tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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EncryptedContentInfo.ts (10280B)

      1 import * as asn1js from "asn1js";
      2 import * as pvutils from "pvutils";
      3 import { AlgorithmIdentifier, AlgorithmIdentifierJson, AlgorithmIdentifierSchema } from "./AlgorithmIdentifier";
      4 import { EMPTY_STRING } from "./constants";
      5 import { AsnError } from "./errors";
      6 import { PkiObject, PkiObjectParameters } from "./PkiObject";
      7 import * as Schema from "./Schema";
      8 
      9 const CONTENT_TYPE = "contentType";
     10 const CONTENT_ENCRYPTION_ALGORITHM = "contentEncryptionAlgorithm";
     11 const ENCRYPTED_CONTENT = "encryptedContent";
     12 const CLEAR_PROPS = [
     13  CONTENT_TYPE,
     14  CONTENT_ENCRYPTION_ALGORITHM,
     15  ENCRYPTED_CONTENT,
     16 ];
     17 
     18 export interface IEncryptedContentInfo {
     19  contentType: string;
     20  contentEncryptionAlgorithm: AlgorithmIdentifier;
     21  encryptedContent?: asn1js.OctetString;
     22 }
     23 
     24 export interface EncryptedContentInfoJson {
     25  contentType: string;
     26  contentEncryptionAlgorithm: AlgorithmIdentifierJson;
     27  encryptedContent?: asn1js.OctetStringJson;
     28 }
     29 
     30 export interface EncryptedContentInfoSplit {
     31  /**
     32   * Disables OctetString splitting for encryptedContent.
     33   */
     34  disableSplit?: boolean;
     35 }
     36 
     37 export type EncryptedContentParameters = PkiObjectParameters & Partial<IEncryptedContentInfo> & EncryptedContentInfoSplit;
     38 
     39 export type EncryptedContentInfoSchema = Schema.SchemaParameters<{
     40  contentType?: string;
     41  contentEncryptionAlgorithm?: AlgorithmIdentifierSchema;
     42  encryptedContent?: string;
     43 }>;
     44 
     45 const PIECE_SIZE = 1024;
     46 
     47 /**
     48 * Represents the EncryptedContentInfo structure described in [RFC5652](https://datatracker.ietf.org/doc/html/rfc5652)
     49 */
     50 export class EncryptedContentInfo extends PkiObject implements IEncryptedContentInfo {
     51 
     52  public static override CLASS_NAME = "EncryptedContentInfo";
     53 
     54  public contentType!: string;
     55  public contentEncryptionAlgorithm!: AlgorithmIdentifier;
     56  public encryptedContent?: asn1js.OctetString;
     57 
     58  /**
     59   * Initializes a new instance of the {@link EncryptedContentInfo} class
     60   * @param parameters Initialization parameters
     61   */
     62  constructor(parameters: EncryptedContentParameters = {}) {
     63    super();
     64 
     65    this.contentType = pvutils.getParametersValue(parameters, CONTENT_TYPE, EncryptedContentInfo.defaultValues(CONTENT_TYPE));
     66    this.contentEncryptionAlgorithm = pvutils.getParametersValue(parameters, CONTENT_ENCRYPTION_ALGORITHM, EncryptedContentInfo.defaultValues(CONTENT_ENCRYPTION_ALGORITHM));
     67 
     68    if (ENCRYPTED_CONTENT in parameters && parameters.encryptedContent) {
     69      // encryptedContent (!!!) could be constructive or primitive value (!!!)
