From 007cc0b97b265f140bec8773ce5692d297a42f0a Mon Sep 17 00:00:00 2001
From: Juan Cruz Viotti <jv@jviotti.com>
Date: Tue, 28 Oct 2025 17:02:04 -0400
Subject: [PATCH] Define IETF RFC 4648 schemas

Signed-off-by: Juan Cruz Viotti <jv@jviotti.com>
---
 README.markdown                        |   1 +
 schemas/ietf/encoding/base16.json      |  20 +
 schemas/ietf/encoding/base32.json      |  18 +
 schemas/ietf/encoding/base32hex.json   |  18 +
 schemas/ietf/encoding/base64.json      |  18 +
 schemas/ietf/encoding/base64url.json   |  18 +
 test/ietf/encoding/base16.test.json    | 501 +++++++++++++++++++++++
 test/ietf/encoding/base32.test.json    | 491 ++++++++++++++++++++++
 test/ietf/encoding/base32hex.test.json | 511 +++++++++++++++++++++++
 test/ietf/encoding/base64.test.json    | 526 ++++++++++++++++++++++++
 test/ietf/encoding/base64url.test.json | 541 +++++++++++++++++++++++++
 11 files changed, 2663 insertions(+)
 create mode 100644 schemas/ietf/encoding/base16.json
 create mode 100644 schemas/ietf/encoding/base32.json
 create mode 100644 schemas/ietf/encoding/base32hex.json
 create mode 100644 schemas/ietf/encoding/base64.json
 create mode 100644 schemas/ietf/encoding/base64url.json
 create mode 100644 test/ietf/encoding/base16.test.json
 create mode 100644 test/ietf/encoding/base32.test.json
 create mode 100644 test/ietf/encoding/base32hex.test.json
 create mode 100644 test/ietf/encoding/base64.test.json
 create mode 100644 test/ietf/encoding/base64url.test.json

diff --git a/README.markdown b/README.markdown
index 01e97c5..324024f 100644
--- a/README.markdown
+++ b/README.markdown
@@ -53,6 +53,7 @@ expressed as JSON Schema definitions.
 | IEEE | [IEEE Std 754-2019](https://ieeexplore.ieee.org/document/8766229) | IEEE Standard for Floating-Point Arithmetic |
 | IEEE | [IEEE Std 1003.1-2017](https://pubs.opengroup.org/onlinepubs/9699919799/) | IEEE Standard for Information Technology—Portable Operating System Interface (POSIX) Base Specifications, Issue 7 |
 | IETF | [RFC 3986](https://www.rfc-editor.org/rfc/rfc3986) | Uniform Resource Identifier (URI): Generic Syntax |
+| IETF | [RFC 4648](https://www.rfc-editor.org/rfc/rfc4648) | The Base16, Base32, and Base64 Data Encodings |
 | IETF | [RFC 4918](https://www.rfc-editor.org/rfc/rfc4918) | HTTP Extensions for Web Distributed Authoring and Versioning (WebDAV) |
 | IETF | [RFC 5322](https://www.rfc-editor.org/rfc/rfc5322) | Internet Message Format |
 | IETF | [RFC 5646](https://www.rfc-editor.org/rfc/rfc5646) | Tags for Identifying Languages (BCP 47) |
diff --git a/schemas/ietf/encoding/base16.json b/schemas/ietf/encoding/base16.json
new file mode 100644
index 0000000..0b78118
--- /dev/null
+++ b/schemas/ietf/encoding/base16.json
@@ -0,0 +1,20 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "title": "RFC 4648 Base16 Encoding",
+  "description": "Uses digits 0-9 and letters A-F (case-insensitive). Each byte encodes to exactly 2 characters, no padding required",
+  "examples": [
+    "48656C6C6F20576F726C6421",
+    "DEADBEEF",
+    "0FB7",
+    "666F6F626172",
+    ""
+  ],
+  "x-license": "https://github.com/sourcemeta/std/blob/main/LICENSE",
+  "x-links": [ "https://www.rfc-editor.org/rfc/rfc4648.html#section-8" ],
+  "type": "string",
+  "not": {
+    "pattern": "[\\x00-\\x1F]"
+  },
+  "pattern": "^([0-9A-Fa-f]{2})*$",
+  "contentEncoding": "base16"
+}
diff --git a/schemas/ietf/encoding/base32.json b/schemas/ietf/encoding/base32.json
new file mode 100644
index 0000000..bebf88f
--- /dev/null
+++ b/schemas/ietf/encoding/base32.json
@@ -0,0 +1,18 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "title": "RFC 4648 Base32 Encoding",
+  "description": "Uses uppercase letters A-Z and digits 2-7 (32 characters total). Padding with = to multiple of 8 characters",
+  "examples": [
+    "JBSWY3DPEBLW64TMMQ======",
+    "MFRGG===",
+    "MZXW6===",
+    "MZXW6YQ=",
+    "MZXW6YTB",
+    ""
+  ],
+  "x-license": "https://github.com/sourcemeta/std/blob/main/LICENSE",
+  "x-links": [ "https://www.rfc-editor.org/rfc/rfc4648.html#section-6" ],
+  "type": "string",
+  "pattern": "^([A-Z2-7]{8})*([A-Z2-7]{2}={6}|[A-Z2-7]{4}={4}|[A-Z2-7]{5}={3}|[A-Z2-7]{7}=)?$",
+  "contentEncoding": "base32"
+}
diff --git a/schemas/ietf/encoding/base32hex.json b/schemas/ietf/encoding/base32hex.json
new file mode 100644
index 0000000..85c996c
--- /dev/null
+++ b/schemas/ietf/encoding/base32hex.json
@@ -0,0 +1,18 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "title": "RFC 4648 Base32hex Encoding",
+  "description": "Uses digits 0-9 and uppercase letters A-V (32 characters total). Padding with = to multiple of 8 characters",
