mirror of
https://github.com/michaelrsweet/pdfio.git
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Move AES code to separate file, prep private API for making keys/contexts/callbacks for encryption.
This commit is contained in:
Michael R Sweet
parent
27e4ce9f42
commit
2245c9d4f5
1
Makefile
1
Makefile
@ -40,6 +40,7 @@ PUBHEADERS = \
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pdfio.h \
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pdfio-content.h
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PUBOBJS = \
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pdfio-aes.o \
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pdfio-array.o \
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pdfio-common.o \
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pdfio-content.o \
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512
pdfio-aes.c
Normal file
512
pdfio-aes.c
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@ -0,0 +1,512 @@
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//
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// AES functions for PDFio.
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//
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// Copyright © 2021 by Michael R Sweet.
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//
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// Licensed under Apache License v2.0. See the file "LICENSE" for more
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// information.
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//
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// AES code is adapted from the "tiny-AES-c" project
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// (<https://github.com/kokke/tiny-AES-c>)
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//
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//
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// Include necessary headers...
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//
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#include "pdfio-private.h"
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//
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// Local types...
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//
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typedef uint8_t state_t[4][4]; // 4x4 AES state table
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//
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// Local globals...
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//
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static const uint8_t sbox[256] = // S-box lookup table
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{
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//0 1 2 3 4 5 6 7 8 9 A B C D E F
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0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76,
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0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0,
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0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15,
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0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75,
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0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84,
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0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf,
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0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8,
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0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2,
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0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73,
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0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb,
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0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79,
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0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08,
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0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a,
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0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e,
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0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf,
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0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16
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};
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static const uint8_t rsbox[256] = // Reverse S-box lookup table
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{
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0x52, 0x09, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38, 0xbf, 0x40, 0xa3, 0x9e, 0x81, 0xf3, 0xd7, 0xfb,
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0x7c, 0xe3, 0x39, 0x82, 0x9b, 0x2f, 0xff, 0x87, 0x34, 0x8e, 0x43, 0x44, 0xc4, 0xde, 0xe9, 0xcb,
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0x54, 0x7b, 0x94, 0x32, 0xa6, 0xc2, 0x23, 0x3d, 0xee, 0x4c, 0x95, 0x0b, 0x42, 0xfa, 0xc3, 0x4e,
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0x08, 0x2e, 0xa1, 0x66, 0x28, 0xd9, 0x24, 0xb2, 0x76, 0x5b, 0xa2, 0x49, 0x6d, 0x8b, 0xd1, 0x25,
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0x72, 0xf8, 0xf6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xd4, 0xa4, 0x5c, 0xcc, 0x5d, 0x65, 0xb6, 0x92,
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0x6c, 0x70, 0x48, 0x50, 0xfd, 0xed, 0xb9, 0xda, 0x5e, 0x15, 0x46, 0x57, 0xa7, 0x8d, 0x9d, 0x84,
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0x90, 0xd8, 0xab, 0x00, 0x8c, 0xbc, 0xd3, 0x0a, 0xf7, 0xe4, 0x58, 0x05, 0xb8, 0xb3, 0x45, 0x06,
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0xd0, 0x2c, 0x1e, 0x8f, 0xca, 0x3f, 0x0f, 0x02, 0xc1, 0xaf, 0xbd, 0x03, 0x01, 0x13, 0x8a, 0x6b,
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0x3a, 0x91, 0x11, 0x41, 0x4f, 0x67, 0xdc, 0xea, 0x97, 0xf2, 0xcf, 0xce, 0xf0, 0xb4, 0xe6, 0x73,
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0x96, 0xac, 0x74, 0x22, 0xe7, 0xad, 0x35, 0x85, 0xe2, 0xf9, 0x37, 0xe8, 0x1c, 0x75, 0xdf, 0x6e,
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0x47, 0xf1, 0x1a, 0x71, 0x1d, 0x29, 0xc5, 0x89, 0x6f, 0xb7, 0x62, 0x0e, 0xaa, 0x18, 0xbe, 0x1b,
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0xfc, 0x56, 0x3e, 0x4b, 0xc6, 0xd2, 0x79, 0x20, 0x9a, 0xdb, 0xc0, 0xfe, 0x78, 0xcd, 0x5a, 0xf4,
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0x1f, 0xdd, 0xa8, 0x33, 0x88, 0x07, 0xc7, 0x31, 0xb1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xec, 0x5f,
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0x60, 0x51, 0x7f, 0xa9, 0x19, 0xb5, 0x4a, 0x0d, 0x2d, 0xe5, 0x7a, 0x9f, 0x93, 0xc9, 0x9c, 0xef,
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0xa0, 0xe0, 0x3b, 0x4d, 0xae, 0x2a, 0xf5, 0xb0, 0xc8, 0xeb, 0xbb, 0x3c, 0x83, 0x53, 0x99, 0x61,
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0x17, 0x2b, 0x04, 0x7e, 0xba, 0x77, 0xd6, 0x26, 0xe1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0c, 0x7d
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};
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// The round constant word array, Rcon[i], contains the values given by
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// x to the power (i-1) being powers of x (x is denoted as {02}) in the field GF(2^8)
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static const uint8_t Rcon[11] = // Round constants
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{
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0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36
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};
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//
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// Local functions...
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//
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static void AddRoundKey(size_t round, state_t *state, const uint8_t *RoundKey);
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static void SubBytes(state_t *state);
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static void ShiftRows(state_t *state);
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static uint8_t xtime(uint8_t x);
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static void MixColumns(state_t *state);
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static uint8_t Multiply(uint8_t x, uint8_t y);
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static void InvMixColumns(state_t *state);
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static void InvSubBytes(state_t *state);
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static void InvShiftRows(state_t *state);
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static void Cipher(state_t *state, const _pdfio_aes_t *ctx);
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static void InvCipher(state_t *state, const _pdfio_aes_t *ctx);
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static void XorWithIv(uint8_t *buf, const uint8_t *Iv);
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//
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// '_pdfioCryptoAESInit()' - Initialize an AES context.
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//
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void
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_pdfioCryptoAESInit(
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_pdfio_aes_t *ctx, // I - AES context
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const uint8_t *key, // I - Key
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size_t keylen, // I - Length of key (must be 16 or 32)
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const uint8_t *iv) // I - 16-byte initialization vector
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{
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size_t i; // Looping var
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uint8_t *rkptr0, // Previous round_key values
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*rkptr, // Current round_key values
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*rkend, // End of round_key values
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tempa[4]; // Used for the column/row operations
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size_t roundlen = keylen + 24; // Length of round_key
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size_t nwords = keylen / 4; // Number of 32-bit words in key
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// Clear context
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memset(ctx, 0, sizeof(_pdfio_aes_t));
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// The first round key is the key itself.
