From 2e12f719e86205b77e7c7859ca90ee2862753ff9 Mon Sep 17 00:00:00 2001 From: N-Pex Date: Tue, 16 Sep 2025 12:45:50 +0200 Subject: [PATCH] Add random comment header to built-in avatar PNGs To make them unique. For issue #659. --- src/components/CreateRoom.vue | 4 +- src/components/Join.vue | 3 +- src/plugins/png.ts | 152 ++++++++++++++++++++++++++++++++++ src/plugins/utils.js | 29 ++++++- 4 files changed, 184 insertions(+), 4 deletions(-) create mode 100644 src/plugins/png.ts diff --git a/src/components/CreateRoom.vue b/src/components/CreateRoom.vue index ebbfb84..a34dd22 100644 --- a/src/components/CreateRoom.vue +++ b/src/components/CreateRoom.vue @@ -268,7 +268,8 @@ export default { this.selectedProfile.image, function (progress) { console.log("Progress: " + JSON.stringify(progress)); - } + }, + !this.selectedProfile.imageSelectedByUser ); } } @@ -377,6 +378,7 @@ export default { handlePickedUserAvatar(event) { util.loadAvatarFromFile(event, (image) => { this.selectedProfile.image = image; + this.selectedProfile.imageSelectedByUser = true; }); }, diff --git a/src/components/Join.vue b/src/components/Join.vue index 70f5016..103c245 100644 --- a/src/components/Join.vue +++ b/src/components/Join.vue @@ -412,7 +412,7 @@ export default { console.log("Join: Updating avatar"); return util.setAvatar(this.$matrix, this.selectedProfile.image, function (progress) { console.log("Progress: " + JSON.stringify(progress)); - }); + }, !this.selectedProfile.imageSelectedByUser); } }.bind(this) ) @@ -480,6 +480,7 @@ export default { handlePickedAvatar(event) { util.loadAvatarFromFile(event, (image) => { this.selectedProfile.image = image; + this.selectedProfile.imageSelectedByUser = true; }); }, }, diff --git a/src/plugins/png.ts b/src/plugins/png.ts new file mode 100644 index 0000000..e7245b0 --- /dev/null +++ b/src/plugins/png.ts @@ -0,0 +1,152 @@ +var metadata: any = {}; + +type PNGChunk = { + size: number; + type: string; + data: Uint8Array; + crc: number; +} + +metadata.PNG_SIG = new Uint8Array([0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a]); +metadata.decoder = new TextDecoder("ascii"); +metadata.encoder = new TextEncoder(); + +metadata.compare = (buf1: Uint8Array, buf2: Uint8Array) => { + if (buf1.byteLength != buf2.byteLength) return false; + var dv1 = new Int8Array(buf1); + var dv2 = new Int8Array(buf2); + for (var i = 0; i != buf1.byteLength; i++) { + if (dv1[i] != dv2[i]) return false; + } + return true; +}; + +// check PNG signature +metadata.isPNG = function (data: Uint8Array) { + return metadata.compare(data, metadata.PNG_SIG); +}; + +metadata.splitChunk = (arraybuffer: ArrayBuffer): PNGChunk[] => { + let data = new Uint8Array(arraybuffer); + + const sig = data.slice(0, 8); + if (!metadata.isPNG(sig)) return []; + + data = data.slice(8); // chomp sig + + var chunklist = []; + // read chunk list + while (data.length > 0) { + // read chunk size + var size = stoi(data.slice(0, 4)); + if (size < 0) { + // If the size is negative, the data is likely corrupt, but we'll let + // the caller decide if any of the returned chunks are usable. + // We'll move forward in the file with the minimum chunk length (12 bytes). + size = 0; + } + let buf = data.slice(0, size + 12); + data = data.slice(size + 12); // delete this chunk + // read chunk data + let chunk: PNGChunk = { + size: size, + type: metadata.decoder.decode(buf.slice(4, 8)), + data: buf.slice(8, 8 + size), + crc: stoi(buf.slice(8 + size, 8 + size + 4)) + }; + chunklist.push(chunk); + } + return chunklist; +}; + +metadata.joinChunk = function (chunklist: PNGChunk[]) { + let buffers = new Array(); + buffers.push(metadata.PNG_SIG); + chunklist.forEach((chunk) => { + buffers.push(new Uint8Array(itos(chunk.size, 4))); + buffers.push(new Uint8Array([chunk.type.charCodeAt(0), chunk.type.charCodeAt(1), chunk.type.charCodeAt(2), chunk.type.charCodeAt(3)])); + buffers.push(chunk.data); + buffers.push(new Uint8Array(itos(chunk.crc, 4))); + }); + + const cb = buffers.reduce((cb, buffer) => cb + buffer.byteLength, 0); + const res = new Uint8Array(cb); + let offset = 0; + buffers.forEach((b) => { + res.set(b, offset); + offset += b.byteLength; + }); + return res; +}; + +metadata.createChunk = (type: string, data: string): PNGChunk => { + return { + size: data.length, + type:type, + data: metadata.encoder.encode(data), + crc: crc32(type + data) + }; +}; + +metadata.itos = itos; +function itos(v: number, size: number) { + let a = []; + var t = size - 1; + while (t >= 0) { + var c = v & 0xff; + a[t--] = c; + v = v >> 8; + } + return a; +} + +metadata.stoi = stoi; +function stoi(data: Uint8Array) { + var v = 0; + for (var i = 0; i < data.length; i++) { + var c = data[i]; + v = (v << 8) | (c & 0xff); + } + return v; +} + +function crc32(str: string) { + const hexTable = [ + 0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, + 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, 0x1db71064, 0x6ab020f2, + 0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856, 0x646ba8c0, 0xfd62f97a, + 0x8a65c9ec, 0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172, + 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, + 0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, + 0xcfba9599, 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, 0x2f6f7c87, 0x58684c11, 0xc1611dab, + 0xb6662d3d, 0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433, + 0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01, 0x6b6b51f4, + 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950, + 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65, 0x4db26158, 0x3ab551ce, 0xa3bc0074, + 0xd4bb30e2, 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0, + 0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086, 0x5768b525, + 0x206f85b3, 0xb966d409, 0xce61e49f, 0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81, + 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615, + 0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, + 0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7, 0xfed41b76, + 0x89d32be0, 0x10da7a5a, 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 0xd6d6a3e8, 0xa1d1937e, + 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c, 0x36034af6, + 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, + 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, + 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f, + 0x72076785, 0x05005713, 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, + 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777, + 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, 0xa00ae278, + 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc, + 0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9, 0xbdbdf21c, 0xcabac28a, 0x53b39330, + 0x24b4a3a6, 0xbad03605, 0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94, + 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d, + ]; + var crc = 0 ^ -1; + for (var i = 0; i < str.length; i++) { + crc = (crc >>> 8) ^ hexTable[(crc ^ str.charCodeAt(i)) & 0xff]; + } + return (crc ^ -1) >>> 0; +} + +export default metadata; diff --git a/src/plugins/utils.js b/src/plugins/utils.js index a1f0b91..9089d4a 100644 --- a/src/plugins/utils.js +++ b/src/plugins/utils.js @@ -13,6 +13,7 @@ import duration from "dayjs/plugin/duration"; import i18n from "./lang"; import { toRaw, isRef, isReactive, isProxy } from "vue"; import { UploadPromise } from "../models/attachment"; +import png from "@/plugins/png.ts"; export const STATE_EVENT_ROOM_DELETION_NOTICE = "im.keanu.room_deletion_notice"; export const STATE_EVENT_ROOM_DELETED = "im.keanu.room_deleted"; @@ -831,7 +832,24 @@ class Util { return images; } - setAvatar(matrix, file, onUploadProgress) { + /** + * For one of the predefined avatars, make it system unique by adding a random PNG comment header. + */ + makeUniqueAvatar(image) { + var list = png.splitChunk(image); + + // append + var iend = list.pop(); // remove IEND + var newchunk = png.createChunk("tEXt","Comment\0Keanu avatar - " + this.randomPass()); + list.push(newchunk); + list.push(iend); + + // join + var newpng = png.joinChunk(list); + return newpng; + } + + setAvatar(matrix, file, onUploadProgress, makeUnique) { return new Promise((resolve, reject) => { axios .get(file, { responseType: "arraybuffer" }) @@ -842,9 +860,16 @@ class Util { progressHandler: onUploadProgress, onlyContentUri: false, }; + let data = response.data; + + // If making a system unique avatar, we add a random PNG header in here + if (makeUnique) { + data = this.makeUniqueAvatar(data); + } + var avatarUri; matrix.matrixClient - .uploadContent(response.data, opts) + .uploadContent(data, opts) .then((response) => { avatarUri = response.content_uri; return matrix.matrixClient.setAvatarUrl(avatarUri);