+  "examples": [
+    "91IMOR3F41BMUSJCCG======",
+    "C5H66===",
+    "CPNMU===",
+    "CPNMUO8=",
+    "CPNMUOJ1",
+    ""
+  ],
+  "x-license": "https://github.com/sourcemeta/std/blob/main/LICENSE",
+  "x-links": [ "https://www.rfc-editor.org/rfc/rfc4648.html#section-7" ],
+  "type": "string",
+  "pattern": "^([0-9A-V]{8})*([0-9A-V]{2}={6}|[0-9A-V]{4}={4}|[0-9A-V]{5}={3}|[0-9A-V]{7}=)?$",
+  "contentEncoding": "base32hex"
+}
diff --git a/schemas/ietf/encoding/base64.json b/schemas/ietf/encoding/base64.json
new file mode 100644
index 0000000..e988363
--- /dev/null
+++ b/schemas/ietf/encoding/base64.json
@@ -0,0 +1,18 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "title": "RFC 4648 Base64 Encoding",
+  "description": "Uses uppercase letters A-Z, lowercase letters a-z, digits 0-9, plus sign (+), and forward slash (/), with equals sign (=) used for padding",
+  "examples": [
+    "R0lGODlhAQABAAAAACw=",
+    "SGVsbG8gV29ybGQh",
+    "YQ==",
+    "YWI=",
+    "YWJj",
+    ""
+  ],
+  "x-license": "https://github.com/sourcemeta/std/blob/main/LICENSE",
+  "x-links": [ "https://www.rfc-editor.org/rfc/rfc4648.html#section-4" ],
+  "type": "string",
+  "pattern": "^([A-Za-z0-9+/]{4})*([A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=)?$",
+  "contentEncoding": "base64"
+}
diff --git a/schemas/ietf/encoding/base64url.json b/schemas/ietf/encoding/base64url.json
new file mode 100644
index 0000000..3d1ca14
--- /dev/null
+++ b/schemas/ietf/encoding/base64url.json
@@ -0,0 +1,18 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "title": "RFC 4648 Base64url Encoding",
+  "description": "Base64 encoding with URL and filename safe alphabet as defined in RFC 4648 section 5. Uses hyphen (-) and underscore (_) instead of plus (+) and slash (/)",
+  "examples": [
+    "R0lGODlhAQABAAAAACw=",
+    "SGVsbG8gV29ybGQh",
+    "YQ==",
+    "YWI=",
+    "YWJj",
+    ""
+  ],
+  "x-license": "https://github.com/sourcemeta/std/blob/main/LICENSE",
+  "x-links": [ "https://www.rfc-editor.org/rfc/rfc4648.html#section-5" ],
+  "type": "string",
+  "pattern": "^([A-Za-z0-9_-]{4})*([A-Za-z0-9_-]{2}==|[A-Za-z0-9_-]{3}=)?$",
+  "contentEncoding": "base64url"
+}
diff --git a/test/ietf/encoding/base16.test.json b/test/ietf/encoding/base16.test.json
new file mode 100644
index 0000000..eb43979
--- /dev/null
+++ b/test/ietf/encoding/base16.test.json
@@ -0,0 +1,501 @@
+{
+  "x-license": "https://github.com/sourcemeta/std/blob/main/LICENSE",
+  "target": "../../../schemas/ietf/encoding/base16.json",
+  "tests": [
+    {
+      "description": "Valid - empty string",
+      "data": "",
+      "valid": true
+    },
+    {
+      "description": "Valid - single byte uppercase",
+      "data": "0F",
+      "valid": true
+    },
+    {
+      "description": "Valid - single byte lowercase",
+      "data": "0f",
+      "valid": true
+    },
+    {
+      "description": "Valid - single byte mixed case",
+      "data": "0F",
+      "valid": true
+    },
+    {
+      "description": "Valid - 'Hello World!' in hex",
+      "data": "48656C6C6F20576F726C6421",
+      "valid": true
+    },
+    {
+      "description": "Valid - 'foo' in hex",
+      "data": "666F6F",
+      "valid": true
+    },
+    {
+      "description": "Valid - all uppercase",
+      "data": "DEADBEEF",
+      "valid": true
+    },
+    {
+      "description": "Valid - all lowercase",
+      "data": "deadbeef",
+      "valid": true
+    },
+    {
+      "description": "Valid - mixed case",
+      "data": "DeAdBeEf",
+      "valid": true
+    },
+    {
+      "description": "Valid - all zeros",
+      "data": "0000",
+      "valid": true
+    },
+    {
+      "description": "Valid - all F's uppercase",
+      "data": "FFFF",
+      "valid": true
+    },
+    {
+      "description": "Valid - all f's lowercase",
+      "data": "ffff",
+      "valid": true
+    },
+    {
+      "description": "Valid - only digits 0-9",
+      "data": "0123456789",
+      "valid": true
+    },
+    {
+      "description": "Valid - only letters A-F uppercase",
+      "data": "ABCDEF",
+      "valid": true
+    },
+    {
+      "description": "Valid - only letters a-f lowercase",
+      "data": "abcdef",
+      "valid": true
+    },
+    {
+      "description": "Valid - two bytes",
+      "data": "0FB7",
+      "valid": true
+    },
+    {
+      "description": "Valid - four bytes",
+      "data": "DEADBEEF",
+      "valid": true
+    },
+    {
+      "description": "Valid - eight bytes",
+      "data": "0123456789ABCDEF",
+      "valid": true
+    },
+    {