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memcpy(ctx->round_key, key, keylen);
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// All other round keys are found from the previous round keys.
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for (rkptr0 = ctx->round_key, rkptr = rkptr0 + keylen, rkend = rkptr + roundlen, i = nwords; rkptr < rkend; i ++)
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{
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if ((i % nwords) == 0)
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{
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// Shifts word left once - [a0,a1,a2,a3] becomes [a1,a2,a3,a0]
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tempa[0] = rkptr[-3];
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tempa[1] = rkptr[-2];
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tempa[2] = rkptr[-1];
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tempa[3] = rkptr[-4];
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// Apply the S-box to each of the four bytes to produce an output word.
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tempa[0] = sbox[tempa[0]];
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tempa[1] = sbox[tempa[1]];
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tempa[2] = sbox[tempa[2]];
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tempa[3] = sbox[tempa[3]];
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tempa[0] = tempa[0] ^ Rcon[i / nwords];
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}
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else if (keylen == 32 && (i % nwords) == 4)
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{
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// Apply the S-box to each of the four bytes to produce an output word.
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tempa[0] = sbox[rkptr[-4]];
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tempa[1] = sbox[rkptr[-3]];
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tempa[2] = sbox[rkptr[-2]];
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tempa[3] = sbox[rkptr[-1]];
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}
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else
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{
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tempa[0] = rkptr[-4];
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tempa[1] = rkptr[-3];
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tempa[2] = rkptr[-2];
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tempa[3] = rkptr[-1];
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}
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*rkptr++ = *rkptr0++ ^ tempa[0];
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*rkptr++ = *rkptr0++ ^ tempa[1];
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*rkptr++ = *rkptr0++ ^ tempa[2];
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*rkptr++ = *rkptr0++ ^ tempa[3];
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}
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// Copy the initialization vector...
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if (iv)
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memcpy(ctx->iv, iv, sizeof(ctx->iv));
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}
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//
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// '_pdfioCryptoAESDecrypt()' - Decrypt a block of bytes with AES.
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//
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void
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_pdfioCryptoAESDecrypt(
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_pdfio_aes_t *ctx, // I - AES context
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uint8_t *buffer, // I - Buffer
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size_t len) // I - Number of bytes to decrypt
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{
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uint8_t next_iv[16]; // Next IV value
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while (len > 15)
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{
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memcpy(next_iv, buffer, 16);
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InvCipher((state_t *)buffer, ctx);
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XorWithIv(buffer, ctx->iv);
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memcpy(ctx->iv, next_iv, 16);
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buffer += 16;
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len -= 16;
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}
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if (len > 0)
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{
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// Pad the final buffer with (16 - len)...
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uint8_t temp[16]; // Temporary buffer
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memset(temp, 16 - len, sizeof(temp));
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memcpy(temp, buffer, len);
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memcpy(next_iv, temp, 16);
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InvCipher((state_t *)temp, ctx);
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XorWithIv(temp, ctx->iv);
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memcpy(ctx->iv, next_iv, 16);
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memcpy(buffer, temp, len);
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}
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}
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//
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// '_pdfioCryptoAESEncrypt()' - Encrypt a block of bytes with AES.
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//
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void
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_pdfioCryptoAESEncrypt(
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_pdfio_aes_t *ctx, // I - AES context
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uint8_t *buffer, // I - Buffer
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size_t len) // I - Number of bytes to decrypt
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{
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uint8_t *iv = ctx->iv; // Current IV for CBC
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uint8_t temp[16]; // Temporary buffer
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while (len > 15)
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{
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XorWithIv(buffer, iv);
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Cipher((state_t*)buffer, ctx);
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iv = buffer;
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buffer += 16;
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len -= 16;
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}
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if (len > 0)
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{
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// Pad the final buffer with (16 - len)...
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memset(temp, 16 - len, sizeof(temp));
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memcpy(temp, buffer, len);
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XorWithIv(temp, iv);
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Cipher((state_t*)temp, ctx);
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iv = temp;
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memcpy(buffer, temp, len);
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}
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/* store Iv in ctx for next call */
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memcpy(ctx->iv, iv, 16);
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}
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// This function adds the round key to state.
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// The round key is added to the state by an XOR function.
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static void
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AddRoundKey(size_t round, state_t *state, const uint8_t *RoundKey)
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{
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unsigned i; // Looping var
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uint8_t *sptr = (*state)[0]; // Pointer into state
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for (RoundKey += round * 16, i = 16; i > 0; i --, sptr ++, RoundKey ++)
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*sptr ^= *RoundKey;
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}
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// The SubBytes Function Substitutes the values in the
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// state matrix with values in an S-box.
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static void
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SubBytes(state_t *state)
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{
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unsigned i; // Looping var
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uint8_t *sptr = (*state)[0]; // Pointer into state
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for (i = 16; i > 0; i --, sptr ++)
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*sptr = sbox[*sptr];
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}
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// The ShiftRows() function shifts the rows in the state to the left.
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// Each row is shifted with different offset.
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// Offset = Row number. So the first row is not shifted.
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static void
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ShiftRows(state_t *state)
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{
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uint8_t *sptr = (*state)[0]; // Pointer into state
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uint8_t temp; // Temporary value
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// Rotate first row 1 columns to left
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temp = sptr[1];
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sptr[1] = sptr[5];
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sptr[5] = sptr[9];
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sptr[9] = sptr[13];
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sptr[13] = temp;
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// Rotate second row 2 columns to left
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temp = sptr[2];
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sptr[2] = sptr[10];
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sptr[10] = temp;
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temp = sptr[6];
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sptr[6] = sptr[14];
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sptr[14] = temp;
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// Rotate third row 3 columns to left
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temp = sptr[3];
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sptr[3] = sptr[15];
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sptr[15] = sptr[11];
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sptr[11] = sptr[7];
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sptr[7] = temp;
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}
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static uint8_t
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xtime(uint8_t x)
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{
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return ((uint8_t)((x << 1) ^ ((x >> 7) * 0x1b)));
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}
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// MixColumns function mixes the columns of the state matrix
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static void
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MixColumns(state_t *state)
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{
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unsigned i; // Looping var
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uint8_t *sptr = (*state)[0]; // Pointer into state
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uint8_t Tmp, Tm, t; // Temporary values
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for (i = 4; i > 0; i --, sptr += 4)
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{
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t = sptr[0];
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Tmp = sptr[0] ^ sptr[1] ^ sptr[2] ^ sptr[3];
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Tm = sptr[0] ^ sptr[1];
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Tm = xtime(Tm);
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sptr[0] ^= Tm ^ Tmp;
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Tm = sptr[1] ^ sptr[2];
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Tm = xtime(Tm);
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sptr[1] ^= Tm ^ Tmp;
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Tm = sptr[2] ^ sptr[3];
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Tm = xtime(Tm);
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sptr[2] ^= Tm ^ Tmp;
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Tm = sptr[3] ^ t;
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Tm = xtime(Tm);
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sptr[3] ^= Tm ^ Tmp;
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}
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}
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// Multiply is used to multiply numbers in the field GF(2^8)
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// Note: The last call to xtime() is unneeded, but often ends up generating a smaller binary
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// The compiler seems to be able to vectorize the operation better this way.
