diff options
Diffstat (limited to 'comm/third_party/botan/src/lib/modes/mode_pad')
3 files changed, 496 insertions, 0 deletions
diff --git a/comm/third_party/botan/src/lib/modes/mode_pad/info.txt b/comm/third_party/botan/src/lib/modes/mode_pad/info.txt new file mode 100644 index 0000000000..12b6e5b3a9 --- /dev/null +++ b/comm/third_party/botan/src/lib/modes/mode_pad/info.txt @@ -0,0 +1,3 @@ +<defines> +CIPHER_MODE_PADDING -> 20131128 +</defines> diff --git a/comm/third_party/botan/src/lib/modes/mode_pad/mode_pad.cpp b/comm/third_party/botan/src/lib/modes/mode_pad/mode_pad.cpp new file mode 100644 index 0000000000..18bb71af5d --- /dev/null +++ b/comm/third_party/botan/src/lib/modes/mode_pad/mode_pad.cpp @@ -0,0 +1,333 @@ +/* +* CBC Padding Methods +* (C) 1999-2007,2013,2018,2020 Jack Lloyd +* (C) 2016 René Korthaus, Rohde & Schwarz Cybersecurity +* +* Botan is released under the Simplified BSD License (see license.txt) +*/ + +#include <botan/mode_pad.h> +#include <botan/exceptn.h> +#include <botan/internal/ct_utils.h> + +namespace Botan { + +/** +* Get a block cipher padding method by name +*/ +BlockCipherModePaddingMethod* get_bc_pad(const std::string& algo_spec) + { + if(algo_spec == "NoPadding") + return new Null_Padding; + + if(algo_spec == "PKCS7") + return new PKCS7_Padding; + + if(algo_spec == "OneAndZeros") + return new OneAndZeros_Padding; + + if(algo_spec == "X9.23") + return new ANSI_X923_Padding; + + if(algo_spec == "ESP") + return new ESP_Padding; + + return nullptr; + } + +/* +* Pad with PKCS #7 Method +*/ +void PKCS7_Padding::add_padding(secure_vector<uint8_t>& buffer, + size_t last_byte_pos, + size_t BS) const + { + /* + Padding format is + 01 + 0202 + 030303 + ... + */ + BOTAN_DEBUG_ASSERT(last_byte_pos < BS); + + const uint8_t padding_len = static_cast<uint8_t>(BS - last_byte_pos); + + buffer.resize(buffer.size() + padding_len); + + CT::poison(&last_byte_pos, 1); + CT::poison(buffer.data(), buffer.size()); + + BOTAN_DEBUG_ASSERT(buffer.size() % BS == 0); + BOTAN_DEBUG_ASSERT(buffer.size() >= BS); + + const size_t start_of_last_block = buffer.size() - BS; + const size_t end_of_last_block = buffer.size(); + const size_t start_of_padding = buffer.size() - padding_len; + + for(size_t i = start_of_last_block; i != end_of_last_block; ++i) + { + auto needs_padding = CT::Mask<uint8_t>(CT::Mask<size_t>::is_gte(i, start_of_padding)); + buffer[i] = needs_padding.select(padding_len, buffer[i]); + } + + CT::unpoison(buffer.data(), buffer.size()); + CT::unpoison(last_byte_pos); + } + +/* +* Unpad with PKCS #7 Method +*/ +size_t PKCS7_Padding::unpad(const uint8_t input[], size_t input_length) const + { + if(!valid_blocksize(input_length)) + return input_length; + + CT::poison(input, input_length); + + const uint8_t last_byte = input[input_length-1]; + + /* + The input should == the block size so if the last byte exceeds + that then the padding is certainly invalid + */ + auto bad_input = CT::Mask<size_t>::is_gt(last_byte, input_length); + + const size_t pad_pos = input_length - last_byte; + + for(size_t i = 0; i != input_length - 1; ++i) + { + // Does this byte equal the expected pad byte? + const auto pad_eq = CT::Mask<size_t>::is_equal(input[i], last_byte); + + // Ignore values that are not part of the padding + const auto in_range = CT::Mask<size_t>::is_gte(i, pad_pos); + bad_input |= in_range & (~pad_eq); + } + + CT::unpoison(input, input_length); + + return bad_input.select_and_unpoison(input_length, pad_pos); + } + +/* +* Pad