# Heimdal Kerberos 5 cryptography functions

## Functions

krb5_error_code KRB5_LIB_FUNCTION | krb5_cksumtype_to_enctype (krb5_context context, krb5_cksumtype ctype, krb5_enctype *etype)
krb5_error_code KRB5_LIB_FUNCTION | krb5_encrypt_iov_ivec (krb5_context context, krb5_crypto crypto, unsigned usage, krb5_crypto_iov *data, int num_data, void *ivec)
krb5_error_code KRB5_LIB_FUNCTION | krb5_decrypt_iov_ivec (krb5_context context, krb5_crypto crypto, unsigned usage, krb5_crypto_iov *data, unsigned int num_data, void *ivec)
krb5_error_code KRB5_LIB_FUNCTION | krb5_create_checksum_iov (krb5_context context, krb5_crypto crypto, unsigned usage, krb5_crypto_iov *data, unsigned int num_data, krb5_cksumtype *type)
krb5_error_code KRB5_LIB_FUNCTION | krb5_verify_checksum_iov (krb5_context context, krb5_crypto crypto, unsigned usage, krb5_crypto_iov *data, unsigned int num_data, krb5_cksumtype *type)
krb5_error_code KRB5_LIB_FUNCTION | krb5_crypto_init (krb5_context context, const krb5_keyblock *key, krb5_enctype etype, krb5_crypto *crypto)
krb5_error_code KRB5_LIB_FUNCTION | krb5_crypto_destroy (krb5_context context, krb5_crypto crypto)
krb5_error_code KRB5_LIB_FUNCTION | krb5_crypto_getblocksize (krb5_context context, krb5_crypto crypto, size_t *blocksize)
krb5_error_code KRB5_LIB_FUNCTION | krb5_crypto_getenctype (krb5_context context, krb5_crypto crypto, krb5_enctype *enctype)
krb5_error_code KRB5_LIB_FUNCTION | krb5_crypto_getpadsize (krb5_context context, krb5_crypto crypto, size_t *padsize)
krb5_error_code KRB5_LIB_FUNCTION | krb5_crypto_getconfoundersize (krb5_context context, krb5_crypto crypto, size_t *confoundersize)
krb5_error_code KRB5_LIB_FUNCTION | krb5_enctype_disable (krb5_context context, krb5_enctype enctype)
krb5_error_code KRB5_LIB_FUNCTION | krb5_enctype_enable (krb5_context context, krb5_enctype enctype)
krb5_error_code KRB5_LIB_FUNCTION | krb5_allow_weak_crypto (krb5_context context, krb5_boolean enable)
krb5_error_code KRB5_LIB_FUNCTION | krb5_random_to_key (krb5_context context, krb5_enctype type, const void *data, size_t size, krb5_keyblock *key)
krb5_error_code KRB5_LIB_FUNCTION | krb5_crypto_fx_cf2 (krb5_context context, const krb5_crypto crypto1, const krb5_crypto crypto2, krb5_data *pepper1, krb5_data *pepper2, krb5_enctype enctype, krb5_keyblock *res)
krb5_error_code KRB5_LIB_FUNCTION | krb5_generate_subkey_extended (krb5_context context, const krb5_keyblock *key, krb5_enctype etype, krb5_keyblock **subkey)
void KRB5_LIB_FUNCTION | krb5_keyblock_zero (krb5_keyblock *keyblock)
void KRB5_LIB_FUNCTION | krb5_free_keyblock_contents (krb5_context context, krb5_keyblock *keyblock)
void KRB5_LIB_FUNCTION | krb5_free_keyblock (krb5_context context, krb5_keyblock *keyblock)
krb5_error_code KRB5_LIB_FUNCTION | krb5_copy_keyblock_contents (krb5_context context, const krb5_keyblock *inblock, krb5_keyblock *to)
krb5_error_code KRB5_LIB_FUNCTION | krb5_copy_keyblock (krb5_context context, const krb5_keyblock *inblock, krb5_keyblock **to)
krb5_enctype | krb5_keyblock_get_enctype (const krb5_keyblock *block)
krb5_error_code KRB5_LIB_FUNCTION | krb5_keyblock_init (krb5_context context, krb5_enctype type, const void *data, size_t size, krb5_keyblock *key)