+      "description": "Valid - sixteen bytes",
+      "data": "0123456789ABCDEF0123456789ABCDEF",
+      "valid": true
+    },
+    {
+      "description": "Valid - long hex string",
+      "data": "48656C6C6F20576F726C64212048657265206973206120766572792076657279206C6F6E672068657820737472696E67",
+      "valid": true
+    },
+    {
+      "description": "Invalid - single character (odd length)",
+      "data": "0",
+      "valid": false
+    },
+    {
+      "description": "Invalid - three characters (odd length)",
+      "data": "ABC",
+      "valid": false
+    },
+    {
+      "description": "Invalid - five characters (odd length)",
+      "data": "ABCDE",
+      "valid": false
+    },
+    {
+      "description": "Invalid - seven characters (odd length)",
+      "data": "ABCDEFG",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains G",
+      "data": "0G",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains H",
+      "data": "0H",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains Z",
+      "data": "0Z",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains g",
+      "data": "0g",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains h",
+      "data": "0h",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains z",
+      "data": "0z",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains space",
+      "data": "DE AD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains hyphen",
+      "data": "DE-AD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains underscore",
+      "data": "DE_AD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains plus",
+      "data": "DE+AD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains slash",
+      "data": "DE/AD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains period",
+      "data": "DE.AD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains comma",
+      "data": "DE,AD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains colon",
+      "data": "DE:AD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains semicolon",
+      "data": "DE;AD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains (",
+      "data": "DE(AD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains )",
+      "data": "DE)AD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains [",
+      "data": "DE[AD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains ]",
+      "data": "DE]AD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains {",
+      "data": "DE{AD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains }",
+      "data": "DE}AD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains !",
+      "data": "DE!AD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains ?",
+      "data": "DE?AD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains @",
+      "data": "DE@AD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains #",
+      "data": "DE#AD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains $",
+      "data": "DE$AD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains %",
+      "data": "DE%AD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains ^",
+      "data": "DE^AD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains &",
+      "data": "DE&AD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains *",
+      "data": "DE*AD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains ~",
+      "data": "DE~AD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains `",
+      "data": "DE`AD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains |",
+      "data": "DE|AD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains \\",
+      "data": "DE\\AD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains '",
+      "data": "DE'AD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains \"",
+      "data": "DE\"AD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains <",
+      "data": "DE<AD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains >",
+      "data": "DE>AD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - leading space",
+      "data": " DEAD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - trailing space",
+      "data": "DEAD ",
+      "valid": false
+    },
+    {
+      "description": "Invalid - leading tab",
+      "data": "\tDEAD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - trailing tab",
+      "data": "DEAD\t",
+      "valid": false
+    },
+    {
+      "description": "Invalid - tab in middle",
+      "data": "DE\tAD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains newline",
