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CommonCrypto.h
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gistfile1.txt
/*
* Copyright (c) 2006-2010 Apple, Inc. All Rights Reserved.
*
* @APPLE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this
* file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_LICENSE_HEADER_END@
*/
/*!
@header CommonCryptor.h
@abstract Generic interface for symmetric encryption.
@discussion This interface provides access to a number of symmetric
encryption algorithms. Symmetric encryption algorithms come
in two "flavors" - block ciphers, and stream ciphers. Block
ciphers process data (while both encrypting and decrypting)
in discrete chunks of data called blocks; stream ciphers
operate on arbitrary sized data.
The object declared in this interface, CCCryptor, provides
access to both block ciphers and stream ciphers with the same
API; however some options are available for block ciphers that
do not apply to stream ciphers.
The general operation of a CCCryptor is: initialize it
with raw key data and other optional fields with
CCCryptorCreate(); process input data via one or more calls to
CCCryptorUpdate(), each of which may result in output data
being written to caller-supplied memory; and obtain possible
remaining output data with CCCryptorFinal(). The CCCryptor is
disposed of via CCCryptorRelease(), or it can be reused (with
the same key data as provided to CCCryptorCreate()) by calling
CCCryptorReset().
CCCryptors can be dynamically allocated by this module, or
their memory can be allocated by the caller. See discussion for
CCCryptorCreate() and CCCryptorCreateFromData() for information
on CCCryptor allocation.
One option for block ciphers is padding, as defined in PKCS7;
when padding is enabled, the total amount of data encrypted
does not have to be an even multiple of the block size, and
the actual length of plaintext is calculated during decryption.
Another option for block ciphers is Cipher Block Chaining, known
as CBC mode. When using CBC mode, an Initialization Vector (IV)
is provided along with the key when starting an encrypt
or decrypt operation. If CBC mode is selected and no IV is
provided, an IV of all zeroes will be used.
CCCryptor also implements block bufferring, so that individual
calls to CCCryptorUpdate() do not have to provide data whose
length is aligned to the block size. (If padding is disabled,
encrypting with block ciphers does require that the *total*
length of data input to CCCryptorUpdate() call(s) be aligned
to the block size.)
A given CCCryptor can only be used by one thread at a time;
multiple threads can use safely different CCCryptors at the
same time.
*/
#ifndef _CC_COMMON_CRYPTOR_
#define _CC_COMMON_CRYPTOR_
#include <stdbool.h>
#include <stdint.h>
#ifndef KERNEL
#include <stddef.h>
#endif /* KERNEL */
#include <Availability.h>
#ifdef __cplusplus
extern "C" {
#endif
/*!
@typedef CCCryptorRef
@abstract Opaque reference to a CCCryptor object.
*/
typedef struct _CCCryptor *CCCryptorRef;
/*!
@enum CCCryptorStatus
@abstract Return values from CommonCryptor operations.
@constant kCCSuccess Operation completed normally.
@constant kCCParamError Illegal parameter value.
@constant kCCBufferTooSmall Insufficent buffer provided for specified
operation.
@constant kCCMemoryFailure Memory allocation failure.
@constant kCCAlignmentError Input size was not aligned properly.
@constant kCCDecodeError Input data did not decode or decrypt
properly.
@constant kCCUnimplemented Function not implemented for the current
algorithm.
*/
enum {
kCCSuccess = 0,
kCCParamError = -4300,
kCCBufferTooSmall = -4301,
kCCMemoryFailure = -4302,
kCCAlignmentError = -4303,
kCCDecodeError = -4304,
kCCUnimplemented = -4305,
kCCOverflow = -4306
};
typedef int32_t CCCryptorStatus;
/*!
@enum CCOperation
@abstract Operations that an CCCryptor can perform.
@constant kCCEncrypt Symmetric encryption.
@constant kCCDecrypt Symmetric decryption.
*/
enum {
kCCEncrypt = 0,
kCCDecrypt,
};
typedef uint32_t CCOperation;
/*!
@enum CCAlgorithm
@abstract Encryption algorithms implemented by this module.
@constant kCCAlgorithmAES128 Advanced Encryption Standard, 128-bit block
This is kept for historical reasons. It's
preferred now to use kCCAlgorithmAES since
128-bit blocks are part of the standard.
