Security

Data Structures

• struct _Twofish_key

Typedefs

• typedef _Twofish_key Twofish_key

Functions

• void xrand (u8 buf[8])
• u8 password (u8 *key, u8 len_8, const u8 *text)
• u8 twofish_setup (u8 *key, u8 keylen, Twofish_key *skey)
• void twofish_ecb_decrypt (u8 *ct, u8 *pt, Twofish_key *key)
• void twofish_ecb_encrypt (u8 *pt, u8 *ct, Twofish_key *key)
• u8 twofish_cbc_encrypt (u8 *in, u8 *out, u8 nr_blocks, Twofish_key *key)
• u8 twofish_cbc_decrypt (u8 *in, u8 *out, u8 nr_blocks, Twofish_key *key)

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Typedef Documentation

typedef struct _Twofish_key Twofish_key

Twofish key structure holding the internal state. Set up by twofish_setup().

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Function Documentation

u8 password (  u8 *  key, u8  len_8, const u8 *  text )

Ask for password/key. The resulting key is in format: key[0] is nr of chars (septets), then follow the chars compressed to 7b padded with len_8-key[0]. Note: Number of chars is (len_8-1)*8/7, not the len_8. Warning: SIM Toolkit function, usable only in stk_thread(). Parameters: key  pointer on buf[len_8] to fill the resulting key in len_8  number of bytes the resulting key should have text  if NULL then default "Key" text is used, ALPHA coding or STRING_SLV coding, can be from RAM, EEPROM, PROGMEM Returns: APP_OK if key valid, APP_END if user end, APP_BACK if user back. Examples: certs.c, and mc.c.

u8 twofish_cbc_decrypt (  u8 *  in, u8 *  out, u8  nr_blocks, Twofish_key *  key )

Decrypt in CBC mode. Parameters: in  pointer on input buffer (len has to be nr_blocks*16) stored in RAM, EEPROM, PROGMEM out  pointer on output buffer (len has to be nr_blocks*16), RAM or EEPROM nr_blocks  number of blocks key  key Returns: NO_ERROR, ERR_NO_RAM

u8 twofish_cbc_encrypt (  u8 *  in, u8 *  out, u8  nr_blocks, Twofish_key *  key )

Encrypt in CBC mode. Parameters: in  pointer on input buffer (len has to be nr_blocks*16), stored in RAM, EEPROM, PROGMEM out  pointer on output buffer (len has to be nr_blocks*16), RAM or EEPROM nr_blocks  number of blocks key  key Returns: NO_ERROR, ERR_NO_RAM

void twofish_ecb_decrypt (  u8 *  ct, u8 *  pt, Twofish_key *  key )

Decrypt cipher text to plain text. Parameters: ct  cipher text of len 16 bytes, stored in RAM, EEPROM or PROGMEM. pt  plain text, RAM or EEPROM. key  Examples: certs.c, and test_prot_mem.c.

void twofish_ecb_encrypt (  u8 *  pt, u8 *  ct, Twofish_key *  key )

Encrypt plain text to cipher text. Parameters: ct  cipher text of len 16 bytes, stored in RAM, EEPROM or PROGMEM. pt  plain text, RAM or EEPROM. key  Examples: certs.c, and test_prot_mem.c.

u8 twofish_setup (  u8 *  key, u8  keylen, Twofish_key *  skey )

Prepare twofish key structure for de/encryption. Parameters: key  pointer on '\0' terminated key, can be RAM, EEPROM, PROGMEM. keylen  requested keylen 16 (=128bits), 24 (=192bits), 32 (=256bits). skey  result. Returns: NO_ERROR or ERR_TWOFISH_KEYLEN, ERR_NO_RAM. Examples: certs.c, and test_prot_mem.c.

void xrand (  u8  buf[8]  )

Returns random 8 bytes. The random number generator is influenced by several variables: previous random, 8bit timer running permanently, EF_BCCH, EF_LOCINFO (random TMSI), random input for GSM algorithm. Everything together is randomly twofished. Parameters: buf  Examples: certs.c.