EC2N::EC2N(BufferedTransformation &bt) : m_field(BERDecodeGF2NP(bt)) { BERSequenceDecoder seq(bt); m_field->BERDecodeElement(seq, m_a); m_field->BERDecodeElement(seq, m_b); // skip optional seed if (!seq.EndReached()) { SecByteBlock seed; unsigned int unused; BERDecodeBitString(seq, seed, unused); } seq.MessageEnd(); }
void DL_PrivateKey_EC<EC>::BERDecodeKey2(BufferedTransformation &bt, bool parametersPresent, unsigned int size) { BERSequenceDecoder seq(bt); word32 version; BERDecodeUnsigned<word32>(seq, version, INTEGER, 1, 1); // check version BERGeneralDecoder dec(seq, OCTET_STRING); if (!dec.IsDefiniteLength()) BERDecodeError(); Integer x; x.Decode(dec, dec.RemainingLength()); dec.MessageEnd(); if (!parametersPresent && seq.PeekByte() != (CONTEXT_SPECIFIC | CONSTRUCTED | 0)) BERDecodeError(); if (!seq.EndReached() && seq.PeekByte() == (CONTEXT_SPECIFIC | CONSTRUCTED | 0)) { BERGeneralDecoder parameters(seq, CONTEXT_SPECIFIC | CONSTRUCTED | 0); AccessGroupParameters().BERDecode(parameters); parameters.MessageEnd(); } if (!seq.EndReached()) { // skip over the public element SecByteBlock subjectPublicKey; unsigned int unusedBits; BERGeneralDecoder publicKey(seq, CONTEXT_SPECIFIC | CONSTRUCTED | 1); BERDecodeBitString(publicKey, subjectPublicKey, unusedBits); publicKey.MessageEnd(); Element Q; if (!(unusedBits == 0 && GetGroupParameters().GetCurve().DecodePoint(Q, subjectPublicKey, subjectPublicKey.size()))) BERDecodeError(); } seq.MessageEnd(); SetPrivateExponent(x); }