Module crypto 

Low-level cryptographic primitives for PDF encryption.

Split into three submodules mirroring the upstream core/fdrm/ source layout:

• fx_crypt — MD5, SHA-1, RC4, and CryptoError
• fx_crypt_sha — SHA-256, SHA-384, SHA-512
• fx_crypt_aes — AES-128/192/256-CBC and AES-256-ECB

RC4 manual implementation

RC4 is implemented manually rather than using the rc4 crate because that crate requires a compile-time fixed key length via a type parameter (Rc4<U5>, Rc4<U16>, etc.), which is incompatible with PDF encryption’s variable-length keys (5-16 bytes for R2-R4, determined at runtime from the encryption dictionary).

SHA-1

SHA-1 is used for digital signature verification (PKCS#7/CMS with sha1WithRSAEncryption) and some legacy PDF encryption extensions. Delegated to the RustCrypto sha1 crate, matching the same delegation pattern as sha2 for SHA-256/384/512.

Re-exports

pub use fx_crypt::CryptoError;

pub use fx_crypt::md5;

pub use fx_crypt::rc4_crypt;

pub use fx_crypt::sha1;

pub use fx_crypt_aes::aes128_cbc_decrypt;

pub use fx_crypt_aes::aes128_cbc_encrypt;

pub use fx_crypt_aes::aes128_cbc_encrypt_no_padding;

pub use fx_crypt_aes::aes192_cbc_decrypt;

pub use fx_crypt_aes::aes192_cbc_encrypt;

pub use fx_crypt_aes::aes256_cbc_decrypt;

pub use fx_crypt_aes::aes256_cbc_decrypt_no_padding;

pub use fx_crypt_aes::aes256_cbc_encrypt;

pub use fx_crypt_aes::aes256_cbc_encrypt_no_padding;

pub use fx_crypt_aes::aes256_ecb_decrypt_block;

pub use fx_crypt_sha::sha256;

pub use fx_crypt_sha::sha384;

pub use fx_crypt_sha::sha512;

Modules

fx_crypt

MD5, SHA-1, and RC4 primitives.

fx_crypt_aes

AES-128/192/256-CBC and AES-256-ECB primitives.

fx_crypt_sha

SHA-256, SHA-384, and SHA-512 hash functions.