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authorlloyd <[email protected]>2014-01-10 03:41:59 +0000
committerlloyd <[email protected]>2014-01-10 03:41:59 +0000
commit6894dca64c04936d07048c0e8cbf7e25858548c3 (patch)
tree5d572bfde9fe667dab14e3f04b5285a85d8acd95 /src/lib/asn1/der_enc.cpp
parent9efa3be92442afb3d0b69890a36c7f122df18eda (diff)
Move lib into src
Diffstat (limited to 'src/lib/asn1/der_enc.cpp')
-rw-r--r--src/lib/asn1/der_enc.cpp410
1 files changed, 410 insertions, 0 deletions
diff --git a/src/lib/asn1/der_enc.cpp b/src/lib/asn1/der_enc.cpp
new file mode 100644
index 000000000..c1e5fd45c
--- /dev/null
+++ b/src/lib/asn1/der_enc.cpp
@@ -0,0 +1,410 @@
+/*
+* DER Encoder
+* (C) 1999-2007 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#include <botan/der_enc.h>
+#include <botan/asn1_obj.h>
+#include <botan/bigint.h>
+#include <botan/get_byte.h>
+#include <botan/parsing.h>
+#include <botan/internal/bit_ops.h>
+#include <algorithm>
+
+namespace Botan {
+
+namespace {
+
+/*
+* DER encode an ASN.1 type tag
+*/
+secure_vector<byte> encode_tag(ASN1_Tag type_tag, ASN1_Tag class_tag)
+ {
+ if((class_tag | 0xE0) != 0xE0)
+ throw Encoding_Error("DER_Encoder: Invalid class tag " +
+ std::to_string(class_tag));
+
+ secure_vector<byte> encoded_tag;
+ if(type_tag <= 30)
+ encoded_tag.push_back(static_cast<byte>(type_tag | class_tag));
+ else
+ {
+ size_t blocks = high_bit(type_tag) + 6;
+ blocks = (blocks - (blocks % 7)) / 7;
+
+ encoded_tag.push_back(class_tag | 0x1F);
+ for(size_t i = 0; i != blocks - 1; ++i)
+ encoded_tag.push_back(0x80 | ((type_tag >> 7*(blocks-i-1)) & 0x7F));
+ encoded_tag.push_back(type_tag & 0x7F);
+ }
+
+ return encoded_tag;
+ }
+
+/*
+* DER encode an ASN.1 length field
+*/
+secure_vector<byte> encode_length(size_t length)
+ {
+ secure_vector<byte> encoded_length;
+ if(length <= 127)
+ encoded_length.push_back(static_cast<byte>(length));
+ else
+ {
+ const size_t top_byte = significant_bytes(length);
+
+ encoded_length.push_back(static_cast<byte>(0x80 | top_byte));
+
+ for(size_t i = sizeof(length) - top_byte; i != sizeof(length); ++i)
+ encoded_length.push_back(get_byte(i, length));
+ }
+ return encoded_length;
+ }
+
+}
+
+/*
+* Return the encoded SEQUENCE/SET
+*/
+secure_vector<byte> DER_Encoder::DER_Sequence::get_contents()
+ {
+ const ASN1_Tag real_class_tag = ASN1_Tag(class_tag | CONSTRUCTED);
+
+ if(type_tag == SET)
+ {
+ std::sort(set_contents.begin(), set_contents.end());
+ for(size_t i = 0; i != set_contents.size(); ++i)
+ contents += set_contents[i];
+ set_contents.clear();
+ }
+
+ secure_vector<byte> result;
+ result += encode_tag(type_tag, real_class_tag);
+ result += encode_length(contents.size());
+ result += contents;
+ contents.clear();
+
+ return result;
+ }
+
+/*
+* Add an encoded value to the SEQUENCE/SET
+*/
+void DER_Encoder::DER_Sequence::add_bytes(const byte data[], size_t length)
+ {
+ if(type_tag == SET)
+ set_contents.push_back(secure_vector<byte>(data, data + length));
+ else
+ contents += std::make_pair(data, length);
+ }
+
+/*
+* Return the type and class taggings
+*/
+ASN1_Tag DER_Encoder::DER_Sequence::tag_of() const
+ {
+ return ASN1_Tag(type_tag | class_tag);
+ }
+
+/*
+* DER_Sequence Constructor
+*/
+DER_Encoder::DER_Sequence::DER_Sequence(ASN1_Tag t1, ASN1_Tag t2) :