## Detailed Description

## Function Documentation

krb5_error_code KRB5_LIB_FUNCTION krb5_allow_weak_crypto | ( | krb5_context | context,
|  | krb5_boolean | enable |
| ) |  |  |

Enable or disable all weak encryption types

Parameters:

  | context | Kerberos 5 context
  | enable | true to enable, false to disable

Returns:
  Return an error code or 0.

krb5_error_code KRB5_LIB_FUNCTION krb5_cksumtype_to_enctype | ( | krb5_context | context,
|  | krb5_cksumtype | ctype,
|  | krb5_enctype * | etype |
| ) |  |  |

Return the coresponding encryption type for a checksum type.

Parameters:

  | context | Kerberos context
  | ctype | The checksum type to get the result enctype for
  | etype | The returned encryption, when the matching etype is not found, etype is set to ETYPE_NULL.

Returns:
  Return an error code for an failure or 0 on success.

krb5_error_code KRB5_LIB_FUNCTION krb5_copy_keyblock | ( | krb5_context | context,
|  | const krb5_keyblock * | inblock,
|  | krb5_keyblock ** | to |
| ) |  |  |

Copy a keyblock, free the output keyblock with krb5_free_keyblock().

Parameters:

  | context | a Kerberos 5 context
  | inblock | the key to copy
  | to | the output key.

Returns:
  0 on success or a Kerberos 5 error code

krb5_error_code KRB5_LIB_FUNCTION krb5_copy_keyblock_contents | ( | krb5_context | context,
|  | const krb5_keyblock * | inblock,
|  | krb5_keyblock * | to |
| ) |  |  |

Copy a keyblock, free the output keyblock with krb5_free_keyblock_contents().

Parameters:

  | context | a Kerberos 5 context
  | inblock | the key to copy
  | to | the output key.

Returns:
  0 on success or a Kerberos 5 error code

krb5_error_code KRB5_LIB_FUNCTION krb5_create_checksum_iov | ( | krb5_context | context,
|  | krb5_crypto | crypto,
|  | unsigned | usage,
|  | krb5_crypto_iov * | data,
|  | unsigned int | num_data,
|  | krb5_cksumtype * | type |
| ) |  |  |

Create a Kerberos message checksum.

Parameters:

  | context | Kerberos context
  | crypto | Kerberos crypto context
  | usage | Key usage for this buffer
  | data | array of buffers to process
  | num_data | length of array
  | type | output data

Returns:
  Return an error code or 0.

krb5_error_code KRB5_LIB_FUNCTION krb5_crypto_destroy | ( | krb5_context | context,
|  | krb5_crypto | crypto |
| ) |  |  |

Free a crypto context created by krb5_crypto_init().

Parameters:

  | context | Kerberos context
  | crypto | crypto context to free

Returns:
  Return an error code or 0.

krb5_error_code KRB5_LIB_FUNCTION krb5_crypto_fx_cf2 | ( | krb5_context | context,
|  | const krb5_crypto | crypto1,
|  | const krb5_crypto | crypto2,
|  | krb5_data * | pepper1,
|  | krb5_data * | pepper2,
|  | krb5_enctype | enctype,
|  | krb5_keyblock * | res |
| ) |  |  |

The FX-CF2 key derivation function, used in FAST and preauth framework.

Parameters:

  | context | Kerberos 5 context
  | crypto1 | first key to combine
  | crypto2 | second key to combine
  | pepper1 | factor to combine with first key to garante uniqueness
  | pepper2 | factor to combine with second key to garante uniqueness
  | enctype | the encryption type of the resulting key
  | res | allocated key, free with krb5_free_keyblock_contents()

Returns:
  Return an error code or 0.

krb5_error_code KRB5_LIB_FUNCTION krb5_crypto_getblocksize | ( | krb5_context | context,
|  | krb5_crypto | crypto,
|  | size_t * | blocksize |
| ) |  |  |

Return the blocksize used algorithm referenced by the crypto context

Parameters:

  | context | Kerberos context
  | crypto | crypto context to query
  | blocksize | the resulting blocksize

