blowfish.h File Reference

Blowfish context structure.

Perform a Blowfish-CBC buffer encryption/decryption operation.

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	The Blowfish context to use. This must be initialized and bound to a key.
mode	The mode of operation. Possible values are MBEDTLS_BLOWFISH_ENCRYPT for encryption, or MBEDTLS_BLOWFISH_DECRYPT for decryption.
length	The length of the input data in Bytes. This must be multiple of 8.
iv	The initialization vector. This must be a read/write buffer of length 8 Bytes. It is updated by this function.
input	The input data. This must be a readable buffer of length length Bytes.
output	The output data. This must be a writable buffer of length length Bytes.

Returns:

0 if successful.

A negative error code on failure.

Definition at line 273 of file blowfish.c.

Perform a Blowfish CFB buffer encryption/decryption operation.

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	The Blowfish context to use. This must be initialized and bound to a key.
mode	The mode of operation. Possible values are MBEDTLS_BLOWFISH_ENCRYPT for encryption, or MBEDTLS_BLOWFISH_DECRYPT for decryption.
length	The length of the input data in Bytes.
iv_off	The offset in the initialiation vector. The value pointed to must be smaller than 8 Bytes. It is updated by this function to support the aforementioned streaming usage.
iv	The initialization vector. This must be a read/write buffer of size 8 Bytes. It is updated after use.
input	The input data. This must be a readable buffer of length length Bytes.
output	The output data. This must be a writable buffer of length length Bytes.

Returns:

0 if successful.

A negative error code on failure.

Definition at line 333 of file blowfish.c.

Perform a Blowfish-CTR buffer encryption/decryption operation.

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	The Blowfish context to use. This must be initialized and bound to a key.
length	The length of the input data in Bytes.
nc_off	The offset in the current stream_block (for resuming within current cipher stream). The offset pointer should be 0 at the start of a stream and must be smaller than 8. It is updated by this function.
nonce_counter	The 64-bit nonce and counter. This must point to a read/write buffer of length 8 Bytes.
stream_block	The saved stream-block for resuming. This must point to a read/write buffer of length 8 Bytes.
input	The input data. This must be a readable buffer of length length Bytes.
output	The output data. This must be a writable buffer of length length Bytes.

Returns:

0 if successful.

A negative error code on failure.

Definition at line 393 of file blowfish.c.

Perform a Blowfish-ECB block encryption/decryption operation.

Parameters:

ctx	The Blowfish context to use. This must be initialized and bound to a key.
mode	The mode of operation. Possible values are MBEDTLS_BLOWFISH_ENCRYPT for encryption, or MBEDTLS_BLOWFISH_DECRYPT for decryption.
input	The input block. This must be a readable buffer of size 8 Bytes.
output	The output block. This must be a writable buffer of size 8 Bytes.

Returns:

0 if successful.

A negative error code on failure.

Definition at line 239 of file blowfish.c.

Clear a Blowfish context.

Parameters:

ctx	The Blowfish context to be cleared. This may be NULL, in which case this function returns immediately. If it is not NULL, it must point to an initialized Blowfish context.

Definition at line 166 of file blowfish.c.

Initialize a Blowfish context.

Parameters:

ctx	The Blowfish context to be initialized. This must not be NULL.

Definition at line 160 of file blowfish.c.

Perform a Blowfish key schedule operation.

Parameters:

ctx	The Blowfish context to perform the key schedule on.
key	The encryption key. This must be a readable buffer of length keybits Bits.
keybits	The length of key in Bits. This must be between 32 and 448 and a multiple of 8.

Returns:

0 if successful.

A negative error code on failure.

Definition at line 177 of file blowfish.c.