+      "data": "DE\nAD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains carriage return",
+      "data": "DE\rAD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - non-ASCII character",
+      "data": "DEéAD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - emoji",
+      "data": "DE😀AD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - number type",
+      "data": 123,
+      "valid": false
+    },
+    {
+      "description": "Invalid - boolean type",
+      "data": true,
+      "valid": false
+    },
+    {
+      "description": "Invalid - null type",
+      "data": null,
+      "valid": false
+    },
+    {
+      "description": "Valid - digit 0",
+      "data": "00",
+      "valid": true
+    },
+    {
+      "description": "Valid - digit 1",
+      "data": "11",
+      "valid": true
+    },
+    {
+      "description": "Valid - digit 2",
+      "data": "22",
+      "valid": true
+    },
+    {
+      "description": "Valid - digit 3",
+      "data": "33",
+      "valid": true
+    },
+    {
+      "description": "Valid - digit 4",
+      "data": "44",
+      "valid": true
+    },
+    {
+      "description": "Valid - digit 5",
+      "data": "55",
+      "valid": true
+    },
+    {
+      "description": "Valid - digit 6",
+      "data": "66",
+      "valid": true
+    },
+    {
+      "description": "Valid - digit 7",
+      "data": "77",
+      "valid": true
+    },
+    {
+      "description": "Valid - digit 8",
+      "data": "88",
+      "valid": true
+    },
+    {
+      "description": "Valid - digit 9",
+      "data": "99",
+      "valid": true
+    },
+    {
+      "description": "Valid - letter A uppercase",
+      "data": "AA",
+      "valid": true
+    },
+    {
+      "description": "Valid - letter B uppercase",
+      "data": "BB",
+      "valid": true
+    },
+    {
+      "description": "Valid - letter C uppercase",
+      "data": "CC",
+      "valid": true
+    },
+    {
+      "description": "Valid - letter D uppercase",
+      "data": "DD",
+      "valid": true
+    },
+    {
+      "description": "Valid - letter E uppercase",
+      "data": "EE",
+      "valid": true
+    },
+    {
+      "description": "Valid - letter F uppercase",
+      "data": "FF",
+      "valid": true
+    },
+    {
+      "description": "Valid - letter a lowercase",
+      "data": "aa",
+      "valid": true
+    },
+    {
+      "description": "Valid - letter b lowercase",
+      "data": "bb",
+      "valid": true
+    },
+    {
+      "description": "Valid - letter c lowercase",
+      "data": "cc",
+      "valid": true
+    },
+    {
+      "description": "Valid - letter d lowercase",
+      "data": "dd",
+      "valid": true
+    },
+    {
+      "description": "Valid - letter e lowercase",
+      "data": "ee",
+      "valid": true
+    },
+    {
+      "description": "Valid - letter f lowercase",
+      "data": "ff",
+      "valid": true
+    },
+    {
+      "description": "Valid - repeating pattern",
+      "data": "0F0F0F0F",
+      "valid": true
+    },
+    {
+      "description": "Valid - alternating case",
+      "data": "AaBbCcDd",
+      "valid": true
+    },
+    {
+      "description": "Valid - all digits and letters mixed",
+      "data": "0123456789ABCDEFabcdef",
+      "valid": true
+    }
+  ]
+}
diff --git a/test/ietf/encoding/base32.test.json b/test/ietf/encoding/base32.test.json
new file mode 100644
index 0000000..eeed8b7
--- /dev/null
+++ b/test/ietf/encoding/base32.test.json
@@ -0,0 +1,491 @@
+{
+  "x-license": "https://github.com/sourcemeta/std/blob/main/LICENSE",
+  "target": "../../../schemas/ietf/encoding/base32.json",
+  "tests": [
+    {
+      "description": "Valid - empty string",
+      "data": "",
+      "valid": true
+    },
+    {
+      "description": "Valid - single byte (2 chars + 6 padding)",
+      "data": "ME======",
+      "valid": true
+    },
+    {
+      "description": "Valid - two bytes (4 chars + 4 padding)",
+      "data": "MZXQ====",
+      "valid": true
+    },
+    {
+      "description": "Valid - three bytes (5 chars + 3 padding)",
+      "data": "MZXW6===",
+      "valid": true
+    },
+    {
+      "description": "Valid - four bytes (7 chars + 1 padding)",
+      "data": "MZXW6YQ=",
+      "valid": true
+    },
+    {
+      "description": "Valid - five bytes (8 chars, no padding)",
+      "data": "MZXW6YTB",
+      "valid": true
+    },
+    {
+      "description": "Valid - 'Hello World!'",
+      "data": "JBSWY3DPEBLW64TMMQ======",
+      "valid": true
+    },
+    {
+      "description": "Valid - 'foo'",
+      "data": "MZXW6===",
+      "valid": true
+    },
+    {
