blowfish.h File Reference

Blowfish context structure.

Blowfish-CBC buffer encryption/decryption Length should be a multiple of the block size (8 bytes)

Note:

Upon exit, the content of the IV is updated so that you can call the function same function again on the following block(s) of data and get the same result as if it was encrypted in one call. This allows a "streaming" usage. If on the other hand you need to retain the contents of the IV, you should either save it manually or use the cipher module instead.

Parameters:

ctx	Blowfish context
mode	MBEDTLS_BLOWFISH_ENCRYPT or MBEDTLS_BLOWFISH_DECRYPT
length	length of the input data
iv	initialization vector (updated after use)
input	buffer holding the input data
output	buffer holding the output data

Returns:

0 if successful, or MBEDTLS_ERR_BLOWFISH_INVALID_INPUT_LENGTH

Definition at line 257 of file blowfish.c.

Blowfish CFB buffer encryption/decryption.

Note:

Upon exit, the content of the IV is updated so that you can call the function same function again on the following block(s) of data and get the same result as if it was encrypted in one call. This allows a "streaming" usage. If on the other hand you need to retain the contents of the IV, you should either save it manually or use the cipher module instead.

Parameters:

ctx	Blowfish context
mode	MBEDTLS_BLOWFISH_ENCRYPT or MBEDTLS_BLOWFISH_DECRYPT
length	length of the input data
iv_off	offset in IV (updated after use)
iv	initialization vector (updated after use)
input	buffer holding the input data
output	buffer holding the output data

Returns:

0 if successful

Definition at line 311 of file blowfish.c.

Blowfish-CTR buffer encryption/decryption.

Warning:

You must never reuse a nonce value with the same key. Doing so would void the encryption for the two messages encrypted with the same nonce and key.

There are two common strategies for managing nonces with CTR:

1. You can handle everything as a single message processed over successive calls to this function. In that case, you want to set nonce_counter and nc_off to 0 for the first call, and then preserve the values of nonce_counter, nc_off and stream_block across calls to this function as they will be updated by this function.

With this strategy, you must not encrypt more than 2**64 blocks of data with the same key.

2. You can encrypt separate messages by dividing the nonce_counter buffer in two areas: the first one used for a per-message nonce, handled by yourself, and the second one updated by this function internally.

For example, you might reserve the first 4 bytes for the per-message nonce, and the last 4 bytes for internal use. In that case, before calling this function on a new message you need to set the first 4 bytes of nonce_counter to your chosen nonce value, the last 4 to 0, and nc_off to 0 (which will cause stream_block to be ignored). That way, you can encrypt at most 2**32 messages of up to 2**32 blocks each with the same key.

The per-message nonce (or information sufficient to reconstruct it) needs to be communicated with the ciphertext and must be unique. The recommended way to ensure uniqueness is to use a message counter.

Note that for both stategies, sizes are measured in blocks and that a Blowfish block is 8 bytes.

Warning:

Upon return, stream_block contains sensitive data. Its content must not be written to insecure storage and should be securely discarded as soon as it's no longer needed.

Parameters:

ctx	Blowfish context
length	The length of the data
nc_off	The offset in the current stream_block (for resuming within current cipher stream). The offset pointer to should be 0 at the start of a stream.
nonce_counter	The 64-bit nonce and counter.
stream_block	The saved stream-block for resuming. Is overwritten by the function.
input	The input data stream
output	The output data stream

Returns:

0 if successful

Definition at line 359 of file blowfish.c.

Blowfish-ECB block encryption/decryption.

Parameters:

ctx	Blowfish context
mode	MBEDTLS_BLOWFISH_ENCRYPT or MBEDTLS_BLOWFISH_DECRYPT
input	8-byte input block
output	8-byte output block

Returns:

0 if successful

Definition at line 228 of file blowfish.c.

Clear Blowfish context.

Parameters:

ctx	Blowfish context to be cleared

Definition at line 159 of file blowfish.c.

Initialize Blowfish context.

Parameters:

ctx	Blowfish context to be initialized

Definition at line 154 of file blowfish.c.

Blowfish key schedule.

Parameters:

ctx	Blowfish context to be initialized
key	encryption key
keybits	must be between 32 and 448 bits

Returns:

0 if successful, or MBEDTLS_ERR_BLOWFISH_INVALID_KEY_LENGTH

Definition at line 170 of file blowfish.c.