base64_decode opcode from TEALv7

CHANGELOG.md

@@ -48,6 +48,8 @@ Added:
 
 - Added support for saving smart contract template params in ASCCache.
 
+- Teal v7 support:
+  - opcode `base64decode` ([##653](https://github.com/scale-it/algo-builder/pull/653))
 
 - `algob test` now runs tests in `test` directory and all its subdirectories. Before only the files inside `test directory where run `. 
 
@@ -60,6 +62,7 @@ Added:
   console.log("txn1 information: ", receipts[2]);
 ```
 
+
 ### Template improvements
 
 - We updated the examples/DAO design. We removed treasury Smart Signature to simplify deposit management. Now a DAO app is managing voting, deposits and treasury.

packages/runtime/src/errors/errors-list.ts

@@ -126,7 +126,8 @@ by an index that does not exist.`,
 	},
 	PRAGMA_VERSION_ERROR: {
 		number: 1017,
-		message: "Pragma version Error - Expected version: %expected%, got: %got%, Line: %line%",
+		message:
+			"Pragma version Error - Expected version up to: %expected%, got: %got%, Line: %line%",
 		title: PARSE_ERROR,
 		description: ``,
 	},
@@ -398,6 +399,18 @@ maximun uint128`,
 		title: "itxn_next without itxn_begin",
 		description: `itxn_next without itxn_begin`,
 	},
+	UNKNOWN_ENCODING: {
+		number: 1058,
+		message: "Encoding e must be {URLEncoding, StdEncoding}, got :%encoding%, at line %line%",
+		title: "Unknown encoding",
+		description: "Unknown encoding",
+	},
+	INVALID_BASE64URL: {
+		number: 1059,
+		message: "Invalid Base64Url Error - value %val% is not base64Url, Line: %line%",
+		title: PARSE_ERROR,
+		description: `value %exp% is not base64Url`,
+	},
 };
 
 const runtimeGeneralErrors = {

packages/runtime/src/interpreter/interpreter.ts

@@ -536,7 +536,8 @@ export class Interpreter {
 
 		while (this.instructionIndex < this.instructions.length) {
 			const instruction = this.instructions[this.instructionIndex];
-			instruction.execute(this.stack);
+			//TODO this should return cost
+			const costFromExecute = instruction.execute(this.stack);
 
 			if (
 				this.runtime.ctx.isInnerTx &&
@@ -550,7 +551,11 @@ export class Interpreter {
 
 			// for teal version >= 4, cost is calculated dynamically at the time of execution
 			// for teal version < 4, cost is handled statically during parsing
-			this.cost += this.lineToCost[instruction.line];
+			if (costFromExecute === undefined) {
+				this.cost += this.lineToCost[instruction.line];
+			} else {
+				this.cost = costFromExecute;
+			}
 			if (this.tealVersion < 4) {
 				txReceipt.gas = this.gas;
 			}

packages/runtime/src/interpreter/opcode-list.ts

@@ -43,6 +43,8 @@ import {
 import { addInnerTransaction, calculateInnerTxCredit, setInnerTxField } from "../lib/itxn";
 import { bigintSqrt } from "../lib/math";
 import {
+	assertBase64,
+	assertBase64Url,
 	assertLen,
 	assertNumber,
 	assertOnlyDigits,
@@ -61,6 +63,7 @@ import {
 	txnSpecByField,
 } from "../lib/txn";
 import {
+	Base64Encoding,
 	DecodingMode,
 	EncodingType,
 	EncTx,
@@ -98,7 +101,7 @@ export class Pragma extends Op {
 			interpreter.tealVersion = this.version;
 		} else {
 			throw new RuntimeError(RUNTIME_ERRORS.TEAL.PRAGMA_VERSION_ERROR, {
-				expected: "till #4",
+				expected: MaxTEALVersion,
 				got: args.join(" "),
 				line: line,
 			});
@@ -4754,3 +4757,56 @@ export class Gitxnas extends Gtxnas {
 		super.execute(stack);
 	}
 }
+
+/**
+ * Takes the last value from stack and if base64encoded, decodes it acording to the
+ * encoding e and pushes it back to the stack, otherwise throws an error
+ */
+export class Base64Decode extends Op {
+	readonly line: number;
+	readonly encoding: BufferEncoding;
+
+	/**
+	 * Asserts 1 argument is passed.