@constant kCCAlgorithmAES Advanced Encryption Standard, 128-bit block
@constant kCCAlgorithmDES Data Encryption Standard
@constant kCCAlgorithm3DES Triple-DES, three key, EDE configuration
@constant kCCAlgorithmCAST CAST
@constant kCCAlgorithmRC4 RC4 stream cipher
@constant kCCAlgorithmBlowfish Blowfish block cipher
*/
enum {
kCCAlgorithmAES128 = 0,
kCCAlgorithmAES = 0,
kCCAlgorithmDES,
kCCAlgorithm3DES,
kCCAlgorithmCAST,
kCCAlgorithmRC4,
kCCAlgorithmRC2,
kCCAlgorithmBlowfish
};
typedef uint32_t CCAlgorithm;
/*!
@enum CCOptions
@abstract Options flags, passed to CCCryptorCreate().
@constant kCCOptionPKCS7Padding Perform PKCS7 padding.
@constant kCCOptionECBMode Electronic Code Book Mode.
Default is CBC.
*/
enum {
/* options for block ciphers */
kCCOptionPKCS7Padding = 0x0001,
kCCOptionECBMode = 0x0002
/* stream ciphers currently have no options */
};
typedef uint32_t CCOptions;
/*!
@enum Key sizes
@discussion Key sizes, in bytes, for supported algorithms. Use these
constants to select any keysize variants you wish to use
for algorithms that support them (ie AES-128, AES-192, AES-256)
@constant kCCKeySizeAES128 128 bit AES key size.
@constant kCCKeySizeAES192 192 bit AES key size.
@constant kCCKeySizeAES256 256 bit AES key size.
@constant kCCKeySizeDES DES key size.
@constant kCCKeySize3DES Triple DES key size.
@constant kCCKeySizeMinCAST CAST minimum key size.
@constant kCCKeySizeMaxCAST CAST maximum key size.
@constant kCCKeySizeMinRC4 RC4 minimum key size.
@constant kCCKeySizeMaxRC4 RC4 maximum key size.
@discussion DES and TripleDES have fixed key sizes.
AES has three discrete key sizes.
CAST and RC4 have variable key sizes.
*/
enum {
kCCKeySizeAES128 = 16,
kCCKeySizeAES192 = 24,
kCCKeySizeAES256 = 32,
kCCKeySizeDES = 8,
kCCKeySize3DES = 24,
kCCKeySizeMinCAST = 5,
kCCKeySizeMaxCAST = 16,
kCCKeySizeMinRC4 = 1,
kCCKeySizeMaxRC4 = 512,
kCCKeySizeMinRC2 = 1,
kCCKeySizeMaxRC2 = 128,
kCCKeySizeMinBlowfish = 8,
kCCKeySizeMaxBlowfish = 56,
};
/*!
@enum Block sizes
@discussion Block sizes, in bytes, for supported algorithms.
@constant kCCBlockSizeAES128 AES block size (currently, only 128-bit
blocks are supported).
@constant kCCBlockSizeDES DES block size.
@constant kCCBlockSize3DES Triple DES block size.
@constant kCCBlockSizeCAST CAST block size.
*/
enum {
/* AES */
kCCBlockSizeAES128 = 16,
/* DES */
kCCBlockSizeDES = 8,
/* 3DES */
kCCBlockSize3DES = 8,
/* CAST */
kCCBlockSizeCAST = 8,
kCCBlockSizeRC2 = 8,
kCCBlockSizeBlowfish = 8,
};
/*!
@enum Minimum context sizes
@discussion Minimum context sizes, for caller-allocated CCCryptorRefs.
To minimize dynamic allocation memory, a caller can create
a CCCryptorRef by passing caller-supplied memory to the
CCCryptorCreateFromData() function.
These constants define the minimum amount of memory, in
bytes, needed for CCCryptorRefs for each supported algorithm.
Note: these constants are valid for the current version of
this library; they may change in subsequent releases, so
applications wishing to allocate their own memory for use
in creating CCCryptorRefs must be prepared to deal with
a kCCBufferTooSmall return from CCCryptorCreateFromData().
See discussion for the CCCryptorCreateFromData() function.
@constant kCCContextSizeAES128 - Minimum context size for kCCAlgorithmAES128.
@constant kCCContextSizeDES - Minimum context size for kCCAlgorithmDES.
@constant kCCContextSize3DES - Minimum context size for kCCAlgorithm3DES.
@constant kCCContextSizeCAST - Minimum context size for kCCAlgorithmCAST.
@constant kCCContextSizeRC4 - Minimum context size for kCCAlgorithmRC4.
