcut's associated base entry's UUID (field type 0x01). This representation is the same as the standard 36-character string representation as defined in RFC4122 but with the four hyphens removed. If an entry with this UUID is not in the database, this is treated just as an 'unusual' password. The shortcut will use all its base's data when used in any action. It has no fields of its own. [5] Representation is as described in Section 3.1.3. [6] This will be updated whenever any part of this entry is accessed i.e., to copy its username, password or notes to the clipboard; to perform autotype or to browse to url. [7] This will allow the user to enter an expiry date for an entry. The application can then prompt the user about passwords that need to be changed. A value of zero means "forever". [8] Although earmarked for Password Policy, the coding in versions prior to V3.12 does not correctly handle the presence of this field. For this reason, this value cannot be used for any future V3 field without causing a potential issue when a user opens a V3.12 or later database with program version V3.11 or earlier. See note [14]. [9] This is the time that any field of the record was modified, useful for merging databases. [10] The URL will be passed to the shell when the user chooses the "Browse to" action for this entry. In version 2 of the format, this was extracted from the Notes field. By placing it in a separate field, we are no longer restricted to a URL - any action that may be executed by the shell may be specified here. [11] The text to be 'typed' by PasswordSafe upon the "Perform Autotype" action maybe specified here. If unspecified, the default value of 'username, tab, password, tab, enter' is used. In version 2 of the format, this was extracted from the Notes field. Several codes are recognized here, e.g, '\p' is replaced by the record's password. See the user documentation for the complete list of codes. The replacement is done by the application at runtime, and is not stored in the database. [12] Password History is an optional record. If it exists, it stores the creation times and values of the last few passwords used in the current entry, in the following format: "fmmnnTLPTLP...TLP" where: f = {0,1} if password history is off(0) / on(1) mm = 2 hexadecimal digits max size of history list (i.e. max = 255) nn = 2 hexadecimal digits current size of history list T = Time password was set (time_t written out in %08x) L = 4 hexadecimal digit password length (in TCHAR) P = Password The list is sorted by T, with the oldest entry first. Newer entries are appended to the end of the list. No history being kept for a record can be represented either by the lack of the PWH field (preferred), or by a header of _T("00000"): flag = 0, max = 00, num = 00 Note that 0aabb, where bb <= aa, is possible if password history was enabled in the past and has then been disabled but the history hasn't been cleared. [13] This field allows a specific Password Policy per entry. This field is mutually exclusive with the policy name field [0x18]. The format is: "ffffnnnllluuudddsss" where: ffff = 4 hexadecimal digits representing the following flags UseLowercase 0x8000 UseUppercase 0x4000 UseDigits 0x2000 UseSymbols 0x1000 UseHexDigits 0x0800 (if set, then no other flags can be set) UseEasyVision 0x0400 MakePronounceable 0x0200 Unused 0x01ff nnn = 3 hexadecimal digits password total length lll = 3 hexadecimal digits password minimum number of lowercase characters uuu = 3 hexadecimal digits password minimum number of uppercase characters ddd = 3 hexadecimal digits password minimum number of digit characters sss = 3 hexadecimal digits password minimum number of symbol characters [14] Password Expiry Interval, in days, before this password expires. Once set, this value is used when the password is first generated and thereafter whenever the password is changed, until this value is unset. Valid values are 1-3650 corresponding to up to approximately 10 years. A value of zero is equivalent to this field not being set. Note that until Nov. 2013 this was specified as a 16 bit field, but implemented as a 32 bit value. The specification was updated, rather than the implementation, in order not to break backwards compatibility. Value is stored in little-endian format. [15] A two byte field contain the value of the Double-Click Action and Shift Double-Click Action'preference value' (0xff means use the current Application default): Current 'preference values' are: CopyPassword 0 ViewEdit 1 AutoType 2 Browse 3 CopyNotes 4 CopyUsername 5 CopyPasswordMinimize 6 BrowsePlus 7 Run Command 8 Send email 9 [16] Separate Email address field as per RFC 2368 (without the 'mailto:' prefix. This field was introduced in version 0x0306 (PasswordSafe V3.19). [17] Entry is protected, i.e., the entry cannot be changed or deleted while this field is set. This field was introduced in version 0x0308 (PasswordSafe V3.25). This a single byte. An absent field or a zero valued field means that the entry is not protected. Any non-zero value means that the entry is protected. [18] Each entry