+      "description": "Valid - 'foobar'",
+      "data": "MZXW6YTBOI======",
+      "valid": true
+    },
+    {
+      "description": "Valid - all A's",
+      "data": "AAAAAAAA",
+      "valid": true
+    },
+    {
+      "description": "Valid - all 7's",
+      "data": "77777777",
+      "valid": true
+    },
+    {
+      "description": "Valid - mixed alphabet",
+      "data": "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567",
+      "valid": true
+    },
+    {
+      "description": "Valid - only letters A-Z",
+      "data": "ABCDEFGHIJKLMNOP",
+      "valid": true
+    },
+    {
+      "description": "Valid - only digits 2-7",
+      "data": "23456723",
+      "valid": true
+    },
+    {
+      "description": "Valid - 16 chars no padding",
+      "data": "ABCDEFGHIJKLMNOP",
+      "valid": true
+    },
+    {
+      "description": "Valid - 24 chars no padding",
+      "data": "ABCDEFGHIJKLMNOPQRSTUVWX",
+      "valid": true
+    },
+    {
+      "description": "Valid - long string with padding",
+      "data": "JBSWY3DPEBLW64TMMQQQ====",
+      "valid": true
+    },
+    {
+      "description": "Invalid - single char without padding",
+      "data": "M",
+      "valid": false
+    },
+    {
+      "description": "Invalid - two chars without padding",
+      "data": "ME",
+      "valid": false
+    },
+    {
+      "description": "Invalid - three chars without padding",
+      "data": "MEZ",
+      "valid": false
+    },
+    {
+      "description": "Invalid - four chars without padding",
+      "data": "MZXQ",
+      "valid": false
+    },
+    {
+      "description": "Invalid - five chars without padding",
+      "data": "MZXW6",
+      "valid": false
+    },
+    {
+      "description": "Invalid - six chars without padding",
+      "data": "MZXW6Y",
+      "valid": false
+    },
+    {
+      "description": "Invalid - seven chars without padding",
+      "data": "MZXW6YQ",
+      "valid": false
+    },
+    {
+      "description": "Invalid - nine chars without padding",
+      "data": "MZXW6YTBO",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains 0 (not in base32 alphabet)",
+      "data": "M0======",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains 1 (not in base32 alphabet)",
+      "data": "M1======",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains 8 (not in base32 alphabet)",
+      "data": "M8======",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains 9 (not in base32 alphabet)",
+      "data": "M9======",
+      "valid": false
+    },
+    {
+      "description": "Invalid - lowercase letters",
+      "data": "mzxw6===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - mixed case",
+      "data": "MzXw6===",
+      "valid": false
+    },
+    {
+      "description": "Valid - 7 chars + 1 padding (non-canonical but syntactically valid)",
+      "data": "MZXW6YT=",
+      "valid": true
+    },
+    {
+      "description": "Invalid - wrong padding count (2 equals)",
+      "data": "MZXW6Y==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - wrong padding count (5 equals)",
+      "data": "MZX=====",
+      "valid": false
+    },
+    {
+      "description": "Invalid - wrong padding count (7 equals)",
+      "data": "M=======",
+      "valid": false
+    },
+    {
+      "description": "Invalid - too much padding (8 equals)",
+      "data": "========",
+      "valid": false
+    },
+    {
+      "description": "Invalid - padding in middle",
+      "data": "ME======MZXW6===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - padding not at end",
+      "data": "M=ZXQAAA",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains space",
+      "data": "MZXW 6===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains hyphen",
+      "data": "MZXW-6===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains underscore",
+      "data": "MZXW_6===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains plus",
+      "data": "MZXW+6===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains slash",
+      "data": "MZXW/6===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains period",
+      "data": "MZXW.6===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains comma",
+      "data": "MZXW,6===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains (",
+      "data": "MZXW(===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains )",
+      "data": "MZXW)===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains [",
+      "data": "MZXW[===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains ]",
+      "data": "MZXW]===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains {",
