///|
pub(all) enum PdfCryptType {
PdfCryptARC4(Int, Int)
PdfCryptAESV2
PdfCryptAESV3(Bool)
} derive(Debug, Eq, ToJson)
///|
fn pdf_crypto_low_byte(value : Int, shift : Int) -> Byte {
((value >> shift) & 0xff).to_byte()
}
///|
fn pdf_arc4_swap(state : Array[Int], left : Int, right : Int) -> Unit {
let value = state[left]
state[left] = state[right]
state[right] = value
}
///|
pub fn pdf_arc4_crypt(
key : BytesView,
data : BytesView,
) -> PdfBytes raise PdfError {
guard key.length() > 0 else { raise CryptoKeyExpected }
let state : Array[Int] = []
for value in 0..<256 {
state.push(value)
}
let mut j = 0
for i in 0..<256 {
j = (j + state[i] + key[i % key.length()].to_int()) % 256
pdf_arc4_swap(state, i, j)
}
let output : Array[Byte] = []
let mut i = 0
j = 0
for byte in data {
i = (i + 1) % 256
j = (j + state[i]) % 256
pdf_arc4_swap(state, i, j)
let stream_byte = state[(state[i] + state[j]) % 256]
output.push((byte.to_int() ^ stream_byte).to_byte())
}
Bytes::from_array(output)
}
///|
pub fn pdf_md5_digest(data : BytesView) -> PdfBytes {
Bytes::from_array(@crypto.md5(data))
}
///|
pub fn pdf_sha256_digest(data : BytesView) -> PdfBytes {
Bytes::from_array(@crypto.sha256(data))
}
///|
let pdf_sha512_k : Array[UInt64] = [
0x428a2f98d728ae22, 0x7137449123ef65cd, 0xb5c0fbcfec4d3b2f, 0xe9b5dba58189dbbc,
0x3956c25bf348b538, 0x59f111f1b605d019, 0x923f82a4af194f9b, 0xab1c5ed5da6d8118,
0xd807aa98a3030242, 0x12835b0145706fbe, 0x243185be4ee4b28c, 0x550c7dc3d5ffb4e2,
0x72be5d74f27b896f, 0x80deb1fe3b1696b1, 0x9bdc06a725c71235, 0xc19bf174cf692694,
0xe49b69c19ef14ad2, 0xefbe4786384f25e3, 0x0fc19dc68b8cd5b5, 0x240ca1cc77ac9c65,
0x2de92c6f592b0275, 0x4a7484aa6ea6e483, 0x5cb0a9dcbd41fbd4, 0x76f988da831153b5,
0x983e5152ee66dfab, 0xa831c66d2db43210, 0xb00327c898fb213f, 0xbf597fc7beef0ee4,
0xc6e00bf33da88fc2, 0xd5a79147930aa725, 0x06ca6351e003826f, 0x142929670a0e6e70,
0x27b70a8546d22ffc, 0x2e1b21385c26c926, 0x4d2c6dfc5ac42aed, 0x53380d139d95b3df,
0x650a73548baf63de, 0x766a0abb3c77b2a8, 0x81c2c92e47edaee6, 0x92722c851482353b,
0xa2bfe8a14cf10364, 0xa81a664bbc423001, 0xc24b8b70d0f89791, 0xc76c51a30654be30,
0xd192e819d6ef5218, 0xd69906245565a910, 0xf40e35855771202a, 0x106aa07032bbd1b8,
0x19a4c116b8d2d0c8, 0x1e376c085141ab53, 0x2748774cdf8eeb99, 0x34b0bcb5e19b48a8,
0x391c0cb3c5c95a63, 0x4ed8aa4ae3418acb, 0x5b9cca4f7763e373, 0x682e6ff3d6b2b8a3,
0x748f82ee5defb2fc, 0x78a5636f43172f60, 0x84c87814a1f0ab72, 0x8cc702081a6439ec,
0x90befffa23631e28, 0xa4506cebde82bde9, 0xbef9a3f7b2c67915, 0xc67178f2e372532b,
0xca273eceea26619c, 0xd186b8c721c0c207, 0xeada7dd6cde0eb1e, 0xf57d4f7fee6ed178,
0x06f067aa72176fba, 0x0a637dc5a2c898a6, 0x113f9804bef90dae, 0x1b710b35131c471b,
0x28db77f523047d84, 0x32caab7b40c72493, 0x3c9ebe0a15c9bebc, 0x431d67c49c100d4c,
0x4cc5d4becb3e42b6, 0x597f299cfc657e2a, 0x5fcb6fab3ad6faec, 0x6c44198c4a475817,
]
///|
fn pdf_sha512_rotr(value : UInt64, bits : Int) -> UInt64 {
(value >> bits) | (value << (64 - bits))