     70      this.encryptedContent = parameters.encryptedContent;
     71 
     72      if ((this.encryptedContent.idBlock.tagClass === 1) &&
     73        (this.encryptedContent.idBlock.tagNumber === 4)) {
     74        //#region Divide OCTET STRING value down to small pieces
     75        // NOTE: Acrobat cannot decrypt the content, if constructed OctetString is used
     76        if (this.encryptedContent.idBlock.isConstructed === false && !parameters.disableSplit) {
     77          const constrString = new asn1js.OctetString({
     78            idBlock: { isConstructed: true },
     79            isConstructed: true
     80          });
     81 
     82          let offset = 0;
     83          const valueHex = this.encryptedContent.valueBlock.valueHexView.slice().buffer;
     84          let length = valueHex.byteLength;
     85 
     86          while (length > 0) {
     87            const pieceView = new Uint8Array(valueHex, offset, ((offset + PIECE_SIZE) > valueHex.byteLength) ? (valueHex.byteLength - offset) : PIECE_SIZE);
     88            const _array = new ArrayBuffer(pieceView.length);
     89            const _view = new Uint8Array(_array);
     90 
     91            for (let i = 0; i < _view.length; i++)
     92              _view[i] = pieceView[i];
     93 
     94            constrString.valueBlock.value.push(new asn1js.OctetString({ valueHex: _array }));
     95 
     96            length -= pieceView.length;
     97            offset += pieceView.length;
     98          }
     99 
    100          this.encryptedContent = constrString;
    101        }
    102        //#endregion
    103      }
    104    }
    105 
    106    if (parameters.schema) {
    107      this.fromSchema(parameters.schema);
    108    }
    109  }
    110 
    111  /**
    112   * Returns default values for all class members
    113   * @param memberName String name for a class member
    114   * @returns Default value
    115   */
    116  public static override defaultValues(memberName: typeof CONTENT_TYPE): string;
    117  public static override defaultValues(memberName: typeof CONTENT_ENCRYPTION_ALGORITHM): AlgorithmIdentifier;
    118  public static override defaultValues(memberName: typeof ENCRYPTED_CONTENT): asn1js.OctetString;
    119  public static override defaultValues(memberName: string): any {
    120    switch (memberName) {
    121      case CONTENT_TYPE:
    122        return EMPTY_STRING;
    123      case CONTENT_ENCRYPTION_ALGORITHM:
    124        return new AlgorithmIdentifier();
    125      case ENCRYPTED_CONTENT:
    126        return new asn1js.OctetString();
    127      default:
    128        return super.defaultValues(memberName);
    129    }
    130  }
    131 
    132  /**
    133   * Compare values with default values for all class members
    134   * @param memberName String name for a class member
    135   * @param memberValue Value to compare with default value
    136   */
    137  public static compareWithDefault(memberName: string, memberValue: any): boolean {
    138    switch (memberName) {
    139      case CONTENT_TYPE:
    140        return (memberValue === EMPTY_STRING);
    141      case CONTENT_ENCRYPTION_ALGORITHM:
    142        return ((memberValue.algorithmId === EMPTY_STRING) && (("algorithmParams" in memberValue) === false));
    143      case ENCRYPTED_CONTENT:
    144        return (memberValue.isEqual(EncryptedContentInfo.defaultValues(ENCRYPTED_CONTENT)));
    145      default:
    146        return super.defaultValues(memberName);
    147    }
    148  }
    149 
    150  /**
    151   * @inheritdoc
    152   * @asn ASN.1 schema
    153   * ```asn
    154   * EncryptedContentInfo ::= SEQUENCE {
    155   *    contentType ContentType,
    156   *    contentEncryptionAlgorithm ContentEncryptionAlgorithmIdentifier,
    157   *    encryptedContent [0] IMPLICIT EncryptedContent OPTIONAL }
    158   *
    159   * Comment: Strange, but modern crypto engines create ENCRYPTED_CONTENT as "[0] EXPLICIT EncryptedContent"
    160   *
    161   * EncryptedContent ::= OCTET STRING
    162   *```
    163   */
    164  public static override schema(parameters: EncryptedContentInfoSchema = {}): Schema.SchemaType {
    165    const names = pvutils.getParametersValue<NonNullable<typeof parameters.names>>(parameters, "names", {});
    166 
    167    return (new asn1js.Sequence({
    168      name: (names.blockName || EMPTY_STRING),
    169      value: [
    170        new asn1js.ObjectIdentifier({ name: (names.contentType || EMPTY_STRING) }),
    171        AlgorithmIdentifier.schema(names.contentEncryptionAlgorithm || {}),