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// See https://github.com/kokke/tiny-AES-c/pull/34
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static uint8_t Multiply(uint8_t x, uint8_t y)
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{
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return (((y & 1) * x) ^
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((y>>1 & 1) * xtime(x)) ^
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((y>>2 & 1) * xtime(xtime(x))) ^
|
||||
((y>>3 & 1) * xtime(xtime(xtime(x)))) ^
|
||||
((y>>4 & 1) * xtime(xtime(xtime(xtime(x)))))); /* this last call to xtime() can be omitted */
|
||||
}
|
||||
|
||||
|
||||
// MixColumns function mixes the columns of the state matrix.
|
||||
// The method used to multiply may be difficult to understand for the inexperienced.
|
||||
// Please use the references to gain more information.
|
||||
static void
|
||||
InvMixColumns(state_t *state)
|
||||
{
|
||||
unsigned i; // Looping var
|
||||
uint8_t *sptr = (*state)[0]; // Pointer into state
|
||||
uint8_t a, b, c, d; // Temporary values
|
||||
|
||||
|
||||
for (i = 4; i > 0; i --)
|
||||
{
|
||||
a = sptr[0];
|
||||
b = sptr[1];
|
||||
c = sptr[2];
|
||||
d = sptr[3];
|
||||
|
||||
*sptr++ = Multiply(a, 0x0e) ^ Multiply(b, 0x0b) ^ Multiply(c, 0x0d) ^ Multiply(d, 0x09);
|
||||
*sptr++ = Multiply(a, 0x09) ^ Multiply(b, 0x0e) ^ Multiply(c, 0x0b) ^ Multiply(d, 0x0d);
|
||||
*sptr++ = Multiply(a, 0x0d) ^ Multiply(b, 0x09) ^ Multiply(c, 0x0e) ^ Multiply(d, 0x0b);
|
||||
*sptr++ = Multiply(a, 0x0b) ^ Multiply(b, 0x0d) ^ Multiply(c, 0x09) ^ Multiply(d, 0x0e);
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
// The SubBytes Function Substitutes the values in the
|
||||
// state matrix with values in an S-box.
|
||||
static void
|
||||
InvSubBytes(state_t *state)
|
||||
{
|
||||
unsigned i; // Looping var
|
||||
uint8_t *sptr = (*state)[0]; // Pointer into state
|
||||
|
||||
|
||||
for (i = 16; i > 0; i --, sptr ++)
|
||||
*sptr = rsbox[*sptr];
|
||||
}
|
||||
|
||||
|
||||
static void
|
||||
InvShiftRows(state_t *state)
|
||||
{
|
||||
uint8_t *sptr = (*state)[0]; // Pointer into state
|
||||
uint8_t temp; // Temporary value
|
||||
|
||||
|
||||
// Rotate first row 1 columns to right
|
||||
temp = sptr[13];
|
||||
sptr[13] = sptr[9];
|
||||
sptr[9] = sptr[5];
|
||||
sptr[5] = sptr[1];
|
||||
sptr[1] = temp;
|
||||
|
||||
// Rotate second row 2 columns to right
|
||||
temp = sptr[2];
|
||||
sptr[2] = sptr[10];
|
||||
sptr[10] = temp;
|
||||
|
||||
temp = sptr[6];
|
||||
sptr[6] = sptr[14];
|
||||
sptr[14] = temp;
|
||||
|
||||
// Rotate third row 3 columns to right
|
||||
temp = sptr[3];
|
||||
sptr[3] = sptr[7];
|
||||
sptr[7] = sptr[11];
|
||||
sptr[11] = sptr[15];
|
||||
sptr[15] = temp;
|
||||
}
|
||||
|
||||
|
||||
// Cipher is the main function that encrypts the PlainText.
|
||||
static void
|
||||
Cipher(state_t *state, const _pdfio_aes_t *ctx)
|
||||
{
|
||||
uint8_t round = 0;
|
||||
|
||||
// Add the First round key to the state before starting the rounds.
|
||||
AddRoundKey(0, state, ctx->round_key);
|
||||
|
||||
// There will be Nr rounds.
|
||||
// The first Nr-1 rounds are identical.
|
||||
// These Nr rounds are executed in the loop below.
|
||||
// Last one without MixColumns()
|
||||
for (round = 1; ; ++round)
|
||||
{
|
||||
SubBytes(state);
|
||||
ShiftRows(state);
|
||||
if (round == ctx->round_size)
|
||||
break;
|
||||
|
||||
MixColumns(state);
|
||||
AddRoundKey(round, state, ctx->round_key);
|
||||
}
|
||||
// Add round key to last round
|
||||
AddRoundKey(ctx->round_size, state, ctx->round_key);
|
||||
}
|
||||
|
||||
|
||||
static void
|
||||
InvCipher(state_t *state, const _pdfio_aes_t *ctx)
|
||||
{
|
||||
size_t round;
|
||||
|
||||
// Add the First round key to the state before starting the rounds.
|
||||
AddRoundKey(ctx->round_size, state, ctx->round_key);
|
||||
|
||||
// There will be Nr rounds.
|
||||
// The first Nr-1 rounds are identical.
|
||||
// These Nr rounds are executed in the loop below.
|
||||
// Last one without InvMixColumn()
|
||||
for (round = ctx->round_size - 1; ; round --)
|
||||
{
|
||||
InvShiftRows(state);
|
||||
InvSubBytes(state);
|
||||
AddRoundKey(round, state, ctx->round_key);
|
||||
|
||||
if (round == 0)
|
||||
break;
|
||||
|
||||
InvMixColumns(state);
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
static void
|
||||
XorWithIv(uint8_t *buf, const uint8_t *Iv)
|
||||
{
|
||||
// 16-byte block...