*/
enum {
kCCContextSizeAES128 = 404,
kCCContextSizeDES = 240,
kCCContextSize3DES = 496,
kCCContextSizeCAST = 240,
kCCContextSizeRC4 = 1072
};
/*!
@function CCCryptorCreate
@abstract Create a cryptographic context.
@param op Defines the basic operation: kCCEncrypt or
kCCDecrypt.
@param alg Defines the algorithm.
@param options A word of flags defining options. See discussion
for the CCOptions type.
@param key Raw key material, length keyLength bytes.
@param keyLength Length of key material. Must be appropriate
for the selected operation and algorithm. Some
algorithms provide for varying key lengths.
@param iv Initialization vector, optional. Used by
block ciphers when Cipher Block Chaining (CBC)
mode is enabled. If present, must be the same
length as the selected algorithm's block size.
If CBC mode is selected (by the absence of the
kCCOptionECBMode bit in the options flags) and no
IV is present, a NULL (all zeroes) IV will be used.
This parameter is ignored if ECB mode is used or
if a stream cipher algorithm is selected.
@param cryptorRef A (required) pointer to the returned CCCryptorRef.
@result Possible error returns are kCCParamError and kCCMemoryFailure.
*/
CCCryptorStatus CCCryptorCreate(
CCOperation op, /* kCCEncrypt, etc. */
CCAlgorithm alg, /* kCCAlgorithmDES, etc. */
CCOptions options, /* kCCOptionPKCS7Padding, etc. */
const void *key, /* raw key material */
size_t keyLength,
const void *iv, /* optional initialization vector */
CCCryptorRef *cryptorRef) /* RETURNED */
__OSX_AVAILABLE_STARTING(__MAC_10_4, __IPHONE_2_0);
/*!
@function CCCryptorCreateFromData
@abstract Create a cryptographic context using caller-supplied memory.
@param op Defines the basic operation: kCCEncrypt or
kCCDecrypt.
@param alg Defines the algorithm.
@param options A word of flags defining options. See discussion
for the CCOptions type.
@param key Raw key material, length keyLength bytes.
@param keyLength Length of key material. Must be appropriate
for the selected operation and algorithm. Some
algorithms provide for varying key lengths.
@param iv Initialization vector, optional. Used by
block ciphers when Cipher Block Chaining (CBC)
mode is enabled. If present, must be the same
length as the selected algorithm's block size.
If CBC mode is selected (by the absence of the
kCCOptionECBMode bit in the options flags) and no
IV is present, a NULL (all zeroes) IV will be used.
This parameter is ignored if ECB mode is used or
if a stream cipher algorithm is selected.
@param data A pointer to caller-supplied memory from which the
CCCryptorRef will be created.
@param dataLength The size of the caller-supplied memory in bytes.
@param cryptorRef A (required) pointer to the returned CCCryptorRef.
@param dataUsed Optional. If present, the actual number of bytes of
the caller-supplied memory which was consumed by
creation of the CCCryptorRef is returned here. Also,
if the supplied memory is of insufficent size to create
a CCCryptorRef, kCCBufferTooSmall is returned, and
the minimum required buffer size is returned via this
parameter if present.
@result Possible error returns are kCCParamError and kCCBufferTooSmall.
@discussion The CCCryptorRef created by this function *may* be disposed of
via CCCRyptorRelease; that call is not strictly necessary, but
if it's not performed, good security practice dictates that the
caller should zero the memory provided to create the CCCryptorRef
when the caller is finished using the CCCryptorRef.
*/
CCCryptorStatus CCCryptorCreateFromData(
CCOperation op, /* kCCEncrypt, etc. */
CCAlgorithm alg, /* kCCAlgorithmDES, etc. */
CCOptions options, /* kCCOptionPKCS7Padding, etc. */
const void *key, /* raw key material */
size_t keyLength,
const void *iv, /* optional initialization vector */
const void *data, /* caller-supplied memory */
size_t dataLength, /* length of data in bytes */
CCCryptorRef *cryptorRef, /* RETURNED */
size_t *dataUsed) /* optional, RETURNED */
__OSX_AVAILABLE_STARTING(__MAC_10_4, __IPHONE_2_0);
/*!
@function CCCryptorRelease
@abstract Free a context created by CCCryptorCreate or
CCCryptorCreateFromData().
@param cryptorRef The CCCryptorRef to release.
@result The only possible error return is kCCParamError resulting
from passing in a null CCCryptorRef.
*/
CCCryptorStatus CCCryptorRelease(
CCCryptorRef cryptorRef)
__OSX_AVAILABLE_STARTING(__MAC_10_4, __IPHONE_2_0);
/*!
