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Update crypto callback to return the number of output bytes (to account for AES 

expansion).
This commit is contained in:
Michael R Sweet 2021-10-23 14:37:25 -04:00
parent 19571d00f2
commit 3af39d5d1f
No known key found for this signature in database
GPG Key ID: 999559A027815955
5 changed files with 38 additions and 18 deletions
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3
.gitignore vendored
View File

@ -8,6 +8,5 @@
/packages
/pdfio.xcodeproj/xcshareddata
/testpdfio
/testpdfio-out.pdf
/testpdfio-out2.pdf
/testpdfio-*.pdf
/x64

13
pdfio-aes.c
View File

@ -170,7 +170,7 @@ _pdfioCryptoAESInit(
// multiple of 16 bytes (excess is not decrypted).
//
void
size_t // O - Number of bytes in output buffer
_pdfioCryptoAESDecrypt(
_pdfio_aes_t *ctx, // I - AES context
uint8_t *outbuffer, // I - Output buffer
@ -178,6 +178,7 @@ _pdfioCryptoAESDecrypt(
size_t len) // I - Number of bytes to decrypt
{
uint8_t next_iv[16]; // Next IV value
size_t outbytes = 0; // Output bytes
if (inbuffer != outbuffer)
@ -196,7 +197,10 @@ _pdfioCryptoAESDecrypt(
memcpy(ctx->iv, next_iv, 16);
outbuffer += 16;
len -= 16;
outbytes += 16;
}
return (outbytes);
}
@ -207,7 +211,7 @@ _pdfioCryptoAESDecrypt(
// be a multiple of 16 bytes.
//
void
size_t // O - Number of bytes in output buffer
_pdfioCryptoAESEncrypt(
_pdfio_aes_t *ctx, // I - AES context
uint8_t *outbuffer, // I - Output buffer
@ -215,6 +219,7 @@ _pdfioCryptoAESEncrypt(
size_t len) // I - Number of bytes to decrypt
{
uint8_t *iv = ctx->iv; // Current IV for CBC
size_t outbytes = 0; // Output bytes
if (inbuffer != outbuffer)
@ -232,6 +237,7 @@ _pdfioCryptoAESEncrypt(
iv = outbuffer;
outbuffer += 16;
len -= 16;
outbytes += 16;
}
if (len > 0)
@ -242,10 +248,13 @@ _pdfioCryptoAESEncrypt(
XorWithIv(outbuffer, iv);
Cipher((state_t*)outbuffer, ctx);
iv = outbuffer;
outbytes += 16;
}
/* store Iv in ctx for next call */
memcpy(ctx->iv, iv, 16);
return (outbytes);
}

8
pdfio-private.h
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@ -211,7 +211,7 @@ 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 *outbuffer, const uint8_t *inbuffer, size_t len);
typedef size_t (*_pdfio_crypto_cb_t)(_pdfio_crypto_ctx_t *ctx, uint8_t *outbuffer, const uint8_t *inbuffer, size_t len);
struct _pdfio_array_s
{
@ -342,8 +342,8 @@ extern pdfio_array_t *_pdfioArrayRead(pdfio_file_t *pdf, _pdfio_token_t *ts) _PD
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 *outbuffer, const uint8_t *inbuffer, size_t len) _PDFIO_INTERNAL;
extern void _pdfioCryptoAESEncrypt(_pdfio_aes_t *ctx, uint8_t *outbuffer, const uint8_t *inbuffer, size_t len) _PDFIO_INTERNAL;
extern size_t _pdfioCryptoAESDecrypt(_pdfio_aes_t *ctx, uint8_t *outbuffer, const uint8_t *inbuffer, size_t len) _PDFIO_INTERNAL;
extern size_t _pdfioCryptoAESEncrypt(_pdfio_aes_t *ctx, uint8_t *outbuffer, const uint8_t *inbuffer, size_t len) _PDFIO_INTERNAL;
extern void _pdfioCryptoMakeRandom(uint8_t *buffer, size_t bytes) _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;
@ -351,7 +351,7 @@ extern void _pdfioCryptoMD5Append(_pdfio_md5_t *pms, const uint8_t *data, size_
extern void _pdfioCryptoMD5Finish(_pdfio_md5_t *pms, uint8_t digest[16]) _PDFIO_INTERNAL;
extern void _pdfioCryptoMD5Init(_pdfio_md5_t *pms) _PDFIO_INTERNAL;
extern void _pdfioCryptoRC4Init(_pdfio_rc4_t *ctx, const uint8_t *key, size_t keylen) _PDFIO_INTERNAL;
extern void _pdfioCryptoRC4Crypt(_pdfio_rc4_t *ctx, uint8_t *outbuffer, const uint8_t *inbuffer, size_t len) _PDFIO_INTERNAL;
extern size_t _pdfioCryptoRC4Crypt(_pdfio_rc4_t *ctx, uint8_t *outbuffer, const uint8_t *inbuffer, size_t len) _PDFIO_INTERNAL;
extern void _pdfioCryptoSHA256Append(_pdfio_sha256_t *, const uint8_t *bytes, size_t bytecount) _PDFIO_INTERNAL;
extern void _pdfioCryptoSHA256Init(_pdfio_sha256_t *ctx) _PDFIO_INTERNAL;
extern void _pdfioCryptoSHA256Finish(_pdfio_sha256_t *ctx, uint8_t *Message_Digest) _PDFIO_INTERNAL;