Returns:
  Return an error code or 0.

krb5_error_code KRB5_LIB_FUNCTION krb5_crypto_getconfoundersize | ( | krb5_context | context,
|  | krb5_crypto | crypto,
|  | size_t * | confoundersize |
| ) |  |  |

Return the confounder size used by the crypto context

Parameters:

  | context | Kerberos context
  | crypto | crypto context to query
  | confoundersize | the returned confounder size

Returns:
  Return an error code or 0.

krb5_error_code KRB5_LIB_FUNCTION krb5_crypto_getenctype | ( | krb5_context | context,
|  | krb5_crypto | crypto,
|  | krb5_enctype * | enctype |
| ) |  |  |

Return the encryption type used by the crypto context

Parameters:

  | context | Kerberos context
  | crypto | crypto context to query
  | enctype | the resulting encryption type

Returns:
  Return an error code or 0.

krb5_error_code KRB5_LIB_FUNCTION krb5_crypto_getpadsize | ( | krb5_context | context,
|  | krb5_crypto | crypto,
|  | size_t * | padsize |
| ) |  |  |

Return the padding size used by the crypto context

Parameters:

  | context | Kerberos context
  | crypto | crypto context to query
  | padsize | the return padding size

Returns:
  Return an error code or 0.

krb5_error_code KRB5_LIB_FUNCTION krb5_crypto_init | ( | krb5_context | context,
|  | const krb5_keyblock * | key,
|  | krb5_enctype | etype,
|  | krb5_crypto * | crypto |
| ) |  |  |

Create a crypto context used for all encryption and signature operation. The encryption type to use is taken from the key, but can be overridden with the enctype parameter. This can be useful for encryptions types which is compatiable (DES for example).

To free the crypto context, use krb5_crypto_destroy().

Parameters:

  | context | Kerberos context
  | key | the key block information with all key data
  | etype | the encryption type
  | crypto | the resulting crypto context

Returns:
  Return an error code or 0.

krb5_error_code KRB5_LIB_FUNCTION krb5_decrypt_iov_ivec | ( | krb5_context | context,
|  | krb5_crypto | crypto,
|  | unsigned | usage,
|  | krb5_crypto_iov * | data,
|  | unsigned int | num_data,
|  | void * | ivec |
| ) |  |  |

Inline decrypt a Kerberos message.

Parameters:

  | context | Kerberos context
  | crypto | Kerberos crypto context
  | usage | Key usage for this buffer
  | data | array of buffers to process
  | num_data | length of array
  | ivec | initial cbc/cts vector

Returns:
  Return an error code or 0.

1. KRB5_CRYPTO_TYPE_HEADER 2. one KRB5_CRYPTO_TYPE_DATA and array [0,...] of KRB5_CRYPTO_TYPE_SIGN_ONLY in any order, however the receiver have to aware of the order. KRB5_CRYPTO_TYPE_SIGN_ONLY is commonly used unencrypoted protocol headers and trailers. The output data will be of same size as the input data or shorter.

krb5_error_code KRB5_LIB_FUNCTION krb5_encrypt_iov_ivec | ( | krb5_context | context,
|  | krb5_crypto | crypto,
|  | unsigned | usage,
|  | krb5_crypto_iov * | data,
|  | int | num_data,
|  | void * | ivec |
| ) |  |  |

Inline encrypt a kerberos message

Parameters:

  | context | Kerberos context
  | crypto | Kerberos crypto context
  | usage | Key usage for this buffer
  | data | array of buffers to process
  | num_data | length of array
  | ivec | initial cbc/cts vector

Returns:
  Return an error code or 0.

