HashString (Function)

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Hash functions

HashString

Presentation

Example

Notes

HashString and UNICODE

Availability of algorithms

Related examples

See also

HashString (Function)

In french: HashChaîne

Calculates the Hash of a character string according to a specific algorithm. You can calculate:

a simple hash.
a hash with message authentication.
a hash obtained with a key derivation function that takes a salt as parameter (PBKDF2).
Not available.

Reminder: Hashing is used to summarize a file or a character string. This summary is called Hash.

Example

See additional examples

// Calculate the Hash of values for two edit controls
Hash1 is Buffer = HashString(HA_MD5_128, EDT_Edit1)
Hash2 is Buffer = HashString(HA_MD5_128, EDT_Edit2)
// Compare the two Hash
IF Hash1 = Hash2 THEN Info("The two strings are identical.")

HashString(HA_SHA_160, "abc", HashString_Callback)

INTERNAL PROCÉDURE HashString_Callback(buffer)
// This code is used to view the buffer
Trace(BufferToHexa(buffer))
END

Syntax

Calculating a simple hash Hide the details

<Result> = HashString(<Type of algorithm> , <String>)

<Result>: Buffer

Result of <String> hashing with the <Type of algorithm> algorithm.
Caution: this result may contain non-displayable characters. If this result must be displayed, it can be converted by BufferToHexa.

<Type of algorithm>: Integer constant

Indicates the type of algorithm used when hashing the <String>:
DJB2 family (Bernstein)
HA_DJB2_32
HA_DJB2_64
The constants of this family are not available.
MD4 family HA_MD4
MD5 family HA_MD5_128
Caution: this type of algorithm is currently deprecated.
MURMUR family
HA_MURMUR_1: Murmur algorithm version 1: 32-bit hash result
HA_MURMUR_2: Murmur algorithm version 2: 32-bit hash result
HA_MURMUR_2_64A: Murmur algorithm version 2: 64-bit hash result optimized for 64-bit processors
HA_MURMUR_2_64B: Murmur algorithm version 2: 64-bit hash result optimized for 32-bit processors
HA_MURMUR_2_A: Incremental Murmur algorithm version 2: 32-bit hash result
HA_MURMUR_2_BIG_ENDIAN: Murmur algorithm version 2 for big-endian machine: 32-bit hash result
HA_MURMUR_2_ALIGNE: Murmur algorithm version 2 for aligned machine: 32-bit hash result
HA_MURMUR_3_32: Murmur algorithm version 3: 32-bit hash result
HA_MURMUR_3_128_X86: Murmur algorithm version 3: 128-bit hash result optimized for 32-bit processors
HA_MURMUR_3_128_X64: Murmur algorithm version 3: 128-bit hash result optimized for 64-bit processors
The constants of this family are not available.
RIPEMD family
HA_RIPEMD_128
HA_RIPEMD_160
The constants of this family are not available.
SHA family
HA_SHA_160 (also called SHA-1)
HA_SHA_256 (FIPS PUB 198 specifications)
HA_SHA_256_DOUBLE
HA_SHA_384
HA_SHA_512
SHA-3 family
HA_SHA3_224
HA_SHA3_256
HA_SHA3_384
HA_SHA3_512
TIGER family
HA_TIGER_128
HA_TIGER_160
HA_TIGER_192
The constants of this family are not available.
WHIRLPOOL family HA_WHIRLPOOL
Not available.
CKSUM family
HA_CKSUM_8
HA_CKSUM_16
HA_CKSUM_32
HA_CKSUM_64
The constants of this family are not available.
MD4 / MD5 / SHA / RIPEMD algorithms: standard cryptographic hash functions.
TIGER/WHIRLPOOL algorithms: hash functions with high cryptographic properties optimized for the 64-bit mode (but can also be used in 32-bit mode).
CKSUM algorithms: hash functions with no cryptographic property, should be used to perform low-level checks or with hashing tables.
DJB2 algorithm (Bernstein): hash functions reserved to strings and with no cryptographic property, should be used to perform low-level checks or with hashing tables. Few risks to get an identical hash.
MURMUR algorithm: very fast hash functions with no cryptographic properties. This algorithm is used by the "bloom filter" of bitcoin wallets.

<String>: Character string

String on which the calculation will be performed. This parameter can contain binary characters.

