Module decryption 

AES Crypt v0–v3 decryption surface.

decrypt() is the high-level entry point and handles every supported format version. The lower-level helpers — header parsing, extension consumption, session-block recovery, and the streaming CBC loop — are exposed so that callers integrating with custom containers can drive each stage themselves.

Compatibility

Stage	v0	v1	v2	v3
read_file_version	Y	Y	Y	Y
consume_all_extensions	n/a	n/a	Y	Y
read_kdf_iterations	n/a	n/a	n/a	Y
extract_session_data	identity	encrypted	encrypted	encrypted+v3-tag
decrypt_ciphertext_stream	StreamConfig::V0	StreamConfig::V1	StreamConfig::V2	StreamConfig::V3

Security

See decrypt() for the decrypt-then-verify caveat: the v3 payload HMAC is checked only after the ciphertext stream has been processed, so partial unauthenticated plaintext may be written to the output before an error is returned. Callers must discard or overwrite the output on error.

Enums

StreamConfig

Per-version configuration for decrypt_ciphertext_stream.

Functions

consume_all_extensions

Consumes all v2/v3 extension blocks from reader, stopping at the zero-length terminator.

decrypt

Decrypts an AES Crypt v0–v3 file streamed from input and writes the recovered plaintext to output.

decrypt_ciphertext_stream

Streams ciphertext from input_reader through AES-256-CBC decryption, writes the recovered plaintext to output_writer, and verifies the version-appropriate HMAC trailer.

extract_session_data

Recovers the session IV and session key from the file header into the caller’s pre-allocated secure-gate buffers.

read_exact_span

Reads exactly N bytes from reader into a fresh auto-zeroizing SpanBuffer<N>.

read_file_version

Reads and validates the 5-byte AES Crypt file header.

read_kdf_iterations

Reads the 4-byte big-endian PBKDF2 iteration count from a v3 file header.