+	 * @param args Expected arguments: [e], where e = {URLEncoding, StdEncoding}.
+	 * @param line line number in TEAL file
+	 */
+	constructor(args: string[], line: number) {
+		super();
+		this.line = line;
+		assertLen(args.length, 1, line);
+		const argument = args[0];
+		switch (argument) {
+			case "URLEncoding": {
+				this.encoding = "base64url";
+				break;
+			}
+			case "StdEncoding": {
+				this.encoding = "base64";
+				break;
+			}
+			default: {
+				throw new RuntimeError(RUNTIME_ERRORS.TEAL.UNKNOWN_ENCODING, {
+					encoding: argument,
+					line: this.line,
+				});
+			}
+		}
+	}
+
+	execute(stack: TEALStack): void {
+		this.assertMinStackLen(stack, 1, this.line);
+		const last = this.assertBytes(stack.pop(), this.line);
+		const enc = new TextDecoder("utf-8");
+		const decoded = enc.decode(last);
+		switch (this.encoding) {
+			case "base64url":
+				assertBase64Url(convertToString(last), this.line);
+				break;
+			case "base64":
+				assertBase64(convertToString(last), this.line);
+				break;
+		}
+		stack.push(new Uint8Array(Buffer.from(decoded.toString(), this.encoding)));
+	}
+}

packages/runtime/src/lib/constants.ts

@@ -12,7 +12,7 @@ export const MAX_CONCAT_SIZE = 4096;
 export const ALGORAND_MIN_TX_FEE = 1000;
 // https://github.com/algorand/go-algorand/blob/master/config/consensus.go#L659
 export const ALGORAND_ACCOUNT_MIN_BALANCE = 0.1e6; // 0.1 ALGO
-export const MaxTEALVersion = 6;
+export const MaxTEALVersion = 7;
 export const MinVersionSupportC2CCall = 6;
 
 // values taken from: https://developer.algorand.org/docs/features/asc1/stateful/#minimum-balance-requirement-for-a-smart-contract
@@ -152,6 +152,10 @@ TxnFields[6] = {
 	...TxnFields[5],
 };
 
+TxnFields[7] = {
+	...TxnFields[6],
+};
+
 export const ITxnFields: { [key: number]: { [key: string]: keyOfEncTx | null } } = {
 	1: {},
 	2: {},
@@ -169,6 +173,10 @@ ITxnFields[6] = {
 	...ITxnFields[5],
 };
 
+ITxnFields[7] = {
+	...ITxnFields[6],
+};
+
 // transaction fields of type array
 export const TxArrFields: { [key: number]: Set<string> } = {
 	1: new Set(),
@@ -178,6 +186,7 @@ TxArrFields[3] = new Set([...TxArrFields[2], "Assets", "Applications"]);
 TxArrFields[4] = cloneDeep(TxArrFields[3]);
 TxArrFields[5] = cloneDeep(TxArrFields[4]);
 TxArrFields[6] = cloneDeep(TxArrFields[5]);
+TxArrFields[7] = cloneDeep(TxArrFields[6]);
 
 // itxn fields of type array
 export const ITxArrFields: { [key: number]: Set<string> } = {
@@ -189,6 +198,7 @@ export const ITxArrFields: { [key: number]: Set<string> } = {
 };
 
 ITxArrFields[6] = cloneDeep(ITxArrFields[5]);
+ITxArrFields[7] = cloneDeep(ITxArrFields[6]);
 
 export const TxFieldDefaults: { [key: string]: any } = {
 	Sender: ZERO_ADDRESS,
@@ -275,6 +285,7 @@ AssetParamMap[5] = {
 };
 
 AssetParamMap[6] = { ...AssetParamMap[5] };
+AssetParamMap[7] = { ...AssetParamMap[6] };
 
 // app param use for app_params_get opcode
 export const AppParamDefined: { [key: number]: Set<string> } = {
@@ -296,6 +307,7 @@ export const AppParamDefined: { [key: number]: Set<string> } = {