Calculating a simple hash Hide the details

HashString(<Type of algorithm> , <String> , <WLanguage procedure>)

<Type of algorithm>: Integer constant

Indicates the type of algorithm used when hashing the <String>:
SHA family
HA_SHA_160 (also called SHA-1)
HA_SHA_256 (FIPS PUB 198 specifications)
HA_SHA_256_DOUBLE
HA_SHA_384
HA_SHA_512

Remarks:
These hash algorithms are not allowed in Internet Explorer.
The HA_SHA_160 algorithm is not allowed in Edge.

<String>: Character string

String on which the calculation will be performed. This parameter can contain binary characters.

<WLanguage procedure>: Procedure name

Name of the WLanguage procedure ("callback") called when hashing. This procedure is used to get the hash result. For more details, see Procedure used by HashString.

Calculating a hash with message authentication (HMAC/MURMUR algorithm) Hide the details

<Result> = HashString(<Type of algorithm> , <String> , <Secret key>)

<Result>: Buffer

Result of <String> hashing with the <Type of algorithm> algorithm. The length of this string depends on the algorithm used. For example, if the HA_HMAC_SHA_256 constant is used, the result will contain 32 bytes.
Caution: this result may contain non-displayable characters.

<Type of algorithm>: Integer constant

Indicates the type of algorithm (HMAC or MURMUR) used to hash the <String>:
MD4 family HA_HMAC_MD4

MD5 family HA_HMAC_MD5_128
Caution: this type of algorithm is currently deprecated.
MURMUR family
HA_MURMUR_1: Murmur algorithm version 1: 32-bit hash result
HA_MURMUR_2: Murmur algorithm version 2: 32-bit hash result
HA_MURMUR_2_64A: Murmur algorithm version 2: 64-bit hash result optimized for 64-bit processors
HA_MURMUR_2_64B: Murmur algorithm version 2: 64-bit hash result optimized for 32-bit processors
HA_MURMUR_2_A: Incremental Murmur algorithm version 2: 32-bit hash result
HA_MURMUR_2_BIG_ENDIAN: Murmur algorithm version 2 for big-endian machine: 32-bit hash result
HA_MURMUR_2_ALIGNE: Murmur algorithm version 2 for aligned machine: 32-bit hash result
HA_MURMUR_3_32: Murmur algorithm version 3: 32-bit hash result
HA_MURMUR_3_128_X86: Murmur algorithm version 3: 128-bit hash result optimized for 32-bit processors
HA_MURMUR_3_128_X64: Murmur algorithm version 3: 128-bit hash result optimized for 64-bit processors
The constants of this family are not available.
RIPEMD family
HA_HMAC_RIPEMD_128
HA_HMAC_RIPEMD_160
The constants of this family are not available.
SHA family
HA_HMAC_SHA_160
HA_HMAC_SHA_256
HA_HMAC_SHA_256_DOUBLE
HA_HMAC_SHA_384
HA_HMAC_SHA_512
SHA-3 family
HA_HMAC_SHA3_224
HA_HMAC_SHA3_256
HA_HMAC_SHA3_384
HA_HMAC_SHA3_512
TIGER family
HA_HMAC_TIGER_128
HA_HMAC_TIGER_160
HA_HMAC_TIGER_192
The constants of this family are not available.
WHIRLPOOL family HA_HMAC_WHIRLPOOL
Not available.
MD4 / MD5 / SHA / RIPEMD algorithms: standard cryptographic hash functions.
TIGER/WHIRLPOOL algorithms: hash functions with high cryptographic properties optimized for the 64-bit mode (but can also be used in 32-bit mode).
MURMUR algorithm: very fast hash functions with no cryptographic properties. This algorithm is used by the "bloom filter" of bitcoin wallets.

<String>: Character string

String on which the calculation will be performed. This parameter can contain binary characters.

<Secret key>: Character string or Integer

Authentication key of message.
If an HMAC algorithm is used, this parameter must be a string.
If a MURMUR algorithm is used, the key must be an integer.
This parameter must not be an empty string.

Calculating a hash with message authentication (HMAC algorithm) Hide the details

HashString(<Type of algorithm> , <String> , <Secret key> , <WLanguage procedure>)

<Type of algorithm>: Integer constant

Indicates the type of algorithm (HMAC) used to hash the <String> string:
SHA family
HA_HMAC_SHA_160
HA_HMAC_SHA_256
HA_HMAC_SHA_384
HA_HMAC_SHA_512

Remarks:
These hash algorithms are not allowed in Internet Explorer.
These hash algorithms are not allowed in Edge.

