pkcs7

PKCS #7 padding in Haskell https://github.com/kisom/pkcs7

Latest on Hackage:1.0.0.1

This package is not currently in any snapshots. If you're interested in using it, we recommend adding it to Stackage Nightly. Doing so will make builds more reliable, and allow stackage.org to host generated Haddocks.

MIT licensed by K. Isom
Maintained by coder@kyleisom.net

pkcs7

Build Status

This implements the PKCS #7 padding scheme. This scheme is defined in RFC 5652, section 6.3.

Strings will be padded out to multiples of the block size; for example, a 5-byte string with an 8-byte block size will have three bytes of padding added. If the length is already a multiple of the block size, an entire block size worth of padding is added.

The padding bytes are all set to the number of padding bytes. Returning to the previous example, the padding string would be three bytes of the byte 0x03.

Unpadding checks the length and padding, and if this is valid, strips off the padding.

The following functions are defined for Strings:

  • pad: apply PKCS #7 padding assuming an AES block size
  • padN: apply PKCS #7 padding, specifying the block size
  • unpad: remove PKCS #7 padding assuming an AES block size
  • unpadN: remove PKCS #7 padding, specifying the block size

The following functions are defined for ByteStrings:

  • padBytes: apply PKCS #7 padding assuming an AES block size
  • padBytesN: apply PKCS #7 padding, specifying the block size
  • unpadBytes: remove PKCS #7 padding assuming an AES block size
  • unpadBytesN: remove PKCS #7 padding, specifying the block size

The unpadding functions return a Maybe a (where a is either a String or ByteString, depending on the function). If there was a padding error, Nothing is returned. Otherwise, Just the string is returned.

Depends on:
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