5
pdfio-rc4.c
View File

@ -69,7 +69,7 @@ _pdfioCryptoRC4Init(
// "inbuffer" and "outbuffer" can point to the same memory.
//
void
size_t // O - Number of output bytes
_pdfioCryptoRC4Crypt(
_pdfio_rc4_t *ctx, // I - Context
uint8_t *outbuffer, // I - Output buffer
@ -79,6 +79,7 @@ _pdfioCryptoRC4Crypt(
uint8_t tmp, // Swap variable
i, j, // Looping vars
t; // Current S box
size_t outbytes = len; // Number of output bytes
// Loop through the entire buffer...
@ -107,4 +108,6 @@ _pdfioCryptoRC4Crypt(
// Copy current S box indices back to context...
ctx->i = i;
ctx->j = j;
return (outbytes);
}

27
pdfio-stream.c
View File

@ -54,6 +54,9 @@ pdfioStreamClose(pdfio_stream_t *st) // I - Stream
while ((status = deflate(&st->flate, Z_FINISH)) != Z_STREAM_END)
{
size_t bytes = sizeof(st->cbuffer) - st->flate.avail_out;
// Bytes to write
if (status < Z_OK && status != Z_BUF_ERROR)
{
_pdfioFileError(st->pdf, "Flate compression failed: %s", zstrerror(status));
@ -64,10 +67,10 @@ pdfioStreamClose(pdfio_stream_t *st) // I - Stream
if (st->crypto_cb)
{
// Encrypt it first...
(st->crypto_cb)(&st->crypto_ctx, st->cbuffer, st->cbuffer, sizeof(st->cbuffer) - st->flate.avail_out);
bytes = (st->crypto_cb)(&st->crypto_ctx, st->cbuffer, st->cbuffer, bytes);
}
if (!_pdfioFileWrite(st->pdf, st->cbuffer, sizeof(st->cbuffer) - st->flate.avail_out))
if (!_pdfioFileWrite(st->pdf, st->cbuffer, bytes))
{
ret = false;
goto done;
@ -80,13 +83,16 @@ pdfioStreamClose(pdfio_stream_t *st) // I - Stream
if (st->flate.avail_out < (uInt)sizeof(st->cbuffer))
{
// Write any residuals...
size_t bytes = sizeof(st->cbuffer) - st->flate.avail_out;
// Bytes to write
if (st->crypto_cb)
{
// Encrypt it first...
(st->crypto_cb)(&st->crypto_ctx, st->cbuffer, st->cbuffer, sizeof(st->cbuffer) - st->flate.avail_out);
bytes = (st->crypto_cb)(&st->crypto_ctx, st->cbuffer, st->cbuffer, bytes);
}
if (!_pdfioFileWrite(st->pdf, st->cbuffer, sizeof(st->cbuffer) - st->flate.avail_out))
if (!_pdfioFileWrite(st->pdf, st->cbuffer, bytes))
{
ret = false;
goto done;
@ -755,7 +761,8 @@ pdfioStreamWrite(
{
// Encrypt data before writing...
unsigned char temp[8192]; // Temporary buffer
size_t cbytes; // Current bytes
size_t cbytes, // Current bytes
outbytes; // Output bytes
bufptr = (const unsigned char *)buffer;
@ -764,8 +771,8 @@ pdfioStreamWrite(
if ((cbytes = bytes) > sizeof(temp))
cbytes = sizeof(temp);
(st->crypto_cb)(&st->crypto_ctx, temp, bufptr, cbytes);
if (!_pdfioFileWrite(st->pdf, temp, cbytes))
outbytes = (st->crypto_cb)(&st->crypto_ctx, temp, bufptr, cbytes);
if (!_pdfioFileWrite(st->pdf, temp, outbytes))
return (false);
bytes -= cbytes;
@ -1153,13 +1160,15 @@ stream_write(pdfio_stream_t *st, // I - Stream
if (st->flate.avail_out < (sizeof(st->cbuffer) / 8))
{
// Flush the compression buffer...
size_t bytes = sizeof(st->cbuffer) - st->flate.avail_out;
if (st->crypto_cb)
{
// Encrypt it first...
(st->crypto_cb)(&st->crypto_ctx, st->cbuffer, st->cbuffer, sizeof(st->cbuffer) - st->flate.avail_out);
bytes = (st->crypto_cb)(&st->crypto_ctx, st->cbuffer, st->cbuffer, bytes);
}
if (!_pdfioFileWrite(st->pdf, st->cbuffer, sizeof(st->cbuffer) - st->flate.avail_out))
if (!_pdfioFileWrite(st->pdf, st->cbuffer, bytes))
return (false);
st->flate.next_out = (Bytef *)st->cbuffer;