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-rw-r--r--comm/third_party/botan/src/lib/modes/mode_pad/mode_pad.cpp333
1 files changed, 333 insertions, 0 deletions
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);
+ }
+
+
+}
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