@function CCCryptorUpdate
@abstract Process (encrypt, decrypt) some data. The result, if any,
is written to a caller-provided buffer.
@param cryptorRef A CCCryptorRef created via CCCryptorCreate() or
CCCryptorCreateFromData().
@param dataIn Data to process, length dataInLength bytes.
@param dataInLength Length of data to process.
@param dataOut Result is written here. Allocated by caller.
Encryption and decryption can be performed
"in-place", with the same buffer used for
input and output.
@param dataOutAvailable The size of the dataOut buffer in bytes.
@param dataOutMoved On successful return, the number of bytes
written to dataOut.
@result kCCBufferTooSmall indicates insufficent space in the dataOut
buffer. The caller can use
CCCryptorGetOutputLength() to determine the
required output buffer size in this case. The
operation can be retried; no state is lost
when this is returned.
@discussion This routine can be called multiple times. The caller does
not need to align input data lengths to block sizes; input is
bufferred as necessary for block ciphers.
When performing symmetric encryption with block ciphers,
and padding is enabled via kCCOptionPKCS7Padding, the total
number of bytes provided by all the calls to this function
when encrypting can be arbitrary (i.e., the total number
of bytes does not have to be block aligned). However if
padding is disabled, or when decrypting, the total number
of bytes does have to be aligned to the block size; otherwise
CCCryptFinal() will return kCCAlignmentError.
A general rule for the size of the output buffer which must be
provided by the caller is that for block ciphers, the output
length is never larger than the input length plus the block size.
For stream ciphers, the output length is always exactly the same
as the input length. See the discussion for
CCCryptorGetOutputLength() for more information on this topic.
Generally, when all data has been processed, call
CCCryptorFinal().
In the following cases, the CCCryptorFinal() is superfluous as
it will not yield any data nor return an error:
1. Encrypting or decrypting with a block cipher with padding
disabled, when the total amount of data provided to
CCCryptorUpdate() is an integral multiple of the block size.
2. Encrypting or decrypting with a stream cipher.
*/
CCCryptorStatus CCCryptorUpdate(
CCCryptorRef cryptorRef,
const void *dataIn,
size_t dataInLength,
void *dataOut, /* data RETURNED here */
size_t dataOutAvailable,
size_t *dataOutMoved) /* number of bytes written */
__OSX_AVAILABLE_STARTING(__MAC_10_4, __IPHONE_2_0);
/*!
@function CCCryptorFinal
@abstract Finish an encrypt or decrypt operation, and obtain the (possible)
final data output.
@param cryptorRef A CCCryptorRef created via CCCryptorCreate() or
CCCryptorCreateFromData().
@param dataOut Result is written here. Allocated by caller.
@param dataOutAvailable The size of the dataOut buffer in bytes.
@param dataOutMoved On successful return, the number of bytes
written to dataOut.
@result kCCBufferTooSmall indicates insufficent space in the dataOut
buffer. The caller can use
CCCryptorGetOutputLength() to determine the
required output buffer size in this case. The
operation can be retried; no state is lost
when this is returned.
kCCAlignmentError When decrypting, or when encrypting with a
block cipher with padding disabled,
kCCAlignmentError will be returned if the total
number of bytes provided to CCCryptUpdate() is
not an integral multiple of the current
algorithm's block size.
kCCDecodeError Indicates garbled ciphertext or the
wrong key during decryption. This can only
be returned while decrypting with padding
enabled.
@discussion Except when kCCBufferTooSmall is returned, the CCCryptorRef
can no longer be used for subsequent operations unless
CCCryptorReset() is called on it.
It is not necessary to call CCCryptorFinal() when performing
symmetric encryption or decryption if padding is disabled, or
when using a stream cipher.
It is not necessary to call CCCryptorFinal() prior to
CCCryptorRelease() when aborting an operation.
*/
CCCryptorStatus CCCryptorFinal(
CCCryptorRef cryptorRef,
void *dataOut,
size_t dataOutAvailable,
size_t *dataOutMoved) /* number of bytes written */
__OSX_AVAILABLE_STARTING(__MAC_10_4, __IPHONE_2_0);
/*!
@function CCCryptorGetOutputLength
@abstract Determine output buffer size required to process a given input
size.
@param cryptorRef A CCCryptorRef created via CCCryptorCreate() or
CCCryptorCreateFromData().
@param inputLength The length of data which will be provided to
CCCryptorUpdate().