}
///|
fn pdf_sha512_small_sigma0(value : UInt64) -> UInt64 {
pdf_sha512_rotr(value, 1) ^ pdf_sha512_rotr(value, 8) ^ (value >> 7)
}
///|
fn pdf_sha512_small_sigma1(value : UInt64) -> UInt64 {
pdf_sha512_rotr(value, 19) ^ pdf_sha512_rotr(value, 61) ^ (value >> 6)
}
///|
fn pdf_sha512_big_sigma0(value : UInt64) -> UInt64 {
pdf_sha512_rotr(value, 28) ^
pdf_sha512_rotr(value, 34) ^
pdf_sha512_rotr(value, 39)
}
///|
fn pdf_sha512_big_sigma1(value : UInt64) -> UInt64 {
pdf_sha512_rotr(value, 14) ^
pdf_sha512_rotr(value, 18) ^
pdf_sha512_rotr(value, 41)
}
///|
fn pdf_sha512_u64_from_be(data : BytesView, offset : Int) -> UInt64 {
let mut value : UInt64 = 0
for index in 0..<8 {
value = (value << 8) | data[offset + index].to_uint64()
}
value
}
///|
fn pdf_sha512_push_u64_be(output : Array[Byte], value : UInt64) -> Unit {
for shift in [56, 48, 40, 32, 24, 16, 8, 0] {
output.push(((value >> shift) & 0xff).to_byte())
}
}
///|
fn pdf_sha512_padded(data : BytesView) -> PdfBytes {
let bit_length = data.length().to_uint64() * 8
let padded_length = (data.length() + 1 + 16 + 127) / 128 * 128
let output : Array[Byte] = Array::new(capacity=padded_length)
for byte in data {
output.push(byte)
}
output.push(0x80)
while output.length() % 128 != 112 {
output.push(0)
}
for _ in 0..<8 {
output.push(0)
}
pdf_sha512_push_u64_be(output, bit_length)
Bytes::from_array(output)
}
///|
fn pdf_sha512_process_block(block : BytesView, state : Array[UInt64]) -> Unit {
let words : Array[UInt64] = Array::make(80, 0)
for index in 0..<16 {
words[index] = pdf_sha512_u64_from_be(block, index * 8)
}
for index in 16..<80 {
words[index] = pdf_sha512_small_sigma1(words[index - 2]) +
words[index - 7] +
pdf_sha512_small_sigma0(words[index - 15]) +
words[index - 16]
}
let mut a = state[0]
let mut b = state[1]
let mut c = state[2]
let mut d = state[3]
let mut e = state[4]
let mut f = state[5]
let mut g = state[6]
let mut h = state[7]
for index in 0..<80 {
let choice = (e & f) ^ (e.lnot() & g)
let majority = (a & b) ^ (a & c) ^ (b & c)
let temp1 = h +
pdf_sha512_big_sigma1(e) +
choice +
pdf_sha512_k[index] +
words[index]
let temp2 = pdf_sha512_big_sigma0(a) + majority
h = g
g = f
f = e
e = d + temp1
d = c
c = b
b = a
a = temp1 + temp2
}
state[0] = state[0] + a
state[1] = state[1] + b
state[2] = state[2] + c
state[3] = state[3] + d
state[4] = state[4] + e
state[5] = state[5] + f
state[6] = state[6] + g
state[7] = state[7] + h
}
///|
fn pdf_sha512_digest_with_state(
data : BytesView,
state : Array[UInt64],
output_words : Int,
) -> PdfBytes {
let padded = pdf_sha512_padded(data)
let mut offset = 0
while offset < padded.length() {
pdf_sha512_process_block(padded[offset:offset + 128], state)
offset += 128
}
let output : Array[Byte] = []
for index in 0.. PdfBytes {
pdf_sha512_digest_with_state(
data,
[
0xcbbb9d5dc1059ed8, 0x629a292a367cd507, 0x9159015a3070dd17, 0x152fecd8f70e5939,