|
||||
*buf++ ^= *Iv++;
|
||||
*buf++ ^= *Iv++;
|
||||
*buf++ ^= *Iv++;
|
||||
*buf++ ^= *Iv++;
|
||||
*buf++ ^= *Iv++;
|
||||
*buf++ ^= *Iv++;
|
||||
*buf++ ^= *Iv++;
|
||||
*buf++ ^= *Iv++;
|
||||
*buf++ ^= *Iv++;
|
||||
*buf++ ^= *Iv++;
|
||||
*buf++ ^= *Iv++;
|
||||
*buf++ ^= *Iv++;
|
||||
*buf++ ^= *Iv++;
|
||||
*buf++ ^= *Iv++;
|
||||
*buf++ ^= *Iv++;
|
||||
*buf++ ^= *Iv++;
|
||||
}
|
||||
510
pdfio-crypto.c
510
pdfio-crypto.c
@ -1,14 +1,11 @@
|
||||
//
|
||||
// Cryptographic functions for PDFio.
|
||||
// Cryptographic support functions for PDFio.
|
||||
//
|
||||
// Copyright © 2021 by Michael R Sweet.
|
||||
//
|
||||
// Licensed under Apache License v2.0. See the file "LICENSE" for more
|
||||
// information.
|
||||
//
|
||||
// AES code is adapted from the "tiny-AES-c" project
|
||||
// (<https://github.com/kokke/tiny-AES-c>)
|
||||
//
|
||||
|
||||
//
|
||||
// Include necessary headers...
|
||||
@ -18,495 +15,50 @@
|
||||
|
||||
|
||||
//
|
||||
// Local types...
|
||||
// '_pdfioCryptoMakeReader()' - Setup a cryptographic context and callback for reading.
|
||||
//
|
||||
|
||||
typedef uint8_t state_t[4][4]; // 4x4 AES state table
|
||||
|
||||
|
||||
//
|
||||
// Local globals...
|
||||
//
|
||||
|
||||
static const uint8_t sbox[256] = // S-box lookup table
|
||||
_pdfio_crypto_cb_t // O - Decryption callback or `NULL` for none
|
||||
_pdfioCryptoMakeReader(
|
||||
pdfio_file_t *pdf, // I - PDF file
|
||||
pdfio_obj_t *obj, // I - PDF object
|
||||
_pdfio_crypto_ctx_t *ctx, // I - Pointer to crypto context
|
||||
uint8_t *iv, // I - Buffer for initialization vector
|
||||
size_t *ivlen) // IO - Size of initialization vector
|
||||
{
|
||||
//0 1 2 3 4 5 6 7 8 9 A B C D E F
|
||||
0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76,
|
||||
0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0,
|
||||
0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15,
|
||||
0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75,
|
||||
0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84,
|
||||
0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf,
|
||||
0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8,
|
||||
0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2,
|
||||
0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73,
|
||||
0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb,
|
||||
0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79,
|
||||
0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08,
|
||||
0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a,
|
||||
0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e,
|
||||
0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf,
|
||||
0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16
|
||||
};
|
||||
static const uint8_t rsbox[256] = // Reverse S-box lookup table
|
||||
{
|
||||
0x52, 0x09, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38, 0xbf, 0x40, 0xa3, 0x9e, 0x81, 0xf3, 0xd7, 0xfb,
|
||||
0x7c, 0xe3, 0x39, 0x82, 0x9b, 0x2f, 0xff, 0x87, 0x34, 0x8e, 0x43, 0x44, 0xc4, 0xde, 0xe9, 0xcb,
|
||||
0x54, 0x7b, 0x94, 0x32, 0xa6, 0xc2, 0x23, 0x3d, 0xee, 0x4c, 0x95, 0x0b, 0x42, 0xfa, 0xc3, 0x4e,
|
||||
0x08, 0x2e, 0xa1, 0x66, 0x28, 0xd9, 0x24, 0xb2, 0x76, 0x5b, 0xa2, 0x49, 0x6d, 0x8b, 0xd1, 0x25,
|
||||
0x72, 0xf8, 0xf6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xd4, 0xa4, 0x5c, 0xcc, 0x5d, 0x65, 0xb6, 0x92,
|
||||
0x6c, 0x70, 0x48, 0x50, 0xfd, 0xed, 0xb9, 0xda, 0x5e, 0x15, 0x46, 0x57, 0xa7, 0x8d, 0x9d, 0x84,
|
||||
0x90, 0xd8, 0xab, 0x00, 0x8c, 0xbc, 0xd3, 0x0a, 0xf7, 0xe4, 0x58, 0x05, 0xb8, 0xb3, 0x45, 0x06,
|
||||
0xd0, 0x2c, 0x1e, 0x8f, 0xca, 0x3f, 0x0f, 0x02, 0xc1, 0xaf, 0xbd, 0x03, 0x01, 0x13, 0x8a, 0x6b,
|
||||
0x3a, 0x91, 0x11, 0x41, 0x4f, 0x67, 0xdc, 0xea, 0x97, 0xf2, 0xcf, 0xce, 0xf0, 0xb4, 0xe6, 0x73,
|
||||
0x96, 0xac, 0x74, 0x22, 0xe7, 0xad, 0x35, 0x85, 0xe2, 0xf9, 0x37, 0xe8, 0x1c, 0x75, 0xdf, 0x6e,
|
||||
0x47, 0xf1, 0x1a, 0x71, 0x1d, 0x29, 0xc5, 0x89, 0x6f, 0xb7, 0x62, 0x0e, 0xaa, 0x18, 0xbe, 0x1b,
|
||||
0xfc, 0x56, 0x3e, 0x4b, 0xc6, 0xd2, 0x79, 0x20, 0x9a, 0xdb, 0xc0, 0xfe, 0x78, 0xcd, 0x5a, 0xf4,
|
||||
0x1f, 0xdd, 0xa8, 0x33, 0x88, 0x07, 0xc7, 0x31, 0xb1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xec, 0x5f,
|
||||
0x60, 0x51, 0x7f, 0xa9, 0x19, 0xb5, 0x4a, 0x0d, 0x2d, 0xe5, 0x7a, 0x9f, 0x93, 0xc9, 0x9c, 0xef,
|
||||
0xa0, 0xe0, 0x3b, 0x4d, 0xae, 0x2a, 0xf5, 0xb0, 0xc8, 0xeb, 0xbb, 0x3c, 0x83, 0x53, 0x99, 0x61,
|
||||
0x17, 0x2b, 0x04, 0x7e, 0xba, 0x77, 0xd6, 0x26, 0xe1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0c, 0x7d
|
||||
};
|
||||
|
||||
// The round constant word array, Rcon[i], contains the values given by
|
||||
// x to the power (i-1) being powers of x (x is denoted as {02}) in the field GF(2^8)
|
||||
static const uint8_t Rcon[11] = // Round constants
|
||||
{
|
||||
0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36
|
||||
};
|
||||
(void)pdf;
|
||||
(void)obj;
|
||||
(void)ctx;
|
||||
(void)iv;
|
||||
|
||||
|
||||
//
|
||||
// Local functions...