 };
 
 AppParamDefined[6] = cloneDeep(AppParamDefined[5]);
+AppParamDefined[7] = cloneDeep(AppParamDefined[6]);
 
 // param use for query acct_params_get opcode
 
@@ -322,6 +334,19 @@ export const reOct = /^0[0-8]+$/;
  */
 export const reBase64 = /^([0-9a-zA-Z+/]{4})*(([0-9a-zA-Z+/]{2}==)|([0-9a-zA-Z+/]{3}=))?$/;
 
+/** is Base64Url regex
+ * ^                          # Start of input
+ * ([0-9a-zA-Z_-]{4})*        # Groups of 4 valid characters decode
+ *                            # to 24 bits of data for each group
+ * (                          # Either ending with:
+ *     ([0-9a-zA-Z_-]{2}==)   # two valid characters followed by ==
+ *     |                      # , or
+ *     ([0-9a-zA-Z_-]{3}=)    # three valid characters followed by =
+ * )?                         # , or nothing
+ * $                          # End of input
+ */
+export const reBase64Url = /^([0-9a-zA-Z_-]{4})*(([0-9a-zA-Z_-]{2}==)|([0-9a-zA-Z_-]{3}=))?$/;
+
 // A-Z and 2-7 repeated, with optional `=` at the end
 export const reBase32 = /^[A-Z2-7]+=*$/;
 
@@ -376,6 +401,10 @@ GlobalFields[6] = {
 	CallerApplicationAddress: null,
 };
 
+GlobalFields[7] = {
+	...GlobalFields[6],
+};
+
 // creating map for opcodes whose cost is other than 1
 export const OpGasCost: { [key: number]: { [key: string]: number } } = {
 	// version => opcode => cost
@@ -432,6 +461,11 @@ OpGasCost[6] = {
 	...OpGasCost[5],
 	bsqrt: 40,
 };
+OpGasCost[7] = {
+	...OpGasCost[6],
+	//TODO: calculate the cost for the base64_decode opcode
+	// https://github.com/algorand/go-algorand/blob/master/data/transactions/logic/TEAL_opcodes.md#base64_decode-e
+};
 
 export const enum MathOp {
 	// arithmetic

packages/runtime/src/lib/parsing.ts

@@ -4,7 +4,7 @@ import * as base32 from "hi-base32";
 import { RUNTIME_ERRORS } from "../errors/errors-list";
 import { RuntimeError } from "../errors/runtime-errors";
 import { EncodingType } from "../types";
-import { reBase32, reBase64, reDec, reDigit, reHex, reOct } from "./constants";
+import { reBase32, reBase64, reBase64Url, reDec, reDigit, reHex, reOct } from "./constants";
 
 /**
  * assert if string contains digits only
@@ -68,6 +68,17 @@ export function assertBase64(str: string, line: number): void {
 	}
 }
 
+/**
+ * Checks if string is base64Url
+ * @param str : string that needs to be checked
+ * @param line : line number in TEAL file
+ */
+export function assertBase64Url(str: string, line: number): void {
+	if (!reBase64Url.test(str)) {
+		throw new RuntimeError(RUNTIME_ERRORS.TEAL.INVALID_BASE64URL, { val: str, line: line });
+	}
+}
+
 /**
  * Checks if string is base32
  * @param str : string that needs to be checked

packages/runtime/src/parser/parser.ts

@@ -21,6 +21,7 @@ import {
 	Args,
 	Assert,
 	Balance,
+	Base64Decode,
 	BitLen,
 	BitwiseAnd,
 	BitwiseNot,
@@ -388,6 +389,14 @@ opCodeMap[6] = {
 	itxnas: ITxnas,
 };
 
+/**
+ * TEALv7
+ */
+opCodeMap[7] = {
+	...opCodeMap[6],
+	base64_decode: Base64Decode,
+};
+
 // list of opcodes with exactly one parameter.
