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Crypto.md

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Crypto (abstract)

Namespace: \ParagonIE\Halite\Symmetric

Methods

authenticate()

public authenticate(string $message, AuthenticationKey $secretKey, $encoding = Halite::ENCODE_BASE64URLSAFE) : string

Calculate a MAC for a given message, using a secret authentication key.

encrypt()

public encrypt(HiddenString $plaintext, EncryptionKey $secretKey, $encoding = Halite::ENCODE_BASE64URLSAFE): string

Encrypt-then-authenticate a message. This method will:

  1. Generate a random HKDF salt.
  2. Split the EncryptionKey into an encryption key and authentication key using salted HKDF.
  3. Generate a random nonce.
  4. Encrypt your plaintext ($source) with the derived encryption key (step 2).
  5. MAC the ciphertext (step 4), along with the current library version, the HKDF salt, and the nonce, with the derived authentication key (step 2).
  6. Return the output of step 5 either as raw binary or as a hex-encoded string.

decrypt()

public decrypt(string $ciphertext, EncryptionKey $secretKey, $encoding = Halite::ENCODE_BASE64URLSAFE) : HiddenString

Verify-then-decrypt a message. This method will:

  1. If we aren't expecting raw data, we treat $source as a hex string and decode it to raw binary.
  2. Parse the library version tag, HKDF salt, and nonce from the message.
  3. Split the EncryptionKey into an encryption key and authentication key using salted HKDF.
  4. Verify the MAC using the derived authentication key (step 3).
  5. If step 4 is successful, decrypt the ciphertext with the derived encryption key (step 3).
  6. Return what should be the original plaintext.

encryptWithAd()

public encryptWithAd(HiddenString $plaintext, EncryptionKey $secretKey, string $additionalData = '', $encoding = Halite::ENCODE_BASE64URLSAFE): string

This is similar to encrypt(), except the $additionalData string is prepended to the ciphertext (after the nonce) when calculating the Message Authentication Code (MAC).

decryptWithAd()

public decryptWithAd(string $ciphertext, EncryptionKey $secretKey, string $additionalData = '', $encoding = Halite::ENCODE_BASE64URLSAFE): HiddenString

This is similar to decrypt(), except the $additionalData string is prepended to the ciphertext (after the nonce) when calculating the Message Authentication Code (MAC).

verify()

public verify(string $message, AuthenticationKey $secretKey, string $mac, $encoding = Halite::ENCODE_BASE64URLSAFE) : boolean

Verify the MAC for a given message and secret authentication key.