diff options
Diffstat (limited to 'backend/node_modules/ecdsa-sig-formatter/src')
3 files changed, 227 insertions, 0 deletions
diff --git a/backend/node_modules/ecdsa-sig-formatter/src/ecdsa-sig-formatter.d.ts b/backend/node_modules/ecdsa-sig-formatter/src/ecdsa-sig-formatter.d.ts new file mode 100644 index 0000000..9693aa0 --- /dev/null +++ b/backend/node_modules/ecdsa-sig-formatter/src/ecdsa-sig-formatter.d.ts @@ -0,0 +1,17 @@ +/// <reference types="node" /> + +declare module "ecdsa-sig-formatter" { + /** + * Convert the ASN.1/DER encoded signature to a JOSE-style concatenated signature. Returns a base64 url encoded String. + * If signature is a String, it should be base64 encoded + * alg must be one of ES256, ES384 or ES512 + */ + export function derToJose(signature: Buffer | string, alg: string): string; + + /** + * Convert the JOSE-style concatenated signature to an ASN.1/DER encoded signature. Returns a Buffer + * If signature is a String, it should be base64 url encoded + * alg must be one of ES256, ES384 or ES512 + */ + export function joseToDer(signature: Buffer | string, alg: string): Buffer +} diff --git a/backend/node_modules/ecdsa-sig-formatter/src/ecdsa-sig-formatter.js b/backend/node_modules/ecdsa-sig-formatter/src/ecdsa-sig-formatter.js new file mode 100644 index 0000000..38eeb9b --- /dev/null +++ b/backend/node_modules/ecdsa-sig-formatter/src/ecdsa-sig-formatter.js @@ -0,0 +1,187 @@ +'use strict'; + +var Buffer = require('safe-buffer').Buffer; + +var getParamBytesForAlg = require('./param-bytes-for-alg'); + +var MAX_OCTET = 0x80, + CLASS_UNIVERSAL = 0, + PRIMITIVE_BIT = 0x20, + TAG_SEQ = 0x10, + TAG_INT = 0x02, + ENCODED_TAG_SEQ = (TAG_SEQ | PRIMITIVE_BIT) | (CLASS_UNIVERSAL << 6), + ENCODED_TAG_INT = TAG_INT | (CLASS_UNIVERSAL << 6); + +function base64Url(base64) { + return base64 + .replace(/=/g, '') + .replace(/\+/g, '-') + .replace(/\//g, '_'); +} + +function signatureAsBuffer(signature) { + if (Buffer.isBuffer(signature)) { + return signature; + } else if ('string' === typeof signature) { + return Buffer.from(signature, 'base64'); + } + + throw new TypeError('ECDSA signature must be a Base64 string or a Buffer'); +} + +function derToJose(signature, alg) { + signature = signatureAsBuffer(signature); + var paramBytes = getParamBytesForAlg(alg); + + // the DER encoded param should at most be the param size, plus a padding + // zero, since due to being a signed integer + var maxEncodedParamLength = paramBytes + 1; + + var inputLength = signature.length; + + var offset = 0; + if (signature[offset++] !== ENCODED_TAG_SEQ) { + throw new Error('Could not find expected "seq"'); + } + + var seqLength = signature[offset++]; + if (seqLength === (MAX_OCTET | 1)) { + seqLength = signature[offset++]; + } + + if (inputLength - offset < seqLength) { + throw new Error('"seq" specified length of "' + seqLength + '", only "' + (inputLength - offset) + '" remaining'); + } + + if (signature[offset++] !== ENCODED_TAG_INT) { + throw new Error('Could not find expected "int" for "r"'); + } + + var rLength = signature[offset++]; + + if (inputLength - offset - 2 < rLength) { + throw new Error('"r" specified length of "' + rLength + '", only "' + (inputLength - offset - 2) + '" available'); + } + + if (maxEncodedParamLength < rLength) { + throw new Error('"r" specified length of "' + rLength + '", max of "' + maxEncodedParamLength + '" is acceptable'); + } + + var rOffset = offset; + offset += rLength; + + if (signature[offset++] !== ENCODED_TAG_INT) { + throw new Error('Could not find expected "int" for "s"'); + } + + var sLength = signature[offset++]; + + if (inputLength - offset !