0x67332667ffc00b31, 0x8eb44a8768581511, 0xdb0c2e0d64f98fa7, 0x47b5481dbefa4fa4,
],
6,
)
}
///|
pub fn pdf_sha512_digest(data : BytesView) -> PdfBytes {
pdf_sha512_digest_with_state(
data,
[
0x6a09e667f3bcc908, 0xbb67ae8584caa73b, 0x3c6ef372fe94f82b, 0xa54ff53a5f1d36f1,
0x510e527fade682d1, 0x9b05688c2b3e6c1f, 0x1f83d9abfb41bd6b, 0x5be0cd19137e2179,
],
8,
)
}
///|
fn pdf_crypto_fixed_array(data : BytesView) -> FixedArray[Byte] {
let output = FixedArray::make(data.length(), b'\x00')
for index, byte in data {
output[index] = byte
}
output
}
///|
fn pdf_aes_valid_key_length(length : Int) -> Bool {
length == 16 || length == 24 || length == 32
}
///|
fn pdf_aes_check_key(key : BytesView) -> Unit raise PdfError {
guard pdf_aes_valid_key_length(key.length()) else { raise CryptoKeyExpected }
}
///|
fn pdf_aes_block(data : BytesView) -> FixedArray[Byte] raise PdfError {
guard data.length() == 16 else {
raise InvalidCryptoDataLength(data.length())
}
pdf_crypto_fixed_array(data)
}
///|
fn pdf_aes_encrypt_key(key : BytesView) -> FixedArray[Byte] raise PdfError {
pdf_aes_check_key(key)
let fixed_key = pdf_crypto_fixed_array(key)
@rijndael.camlpdf_caml_aes_cook_encrypt_key(fixed_key, 0, fixed_key.length())
}
///|
fn pdf_aes_decrypt_key(key : BytesView) -> FixedArray[Byte] raise PdfError {
pdf_aes_check_key(key)
let fixed_key = pdf_crypto_fixed_array(key)
@rijndael.camlpdf_caml_aes_cook_decrypt_key(fixed_key, 0, fixed_key.length())
}
///|
pub fn pdf_aes_encrypt_block(
key : BytesView,
block : BytesView,
) -> PdfBytes raise PdfError {
let cooked_key = pdf_aes_encrypt_key(key)
let src = pdf_aes_block(block)
let dst = FixedArray::make(16, b'\x00')
@rijndael.camlpdf_caml_aes_encrypt(cooked_key, 0, src, 0, dst, 0)
Bytes::from_array(dst)
}
///|
pub fn pdf_aes_decrypt_block(
key : BytesView,
block : BytesView,
) -> PdfBytes raise PdfError {
let cooked_key = pdf_aes_decrypt_key(key)
let src = pdf_aes_block(block)
let dst = FixedArray::make(16, b'\x00')
@rijndael.camlpdf_caml_aes_decrypt(cooked_key, 0, src, 0, dst, 0)
Bytes::from_array(dst)
}
///|
fn pdf_aes_remove_padding(data : BytesView) -> PdfBytes {
let length = data.length()
let padding = data[length - 1].to_int()
guard padding >= 1 && padding <= 16 else { return data.to_owned() }
for index in (length - padding).. Unit {
for byte in block {
output.push(byte)
}
}
///|
pub fn pdf_aes_cbc_decrypt(
key : BytesView,
data : BytesView,
remove_padding? : Bool = true,
) -> PdfBytes raise PdfError {
guard data.length() > 16 else { return Bytes::new(0) }
guard data.length() % 16 == 0 else {
raise InvalidCryptoDataLength(data.length())
}
let cooked_key = pdf_aes_decrypt_key(key)
let output : Array[Byte] = []
let mut previous_ciphertext = pdf_aes_block(data[:16])
let mut position = 16
while position < data.length() {
let ciphertext = pdf_aes_block(data[position:position + 16])
let plaintext = FixedArray::make(16, b'\x00')
@rijndael.camlpdf_caml_aes_decrypt(
cooked_key, 0, ciphertext, 0, plaintext, 0,