@param final If false, the returned value will indicate the
output buffer space needed when 'inputLength'
bytes are provided to CCCryptorUpdate(). When
'final' is true, the returned value will indicate
the total combined buffer space needed when
'inputLength' bytes are provided to
CCCryptorUpdate() and then CCCryptorFinal() is
called.
@result The maximum buffer space need to perform CCCryptorUpdate() and
optionally CCCryptorFinal().
@discussion Some general rules apply that allow clients of this module to
know a priori how much output buffer space will be required
in a given situation. For stream ciphers, the output size is
always equal to the input size, and CCCryptorFinal() never
produces any data. For block ciphers, the output size will
always be less than or equal to the input size plus the size
of one block. For block ciphers, if the input size provided
to each call to CCCryptorUpdate() is is an integral multiple
of the block size, then the output size for each call to
CCCryptorUpdate() is less than or equal to the input size
for that call to CCCryptorUpdate(). CCCryptorFinal() only
produces output when using a block cipher with padding enabled.
*/
size_t CCCryptorGetOutputLength(
CCCryptorRef cryptorRef,
size_t inputLength,
bool final)
__OSX_AVAILABLE_STARTING(__MAC_10_4, __IPHONE_2_0);
/*!
@function CCCryptorReset
@abstract Reinitializes an existing CCCryptorRef with a (possibly)
new initialization vector. The CCCryptorRef's key is
unchanged. Not implemented for stream ciphers.
@param cryptorRef A CCCryptorRef created via CCCryptorCreate() or
CCCryptorCreateFromData().
@param iv Optional initialization vector; if present, must
be the same size as the current algorithm's block
size.
@result The the only possible errors are kCCParamError and
kCCUnimplemented.
@discussion This can be called on a CCCryptorRef with data pending (i.e.
in a padded mode operation before CCCryptFinal is called);
however any pending data will be lost in that case.
*/
CCCryptorStatus CCCryptorReset(
CCCryptorRef cryptorRef,
const void *iv)
__OSX_AVAILABLE_STARTING(__MAC_10_4, __IPHONE_2_0);
/*!
@function CCCrypt
@abstract Stateless, one-shot encrypt or decrypt operation.
This basically performs a sequence of CCCrytorCreate(),
CCCryptorUpdate(), CCCryptorFinal(), and CCCryptorRelease().
@param alg Defines the encryption algorithm.
@param op Defines the basic operation: kCCEncrypt or
kCCDecrypt.
@param options A word of flags defining options. See discussion
for the CCOptions type.
@param key Raw key material, length keyLength bytes.
@param keyLength Length of key material. Must be appropriate
for the select algorithm. Some algorithms may
provide for varying key lengths.
@param iv Initialization vector, optional. Used for
Cipher Block Chaining (CBC) mode. If present,
must be the same length as the selected
algorithm's block size. If CBC mode is
selected (by the absence of any mode bits in
the options flags) and no IV is present, a
NULL (all zeroes) IV will be used. This is
ignored if ECB mode is used or if a stream
cipher algorithm is selected.
@param dataIn Data to encrypt or decrypt, length dataInLength
bytes.
@param dataInLength Length of data to encrypt or decrypt.
@param dataOut Result is written here. Allocated by caller.
Encryption and decryption can be performed
"in-place", with the same buffer used for
input and output.
@param dataOutAvailable The size of the dataOut buffer in bytes.
@param dataOutMoved On successful return, the number of bytes
written to dataOut. If kCCBufferTooSmall is
returned as a result of insufficient buffer
space being provided, the required buffer space
is returned here.
@result kCCBufferTooSmall indicates insufficent space in the dataOut
buffer. In this case, the *dataOutMoved
parameter will indicate the size of the buffer
needed to complete the operation. The
operation can be retried with minimal runtime
penalty.
kCCAlignmentError indicates that dataInLength was not properly
aligned. This can only be returned for block
ciphers, and then only when decrypting or when
encrypting with block with padding disabled.
kCCDecodeError Indicates improperly formatted ciphertext or
a "wrong key" error; occurs only during decrypt
operations.
*/
CCCryptorStatus CCCrypt(
CCOperation op, /* kCCEncrypt, etc. */
CCAlgorithm alg, /* kCCAlgorithmAES128, etc. */
CCOptions options, /* kCCOptionPKCS7Padding, etc. */
const void *key,
size_t keyLength,
const void *iv, /* optional initialization vector */
const void *dataIn, /* optional per op and alg */
size_t dataInLength,
void *dataOut, /* data RETURNED here */
size_t dataOutAvailable,
size_t *dataOutMoved)
__OSX_AVAILABLE_STARTING(__MAC_10_4, __IPHONE_2_0);
/*!