can now specify its own set of allowed special symbols for password generation. This overrides the default set and any database specific set. This field is mutually exclusive with the policy name field [0x18]. This was introduced in version 0x0309 (PasswordSafe V3.26). [19] Each entry can now specify the name of a Password Policy saved in the database header for password generation. This field is mutually exclusive with the specific policy field [0x10] and with the Own symbols for password field [0x16]. This was introduced in version 0x030A (PasswordSafe V3.28). [20] Entry keyboard shortcut. Format is: Bytes 0-1: Virtual KeyCode for the character (Windows only uses byte 0) Byte 2 : Keyboard Modifiers - a bitwise OR of any valid combination of: PWS_HOTKEYF_ALT 0x01 PWS_HOTKEYF_CONTROL 0x02 PWS_HOTKEYF_SHIFT 0x04 PWS_HOTKEYF_EXT 0x08 PWS_HOTKEYF_META 0x10 (not supported by Windows) PWS_HOTKEYF_WIN 0x20 (not supported by Windows) PWS_HOTKEYF_CMD 0x40 (not supported by Windows) Byte 3 : zero This was introduced in version 0x030D (PasswordSafe V3.30). [21] There are five types of entry: a. Normal entry: Without any aliases or shortcuts b. Alias base entry: With one or more aliases (but can't have shortcuts) c. Shortcut base entry: With one or more shortcuts (but can't have aliases) d. Alias entry (as described in note [3]) e. Shortcut entry (as described in note [4]) Note: A 'base' entry can not have both aliases and shortcuts. [22] This value is used in V4 of the PasswordSafe format. Reserving it here to maintain consistency with values that follow. [23] This is the shared secret for sites using Time-Based One-Time Password Algorithm (per RFC6238) such as Google Authenticator. At least 10 bytes. [24] Credit card specific fields. All values are UTF-8 encoded: - Number should consist of digits and spaces. - Expiration should be MM/YY, where MM is 01-12, and YY 00-99. - CVV (CVV2) is three or four digits. - PIN is four to twelve digits long (ISO-9564) [25] UTF-8 encoded text used for QR code generation. Content will be converted to QR code without any further encoding. [26] Reserved for testing forward compatability. [27] Reserved for application-specific use. See 4.2.2. [28] An explicit end of entry field is useful for supporting new fields without breaking backwards compatability. [29] The TOTP parameters fields are TOTP Config (0x21), TOTP Digits (0x22), TOTP Time Step (0x23), and TOTP Start Time (0x24). If any of these fields is not present, a default applies as specified below. These fields, or their implicit default values, are only used by Password Safe if the "Two Factor Key" field (0x1b) is present. These TOTP parameters fields have the following format: TOTP Config = 1 byte with the following format (bit 7 is MSB): bits 0-1: HMAC hash algorithm as follows: 0x00: SHA1 (all other values 0x01 through 0x03 are reserved.) bits 2-7: Reserved. If this TOTP Config field is not present, the default HMAC hash algorithm is SHA1 (HMAC-SHA1). TOTP Length = 1 byte indicating the number of TOTP code digits. This is the RFC4226 "Digit" value. If not specified, the default length for a TOTP code is 6 digits (0x06). TOTP Time Step = 1 byte indicating the RFC6238 time step "X" value in seconds. If not specified, the default is 30 seconds (0x1E). TOTP Start Time = This is the RFC6238 "T0" value, the time at which to start counting time steps. If not specified, the default is 0. The format is that of a 40 bit (5 byte) Password Safe time_t value as specified in Section 3.1.3. 4. Extensibility 4.1 Forward compatability: Implementations of this format SHOULD NOT discard or report an error when encountering a field of an unknown type. Rather, the field(s) type and data should be read, and preserved when the database is saved. 4.2 Field type identifiers: This document specifies the field type identifiers for the current version of the format. Compliant implementations MUST support the mandatory fields, and SHOULD support the other fields described herein. Future versions of the format may specify other type identifiers. 4.2.1 Application-unique type identifiers: The type identifiers 0xc0-0xdf are available for application developers on a first-come first-serve basis. Application developers interested in reserving a type identifier for their application should contact the maintainer of this document (Currently the PasswordSafe project administrator at SourceForge). 4.2.2 Application-specific type identifiers: The type identifiers 0xe0-0xfe are reserved for implementation-specific purposes, and will NOT be specified in this or future versions of the format description. 4.2.3 All unassigned identifiers except as listed in the previous two subsections are reserved, and should not be used by other implementations of this format specification in the interest of interoperability. 5. References: [TWOFISH] http://www.schneier.com/paper-twofish-paper.html [SHA256] http://csrc.nist.gov/publications/fips/fips180-2/fips180-2withchangenotice.pdf [KEYSTRETCH] https://www.schneier.com/wp-content/uploads/2016/02/paper-low-entropy.pdf End of Format description.