|
||||
//
|
||||
// No decryption...
|
||||
*ivlen = 0;
|
||||
|
||||
static void AddRoundKey(size_t round, state_t *state, const uint8_t *RoundKey);
|
||||
static void SubBytes(state_t *state);
|
||||
static void ShiftRows(state_t *state);
|
||||
static uint8_t xtime(uint8_t x);
|
||||
static void MixColumns(state_t *state);
|
||||
static uint8_t Multiply(uint8_t x, uint8_t y);
|
||||
static void InvMixColumns(state_t *state);
|
||||
static void InvSubBytes(state_t *state);
|
||||
static void InvShiftRows(state_t *state);
|
||||
static void Cipher(state_t *state, const _pdfio_aes_t *ctx);
|
||||
static void InvCipher(state_t *state, const _pdfio_aes_t *ctx);
|
||||
static void XorWithIv(uint8_t *buf, const uint8_t *Iv);
|
||||
|
||||
|
||||
//
|
||||
// '_pdfioCryptoAESInit()' - Initialize an AES context.
|
||||
//
|
||||
|
||||
void
|
||||
_pdfioCryptoAESInit(
|
||||
_pdfio_aes_t *ctx, // I - AES context
|
||||
const uint8_t *key, // I - Key
|
||||
size_t keylen, // I - Length of key (must be 16 or 32)
|
||||
const uint8_t *iv) // I - 16-byte initialization vector
|
||||
{
|
||||
size_t i; // Looping var
|
||||
uint8_t *rkptr0, // Previous round_key values
|
||||
*rkptr, // Current round_key values
|
||||
*rkend, // End of round_key values
|
||||
tempa[4]; // Used for the column/row operations
|
||||
size_t roundlen = keylen + 24; // Length of round_key
|
||||
size_t nwords = keylen / 4; // Number of 32-bit words in key
|
||||
|
||||
|
||||
// Clear context
|
||||
memset(ctx, 0, sizeof(_pdfio_aes_t));
|
||||
|
||||
// The first round key is the key itself.
|
||||
memcpy(ctx->round_key, key, keylen);
|
||||
|
||||
// All other round keys are found from the previous round keys.
|
||||
for (rkptr0 = ctx->round_key, rkptr = rkptr0 + keylen, rkend = rkptr + roundlen, i = nwords; rkptr < rkend; i ++)
|
||||
{
|
||||
if ((i % nwords) == 0)
|
||||
{
|
||||
// Shifts word left once - [a0,a1,a2,a3] becomes [a1,a2,a3,a0]
|
||||
tempa[0] = rkptr[-3];
|
||||
tempa[1] = rkptr[-2];
|
||||
tempa[2] = rkptr[-1];
|
||||
tempa[3] = rkptr[-4];
|
||||
|
||||
// Apply the S-box to each of the four bytes to produce an output word.
|
||||
tempa[0] = sbox[tempa[0]];
|
||||
tempa[1] = sbox[tempa[1]];
|
||||
tempa[2] = sbox[tempa[2]];
|
||||
tempa[3] = sbox[tempa[3]];
|
||||
|
||||
tempa[0] = tempa[0] ^ Rcon[i / nwords];
|
||||
}
|
||||
else if (keylen == 32 && (i % nwords) == 4)
|
||||
{
|
||||
// Apply the S-box to each of the four bytes to produce an output word.
|
||||
tempa[0] = sbox[rkptr[-4]];
|
||||
tempa[1] = sbox[rkptr[-3]];
|
||||
tempa[2] = sbox[rkptr[-2]];
|
||||
tempa[3] = sbox[rkptr[-1]];
|
||||
}
|
||||
else
|
||||
{
|
||||
tempa[0] = rkptr[-4];
|
||||
tempa[1] = rkptr[-3];
|
||||
tempa[2] = rkptr[-2];
|
||||
tempa[3] = rkptr[-1];
|
||||
}
|
||||
|
||||
*rkptr++ = *rkptr0++ ^ tempa[0];
|
||||
*rkptr++ = *rkptr0++ ^ tempa[1];
|
||||
*rkptr++ = *rkptr0++ ^ tempa[2];
|
||||
*rkptr++ = *rkptr0++ ^ tempa[3];
|
||||
}
|
||||
|
||||
// Copy the initialization vector...
|
||||
if (iv)
|
||||
memcpy(ctx->iv, iv, sizeof(ctx->iv));
|
||||
return (NULL);
|
||||
}
|
||||
|
||||
|
||||
//
|
||||
// '_pdfioCryptoAESDecrypt()' - Decrypt a block of bytes with AES.
|
||||
// '_pdfioCryptoMakeWriter()' - Setup a cryptographic context and callback for writing.
|
||||
//
|
||||
|
||||
void
|
||||
_pdfioCryptoAESDecrypt(
|
||||
_pdfio_aes_t *ctx, // I - AES context
|
||||
uint8_t *buffer, // I - Buffer
|
||||
size_t len) // I - Number of bytes to decrypt
|
||||
_pdfio_crypto_cb_t // O - Encryption callback or `NULL` for none
|
||||
_pdfioCryptoMakeWriter(
|
||||
pdfio_file_t *pdf, // I - PDF file
|
||||
pdfio_obj_t *obj, // I - PDF object
|
||||
_pdfio_crypto_ctx_t *ctx, // I - Pointer to crypto context
|
||||
uint8_t *iv, // I - Buffer for initialization vector
|
||||
size_t *ivlen) // IO - Size of initialization vector
|
||||
{
|
||||
uint8_t next_iv[16]; // Next IV value
|
||||
(void)pdf;
|
||||
(void)obj;
|
||||
(void)ctx;
|
||||
(void)iv;
|
||||
|
||||
|
||||
while (len > 15)
|
||||
{
|
||||
memcpy(next_iv, buffer, 16);
|
||||
InvCipher((state_t *)buffer, ctx);
|
||||
XorWithIv(buffer, ctx->iv);
|
||||
memcpy(ctx->iv, next_iv, 16);
|
||||
buffer += 16;
|
||||
len -= 16;
|
||||
}
|
||||
// No encryption...
|
||||
*ivlen = 0;
|
||||
|
||||
if (len > 0)
|
||||
{
|
||||
// Pad the final buffer with (16 - len)...
