diff options
Diffstat (limited to 'libqpdf/Pl_AES_PDF.cc')
| -rw-r--r-- | libqpdf/Pl_AES_PDF.cc | 77 |
1 files changed, 57 insertions, 20 deletions
diff --git a/libqpdf/Pl_AES_PDF.cc b/libqpdf/Pl_AES_PDF.cc index 0f73c09c..57bf5766 100644 --- a/libqpdf/Pl_AES_PDF.cc +++ b/libqpdf/Pl_AES_PDF.cc @@ -15,19 +15,24 @@ bool Pl_AES_PDF::use_static_iv = false; Pl_AES_PDF::Pl_AES_PDF(char const* identifier, Pipeline* next, - bool encrypt, unsigned char const key[key_size]) : + bool encrypt, unsigned char const* key, + unsigned int key_bytes) : Pipeline(identifier, next), encrypt(encrypt), cbc_mode(true), first(true), offset(0), - nrounds(0) + nrounds(0), + use_zero_iv(false), + disable_padding(false) { - static int const keybits = 128; - assert(key_size == KEYLENGTH(keybits)); - assert(sizeof(this->rk) / sizeof(uint32_t) == RKLENGTH(keybits)); - std::memcpy(this->key, key, key_size); - std::memset(this->rk, 0, sizeof(this->rk)); + unsigned int keybits = 8 * key_bytes; + assert(key_bytes == KEYLENGTH(keybits)); + this->key = new unsigned char[key_bytes]; + this->rk = new uint32_t[RKLENGTH(keybits)]; + unsigned int rk_bytes = RKLENGTH(keybits) * sizeof(uint32_t); + std::memcpy(this->key, key, key_bytes); + std::memset(this->rk, 0, rk_bytes); std::memset(this->inbuf, 0, this->buf_size); std::memset(this->outbuf, 0, this->buf_size); std::memset(this->cbc_block, 0, this->buf_size); @@ -44,7 +49,20 @@ Pl_AES_PDF::Pl_AES_PDF(char const* identifier, Pipeline* next, Pl_AES_PDF::~Pl_AES_PDF() { - // nothing needed + delete [] this->key; + delete [] this->rk; +} + +void +Pl_AES_PDF::useZeroIV() +{ + this->use_zero_iv = true; +} + +void +Pl_AES_PDF::disablePadding() +{ + this->disable_padding = true; } void @@ -90,13 +108,16 @@ Pl_AES_PDF::finish() { flush(false); } - // Pad as described in section 3.5.1 of version 1.7 of the PDF - // specification, including providing an entire block of padding - // if the input was a multiple of 16 bytes. - unsigned char pad = (unsigned char) (this->buf_size - this->offset); - memset(this->inbuf + this->offset, pad, pad); - this->offset = this->buf_size; - flush(false); + if (! this->disable_padding) + { + // Pad as described in section 3.5.1 of version 1.7 of the PDF + // specification, including providing an entire block of padding + // if the input was a multiple of 16 bytes. + unsigned char pad = (unsigned char) (this->buf_size - this->offset); + memset(this->inbuf + this->offset, pad, pad); + this->offset = this->buf_size; + flush(false); + } } else { @@ -112,7 +133,7 @@ Pl_AES_PDF::finish() this->buf_size - this->offset); this->offset = this->buf_size; } - flush(true); + flush(! this->disable_padding); } getNext()->finish(); } @@ -136,6 +157,13 @@ Pl_AES_PDF::initializeVector() this->cbc_block[i] = 14 * (1 + i); } } + else if (use_zero_iv) + { + for (unsigned int i = 0; i < this->buf_size; ++i) + { + this->cbc_block[i] = 0; + } + } else { for (unsigned int i = 0; i < this->buf_size; ++i) @@ -157,12 +185,21 @@ Pl_AES_PDF::flush(bool strip_padding) { if (encrypt) { - // Set cbc_block to a random initialization vector and - // write it to the output stream + // Set cbc_block to the initialization vector, and if + // not zero, write it to the output stream. initializeVector(); - getNext()->write(this->cbc_block, this->buf_size); + if (! this->use_zero_iv) + { + getNext()->write(this->cbc_block, this->buf_size); + } } - else + else if (this->use_zero_iv) + { + // Initialize vector with zeroes; zero vector was not + // written to the beginning of the input file. + initializeVector(); + } + else { // Take the first block of input as the initialization // vector. There's nothing to write at this time. |