+      "data": "MZXW{===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains }",
+      "data": "MZXW}===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains !",
+      "data": "MZXW!===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains ?",
+      "data": "MZXW?===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains @",
+      "data": "MZXW@===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains #",
+      "data": "MZXW#===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains $",
+      "data": "MZXW$===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains %",
+      "data": "MZXW%===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains ^",
+      "data": "MZXW^===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains &",
+      "data": "MZXW&===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains *",
+      "data": "MZXW*===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains ~",
+      "data": "MZXW~===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains `",
+      "data": "MZXW`===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains |",
+      "data": "MZXW|===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains \\",
+      "data": "MZXW\\===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains :",
+      "data": "MZXW:===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains ;",
+      "data": "MZXW;===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains '",
+      "data": "MZXW'===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains \"",
+      "data": "MZXW\"===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains <",
+      "data": "MZXW<===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains >",
+      "data": "MZXW>===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - leading space",
+      "data": " MZXW6===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - trailing space",
+      "data": "MZXW6=== ",
+      "valid": false
+    },
+    {
+      "description": "Invalid - leading tab",
+      "data": "\tMZXW6===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - trailing tab",
+      "data": "MZXW6===\t",
+      "valid": false
+    },
+    {
+      "description": "Invalid - tab in middle",
+      "data": "MZXW\t6===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains newline",
+      "data": "MZXW\n6===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains carriage return",
+      "data": "MZXW\r6===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - non-ASCII character",
+      "data": "MZXWé===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - emoji",
+      "data": "MZXW😀===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - number type",
+      "data": 123,
+      "valid": false
+    },
+    {
+      "description": "Invalid - boolean type",
+      "data": true,
+      "valid": false
+    },
+    {
+      "description": "Invalid - null type",
+      "data": null,
+      "valid": false
+    },
+    {
+      "description": "Invalid - padding at beginning",
+      "data": "======ME",
+      "valid": false
+    },
+    {
+      "description": "Invalid - only padding",
+      "data": "========",
+      "valid": false
+    },
+    {
+      "description": "Invalid - mixed padding",
+      "data": "M=Z=W===",
+      "valid": false
+    },
+    {
+      "description": "Valid - all alphabet chars at start",
+      "data": "ABCDEFGH",
+      "valid": true
+    },
+    {
+      "description": "Valid - all alphabet chars at end",
+      "data": "STUVWXYZ",
+      "valid": true
+    },
+    {
+      "description": "Valid - digit 2",
+      "data": "2AAAAAAA",
+      "valid": true
+    },
+    {
+      "description": "Valid - digit 3",
+      "data": "3AAAAAAA",
+      "valid": true
+    },
+    {
+      "description": "Valid - digit 4",
+      "data": "4AAAAAAA",
+      "valid": true
+    },
+    {
+      "description": "Valid - digit 5",
+      "data": "5AAAAAAA",
+      "valid": true
+    },
+    {
+      "description": "Valid - digit 6",
+      "data": "6AAAAAAA",
+      "valid": true
+    },
+    {
+      "description": "Valid - digit 7",
+      "data": "7AAAAAAA",
+      "valid": true
+    },
+    {
+      "description": "Valid - repeating pattern",
+      "data": "ABABABABABABABAB",
+      "valid": true
+    },
+    {
+      "description": "Valid - very long valid base32",
+      "data": "JBSWY3DPFQQFO33SNRSCC===",
+      "valid": true
+    },
+    {
+      "description": "Invalid - 3 chars with 4 padding (should be 6 padding for 2 chars)",
+      "data": "MEZ====",