|
||||
uint8_t temp[16]; // Temporary buffer
|
||||
|
||||
memset(temp, 16 - len, sizeof(temp));
|
||||
memcpy(temp, buffer, len);
|
||||
|
||||
memcpy(next_iv, temp, 16);
|
||||
InvCipher((state_t *)temp, ctx);
|
||||
XorWithIv(temp, ctx->iv);
|
||||
memcpy(ctx->iv, next_iv, 16);
|
||||
|
||||
memcpy(buffer, temp, len);
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
//
|
||||
// '_pdfioCryptoAESEncrypt()' - Encrypt a block of bytes with AES.
|
||||
//
|
||||
|
||||
void
|
||||
_pdfioCryptoAESEncrypt(
|
||||
_pdfio_aes_t *ctx, // I - AES context
|
||||
uint8_t *buffer, // I - Buffer
|
||||
size_t len) // I - Number of bytes to decrypt
|
||||
{
|
||||
uint8_t *iv = ctx->iv; // Current IV for CBC
|
||||
uint8_t temp[16]; // Temporary buffer
|
||||
|
||||
|
||||
while (len > 15)
|
||||
{
|
||||
XorWithIv(buffer, iv);
|
||||
Cipher((state_t*)buffer, ctx);
|
||||
iv = buffer;
|
||||
buffer += 16;
|
||||
len -= 16;
|
||||
}
|
||||
|
||||
if (len > 0)
|
||||
{
|
||||
// Pad the final buffer with (16 - len)...
|
||||
memset(temp, 16 - len, sizeof(temp));
|
||||
memcpy(temp, buffer, len);
|
||||
|
||||
XorWithIv(temp, iv);
|
||||
Cipher((state_t*)temp, ctx);
|
||||
iv = temp;
|
||||
|
||||
memcpy(buffer, temp, len);
|
||||
}
|
||||
|
||||
/* store Iv in ctx for next call */
|
||||
memcpy(ctx->iv, iv, 16);
|
||||
}
|
||||
|
||||
|
||||
// This function adds the round key to state.
|
||||
// The round key is added to the state by an XOR function.
|
||||
static void
|
||||
AddRoundKey(size_t round, state_t *state, const uint8_t *RoundKey)
|
||||
{
|
||||
unsigned i; // Looping var
|
||||
uint8_t *sptr = (*state)[0]; // Pointer into state
|
||||
|
||||
|
||||
for (RoundKey += round * 16, i = 16; i > 0; i --, sptr ++, RoundKey ++)
|
||||
*sptr ^= *RoundKey;
|
||||
}
|
||||
|
||||
|
||||
// The SubBytes Function Substitutes the values in the
|
||||
// state matrix with values in an S-box.
|
||||
static void
|
||||
SubBytes(state_t *state)
|
||||
{
|
||||
unsigned i; // Looping var
|
||||
uint8_t *sptr = (*state)[0]; // Pointer into state
|
||||
|
||||
|
||||
for (i = 16; i > 0; i --, sptr ++)
|
||||
*sptr = sbox[*sptr];
|
||||
}
|
||||
|
||||
// The ShiftRows() function shifts the rows in the state to the left.
|
||||
// Each row is shifted with different offset.
|
||||
// Offset = Row number. So the first row is not shifted.
|
||||
static void
|
||||
ShiftRows(state_t *state)
|
||||
{
|
||||
uint8_t *sptr = (*state)[0]; // Pointer into state
|
||||
uint8_t temp; // Temporary value
|
||||
|
||||
|
||||
// Rotate first row 1 columns to left
|
||||
temp = sptr[1];
|
||||
sptr[1] = sptr[5];
|
||||
sptr[5] = sptr[9];
|
||||
sptr[9] = sptr[13];
|
||||
sptr[13] = temp;
|
||||
|
||||
// Rotate second row 2 columns to left
|
||||
temp = sptr[2];
|
||||
sptr[2] = sptr[10];
|
||||
sptr[10] = temp;
|
||||
|
||||
temp = sptr[6];
|
||||
sptr[6] = sptr[14];
|
||||
sptr[14] = temp;
|
||||
|
||||
// Rotate third row 3 columns to left
|
||||
temp = sptr[3];
|
||||
sptr[3] = sptr[15];
|
||||
sptr[15] = sptr[11];
|
||||
sptr[11] = sptr[7];
|
||||
sptr[7] = temp;
|
||||
}
|
||||
|
||||
|
||||
static uint8_t
|
||||
xtime(uint8_t x)
|
||||
{
|
||||
return ((uint8_t)((x << 1) ^ ((x >> 7) * 0x1b)));
|
||||
}
|
||||
|
||||
|
||||
// MixColumns function mixes the columns of the state matrix
|
||||
static void
|
||||
MixColumns(state_t *state)
|
||||
{
|
||||
unsigned i; // Looping var
|
||||
uint8_t *sptr = (*state)[0]; // Pointer into state
|
||||
uint8_t Tmp, Tm, t; // Temporary values
|
||||
|
||||
for (i = 4; i > 0; i --, sptr += 4)
|
||||
{
|
||||
t = sptr[0];
|
||||
Tmp = sptr[0] ^ sptr[1] ^ sptr[2] ^ sptr[3];
|
||||
Tm = sptr[0] ^ sptr[1];
|
||||
Tm = xtime(Tm);
|
||||
sptr[0] ^= Tm ^ Tmp;
|
||||
|
||||
Tm = sptr[1] ^ sptr[2];
|
||||
Tm = xtime(Tm);
|
||||
sptr[1] ^= Tm ^ Tmp;
|
||||
|
||||
Tm = sptr[2] ^ sptr[3];
|
||||
Tm = xtime(Tm);
|
||||
sptr[2] ^= Tm ^ Tmp;
|
||||
|
||||
Tm = sptr[3] ^ t;
|
||||
Tm = xtime(Tm);
|
||||
sptr[3] ^= Tm ^ Tmp;
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
// Multiply is used to multiply numbers in the field GF(2^8)
|
||||
// Note: The last call to xtime() is unneeded, but often ends up generating a smaller binary
|
||||
// The compiler seems to be able to vectorize the operation better this way.
|
||||
// See https://github.com/kokke/tiny-AES-c/pull/34
|
||||
static uint8_t Multiply(uint8_t x, uint8_t y)
|
||||
{
|
||||
return (((y & 1) * x) ^
|
||||
((y>>1 & 1) * xtime(x)) ^
|
||||
((y>>2 & 1) * xtime(xtime(x))) ^
|
||||
((y>>3 & 1) * xtime(xtime(xtime(x)))) ^
|
||||
((y>>4 & 1) * xtime(xtime(xtime(xtime(x)))))); /* this last call to xtime() can be omitted */
|
||||
}
|
||||
|
||||
|
||||
// MixColumns function mixes the columns of the state matrix.