<String>: Character string

String on which the calculation will be performed. This parameter can contain binary characters.

<Secret key>: Character string

Authentication key of message.

<WLanguage procedure>: Procedure name

Name of the WLanguage procedure ("callback") called when hashing. This procedure is used to get the hash result. For more details, see Procedure used by HashString.

Calculating a hash using a key derivation function that takes a salt as parameter (PBKDF2) Hide the details

<Result> = HashString(<Type of algorithm> , <String> , <Salt> , <Iteration> , <Length>)

<Result>: Buffer

Result of <String> hashing with the <Type of algorithm> algorithm.
Caution: this result may contain non-displayable characters. If this result must be displayed, it can be converted by BufferToHexa.

<Type of algorithm>: Integer constant

Specifies the type of pseudo-random algorithm used by PBKDF2 to hash <String>:
MD4 family HA_PBKDF2_HMAC_MD4
MD5 family HA_PBKDF2_HMAC_MD5_128
Caution: this type of algorithm is currently deprecated.
RIPEMD family
HA_PBKDF2_HMAC_RIPEMD_128
HA_PBKDF2_HMAC_RIPEMD_160
SHA family
HA_PBKDF2_HMAC_SHA_160
HA_PBKDF2_HMAC_SHA_256
HA_PBKDF2_HMAC_SHA_256_DOUBLE
HA_PBKDF2_HMAC_SHA_384
HA_PBKDF2_HMAC_SHA_512
SHA-3 family
HA_PBKDF2_HMAC_SHA3_224
HA_PBKDF2_HMAC_SHA3_256
HA_PBKDF2_HMAC_SHA3_384
HA_PBKDF2_HMAC_SHA3_512
TIGER family
HA_PBKDF2_HMAC_TIGER_128
HA_PBKDF2_HMAC_TIGER_160
HA_PBKDF2_HMAC_TIGER_192
WHIRLPOOL family HA_PBKDF2_HMAC_WHIRLPOOL
MD4 / MD5 / SHA / RIPEMD algorithms: standard cryptographic hash functions.
TIGER/WHIRLPOOL algorithms: hash functions with high cryptographic properties optimized for the 64-bit mode (but can also be used in 32-bit mode).

<String>: Character string

String on which the calculation will be performed. This parameter can contain binary characters.

<Salt>: Character string

Cryptographic salt used. String (usually random) added to the original string to make it more complex. For example, it makes it possible for two users to use the same password.

<Iteration>: Integer

Number of iterations of the algorithm (10000 by default). This number depends on the power of the computing machine and the complexity of the hash. A minimum of 1000 iterations is generally recommended.

<Length>: Integer

Length of the derived key. By default, corresponds to the size of the key generated by the pseudo-random function. This length is technically unbounded but due to the algorithm, it is limited to (2^32 - 1) * (output length of the algorithm used by PBKDF2).

Remarks

Notes

Two identical character strings will have, for the same type of algorithm, two identical Hashes.
The result of the Hash may contain non-displayable characters. These characters will not be visible when using Info or Trace for example.

HashString and UNICODE

Caution: The Hash functions operate on the bytes found in the character strings. For the same type of algorithm, the result will differ in UNICODE and in ANSI.
Cross-platform development: To use Hash of strings between several platforms (a hash generated in iOS and checked in Android or Windows for example), no Unicode string must be used. Indeed, the Unicode strings do not have the same format according to the platforms. In this case, we advise you to use strings in ANSI or UTF 8 format (and to convert the Unicode strings if necessary).

Availability of algorithms

Algorithms are available depending on the PHP server configuration ('mhash' extension, PHP 5 with native hash function, etc).

Only the following algorithms are supported :

HA_HMAC_MD5_128
HA_HMAC_SHA_160, HA_HMAC_SHA_256, HA_HMAC_SHA_384, HA_SHA_HMAC_512
HA_HMAC_SHA_256_DOUBLE
HA_MD4
HA_MD5_128
HA_SHA_160, HA_SHA_256, HA_SHA_384, HA_SHA_512
HA_SHA_256_DOUBLE

Related Examples:

Unit examples (WINDEV): The Hash functions

[ + ] Using the hashing functions.
The HashFile and HashString functions are used to calculate a Hash key for a string or for a file.
This Hash key is used to:
- Check whether the file is consistent after a transfer for example
- Find file duplicates
- ...

Business / UI classification: Business Logic

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