X-Git-Url: http://git.silcnet.org/gitweb/?a=blobdiff_plain;f=lib%2Fsilccrypt%2Fsilccipher.h;h=a0503c899105d6ffa06c1f3c72fde2f8e332a2af;hb=e7b6c157b80152bf9fb9266e6bdd93f9fb0db776;hp=709c84113b50f49dc3f2f809434e90ee6ab9b3ee;hpb=205916687fdc130a3c5d7e8f66c74973975f4bca;p=silc.git diff --git a/lib/silccrypt/silccipher.h b/lib/silccrypt/silccipher.h index 709c8411..a0503c89 100644 --- a/lib/silccrypt/silccipher.h +++ b/lib/silccrypt/silccipher.h @@ -2,15 +2,14 @@ silccipher.h - Author: Pekka Riikonen + Author: Pekka Riikonen - Copyright (C) 1997 - 2001 Pekka Riikonen + Copyright (C) 1997 - 2007 Pekka Riikonen This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 2 of the License, or - (at your option) any later version. - + the Free Software Foundation; version 2 of the License. + This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the @@ -18,124 +17,401 @@ */ +/****h* silccrypt/SILC Cipher Interface + * + * DESCRIPTION + * + * This is the interface for cipher functions. It provides cipher + * registering and unregistering routines, encryption and decryption + * routines. + * + ***/ + #ifndef SILCCIPHER_H #define SILCCIPHER_H -/* - SILC Cipher object. - - Default SILC cipher object to represent any cipher. The function - pointers are the stub functions for each implemented cipher. Following - short description of the fields: - - char *name - - Logical name of the cipher. - - uint32 block_len - - Block size of the cipher. +/* Forward declarations */ +typedef struct SilcCipherObjectStruct SilcCipherObject; - uint32 key_len +/****s* silccrypt/SilcCipherAPI/SilcCipher + * + * NAME + * + * typedef struct SilcCipherStruct *SilcCipher; + * + * DESCRIPTION + * + * This context is the actual cipher context and is allocated + * by silc_cipher_alloc and given as argument usually to all + * silc_cipher _* functions. It is freed by the silc_cipher_free + * function. + * + ***/ +typedef struct SilcCipherStruct *SilcCipher; - Length of the key of the cipher (in bits). +/****d* silccrypt/SilcCipherAPI/SilcCipherMode + * + * NAME + * + * typedef enum { ... } SilcCipherMode; + * + * DESCRIPTION + * + * Cipher modes. Notes about cipher modes and implementation: + * + * SILC_CIPHER_MODE_CBC + * + * The Cipher-block Chaining mode. The CBC is mode is a standard CBC + * mode. The plaintext length must be multiple by the cipher block size. + * If it isn't the plaintext must be padded. + * + * SILC_CIPHER_MODE_CTR + * + * The Counter mode. The CTR is normal counter mode. The CTR mode does + * not require the plaintext length to be multiple by the cipher block + * size. If the last plaintext block is shorter the remaining bits of + * the key stream are used next time silc_cipher_encrypt is called. If + * silc_cipher_set_iv is called it will reset the counter for a new block + * (discarding any remaining bits from previous key stream). The counter + * mode expects MSB first ordered counter. Note also, the counter is + * incremented when silc_cipher_encrypt is called for the first time, + * before encrypting. + * + * SILC_CIPHER_MODE_CFB + * + * The Cipher Feedback mode. The CFB mode is normal cipher feedback mode. + * The CFB mode does not require the plaintext length to be multiple by + * the cipher block size. If the last plaintext block is shorter the + * remaining bits of the stream are used next time silc_cipher_encrypt is + * called. If silc_cipher_set_iv is called it will reset the feedback + * for a new block (discarding any remaining bits from previous stream). + * + * SILC_CIPHER_MODE_OFB + * + * The Output Feedback mode. + * + * SILC_CIPHER_MODE_ECB + * + * The Electronic Codebook mode. This mode does not provide sufficient + * security and should not be used. + * + * Each mode modifies the IV (initialization vector) of the cipher when + * silc_cipher_encrypt or silc_cipher_decrypt is called. The IV may be + * set/reset by calling silc_cipher_set_iv and the current IV can be + * retrieved by calling silc_cipher_get_iv. + * + * SOURCE + */ +typedef enum { + SILC_CIPHER_MODE_ECB = 1, /* ECB mode */ + SILC_CIPHER_MODE_CBC = 2, /* CBC mode */ + SILC_CIPHER_MODE_CTR = 3, /* CTR mode */ + SILC_CIPHER_MODE_CFB = 4, /* CFB mode */ + SILC_CIPHER_MODE_OFB = 5, /* OFB mode */ +} SilcCipherMode; +/***/ -*/ -typedef struct { - char *name; - uint32 block_len; - uint32 key_len; - - bool (*set_key)(void *, const unsigned char *, uint32); - bool (*set_key_with_string)(void *, const unsigned char *, uint32); - bool (*encrypt)(void *, const unsigned char *, unsigned char *, - uint32, unsigned char *); - bool (*decrypt)(void *, const unsigned char *, unsigned char *, - uint32, unsigned char *); - uint32 (*context_len)(); -} SilcCipherObject; - -#define SILC_CIPHER_MAX_IV_SIZE 16 - -/* The main SilcCipher structure. Use SilcCipher instead of SilcCipherStruct. - Also remember that SilcCipher is a pointer. */ -typedef struct SilcCipherStruct { - SilcCipherObject *cipher; - void *context; - unsigned char iv[SILC_CIPHER_MAX_IV_SIZE]; - - void (*set_iv)(struct SilcCipherStruct *, const unsigned char *); - void (*get_iv)(struct SilcCipherStruct *, unsigned char *); - uint32 (*get_key_len)(struct SilcCipherStruct *); - uint32 (*get_block_len)(struct SilcCipherStruct *); -} *SilcCipher; +#define SILC_CIPHER_MAX_IV_SIZE 16 /* Maximum IV size */ +#define SILC_DEFAULT_CIPHER "aes-256-cbc" /* Default cipher */ /* Marks for all ciphers in silc. This can be used in silc_cipher_unregister to unregister all ciphers at once. */ #define SILC_ALL_CIPHERS ((SilcCipherObject *)1) +#include "silccipher_i.h" + /* Static list of ciphers for silc_cipher_register_default(). */ -extern SilcCipherObject silc_default_ciphers[]; - -/* Default cipher in the SILC protocol */ -#define SILC_DEFAULT_CIPHER "aes-256-cbc" - -/* Macros */ - -/* Function names in SILC Crypto modules. The name of the cipher - is appended into these names and used to the get correct symbol out - of the module. All SILC Crypto API compliant modules must support - these function names (use macros below to assure this). */ -#define SILC_CIPHER_SIM_SET_KEY "set_key" -#define SILC_CIPHER_SIM_SET_KEY_WITH_STRING "set_key_with_string" -#define SILC_CIPHER_SIM_ENCRYPT_CBC "encrypt_cbc" -#define SILC_CIPHER_SIM_DECRYPT_CBC "decrypt_cbc" -#define SILC_CIPHER_SIM_CONTEXT_LEN "context_len" - -/* These macros can be used to implement the SILC Crypto API and to avoid - errors in the API these macros should be used always. */ -#define SILC_CIPHER_API_SET_KEY(cipher) \ -bool silc_##cipher##_set_key(void *context, \ - const unsigned char *key, \ - uint32 keylen) -#define SILC_CIPHER_API_SET_KEY_WITH_STRING(cipher) \ -bool silc_##cipher##_set_key_with_string(void *context, \ - const unsigned char *string, \ - uint32 stringlen) -#define SILC_CIPHER_API_ENCRYPT_CBC(cipher) \ -bool silc_##cipher##_encrypt_cbc(void *context, \ - const unsigned char *src, \ - unsigned char *dst, \ - uint32 len, \ - unsigned char *iv) -#define SILC_CIPHER_API_DECRYPT_CBC(cipher) \ -bool silc_##cipher##_decrypt_cbc(void *context, \ - const unsigned char *src, \ - unsigned char *dst, \ - uint32 len, \ - unsigned char *iv) -#define SILC_CIPHER_API_CONTEXT_LEN(cipher) \ -uint32 silc_##cipher##_context_len() +extern DLLAPI const SilcCipherObject silc_default_ciphers[]; /* Prototypes */ -bool silc_cipher_register(SilcCipherObject *cipher); -bool silc_cipher_unregister(SilcCipherObject *cipher); -bool silc_cipher_register_default(void); -bool silc_cipher_alloc(const unsigned char *name, SilcCipher *new_cipher); + +/****f* silccrypt/SilcCipherAPI/silc_cipher_register + * + * SYNOPSIS + * + * SilcBool silc_cipher_register(const SilcCipherObject *cipher); + * + * DESCRIPTION + * + * Register a new cipher into SILC. This is used at the initialization of + * the SILC. This function allocates a new object for the cipher to be + * registered. Therefore, if memory has been allocated for the object sent + * as argument it has to be free'd after this function returns succesfully. + * + ***/ +SilcBool silc_cipher_register(const SilcCipherObject *cipher); + +/****f* silccrypt/SilcCipherAPI/silc_cipher_unregister + * + * SYNOPSIS + * + * SilcBool silc_cipher_unregister(SilcCipherObject *cipher); + * + * DESCRIPTION + * + * Unregister a cipher from the SILC. + * + ***/ +SilcBool silc_cipher_unregister(SilcCipherObject *cipher); + +/****f* silccrypt/SilcCipherAPI/silc_cipher_register_default + * + * SYNOPSIS + * + * SilcBool silc_cipher_register_default(void); + * + * DESCRIPTION + * + * Function that registers all the default ciphers (all builtin ciphers). + * The application may use this to register the default ciphers if specific + * ciphers in any specific order is not wanted. + * + ***/ +SilcBool silc_cipher_register_default(void); + +/****f* silccrypt/SilcCipherAPI/silc_cipher_unregister_all + * + * SYNOPSIS + * + * SilcBool silc_cipher_unregister_all(void); + * + * DESCRIPTION + * + * Unregisters all ciphers. + * + ***/ +SilcBool silc_cipher_unregister_all(void); + +/****f* silccrypt/SilcCipherAPI/silc_cipher_alloc + * + * SYNOPSIS + * + * SilcBool silc_cipher_alloc(const char *name, + * SilcCipher *new_cipher); + * + * DESCRIPTION + * + * Allocates a new SILC cipher object. Function returns 1 on succes and 0 + * on error. The allocated cipher is returned in new_cipher argument. The + * caller must set the key to the cipher after this function has returned + * by calling the ciphers set_key function. + * + * The following ciphers are supported: + * + * aes-256-ctr AES-256, Counter mode + * aes-192-ctr AES-192, Counter mode + * aes-128-ctr AES,128, Counter mode + * aes-256-cbc AES-256, Cipher block chaining mode + * aes-192-cbc AES-192, Cipher block chaining mode + * aes-128-cbc AES,128, Cipher block chaining mode + * twofish-256-cbc Twofish-256, Cipher block chaining mode + * twofish-192-cbc Twofish-192, Cipher block chaining mode + * twofish-128-cbc Twofish-128, Cipher block chaining mode + * + * Notes about modes: + * + ***/ +SilcBool silc_cipher_alloc(const char *name, SilcCipher *new_cipher); + +/****f* silccrypt/SilcCipherAPI/silc_cipher_free + * + * SYNOPSIS + * + * void silc_cipher_free(SilcCipher cipher); + * + * DESCRIPTION + * + * Frees the given cipher. + * + ***/ void silc_cipher_free(SilcCipher cipher); -bool silc_cipher_is_supported(const unsigned char *name); -char *silc_cipher_get_supported(void); -bool silc_cipher_encrypt(SilcCipher cipher, const unsigned char *src, - unsigned char *dst, uint32 len, - unsigned char *iv); -bool silc_cipher_decrypt(SilcCipher cipher, const unsigned char *src, - unsigned char *dst, uint32 len, - unsigned char *iv); -bool silc_cipher_set_key(SilcCipher cipher, const unsigned char *key, - uint32 keylen); + +/****f* silccrypt/SilcCipherAPI/silc_cipher_is_supported + * + * SYNOPSIS + * + * SilcBool silc_cipher_is_supported(const char *name); + * + * DESCRIPTION + * + * Returns TRUE if cipher `name' is supported. + * + ***/ +SilcBool silc_cipher_is_supported(const char *name); + +/****f* silccrypt/SilcCipherAPI/silc_cipher_get_supported + * + * SYNOPSIS + * + * char *silc_cipher_get_supported(SilcBool only_registered); + * + * DESCRIPTION + * + * Returns comma separated list of supported ciphers. If `only_registered' + * is TRUE only ciphers explicitly registered with silc_cipher_register + * are returned. If FALSE, then all registered and default builtin + * ciphers are returned. However, if there are no registered ciphers + * and `only_registered' is TRUE, the builtin ciphers are returned. + * + ***/ +char *silc_cipher_get_supported(SilcBool only_registered); + +/****f* silccrypt/SilcCipherAPI/silc_cipher_encrypt + * + * SYNOPSIS + * + * SilcBool silc_cipher_encrypt(SilcCipher cipher, + * const unsigned char *src, + * unsigned char *dst, SilcUInt32 len, + * unsigned char *iv); + * + * DESCRIPTION + * + * Encrypts data from `src' into `dst' with the specified cipher and + * Initial Vector (IV). If the `iv' is NULL then the cipher's internal + * IV is used. The `src' and `dst' maybe same buffer. + * + ***/ +SilcBool silc_cipher_encrypt(SilcCipher cipher, const unsigned char *src, + unsigned char *dst, SilcUInt32 len, + unsigned char *iv); + +/****f* silccrypt/SilcCipherAPI/silc_cipher_decrypt + * + * SYNOPSIS + * + * SilcBool silc_cipher_decrypt(SilcCipher cipher, + * const unsigned char *src, + * unsigned char *dst, SilcUInt32 len, + * unsigned char *iv); + * + * DESCRIPTION + * + * Decrypts data from `src' into `dst' with the specified cipher and + * Initial Vector (IV). If the `iv' is NULL then the cipher's internal + * IV is used. The `src' and `dst' maybe same buffer. + * + ***/ +SilcBool silc_cipher_decrypt(SilcCipher cipher, const unsigned char *src, + unsigned char *dst, SilcUInt32 len, + unsigned char *iv); + +/****f* silccrypt/SilcCipherAPI/silc_cipher_set_key + * + * SYNOPSIS + * + * SilcBool silc_cipher_set_key(SilcCipher cipher, const unsigned char *key, + * SilcUInt32 keylen, SilcBool encryption); + * + * DESCRIPTION + * + * Sets the key for the cipher. The `keylen' is the key length in + * bits. If the `encryption' is TRUE the key is for encryption, if FALSE + * the key is for decryption. + * + ***/ +SilcBool silc_cipher_set_key(SilcCipher cipher, const unsigned char *key, + SilcUInt32 keylen, SilcBool encryption); + +/****f* silccrypt/SilcCipherAPI/silc_cipher_set_iv + * + * SYNOPSIS + * + * void silc_cipher_set_iv(SilcCipher cipher, const unsigned char *iv); + * + * DESCRIPTION + * + * Sets the IV (initialization vector) for the cipher. The `iv' must be + * the size of the block size of the cipher. If `iv' is NULL this + * does not do anything. + * + * If the encryption mode is CTR (Counter mode) this also resets the + * the counter for a new block. This is done also if `iv' is NULL. + * + * If the encryption mode is CFB (cipher feedback) this also resets the + * the feedback stream for a new block. This is done also if `iv' is NULL. + * + ***/ void silc_cipher_set_iv(SilcCipher cipher, const unsigned char *iv); -void silc_cipher_get_iv(SilcCipher cipher, unsigned char *iv); -uint32 silc_cipher_get_key_len(SilcCipher cipher); -uint32 silc_cipher_get_block_len(SilcCipher cipher); -#endif +/****f* silccrypt/SilcCipherAPI/silc_cipher_get_iv + * + * SYNOPSIS + * + * unsigned char *silc_cipher_get_iv(SilcCipher cipher); + * + * DESCRIPTION + * + * Returns the IV (initial vector) of the cipher. The returned + * pointer must not be freed by the caller. If the caller modifies + * the returned pointer the IV inside cipher is also modified. + * + ***/ +unsigned char *silc_cipher_get_iv(SilcCipher cipher); + +/****f* silccrypt/SilcCipherAPI/silc_cipher_get_key_len + * + * SYNOPSIS + * + * SilcUInt32 silc_cipher_get_key_len(SilcCipher cipher); + * + * DESCRIPTION + * + * Returns the key length of the cipher in bits. + * + ***/ +SilcUInt32 silc_cipher_get_key_len(SilcCipher cipher); + +/****f* silccrypt/SilcCipherAPI/silc_cipher_get_block_len + * + * SYNOPSIS + * + * SilcUInt32 silc_cipher_get_block_len(SilcCipher cipher); + * + * DESCRIPTION + * + * Returns the block size of the cipher in bytes. + * + ***/ +SilcUInt32 silc_cipher_get_block_len(SilcCipher cipher); + +/****f* silccrypt/SilcCipherAPI/silc_cipher_get_iv_len + * + * SYNOPSIS + * + * SilcUInt32 silc_cipher_get_iv_len(SilcCipher cipher); + * + * DESCRIPTION + * + * Returns the IV length of the cipher in bytes. + * + ***/ +SilcUInt32 silc_cipher_get_iv_len(SilcCipher cipher); + +/****f* silccrypt/SilcCipherAPI/silc_cipher_get_name + * + * SYNOPSIS + * + * const char *silc_cipher_get_name(SilcCipher cipher); + * + * DESCRIPTION + * + * Returns the name of the cipher. + * + ***/ +const char *silc_cipher_get_name(SilcCipher cipher); + +/****f* silccrypt/SilcCipherAPI/silc_cipher_get_mode + * + * SYNOPSIS + * + * SilcCipherMode silc_cipher_get_mode(SilcCipher cipher); + * + * DESCRIPTION + * + * Returns the cipher mode. + * + ***/ +SilcCipherMode silc_cipher_get_mode(SilcCipher cipher); + +#endif /* SILCCIPHER_H */