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hash ​

NAME ​

hash - compute cryptographic hash of a string

SYNOPSIS ​

string hash(string algorithm, string data);

DESCRIPTION ​

Computes a cryptographic hash of the input data using the specified algorithm.
Returns the hash as a hexadecimal string.

This efun utilizes the OpenSSL crypto library and supports a wide range of
hash algorithms from legacy to modern cryptographic hash functions.

SUPPORTED ALGORITHMS ​

Legacy Hash Algorithms (OpenSSL 1.0.0+):

  • "md2" - MD2 (deprecated, removed in OpenSSL 3.0+)
  • "md4" - MD4 (insecure, for legacy compatibility only)
  • "md5" - MD5 (128-bit, insecure for cryptographic purposes)
  • "mdc2" - MDC2 (deprecated, removed in OpenSSL 3.0+)
  • "sha1" - SHA-1 (160-bit, deprecated for cryptographic use)
  • "ripemd160" - RIPEMD-160 (160-bit)

SHA-2 Family (OpenSSL 1.0.0+):

  • "sha224" - SHA-224 (224-bit)
  • "sha256" - SHA-256 (256-bit, recommended for general use)
  • "sha384" - SHA-384 (384-bit)
  • "sha512" - SHA-512 (512-bit)

SHA-3 Family (OpenSSL 1.1.1+, FIPS 202 standard):

  • "sha3-224" - SHA3-224 (224-bit)
  • "sha3-256" - SHA3-256 (256-bit, recommended modern algorithm)
  • "sha3-384" - SHA3-384 (384-bit)
  • "sha3-512" - SHA3-512 (512-bit)

BLAKE2 Family (OpenSSL 1.1.0+, RFC 7693):

  • "blake2b512" - BLAKE2b-512 (512-bit, very fast and secure)
  • "blake2s256" - BLAKE2s-256 (256-bit, optimized for 8-32 bit platforms)

Other Modern Algorithms:

  • "sm3" - SM3 (256-bit, Chinese national standard, OpenSSL 1.1.1+)

ARGUMENTS ​

  • algorithm - The hash algorithm name (case-insensitive)
  • data - The string data to hash

RETURN VALUE ​

Returns a hexadecimal string representation of the computed hash.

ERRORS ​

Generates an error if the specified algorithm is unknown or not supported by the OpenSSL version linked with FluffOS.

EXAMPLES ​

c
// Hash a password with SHA-256
string password_hash = hash("sha256", "my_password");
// Result: "d80e3a0e7c0c67c7e5e8c5c5e4c7c5e..."

// Use modern SHA-3
string secure_hash = hash("sha3-256", "important data");

// Use BLAKE2 for high performance hashing
string fast_hash = hash("blake2b512", large_data);

// Legacy MD5 (for compatibility only, not secure)
string md5_sum = hash("md5", "test data");
// Result: "eb733a00c0c9d336e65691a37ab54293"

SECURITY NOTES ​

Recommended Algorithms:

  • General purpose: sha256, sha3-256, or blake2b512
  • High performance: blake2b512 or blake2s256
  • Standards compliance: sha256 (FIPS 180-4) or sha3-256 (FIPS 202)

Deprecated/Insecure Algorithms:

  • DO NOT USE for security: md2, md4, md5, sha1
  • These are provided only for legacy compatibility and non-cryptographic uses
  • md5 and sha1 are vulnerable to collision attacks

Version Requirements:

  • Legacy algorithms (MD4, MD5, SHA-1, SHA-2, RIPEMD160): OpenSSL 1.0.0+
  • BLAKE2 family: OpenSSL 1.1.0+
  • SHA-3 family and SM3: OpenSSL 1.1.1+
  • MD2 and MDC2: Only available in OpenSSL versions prior to 3.0

SEE ALSO ​

  • crypt(3) - Password hashing with salts
  • oldcrypt(3) - Legacy password hashing

NOTES ​

  • Algorithm names are case-insensitive
  • The package must be compiled with PACKAGE_CRYPTO enabled
  • Requires linking against OpenSSL crypto library (-lssl -lcrypto)
  • On Windows, PACKAGE_CRYPTO is typically disabled by default

AVAILABILITY ​

Requires the crypto package to be enabled at compile time. Not available on all platforms (typically disabled on Windows).