== sLength) { + throw new Error('"s" specified length of "' + sLength + '", expected "' + (inputLength - offset) + '"'); + } + + if (maxEncodedParamLength < sLength) { + throw new Error('"s" specified length of "' + sLength + '", max of "' + maxEncodedParamLength + '" is acceptable'); + } + + var sOffset = offset; + offset += sLength; + + if (offset !== inputLength) { + throw new Error('Expected to consume entire buffer, but "' + (inputLength - offset) + '" bytes remain'); + } + + var rPadding = paramBytes - rLength, + sPadding = paramBytes - sLength; + + var dst = Buffer.allocUnsafe(rPadding + rLength + sPadding + sLength); + + for (offset = 0; offset < rPadding; ++offset) { + dst[offset] = 0; + } + signature.copy(dst, offset, rOffset + Math.max(-rPadding, 0), rOffset + rLength); + + offset = paramBytes; + + for (var o = offset; offset < o + sPadding; ++offset) { + dst[offset] = 0; + } + signature.copy(dst, offset, sOffset + Math.max(-sPadding, 0), sOffset + sLength); + + dst = dst.toString('base64'); + dst = base64Url(dst); + + return dst; +} + +function countPadding(buf, start, stop) { + var padding = 0; + while (start + padding < stop && buf[start + padding] === 0) { + ++padding; + } + + var needsSign = buf[start + padding] >= MAX_OCTET; + if (needsSign) { + --padding; + } + + return padding; +} + +function joseToDer(signature, alg) { + signature = signatureAsBuffer(signature); + var paramBytes = getParamBytesForAlg(alg); + + var signatureBytes = signature.length; + if (signatureBytes !== paramBytes * 2) { + throw new TypeError('"' + alg + '" signatures must be "' + paramBytes * 2 + '" bytes, saw "' + signatureBytes + '"'); + } + + var rPadding = countPadding(signature, 0, paramBytes); + var sPadding = countPadding(signature, paramBytes, signature.length); + var rLength = paramBytes - rPadding; + var sLength = paramBytes - sPadding; + + var rsBytes = 1 + 1 + rLength + 1 + 1 + sLength; + + var shortLength = rsBytes < MAX_OCTET; + + var dst = Buffer.allocUnsafe((shortLength ? 2 : 3) + rsBytes); + + var offset = 0; + dst[offset++] = ENCODED_TAG_SEQ; + if (shortLength) { + // Bit 8 has value "0" + // bits 7-1 give the length. + dst[offset++] = rsBytes; + } else { + // Bit 8 of first octet has value "1" + // bits 7-1 give the number of additional length octets. + dst[offset++] = MAX_OCTET | 1; + // length, base 256 + dst[offset++] = rsBytes & 0xff; + } + dst[offset++] = ENCODED_TAG_INT; + dst[offset++] = rLength; + if (rPadding < 0) { + dst[offset++] = 0; + offset += signature.copy(dst, offset, 0, paramBytes); + } else { + offset += signature.copy(dst, offset, rPadding, paramBytes); + } + dst[offset++] = ENCODED_TAG_INT; + dst[offset++] = sLength; + if (sPadding < 0) { + dst[offset++] = 0; + signature.copy(dst, offset, paramBytes); + } else { + signature.copy(dst, offset, paramBytes + sPadding); + } + + return dst; +} + +module.exports = { + derToJose: derToJose, + joseToDer: joseToDer +}; diff --git a/backend/node_modules/ecdsa-sig-formatter/src/param-bytes-for-alg.js b/backend/node_modules/ecdsa-sig-formatter/src/param-bytes-for-alg.js new file mode 100644 index 0000000..9fe67ac --- /dev/null +++ b/backend/node_modules/ecdsa-sig-formatter/src/param-bytes-for-alg.js @@ -0,0 +1,23 @@ +'use strict'; + +function getParamSize(keySize) { + var result = ((keySize / 8) | 0) + (keySize % 8 === 0 ? 0 : 1); + return result; +} + +var paramBytesForAlg = { + ES256: getParamSize(256), + ES384: getParamSize(384), + ES512: getParamSize(521) +}; + +function getParamBytesForAlg(alg) { + var paramBytes = paramBytesForAlg[alg]; + if (paramBytes) { + return paramBytes; + } + + throw new Error('Unknown algorithm "' + alg + '"'); +} + +module.exports = getParamBytesForAlg; |