with ANSI X9.23 Method +*/ +void ANSI_X923_Padding::add_padding(secure_vector<uint8_t>& buffer, + size_t last_byte_pos, + size_t BS) const + { + /* + Padding format is + 01 + 0002 + 000003 + ... + */ + BOTAN_DEBUG_ASSERT(last_byte_pos < BS); + + const uint8_t padding_len = static_cast<uint8_t>(BS - last_byte_pos); + + buffer.resize(buffer.size() + padding_len); + + CT::poison(&last_byte_pos, 1); + CT::poison(buffer.data(), buffer.size()); + + BOTAN_DEBUG_ASSERT(buffer.size() % BS == 0); + BOTAN_DEBUG_ASSERT(buffer.size() >= BS); + + const size_t start_of_last_block = buffer.size() - BS; + const size_t end_of_zero_padding = buffer.size() - 1; + const size_t start_of_padding = buffer.size() - padding_len; + + for(size_t i = start_of_last_block; i != end_of_zero_padding; ++i) + { + auto needs_padding = CT::Mask<uint8_t>(CT::Mask<size_t>::is_gte(i, start_of_padding)); + buffer[i] = needs_padding.select(0, buffer[i]); + } + + buffer[buffer.size()-1] = padding_len; + CT::unpoison(buffer.data(), buffer.size()); + CT::unpoison(last_byte_pos); + } + +/* +* Unpad with ANSI X9.23 Method +*/ +size_t ANSI_X923_Padding::unpad(const uint8_t input[], size_t input_length) const + { + if(!valid_blocksize(input_length)) + return input_length; + + CT::poison(input, input_length); + + const size_t last_byte = input[input_length-1]; + + auto bad_input = CT::Mask<size_t>::is_gt(last_byte, input_length); + + const size_t pad_pos = input_length - last_byte; + + for(size_t i = 0; i != input_length - 1; ++i) + { + // Ignore values that are not part of the padding + const auto in_range = CT::Mask<size_t>::is_gte(i, pad_pos); + const auto pad_is_nonzero = CT::Mask<size_t>::expand(input[i]); + bad_input |= pad_is_nonzero & in_range; + } + + CT::unpoison(input, input_length); + + return bad_input.select_and_unpoison(input_length, pad_pos); + } + +/* +* Pad with One and Zeros Method +*/ +void OneAndZeros_Padding::add_padding(secure_vector<uint8_t>& buffer, + size_t last_byte_pos, + size_t BS) const + { + /* + Padding format is + 80 + 8000 + 800000 + ... + */ + + BOTAN_DEBUG_ASSERT(last_byte_pos < BS); + + const uint8_t padding_len = static_cast<uint8_t>(BS - last_byte_pos); + + buffer.resize(buffer.size() + padding_len); + + CT::poison(&last_byte_pos, 1); + CT::poison(buffer.data(), buffer.size()); + + BOTAN_DEBUG_ASSERT(buffer.size() % BS == 0); + BOTAN_DEBUG_ASSERT(buffer.size() >= BS); + + const size_t start_of_last_block = buffer.size() - BS; + const size_t end_of_last_block = buffer.size(); + const size_t start_of_padding = buffer.size() - padding_len; + + for(size_t i = start_of_last_block; i != end_of_last_block; ++i) + { + auto needs_80 = CT::Mask<uint8_t>(CT::Mask<size_t>::is_equal(i, start_of_padding)); + auto needs_00 = CT::Mask<uint8_t>(CT::Mask<size_t>::is_gt(i, start_of_padding)); + buffer[i] = needs_00.select(0x00, needs_80.select(0x80, buffer[i])); + } + + CT::unpoison(buffer.data(), buffer.size()); + CT::unpoison(last_byte_pos); + } + +/* +* Unpad with One and Zeros Method +*/ +size_t OneAndZeros_Padding::unpad(const uint8_t input[], size_t input_length) const + { + if(!valid_blocksize(input_length)) + return input_length; + + CT::poison(input, input_length); + + auto bad_input = CT::Mask<uint8_t>::cleared(); + auto seen_0x80 = CT::Mask<uint8_t>::cleared(); + + size_t pad_pos = input_length - 1; + size_t i = input_length; + + while(i) + { + const auto is_0x80 = CT::Mask<uint8_t>::is_equal(input[i-1], 