+      "valid": false
+    },
+    {
+      "description": "Invalid - 6 chars with 3 padding (no valid padding for 6 chars)",
+      "data": "MZXW6Y===",
+      "valid": false
+    }
+  ]
+}
diff --git a/test/ietf/encoding/base32hex.test.json b/test/ietf/encoding/base32hex.test.json
new file mode 100644
index 0000000..e539397
--- /dev/null
+++ b/test/ietf/encoding/base32hex.test.json
@@ -0,0 +1,511 @@
+{
+  "x-license": "https://github.com/sourcemeta/std/blob/main/LICENSE",
+  "target": "../../../schemas/ietf/encoding/base32hex.json",
+  "tests": [
+    {
+      "description": "Valid - empty string",
+      "data": "",
+      "valid": true
+    },
+    {
+      "description": "Valid - single byte (2 chars + 6 padding)",
+      "data": "C4======",
+      "valid": true
+    },
+    {
+      "description": "Valid - two bytes (4 chars + 4 padding)",
+      "data": "CPNG====",
+      "valid": true
+    },
+    {
+      "description": "Valid - three bytes (5 chars + 3 padding)",
+      "data": "CPNMU===",
+      "valid": true
+    },
+    {
+      "description": "Valid - four bytes (7 chars + 1 padding)",
+      "data": "CPNMUO8=",
+      "valid": true
+    },
+    {
+      "description": "Valid - five bytes (8 chars, no padding)",
+      "data": "CPNMUOJ1",
+      "valid": true
+    },
+    {
+      "description": "Valid - 'Hello World!'",
+      "data": "91IMOR3F41BMUSJCCG======",
+      "valid": true
+    },
+    {
+      "description": "Valid - 'foo'",
+      "data": "CPNMU===",
+      "valid": true
+    },
+    {
+      "description": "Valid - 'foobar'",
+      "data": "CPNMUOJ1E8======",
+      "valid": true
+    },
+    {
+      "description": "Valid - all 0's",
+      "data": "00000000",
+      "valid": true
+    },
+    {
+      "description": "Valid - all V's",
+      "data": "VVVVVVVV",
+      "valid": true
+    },
+    {
+      "description": "Valid - mixed alphabet",
+      "data": "0123456789ABCDEFGHIJKLMNOPQRSTUV",
+      "valid": true
+    },
+    {
+      "description": "Valid - only digits 0-9",
+      "data": "01234567",
+      "valid": true
+    },
+    {
+      "description": "Valid - only letters A-V",
+      "data": "ABCDEFGHIJKLMNOP",
+      "valid": true
+    },
+    {
+      "description": "Valid - 16 chars no padding",
+      "data": "0123456789ABCDEF",
+      "valid": true
+    },
+    {
+      "description": "Valid - 24 chars no padding",
+      "data": "0123456789ABCDEFGHIJKLMN",
+      "valid": true
+    },
+    {
+      "description": "Valid - long string with padding",
+      "data": "91IMOR3F41BMUSJCCGGG====",
+      "valid": true
+    },
+    {
+      "description": "Invalid - single char without padding",
+      "data": "C",
+      "valid": false
+    },
+    {
+      "description": "Invalid - two chars without padding",
+      "data": "C4",
+      "valid": false
+    },
+    {
+      "description": "Invalid - three chars without padding",
+      "data": "C4P",
+      "valid": false
+    },
+    {
+      "description": "Invalid - four chars without padding",
+      "data": "CPNG",
+      "valid": false
+    },
+    {
+      "description": "Invalid - five chars without padding",
+      "data": "CPNMU",
+      "valid": false
+    },
+    {
+      "description": "Invalid - six chars without padding",
+      "data": "CPNMUO",
+      "valid": false
+    },
+    {
+      "description": "Invalid - seven chars without padding",
+      "data": "CPNMUO8",
+      "valid": false
+    },
+    {
+      "description": "Invalid - nine chars without padding",
+      "data": "CPNMUOJ1E",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains W (not in base32hex alphabet)",
+      "data": "CPNMUW==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains X (not in base32hex alphabet)",
+      "data": "CPNMUX==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains Y (not in base32hex alphabet)",
+      "data": "CPNMUY==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains Z (not in base32hex alphabet)",
+      "data": "CPNMUZ==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - lowercase letters",
+      "data": "cpnmu===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - mixed case",
+      "data": "CpNmU===",
+      "valid": false
+    },
+    {
+      "description": "Valid - 7 chars + 1 padding (non-canonical but syntactically valid)",
+      "data": "CPNMUOJ=",
+      "valid": true
+    },
+    {
+      "description": "Invalid - wrong padding count (2 equals)",
+      "data": "CPNMUO==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - wrong padding count (5 equals)",