@enum Cipher Modes
@discussion These are the selections available for modes of operation for
use with block ciphers. If RC4 is selected as the cipher (a stream
cipher) the only correct mode is kCCModeRC4.
@constant kCCModeECB - Electronic Code Book Mode.
@constant kCCModeCBC - Cipher Block Chaining Mode.
@constant kCCModeCFB - Cipher Feedback Mode.
@constant kCCModeOFB - Output Feedback Mode.
@constant kCCModeXTS - XEX-based Tweaked CodeBook Mode.
@constant kCCModeRC4 - RC4 as a streaming cipher is handled internally as a mode.
@constant kCCModeCFB8 - Cipher Feedback Mode producing 8 bits per round.
*/
enum {
kCCModeECB = 1,
kCCModeCBC = 2,
kCCModeCFB = 3,
kCCModeCTR = 4,
kCCModeF8 = 5, // Unimplemented for now (not included)
kCCModeLRW = 6, // Unimplemented for now (not included)
kCCModeOFB = 7,
kCCModeXTS = 8,
kCCModeRC4 = 9,
kCCModeCFB8 = 10,
};
typedef uint32_t CCMode;
/*!
@enum Padding for Block Ciphers
@discussion These are the padding options available for block modes.
@constant ccNoPadding - No padding.
@constant ccPKCS7Padding - PKCS7 Padding.
*/
enum {
ccNoPadding = 0,
ccPKCS7Padding = 1,
};
typedef uint32_t CCPadding;
/*!
@enum Mode options - Not currently in use.
@discussion Values used to specify options for modes. This was used for counter
mode operations in 10.8, now only Big Endian mode is supported.
@constant kCCModeOptionCTR_LE - CTR Mode Little Endian.
@constant kCCModeOptionCTR_BE - CTR Mode Big Endian.
*/
enum {
kCCModeOptionCTR_LE = 0x0001, // Deprecated in iPhoneOS 6.0 and MacOSX10.9
kCCModeOptionCTR_BE = 0x0002 // Deprecated in iPhoneOS 6.0 and MacOSX10.9
};
typedef uint32_t CCModeOptions;
/*!
@function CCCryptorCreateWithMode
@abstract Create a cryptographic context.
@param op Defines the basic operation: kCCEncrypt or
kCCDecrypt.
@param mode Specifies the cipher mode to use for operations.
@param alg Defines the algorithm.
@param padding Specifies the padding to use.
@param iv Initialization vector, optional. Used by
block ciphers with the following modes:
Cipher Block Chaining (CBC)
Cipher Feedback (CFB and CFB8)
Output Feedback (OFB)
Counter (CTR)
If present, must be the same length as the selected
algorithm's block size. If no IV is present, a NULL
(all zeroes) IV will be used.
This parameter is ignored if ECB mode is used or
if a stream cipher algorithm is selected.
@param key Raw key material, length keyLength bytes.
@param keyLength Length of key material. Must be appropriate
for the selected operation and algorithm. Some
algorithms provide for varying key lengths.
@param tweak Raw key material, length keyLength bytes. Used for the
tweak key in XEX-based Tweaked CodeBook (XTS) mode.
@param tweakLength Length of tweak key material. Must be appropriate
for the selected operation and algorithm. Some
algorithms provide for varying key lengths. For XTS
this is the same length as the encryption key.
@param numRounds The number of rounds of the cipher to use. 0 uses the default.
@param options A word of flags defining options. See discussion
for the CCModeOptions type.
@param cryptorRef A (required) pointer to the returned CCCryptorRef.
@result Possible error returns are kCCParamError and kCCMemoryFailure.
*/
CCCryptorStatus CCCryptorCreateWithMode(
CCOperation op, /* kCCEncrypt, kCCEncrypt */
CCMode mode,
CCAlgorithm alg,
CCPadding padding,
const void *iv, /* optional initialization vector */
const void *key, /* raw key material */
size_t keyLength,
const void *tweak, /* raw tweak material */
size_t tweakLength,
int numRounds, /* 0 == default */
CCModeOptions options,
CCCryptorRef *cryptorRef) /* RETURNED */
__OSX_AVAILABLE_STARTING(__MAC_10_7, __IPHONE_5_0);
#ifdef __cplusplus
}
#endif
#endif /* _CC_COMMON_CRYPTOR_ */
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