+ type_tag(t1), class_tag(t2)
+ {
+ }
+
+/*
+* Return the encoded contents
+*/
+secure_vector<byte> DER_Encoder::get_contents()
+ {
+ if(subsequences.size() != 0)
+ throw Invalid_State("DER_Encoder: Sequence hasn't been marked done");
+
+ secure_vector<byte> output;
+ std::swap(output, contents);
+ return output;
+ }
+
+/*
+* Start a new ASN.1 SEQUENCE/SET/EXPLICIT
+*/
+DER_Encoder& DER_Encoder::start_cons(ASN1_Tag type_tag,
+ ASN1_Tag class_tag)
+ {
+ subsequences.push_back(DER_Sequence(type_tag, class_tag));
+ return (*this);
+ }
+
+/*
+* Finish the current ASN.1 SEQUENCE/SET/EXPLICIT
+*/
+DER_Encoder& DER_Encoder::end_cons()
+ {
+ if(subsequences.empty())
+ throw Invalid_State("DER_Encoder::end_cons: No such sequence");
+
+ secure_vector<byte> seq = subsequences[subsequences.size()-1].get_contents();
+ subsequences.pop_back();
+ raw_bytes(seq);
+ return (*this);
+ }
+
+/*
+* Start a new ASN.1 EXPLICIT encoding
+*/
+DER_Encoder& DER_Encoder::start_explicit(u16bit type_no)
+ {
+ ASN1_Tag type_tag = static_cast<ASN1_Tag>(type_no);
+
+ if(type_tag == SET)
+ throw Internal_Error("DER_Encoder.start_explicit(SET); cannot perform");
+
+ return start_cons(type_tag, CONTEXT_SPECIFIC);
+ }
+
+/*
+* Finish the current ASN.1 EXPLICIT encoding
+*/
+DER_Encoder& DER_Encoder::end_explicit()
+ {
+ return end_cons();
+ }
+
+/*
+* Write raw bytes into the stream
+*/
+DER_Encoder& DER_Encoder::raw_bytes(const secure_vector<byte>& val)
+ {
+ return raw_bytes(&val[0], val.size());
+ }
+
+DER_Encoder& DER_Encoder::raw_bytes(const std::vector<byte>& val)
+ {
+ return raw_bytes(&val[0], val.size());
+ }
+
+/*
+* Write raw bytes into the stream
+*/
+DER_Encoder& DER_Encoder::raw_bytes(const byte bytes[], size_t length)
+ {
+ if(subsequences.size())
+ subsequences[subsequences.size()-1].add_bytes(bytes, length);
+ else
+ contents += std::make_pair(bytes, length);
+
+ return (*this);
+ }
+
+/*
+* Encode a NULL object
+*/
+DER_Encoder& DER_Encoder::encode_null()
+ {
+ return add_object(NULL_TAG, UNIVERSAL, nullptr, 0);
+ }
+
+/*
+* DER encode a BOOLEAN
+*/
+DER_Encoder& DER_Encoder::encode(bool is_true)
+ {
+ return encode(is_true, BOOLEAN, UNIVERSAL);
+ }
+
+/*
+* DER encode a small INTEGER
+*/
+DER_Encoder& DER_Encoder::encode(size_t n)
+ {
+ return encode(BigInt(n), INTEGER, UNIVERSAL);
+ }
+
+/*
+* DER encode a small INTEGER
+*/
+DER_Encoder& DER_Encoder::encode(const BigInt& n)
+ {
+ return encode(n, INTEGER, UNIVERSAL);
+ }
+
+/*
+* DER encode an OCTET STRING or BIT STRING
+*/
+DER_Encoder& DER_Encoder::encode(const secure_vector<byte>& bytes,
+ ASN1_Tag real_type)
+ {
+ return encode(&bytes[0], bytes.size(),
+ real_type, real_type, UNIVERSAL);
+ }
+
+/*
+* DER encode an OCTET STRING or BIT STRING
+*/
+DER_Encoder& DER_Encoder::encode(const std::vector<byte>& bytes,
+ ASN1_Tag real_type)
+ {
+ return encode(&bytes[0], bytes.size(),
+ real_type, real_type, UNIVERSAL);
+ }
+
+/*
+* Encode this object
+*/
+DER_Encoder& DER_Encoder::encode(const byte bytes[], size_t length,
+ ASN1_Tag real_type)
+ {
+ return encode(bytes, length, real_type, real_type, UNIVERSAL);
+ }
+
+/*
+* DER encode a BOOLEAN
+*/
+DER_Encoder& DER_Encoder::encode(bool is_true,
+ ASN1_Tag type_tag, ASN1_Tag class_tag)
+ {
+ byte val = is_true ? 0xFF : 0x00;
