vclib/at.asitplus.wallet.lib.jws/JwsExtensions

JwsExtensions

object JwsExtensions

Functions

convertToAsn1Signature

fun ByteArray.convertToAsn1Signature(len: Int): ByteArray

JWS spec concatenates the R and S values, but JCA needs an ASN.1 structure (SEQUENCE of two INTEGER) around it

encodeToByteArray

fun Int.encodeToByteArray(): ByteArray

Encode as a four-byte array

encodeWithLength

fun ByteArray?.encodeWithLength(): ByteArray

Encode the length of (as four bytes) plus the value itself

fun ByteArray.ensureSize(size: Int): ByteArray

Drops or adds zero bytes at the start until the size is reached

extractSignatureValues

fun ByteArray.extractSignatureValues(expectedLength: Int): ByteArray

Extracts the plain R and S values of an ECDSA signature if it is wrapped in an ASN.1 Sequence of two ASN.1 Integers (e.g. when computed in Java)

fun ByteArray.padWithZeros(len: Int): ByteArray

The extracted values from ASN.1 may be too short to be simply concatenated as raw values, so we'll need to pad them with 0x00 bytes to the expected length

stripLeadingSignByte

fun ByteArray.stripLeadingSignByte(): ByteArray

Strips the leading 0x00 byte of an ASN.1-encoded Integer, that will be there if the first bit of the value is set, i.e. it is over 0x7F (or < 0 if it is signed)