shaka::media::AesCryptor Class Reference

Inheritance diagram for shaka::media::AesCryptor:

Public Types
enum	ConstantIvFlag { kUseConstantIv , kDontUseConstantIv }

Public Member Functions
	AesCryptor (ConstantIvFlag constant_iv_flag)
virtual bool	InitializeWithIv (const std::vector< uint8_t > &key, const std::vector< uint8_t > &iv)=0
virtual size_t	RequiredOutputSize (size_t plaintext_size)
bool	SetIv (const std::vector< uint8_t > &iv)
void	UpdateIv ()
const std::vector< uint8_t > &	iv () const
bool	use_constant_iv () const
Various forms of crypt (Encrypt/Decrypt) calls.
It is an Encrypt function for encryptor and a Decrypt function for decryptor. The text and crypt_text pointers can be the same address for in place encryption/decryption.
bool	Crypt (const std::vector< uint8_t > &text, std::vector< uint8_t > *crypt_text)
bool	Crypt (const std::string &text, std::string *crypt_text)
bool	Crypt (const uint8_t *text, size_t text_size, uint8_t *crypt_text)
bool	Crypt (const uint8_t *text, size_t text_size, uint8_t *crypt_text, size_t *crypt_text_size)

Static Public Member Functions
static bool	GenerateRandomIv (FourCC protection_scheme, std::vector< uint8_t > *iv)

Protected Types
enum	CipherMode { kCtrMode , kCbcMode }

Protected Member Functions
bool	SetupCipher (size_t key_size, CipherMode mode)

Protected Attributes
mbedtls_cipher_context_t	cipher_ctx_

Detailed Description

Definition at line 24 of file aes_cryptor.h.

Constructor & Destructor Documentation

AesCryptor()

shaka::media::AesCryptor::AesCryptor ( ConstantIvFlag  constant_iv_flag )

explicit

Parameters

constant_iv_flag

indicates whether a constant iv is used, kUseConstantIv means that the same iv is used for all Crypt calls until iv is changed via SetIv; otherwise, iv can be incremented (for counter mode) or chained (for cipher block chaining mode) internally inside Crypt call, i.e. iv will be updated across Crypt calls.

Definition at line 32 of file aes_cryptor.cc.

Member Function Documentation

Crypt()

bool shaka::media::AesCryptor::Crypt ( const uint8_t *  text, size_t  text_size, uint8_t *  crypt_text  )

inline

Parameters

crypt_text

should have at least text_size bytes.

Definition at line 58 of file aes_cryptor.h.

GenerateRandomIv()

bool shaka::media::AesCryptor::GenerateRandomIv ( FourCC  protection_scheme, std::vector< uint8_t > *  iv  )

static

Parameters

protection_scheme	specifies the protection scheme: 'cenc', 'cens', 'cbc1', 'cbcs', which is useful to determine the random iv size.
iv	points to generated initialization vector.

Returns

true on success, false otherwise.

Definition at line 110 of file aes_cryptor.cc.

InitializeWithIv()

virtual bool shaka::media::AesCryptor::InitializeWithIv ( const std::vector< uint8_t > &  key, const std::vector< uint8_t > &  iv  )

pure virtual

Initialize the cryptor with specified key and IV.

Returns

true on successful initialization, false otherwise.

Implemented in shaka::media::SampleAesEc3Cryptor, shaka::media::AesPatternCryptor, shaka::media::AesCbcEncryptor, shaka::media::AesCtrEncryptor, and shaka::media::AesCbcDecryptor.

iv()

const std::vector<uint8_t>& shaka::media::AesCryptor::iv ( ) const

inline

Returns

The current iv.

Definition at line 85 of file aes_cryptor.h.

SetIv()

bool shaka::media::AesCryptor::SetIv

(

const std::vector< uint8_t > &

iv

)

Set IV. SetIv() implementation guarantees that the iv passed to SetIv() is set to iv() and then calls SetIvInternal().

Returns

true if successful, false if the input is invalid.

Definition at line 70 of file aes_cryptor.cc.

UpdateIv()

void shaka::media::AesCryptor::UpdateIv

(

)

Update IV for next sample. As recommended in ISO/IEC 23001-7: IV need to be updated per sample for CENC. This is used by encryptors only. It is a NOP if using kUseConstantIv.

Definition at line 81 of file aes_cryptor.cc.

use_constant_iv()

bool shaka::media::AesCryptor::use_constant_iv ( ) const

inline

Returns

true if constant iv is used, false otherwise.

Definition at line 88 of file aes_cryptor.h.

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The documentation for this class was generated from the following files:

• packager/media/base/aes_cryptor.h
• packager/media/base/aes_cryptor.cc