)
for index in 0..<16 {
output.push(
(plaintext[index].to_int() ^ previous_ciphertext[index].to_int()).to_byte(),
)
}
previous_ciphertext = ciphertext
position += 16
}
let decrypted = Bytes::from_array(output)
if remove_padding {
pdf_aes_remove_padding(decrypted[:])
} else {
decrypted
}
}
///|
fn pdf_aes_padded_blocks(data : BytesView) -> Array[FixedArray[Byte]] {
let blocks : Array[FixedArray[Byte]] = []
let full_blocks = data.length() / 16
for block_index in 0.. PdfBytes raise PdfError {
let cooked_key = pdf_aes_encrypt_key(key)
let mut previous_ciphertext = pdf_aes_block(iv)
let output : Array[Byte] = []
pdf_aes_append_block(output, previous_ciphertext)
for block in pdf_aes_padded_blocks(data) {
let plaintext = FixedArray::make(16, b'\x00')
for index in 0..<16 {
plaintext[index] = (block[index].to_int() ^
previous_ciphertext[index].to_int()).to_byte()
}
let ciphertext = FixedArray::make(16, b'\x00')
@rijndael.camlpdf_caml_aes_encrypt(
cooked_key, 0, plaintext, 0, ciphertext, 0,
)
pdf_aes_append_block(output, ciphertext)
previous_ciphertext = ciphertext
}
Bytes::from_array(output)
}
///|
pub fn pdf_aes_ecb_decrypt(
key : BytesView,
data : BytesView,
remove_padding? : Bool = true,
) -> PdfBytes raise PdfError {
guard data.length() > 0 else { return Bytes::new(0) }
guard data.length() % 16 == 0 else {
raise InvalidCryptoDataLength(data.length())
}
let cooked_key = pdf_aes_decrypt_key(key)
let output : Array[Byte] = []
let mut position = 0
while position < data.length() {
let ciphertext = pdf_aes_block(data[position:position + 16])
let plaintext = FixedArray::make(16, b'\x00')
@rijndael.camlpdf_caml_aes_decrypt(
cooked_key, 0, ciphertext, 0, plaintext, 0,
)
pdf_aes_append_block(output, plaintext)
position += 16
}
let decrypted = Bytes::from_array(output)
if remove_padding {
pdf_aes_remove_padding(decrypted[:])
} else {
decrypted
}
}
///|
pub fn pdf_encryption_object_key(
crypt_type : PdfCryptType,
object_number : Int,
generation : Int,
file_key : BytesView,
key_length_bits : Int,
) -> PdfBytes {
let md5 = @crypto.MD5::new()
md5.update(file_key)
let object_bytes : FixedArray[Byte] = [
pdf_crypto_low_byte(object_number, 0),
pdf_crypto_low_byte(object_number, 8),
pdf_crypto_low_byte(object_number, 16),
]
md5.update(object_bytes)
let generation_bytes : FixedArray[Byte] = [
pdf_crypto_low_byte(generation, 0),
pdf_crypto_low_byte(generation, 8),
]
md5.update(generation_bytes)
if crypt_type == PdfCryptAESV2 {
let aes_salt : FixedArray[Byte] = [0x73, 0x41, 0x6c, 0x54]
md5.update(aes_salt)
}
let digest = md5.finalize()
let requested_length = key_length_bits / 8 + 5
let length = if requested_length < 16 { requested_length } else { 16 }
let output : Array[Byte] = []
for index in 0.. PdfBytes raise PdfError {
let object_key = pdf_encryption_object_key(
PdfCryptARC4(key_length_bits, 0),
object_number,
generation,
file_key,
key_length_bits,
)
pdf_arc4_crypt(object_key[:], data)
}