 const interpreterReqList = new Set([
 	"#pragma",

packages/runtime/src/types.ts

@@ -393,3 +393,8 @@ export interface SCParams {
 export interface ReplaceParams {
 	[key: string]: string;
 }
+
+export enum Base64Encoding {
+	URL = 0,
+	STD = 1,
+}

packages/runtime/test/fixtures/teal-files/assets/teal-v7.teal

@@ -0,0 +1,2 @@
+#pragma version 7
+base64_decode URLEncoding

packages/runtime/test/fixtures/teal-files/assets/test-pragma-invalid.teal

@@ -1,2 +1,2 @@
-#pragma version 7
+#pragma version 8
 int 1

packages/runtime/test/fixtures/teal-files/assets/test-pragma-v7.teal

@@ -0,0 +1,2 @@
+#pragma version 7
+int 1

packages/runtime/test/src/interpreter/opcode-list.ts

@@ -36,6 +36,7 @@ import {
 	Args,
 	Assert,
 	Balance,
+	Base64Decode,
 	BitLen,
 	BitwiseAnd,
 	BitwiseNot,
@@ -6616,4 +6617,59 @@ describe("Teal Opcodes", function () {
 			expectRuntimeError(() => op.execute(stack), RUNTIME_ERRORS.TEAL.ASSERT_STACK_LENGTH);
 		});
 	});
+
+	describe("Tealv7: base64Decode opcode", function () {
+		let stack: Stack<StackElem>;
+		const encoded64BaseStd = "YWJjMTIzIT8kKiYoKSctPUB+";
+		const encoded64BaseUrl = "YWJjMTIzIT8kKiYoKSctPUB-";
+		const decoded64Base = "abc123!?$*&()'-=@~";
+		const toPushStd = Buffer.from(encoded64BaseStd, "utf-8");
+		const toPushUrl = Buffer.from(encoded64BaseUrl, "utf-8");
+		const expectedBytes = new Uint8Array(Buffer.from(decoded64Base, "utf-8"));
+
+		this.beforeEach(() => {
+			stack = new Stack<StackElem>();
+		});
+
+		it("Should decode base64 encoded data and push it to stack", () => {
+			stack.push(toPushUrl);
+			const opUrl = new Base64Decode(["URLEncoding"], 0);
+			opUrl.execute(stack);
+			assert.deepEqual(expectedBytes, stack.pop());
+			stack.push(toPushStd);
+			const opStd = new Base64Decode(["StdEncoding"], 0);
+			opStd.execute(stack);
+			assert.deepEqual(expectedBytes, stack.pop());
+		});
+
+		it("Should throw an error when last stack element is not base64 encoded", () => {
+			stack.push(new Uint8Array(Buffer.from(encoded64BaseUrl, "utf-8")));
+			const op = new Base64Decode(["StdEncoding"], 0);
+			expectRuntimeError(() => op.execute(stack), RUNTIME_ERRORS.TEAL.INVALID_BASE64);
+		});
+
+		it("Should throw an error when last stack element is not base64Url encoded", () => {
+			stack.push(new Uint8Array(Buffer.from(encoded64BaseStd, "utf-8")));
+			const op = new Base64Decode(["URLEncoding"], 0);
+			expectRuntimeError(() => op.execute(stack), RUNTIME_ERRORS.TEAL.INVALID_BASE64URL);
+		});
+
+		it("Should throw an error when the stack is empty", () => {
+			const op = new Base64Decode(["StdEncoding"], 0);
+			expectRuntimeError(() => op.execute(stack), RUNTIME_ERRORS.TEAL.ASSERT_STACK_LENGTH);
+		});
+
+		it("Should throw an error when argument not in bound", () => {
+			stack.push(toPushStd);
+			expectRuntimeError(
+				() => new Base64Decode(["3"], 0),
+				RUNTIME_ERRORS.TEAL.UNKNOWN_ENCODING
+			);
+		});
+
+		it("Should throw an error when argument not provided", () => {
+			stack.push(toPushStd);
+			expectRuntimeError(() => new Base64Decode([], 0), RUNTIME_ERRORS.TEAL.ASSERT_LENGTH);
+		});
+	});
 });