+ return add_object(type_tag, class_tag, &val, 1);
+ }
+
+/*
+* DER encode a small INTEGER
+*/
+DER_Encoder& DER_Encoder::encode(size_t n,
+ ASN1_Tag type_tag, ASN1_Tag class_tag)
+ {
+ return encode(BigInt(n), type_tag, class_tag);
+ }
+
+/*
+* DER encode an INTEGER
+*/
+DER_Encoder& DER_Encoder::encode(const BigInt& n,
+ ASN1_Tag type_tag, ASN1_Tag class_tag)
+ {
+ if(n == 0)
+ return add_object(type_tag, class_tag, 0);
+
+ bool extra_zero = (n.bits() % 8 == 0);
+ secure_vector<byte> contents(extra_zero + n.bytes());
+ BigInt::encode(&contents[extra_zero], n);
+ if(n < 0)
+ {
+ for(size_t i = 0; i != contents.size(); ++i)
+ contents[i] = ~contents[i];
+ for(size_t i = contents.size(); i > 0; --i)
+ if(++contents[i-1])
+ break;
+ }
+
+ return add_object(type_tag, class_tag, contents);
+ }
+
+/*
+* DER encode an OCTET STRING or BIT STRING
+*/
+DER_Encoder& DER_Encoder::encode(const secure_vector<byte>& bytes,
+ ASN1_Tag real_type,
+ ASN1_Tag type_tag, ASN1_Tag class_tag)
+ {
+ return encode(&bytes[0], bytes.size(),
+ real_type, type_tag, class_tag);
+ }
+
+/*
+* DER encode an OCTET STRING or BIT STRING
+*/
+DER_Encoder& DER_Encoder::encode(const std::vector<byte>& bytes,
+ ASN1_Tag real_type,
+ ASN1_Tag type_tag, ASN1_Tag class_tag)
+ {
+ return encode(&bytes[0], bytes.size(),
+ real_type, type_tag, class_tag);
+ }
+
+/*
+* DER encode an OCTET STRING or BIT STRING
+*/
+DER_Encoder& DER_Encoder::encode(const byte bytes[], size_t length,
+ ASN1_Tag real_type,
+ ASN1_Tag type_tag, ASN1_Tag class_tag)
+ {
+ if(real_type != OCTET_STRING && real_type != BIT_STRING)
+ throw Invalid_Argument("DER_Encoder: Invalid tag for byte/bit string");
+
+ if(real_type == BIT_STRING)
+ {
+ secure_vector<byte> encoded;
+ encoded.push_back(0);
+ encoded += std::make_pair(bytes, length);
+ return add_object(type_tag, class_tag, encoded);
+ }
+ else
+ return add_object(type_tag, class_tag, bytes, length);
+ }
+
+/*
+* Conditionally write some values to the stream
+*/
+DER_Encoder& DER_Encoder::encode_if(bool cond, DER_Encoder& codec)
+ {
+ if(cond)
+ return raw_bytes(codec.get_contents());
+ return (*this);
+ }
+
+DER_Encoder& DER_Encoder::encode_if(bool cond, const ASN1_Object& obj)
+ {
+ if(cond)
+ encode(obj);
+ return (*this);
+ }
+
+/*
+* Request for an object to encode itself
+*/
+DER_Encoder& DER_Encoder::encode(const ASN1_Object& obj)
+ {
+ obj.encode_into(*this);
+ return (*this);
+ }
+
+/*
+* Write the encoding of the byte(s)
+*/
+DER_Encoder& DER_Encoder::add_object(ASN1_Tag type_tag, ASN1_Tag class_tag,
+ const byte rep[], size_t length)
+ {
+ secure_vector<byte> buffer;
+ buffer += encode_tag(type_tag, class_tag);
+ buffer += encode_length(length);
+ buffer += std::make_pair(rep, length);
+
+ return raw_bytes(buffer);
+ }
+
+/*
+* Write the encoding of the byte(s)
+*/
+DER_Encoder& DER_Encoder::add_object(ASN1_Tag type_tag, ASN1_Tag class_tag,
+ const std::string& rep_str)
+ {
+ const byte* rep = reinterpret_cast<const byte*>(rep_str.data());
+ const size_t rep_len = rep_str.size();
+ return add_object(type_tag, class_tag, rep, rep_len);
+ }
+
+/*
+* Write the encoding of the byte
+*/
+DER_Encoder& DER_Encoder::add_object(ASN1_Tag type_tag,
+ ASN1_Tag class_tag, byte rep)
+ {
+ return add_object(type_tag, class_tag, &rep, 1);
+ }
+
+}