|
||||
// The method used to multiply may be difficult to understand for the inexperienced.
|
||||
// Please use the references to gain more information.
|
||||
static void
|
||||
InvMixColumns(state_t *state)
|
||||
{
|
||||
unsigned i; // Looping var
|
||||
uint8_t *sptr = (*state)[0]; // Pointer into state
|
||||
uint8_t a, b, c, d; // Temporary values
|
||||
|
||||
|
||||
for (i = 4; i > 0; i --)
|
||||
{
|
||||
a = sptr[0];
|
||||
b = sptr[1];
|
||||
c = sptr[2];
|
||||
d = sptr[3];
|
||||
|
||||
*sptr++ = Multiply(a, 0x0e) ^ Multiply(b, 0x0b) ^ Multiply(c, 0x0d) ^ Multiply(d, 0x09);
|
||||
*sptr++ = Multiply(a, 0x09) ^ Multiply(b, 0x0e) ^ Multiply(c, 0x0b) ^ Multiply(d, 0x0d);
|
||||
*sptr++ = Multiply(a, 0x0d) ^ Multiply(b, 0x09) ^ Multiply(c, 0x0e) ^ Multiply(d, 0x0b);
|
||||
*sptr++ = Multiply(a, 0x0b) ^ Multiply(b, 0x0d) ^ Multiply(c, 0x09) ^ Multiply(d, 0x0e);
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
// The SubBytes Function Substitutes the values in the
|
||||
// state matrix with values in an S-box.
|
||||
static void
|
||||
InvSubBytes(state_t *state)
|
||||
{
|
||||
unsigned i; // Looping var
|
||||
uint8_t *sptr = (*state)[0]; // Pointer into state
|
||||
|
||||
|
||||
for (i = 16; i > 0; i --, sptr ++)
|
||||
*sptr = rsbox[*sptr];
|
||||
}
|
||||
|
||||
|
||||
static void
|
||||
InvShiftRows(state_t *state)
|
||||
{
|
||||
uint8_t *sptr = (*state)[0]; // Pointer into state
|
||||
uint8_t temp; // Temporary value
|
||||
|
||||
|
||||
// Rotate first row 1 columns to right
|
||||
temp = sptr[13];
|
||||
sptr[13] = sptr[9];
|
||||
sptr[9] = sptr[5];
|
||||
sptr[5] = sptr[1];
|
||||
sptr[1] = temp;
|
||||
|
||||
// Rotate second row 2 columns to right
|
||||
temp = sptr[2];
|
||||
sptr[2] = sptr[10];
|
||||
sptr[10] = temp;
|
||||
|
||||
temp = sptr[6];
|
||||
sptr[6] = sptr[14];
|
||||
sptr[14] = temp;
|
||||
|
||||
// Rotate third row 3 columns to right
|
||||
temp = sptr[3];
|
||||
sptr[3] = sptr[7];
|
||||
sptr[7] = sptr[11];
|
||||
sptr[11] = sptr[15];
|
||||
sptr[15] = temp;
|
||||
}
|
||||
|
||||
|
||||
// Cipher is the main function that encrypts the PlainText.
|
||||
static void
|
||||
Cipher(state_t *state, const _pdfio_aes_t *ctx)
|
||||
{
|
||||
uint8_t round = 0;
|
||||
|
||||
// Add the First round key to the state before starting the rounds.
|
||||
AddRoundKey(0, state, ctx->round_key);
|
||||
|
||||
// There will be Nr rounds.
|
||||
// The first Nr-1 rounds are identical.
|
||||
// These Nr rounds are executed in the loop below.
|
||||
// Last one without MixColumns()
|
||||
for (round = 1; ; ++round)
|
||||
{
|
||||
SubBytes(state);
|
||||
ShiftRows(state);
|
||||
if (round == ctx->round_size)
|
||||
break;
|
||||
|
||||
MixColumns(state);
|
||||
AddRoundKey(round, state, ctx->round_key);
|
||||
}
|
||||
// Add round key to last round
|
||||
AddRoundKey(ctx->round_size, state, ctx->round_key);
|
||||
}
|
||||
|
||||
|
||||
static void
|
||||
InvCipher(state_t *state, const _pdfio_aes_t *ctx)
|
||||
{
|
||||
size_t round;
|
||||
|
||||
// Add the First round key to the state before starting the rounds.
|
||||
AddRoundKey(ctx->round_size, state, ctx->round_key);
|
||||
|
||||
// There will be Nr rounds.
|
||||
// The first Nr-1 rounds are identical.
|
||||
// These Nr rounds are executed in the loop below.
|
||||
// Last one without InvMixColumn()
|
||||
for (round = ctx->round_size - 1; ; round --)
|
||||
{
|
||||
InvShiftRows(state);
|
||||
InvSubBytes(state);
|
||||
AddRoundKey(round, state, ctx->round_key);
|
||||
|
||||
if (round == 0)
|
||||
break;
|
||||
|
||||
InvMixColumns(state);
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
static void
|
||||
XorWithIv(uint8_t *buf, const uint8_t *Iv)
|
||||
{
|
||||
// 16-byte block...