    172        // The CHOICE we need because ENCRYPTED_CONTENT could have either "constructive"
    173        // or "primitive" form of encoding and we need to handle both variants
    174        new asn1js.Choice({
    175          value: [
    176            new asn1js.Constructed({
    177              name: (names.encryptedContent || EMPTY_STRING),
    178              idBlock: {
    179                tagClass: 3, // CONTEXT-SPECIFIC
    180                tagNumber: 0 // [0]
    181              },
    182              value: [
    183                new asn1js.Repeated({
    184                  value: new asn1js.OctetString()
    185                })
    186              ]
    187            }),
    188            new asn1js.Primitive({
    189              name: (names.encryptedContent || EMPTY_STRING),
    190              idBlock: {
    191                tagClass: 3, // CONTEXT-SPECIFIC
    192                tagNumber: 0 // [0]
    193              }
    194            })
    195          ]
    196        })
    197      ]
    198    }));
    199  }
    200 
    201  public fromSchema(schema: Schema.SchemaType): void {
    202    // Clear input data first
    203    pvutils.clearProps(schema, CLEAR_PROPS);
    204 
    205    // Check the schema is valid
    206    const asn1 = asn1js.compareSchema(schema,
    207      schema,
    208      EncryptedContentInfo.schema({
    209        names: {
    210          contentType: CONTENT_TYPE,
    211          contentEncryptionAlgorithm: {
    212            names: {
    213              blockName: CONTENT_ENCRYPTION_ALGORITHM
    214            }
    215          },
    216          encryptedContent: ENCRYPTED_CONTENT
    217        }
    218      })
    219    );
    220    AsnError.assertSchema(asn1, this.className);
    221 
    222    // Get internal properties from parsed schema
    223    this.contentType = asn1.result.contentType.valueBlock.toString();
    224    this.contentEncryptionAlgorithm = new AlgorithmIdentifier({ schema: asn1.result.contentEncryptionAlgorithm });
    225    if (ENCRYPTED_CONTENT in asn1.result) {
    226      this.encryptedContent = asn1.result.encryptedContent as asn1js.OctetString;
    227 
    228      this.encryptedContent.idBlock.tagClass = 1; // UNIVERSAL
    229      this.encryptedContent.idBlock.tagNumber = 4; // OCTET STRING (!!!) The value still has instance of "in_window.org.pkijs.asn1.ASN1_CONSTRUCTED / ASN1_PRIMITIVE"
    230    }
    231  }
    232 
    233  public toSchema(): asn1js.Sequence {
    234    //#region Create array for output sequence
    235    const sequenceLengthBlock = {
    236      isIndefiniteForm: false
    237    };
    238 
    239    const outputArray = [];
    240 
    241    outputArray.push(new asn1js.ObjectIdentifier({ value: this.contentType }));
    242    outputArray.push(this.contentEncryptionAlgorithm.toSchema());
    243 
    244    if (this.encryptedContent) {
    245      sequenceLengthBlock.isIndefiniteForm = this.encryptedContent.idBlock.isConstructed;
    246 
    247      const encryptedValue = this.encryptedContent;
    248 
    249      encryptedValue.idBlock.tagClass = 3; // CONTEXT-SPECIFIC
    250      encryptedValue.idBlock.tagNumber = 0; // [0]
    251 
    252      encryptedValue.lenBlock.isIndefiniteForm = this.encryptedContent.idBlock.isConstructed;
    253 
    254      outputArray.push(encryptedValue);
    255    }
    256    //#endregion
    257 
    258    //#region Construct and return new ASN.1 schema for this object
    259    return (new asn1js.Sequence({
    260      lenBlock: sequenceLengthBlock,
    261      value: outputArray
    262    }));
    263    //#endregion
    264  }
    265 
    266  public toJSON(): EncryptedContentInfoJson {
    267    const res: EncryptedContentInfoJson = {
    268      contentType: this.contentType,
    269      contentEncryptionAlgorithm: this.contentEncryptionAlgorithm.toJSON()
    270    };
    271 
    272    if (this.encryptedContent) {
    273      res.encryptedContent = this.encryptedContent.toJSON();
    274    }
    275 
    276    return res;
    277  }
    278 
    279  /**
    280   * Returns concatenated buffer from `encryptedContent` field.
    281   * @returns Array buffer
    282   * @since 3.0.0
    283   * @throws Throws Error if `encryptedContent` is undefined
    284   */
    285  public getEncryptedContent(): ArrayBuffer {
    286    if (!this.encryptedContent) {
    287      throw new Error("Parameter 'encryptedContent' is undefined");
    288    }
    289    // NOTE encryptedContent can be CONSTRUCTED/PRIMITIVE
    290    return asn1js.OctetString.prototype.getValue.call(this.encryptedContent);
    291  }
    292 
    293 }