0x80); + const auto is_zero = CT::Mask<uint8_t>::is_zero(input[i-1]); + + seen_0x80 |= is_0x80; + pad_pos -= seen_0x80.if_not_set_return(1); + bad_input |= ~seen_0x80 & ~is_zero; + i--; + } + bad_input |= ~seen_0x80; + + CT::unpoison(input, input_length); + + return CT::Mask<size_t>::expand(bad_input).select_and_unpoison(input_length, pad_pos); + } + +/* +* Pad with ESP Padding Method +*/ +void ESP_Padding::add_padding(secure_vector<uint8_t>& buffer, + size_t last_byte_pos, + size_t BS) const + { + /* + Padding format is + 01 + 0102 + 010203 + ... + */ + BOTAN_DEBUG_ASSERT(last_byte_pos < BS); + + const uint8_t padding_len = static_cast<uint8_t>(BS - last_byte_pos); + + buffer.resize(buffer.size() + padding_len); + + CT::poison(&last_byte_pos, 1); + CT::poison(buffer.data(), buffer.size()); + + BOTAN_DEBUG_ASSERT(buffer.size() % BS == 0); + BOTAN_DEBUG_ASSERT(buffer.size() >= BS); + + const size_t start_of_last_block = buffer.size() - BS; + const size_t end_of_last_block = buffer.size(); + const size_t start_of_padding = buffer.size() - padding_len; + + uint8_t pad_ctr = 0x01; + + for(size_t i = start_of_last_block; i != end_of_last_block; ++i) + { + auto needs_padding = CT::Mask<uint8_t>(CT::Mask<size_t>::is_gte(i, start_of_padding)); + buffer[i] = needs_padding.select(pad_ctr, buffer[i]); + pad_ctr = needs_padding.select(pad_ctr + 1, pad_ctr); + } + + CT::unpoison(buffer.data(), buffer.size()); + CT::unpoison(last_byte_pos); + } + +/* +* Unpad with ESP Padding Method +*/ +size_t ESP_Padding::unpad(const uint8_t input[], size_t input_length) const + { + if(!valid_blocksize(input_length)) + return input_length; + + CT::poison(input, input_length); + + const uint8_t input_length_8 = static_cast<uint8_t>(input_length); + const uint8_t last_byte = input[input_length-1]; + + auto bad_input = CT::Mask<uint8_t>::is_zero(last_byte) | + CT::Mask<uint8_t>::is_gt(last_byte, input_length_8); + + const uint8_t pad_pos = input_length_8 - last_byte; + size_t i = input_length_8 - 1; + while(i) + { + const auto in_range = CT::Mask<size_t>::is_gt(i, pad_pos); + const auto incrementing = CT::Mask<uint8_t>::is_equal(input[i-1], input[i]-1); + + bad_input |= CT::Mask<uint8_t>(in_range) & ~incrementing; + --i; + } + + CT::unpoison(input, input_length); + return bad_input.select_and_unpoison(input_length_8, pad_pos); + } + + +} diff --git a/comm/third_party/botan/src/lib/modes/mode_pad/mode_pad.h b/comm/third_party/botan/src/lib/modes/mode_pad/mode_pad.h new file mode 100644 index 0000000000..b0e4a3cfae --- /dev/null +++ b/comm/third_party/botan/src/lib/modes/mode_pad/mode_pad.h @@ -0,0 +1,160 @@ +/* +* CBC Padding Methods +* (C) 1999-2008,2013 Jack Lloyd +* (C) 2016 René Korthaus, Rohde & Schwarz Cybersecurity +* +* Botan is released under the Simplified BSD License (see license.txt) +*/ + +#ifndef BOTAN_MODE_PADDING_H_ +#define BOTAN_MODE_PADDING_H_ + +#include <botan/secmem.h> +#include <string> + +BOTAN_FUTURE_INTERNAL_HEADER(mode_pad.h) + +namespace Botan { + +/** +* Block Cipher Mode Padding Method +* This class is pretty limited, it cannot deal well with +* randomized padding methods, or any padding method that +* wants to add more than one block. For instance, it should +* be possible to define cipher text stealing mode as simply +* a padding mode for CBC, which happens to consume the last +* two block (and requires use of the block cipher). +*/ +class BOTAN_PUBLIC_API(2,0) BlockCipherModePaddingMethod + { + public: + /** + * Add padding bytes to buffer. + * @param buffer data to pad + * @param final_block_bytes size of the final block in bytes + * @param block_size size of each block in bytes + */ + virtual void add_padding(secure_vector<uint8_t>& buffer, + size_t final_block_bytes, + size_t block_size) const = 0; + + /** + * Remove padding bytes from block + * @param block the last block + * @param len the size of the block in bytes + * @return number of data bytes, or if the padding is invalid returns len + */ + virtual size_t unpad(const uint8_t block[], size_t len) const = 0; + + /** + * @param block_size of the cipher + * @return valid block size for this padding mode + */ + virtual bool valid_blocksize(size_t block_size) const = 0; + + /** + * @return name of the mode + */ + virtual std::string name() const = 0; + + /** + * virtual destructor + */ + virtual ~BlockCipherModePaddingMethod() = default; + }; + +/** +* PKCS#7 Padding +*/ +class BOTAN_PUBLIC_API(2,0) PKCS7_Padding final : public BlockCipherModePaddingMethod + { + public: + void add_padding(secure_vector<uint8_t>& buffer, + size_t final_block_bytes, + size_t block_size) const override; + + size_t unpad(const uint8_t[], size_t) const override; + + bool valid_blocksize(size_t bs) const override { return (bs > 2 && bs < 256); } + + std::string name() const override { return "PKCS7"; } + }; + +/** +* ANSI X9.23 Padding +*/ +class BOTAN_PUBLIC_API(2,0) ANSI_X923_Padding final : public BlockCipherModePaddingMethod + { + public: + void add_padding(secure_vector<uint8_t>& buffer, + size_t final_block_bytes, + size_t block_size) const override; + + size_t unpad(const uint8_t[], size_t) const override; + + bool valid_blocksize(size_t bs) const override { return (bs > 2 && bs < 256); } + + std::string name() const override { return "X9.23"; } + }; + +/** +* One And Zeros Padding (ISO/IEC 9797-1, padding method 2) +*/ +class BOTAN_PUBLIC_API(2,0) OneAndZeros_Padding final : public BlockCipherModePaddingMethod + { + public: + void add_padding(secure_vector<uint8_t>& buffer, + size_t final_block_bytes, + size_t block_size) const override; + + size_t unpad(const uint8_t[], size_t) const override; + + bool valid_blocksize(size_t bs) const override { return (bs > 2); } + + std::string name() const override { return "OneAndZeros"; } + }; + +/** +* ESP Padding (RFC 4304) +*/ +class BOTAN_PUBLIC_API(2,0) ESP_Padding final : public BlockCipherModePaddingMethod + { + public: + void add_padding(secure_vector<uint8_t>& buffer, + size_t final_block_bytes, + size_t block_size) const override; + + size_t unpad(const uint8_t[], size_t) const override; + + bool valid_blocksize(size_t bs) const override { return (bs > 2 && bs < 256); } + + std::string name() const override { return "ESP"; } + }; + +/** +* Null Padding +*/ +class BOTAN_PUBLIC_API(2,0) Null_Padding final : public BlockCipherModePaddingMethod + { + public: + void add_padding(secure_vector<uint8_t>&, size_t, size_t) const override + { + /* no padding */ + } + + size_t unpad(const uint8_t[], size_t size) const override { return size; } + + bool valid_blocksize(size_t) const override { return true; } + + std::string name() const override { return "NoPadding"; } + }; + +/** +* Get a block cipher padding mode by name (eg "NoPadding" or "PKCS7") +* @param algo_spec block cipher padding mode name +*/ +BOTAN_PUBLIC_API(2,0) BlockCipherModePaddingMethod* get_bc_pad(const std::string& algo_spec); + +} + +#endif |