|
||||
*buf++ ^= *Iv++;
|
||||
*buf++ ^= *Iv++;
|
||||
*buf++ ^= *Iv++;
|
||||
*buf++ ^= *Iv++;
|
||||
*buf++ ^= *Iv++;
|
||||
*buf++ ^= *Iv++;
|
||||
*buf++ ^= *Iv++;
|
||||
*buf++ ^= *Iv++;
|
||||
*buf++ ^= *Iv++;
|
||||
*buf++ ^= *Iv++;
|
||||
*buf++ ^= *Iv++;
|
||||
*buf++ ^= *Iv++;
|
||||
*buf++ ^= *Iv++;
|
||||
*buf++ ^= *Iv++;
|
||||
*buf++ ^= *Iv++;
|
||||
*buf++ ^= *Iv++;
|
||||
return (NULL);
|
||||
}
|
||||
|
||||
@ -207,6 +207,13 @@ typedef struct _pdfio_sha265_s // SHA-256 hash state
|
||||
int Corrupted; // Cumulative corruption code
|
||||
} _pdfio_sha256_t;
|
||||
|
||||
typedef union _pdfio_crypto_ctx_u // Cryptographic contexts
|
||||
{
|
||||
_pdfio_aes_t aes; // AES-128/256 context
|
||||
_pdfio_rc4_t rc4; // RC4-40/128 context
|
||||
} _pdfio_crypto_ctx_t;
|
||||
typedef void (*_pdfio_crypto_cb_t)(_pdfio_crypto_ctx_t *ctx, uint8_t *buffer, size_t len);
|
||||
|
||||
struct _pdfio_array_s
|
||||
{
|
||||
pdfio_file_t *pdf; // PDF file
|
||||
@ -314,6 +321,8 @@ struct _pdfio_stream_s // Stream
|
||||
unsigned char cbuffer[4096], // Compressed data buffer
|
||||
*prbuffer, // Raw buffer (previous line), as needed
|
||||
*psbuffer; // PNG filter buffer, as needed
|
||||
_pdfio_crypto_cb_t crypto_cb; // Encryption/descryption callback, if any
|
||||
_pdfio_crypto_ctx_t crypto_ctx; // Cryptographic context
|
||||
};
|
||||
|
||||
|
||||
@ -330,6 +339,8 @@ extern bool _pdfioArrayWrite(pdfio_array_t *a) _PDFIO_INTERNAL;
|
||||
extern void _pdfioCryptoAESInit(_pdfio_aes_t *ctx, const uint8_t *key, size_t keylen, const uint8_t *iv) _PDFIO_INTERNAL;
|
||||
extern void _pdfioCryptoAESDecrypt(_pdfio_aes_t *ctx, uint8_t *buffer, size_t len) _PDFIO_INTERNAL;
|
||||
extern void _pdfioCryptoAESEncrypt(_pdfio_aes_t *ctx, uint8_t *buffer, size_t len) _PDFIO_INTERNAL;
|
||||
extern _pdfio_crypto_cb_t _pdfioCryptoMakeReader(pdfio_file_t *pdf, pdfio_obj_t *obj, _pdfio_crypto_ctx_t *ctx, uint8_t *iv, size_t *ivlen) _PDFIO_INTERNAL;
|
||||
extern _pdfio_crypto_cb_t _pdfioCryptoMakeWriter(pdfio_file_t *pdf, pdfio_obj_t *obj, _pdfio_crypto_ctx_t *ctx, uint8_t *iv, size_t *ivlen) _PDFIO_INTERNAL;
|
||||
extern void _pdfioCryptoMD5Append(_pdfio_md5_t *pms, const uint8_t *data, size_t nbytes) _PDFIO_INTERNAL;
|
||||
extern void _pdfioCryptoMD5Finish(_pdfio_md5_t *pms, uint8_t digest[16]) _PDFIO_INTERNAL;
|
||||
extern void _pdfioCryptoMD5Init(_pdfio_md5_t *pms) _PDFIO_INTERNAL;
|
||||
|
||||
@ -25,6 +25,7 @@
|
||||
279E1035267D043B00D3A349 /* ttf.h in Headers */ = {isa = PBXBuildFile; fileRef = 279E1033267D043B00D3A349 /* ttf.h */; };
|
||||
279E1036267D043B00D3A349 /* ttf.c in Sources */ = {isa = PBXBuildFile; fileRef = 279E1034267D043B00D3A349 /* ttf.c */; };
|
||||
279E103B267D04E600D3A349 /* libz.tbd in Frameworks */ = {isa = PBXBuildFile; fileRef = 279E103A267D04E600D3A349 /* libz.tbd */; };
|
||||
27CF90442711DFFE00E50FE4 /* pdfio-aes.c in Sources */ = {isa = PBXBuildFile; fileRef = 27CF90432711DFFE00E50FE4 /* pdfio-aes.c */; };
|
||||
27ECBD8926419DAB0025312A /* libpdfio.a in Frameworks */ = {isa = PBXBuildFile; fileRef = 273440B0263D6FE200FBFD63 /* libpdfio.a */; };
|
||||
27F2F0602710BE92008ECD36 /* pdfio-md5.c in Sources */ = {isa = PBXBuildFile; fileRef = 27F2F05D2710BE92008ECD36 /* pdfio-md5.c */; };
|
||||
27F2F0612710BE92008ECD36 /* pdfio-rc4.c in Sources */ = {isa = PBXBuildFile; fileRef = 27F2F05E2710BE92008ECD36 /* pdfio-rc4.c */; };
|
||||
@ -83,6 +84,7 @@
|
||||
279E1033267D043B00D3A349 /* ttf.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = ttf.h; sourceTree = "<group>"; };
|
||||
279E1034267D043B00D3A349 /* ttf.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; path = ttf.c; sourceTree = "<group>"; };
|
||||
279E103A267D04E600D3A349 /* libz.tbd */ = {isa = PBXFileReference; lastKnownFileType = "sourcecode.text-based-dylib-definition"; name = libz.tbd; path = usr/lib/libz.tbd; sourceTree = SDKROOT; };
|
||||
27CF90432711DFFE00E50FE4 /* pdfio-aes.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; path = "pdfio-aes.c"; sourceTree = "<group>"; };
|
||||
27F2F05D2710BE92008ECD36 /* pdfio-md5.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; path = "pdfio-md5.c"; sourceTree = "<group>"; };
|
||||
27F2F05E2710BE92008ECD36 /* pdfio-rc4.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; path = "pdfio-rc4.c"; sourceTree = "<group>"; };
|
||||
27F2F05F2710BE92008ECD36 /* pdfio-crypto.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; path = "pdfio-crypto.c"; sourceTree = "<group>"; };
|
||||
@ -158,6 +160,7 @@
|
||||
279E1038267D045C00D3A349 /* Library */ = {
|
||||
isa = PBXGroup;
|
||||
children = (
|
||||
27CF90432711DFFE00E50FE4 /* pdfio-aes.c */,
|
||||
273440BA263D727800FBFD63 /* pdfio-array.c */,
|
||||
273440BB263D727800FBFD63 /* pdfio-common.c */,
|
||||
271EA703265B2B1000ACDD39 /* pdfio-content.c */,
|
||||
@ -300,6 +303,7 @@
|
||||
273440C7263D727800FBFD63 /* pdfio-object.c in Sources */,
|
||||
27F2F0602710BE92008ECD36 /* pdfio-md5.c in Sources */,
|
||||
273440C4263D727800FBFD63 /* pdfio-string.c in Sources */,
|
||||
27CF90442711DFFE00E50FE4 /* pdfio-aes.c in Sources */,
|
||||
271EA705265B2B1000ACDD39 /* pdfio-content.c in Sources */,
|
||||
27F2F0612710BE92008ECD36 /* pdfio-rc4.c in Sources */,
|
||||
273440C6263D727800FBFD63 /* pdfio-common.c in Sources */,
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user