Kerberos encrypted data look like this:

1. KRB5_CRYPTO_TYPE_HEADER 2. array [1,...] KRB5_CRYPTO_TYPE_DATA and array [0,...] KRB5_CRYPTO_TYPE_SIGN_ONLY in any order, however the receiver have to aware of the order. KRB5_CRYPTO_TYPE_SIGN_ONLY is commonly used headers and trailers. 3. KRB5_CRYPTO_TYPE_PADDING, at least on padsize long if padsize > 1 4. KRB5_CRYPTO_TYPE_TRAILER

krb5_error_code KRB5_LIB_FUNCTION krb5_enctype_disable | ( | krb5_context | context,
|  | krb5_enctype | enctype |
| ) |  |  |

Disable encryption type

Parameters:

  | context | Kerberos 5 context
  | enctype | encryption type to disable

Returns:
  Return an error code or 0.

krb5_error_code KRB5_LIB_FUNCTION krb5_enctype_enable | ( | krb5_context | context,
|  | krb5_enctype | enctype |
| ) |  |  |

Enable encryption type

Parameters:

  | context | Kerberos 5 context
  | enctype | encryption type to enable

Returns:
  Return an error code or 0.

void KRB5_LIB_FUNCTION krb5_free_keyblock | ( | krb5_context | context,
|  | krb5_keyblock * | keyblock |
| ) |  |  |

Free a keyblock, also zero out the content of the keyblock, uses krb5_free_keyblock_contents() to free the content.

Parameters:

  | context | a Kerberos 5 context
  | keyblock | keyblock to free, NULL is valid argument

void KRB5_LIB_FUNCTION krb5_free_keyblock_contents | ( | krb5_context | context,
|  | krb5_keyblock * | keyblock |
| ) |  |  |

Free a keyblock's content, also zero out the content of the keyblock.

Parameters:

  | context | a Kerberos 5 context
  | keyblock | keyblock content to free, NULL is valid argument

krb5_error_code KRB5_LIB_FUNCTION krb5_generate_subkey_extended | ( | krb5_context | context,
|  | const krb5_keyblock * | key,
|  | krb5_enctype | etype,
|  | krb5_keyblock ** | subkey |
| ) |  |  |

Generate subkey, from keyblock

Parameters:

  | context | kerberos context
  | key | session key
  | etype | encryption type of subkey, if ETYPE_NULL, use key's enctype
  | subkey | returned new, free with krb5_free_keyblock().

Returns:
  0 on success or a Kerberos 5 error code

krb5_enctype krb5_keyblock_get_enctype | ( | const krb5_keyblock * | block | ) |

Get encryption type of a keyblock.

krb5_error_code KRB5_LIB_FUNCTION krb5_keyblock_init | ( | krb5_context | context,
|  | krb5_enctype | type,
|  | const void * | data,
|  | size_t | size,
|  | krb5_keyblock * | key |
| ) |  |  |

Fill in `key' with key data of type `enctype' from `data' of length `size'. Key should be freed using krb5_free_keyblock_contents().

Returns:
  0 on success or a Kerberos 5 error code

void KRB5_LIB_FUNCTION krb5_keyblock_zero | ( | krb5_keyblock * | keyblock | ) |

Zero out a keyblock

Parameters:

  | keyblock | keyblock to zero out

krb5_error_code KRB5_LIB_FUNCTION krb5_random_to_key | ( | krb5_context | context,
|  | krb5_enctype | type,
|  | const void * | data,
|  | size_t | size,
|  | krb5_keyblock * | key |
| ) |  |  |

Converts the random bytestring to a protocol key according to Kerberos crypto frame work. It may be assumed that all the bits of the input string are equally random, even though the entropy present in the random source may be limited.

Parameters:

  | context | Kerberos 5 context
  | type | the enctype resulting key will be of
  | data | input random data to convert to a key
  | size | size of input random data, at least krb5_enctype_keysize() long
  | key | key, output key, free with krb5_free_keyblock_contents()

Returns:
  Return an error code or 0.

krb5_error_code KRB5_LIB_FUNCTION krb5_verify_checksum_iov | ( | krb5_context | context,
|  | krb5_crypto | crypto,
|  | unsigned | usage,
|  | krb5_crypto_iov * | data,
|  | unsigned int | num_data,
|  | krb5_cksumtype * | type |
| ) |  |  |

Verify a Kerberos message checksum.

Parameters:

  | context | Kerberos context
  | crypto | Kerberos crypto context
  | usage | Key usage for this buffer
  | data | array of buffers to process
  | num_data | length of array
  | type | return checksum type if not NULL

Returns:
  Return an error code or 0.