+      "data": "CPN=====",
+      "valid": false
+    },
+    {
+      "description": "Invalid - wrong padding count (7 equals)",
+      "data": "C=======",
+      "valid": false
+    },
+    {
+      "description": "Invalid - too much padding (8 equals)",
+      "data": "========",
+      "valid": false
+    },
+    {
+      "description": "Invalid - padding in middle",
+      "data": "C4======CPNMU===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - padding not at end",
+      "data": "C=PNG000",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains space",
+      "data": "CPNMU ===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains hyphen",
+      "data": "CPNMU-===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains underscore",
+      "data": "CPNMU_===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains plus",
+      "data": "CPNMU+===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains slash",
+      "data": "CPNMU/===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains period",
+      "data": "CPNMU.===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains comma",
+      "data": "CPNMU,===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains (",
+      "data": "CPNMU(==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains )",
+      "data": "CPNMU)==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains [",
+      "data": "CPNMU[==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains ]",
+      "data": "CPNMU]==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains {",
+      "data": "CPNMU{==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains }",
+      "data": "CPNMU}==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains !",
+      "data": "CPNMU!==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains ?",
+      "data": "CPNMU?==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains @",
+      "data": "CPNMU@==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains #",
+      "data": "CPNMU#==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains $",
+      "data": "CPNMU$==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains %",
+      "data": "CPNMU%==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains ^",
+      "data": "CPNMU^==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains &",
+      "data": "CPNMU&==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains *",
+      "data": "CPNMU*==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains ~",
+      "data": "CPNMU~==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains `",
+      "data": "CPNMU`==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains |",
+      "data": "CPNMU|==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains \\",
+      "data": "CPNMU\\==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains :",
+      "data": "CPNMU:==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains ;",
+      "data": "CPNMU;==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains '",
+      "data": "CPNMU'==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains \"",
+      "data": "CPNMU\"==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains <",
+      "data": "CPNMU<==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains >",
+      "data": "CPNMU>==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - leading space",
+      "data": " CPNMU===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - trailing space",
+      "data": "CPNMU=== ",
+      "valid": false
+    },
+    {
+      "description": "Invalid - leading tab",
+      "data": "\tCPNMU===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - trailing tab",
+      "data": "CPNMU===\t",
+      "valid": false
+    },
+    {
+      "description": "Invalid - tab in middle",
+      "data": "CPN\tMU===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains newline",
+      "data": "CPN\nMU===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains carriage return",
+      "data": "CPN\rMU===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - non-ASCII character",
+      "data": "CPNMUé==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - emoji",
+      "data": "CPNMU😀==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - number type",
+      "data": 123,
+      "valid": false
+    },
+    {
+      "description": "Invalid - boolean type",
+      "data": true,
+      "valid": false
+    },
+    {
+      "description": "Invalid - null type",
+      "data": null,
+      "valid": false
+    },
+    {
+      "description": "Invalid - padding at beginning",
+      "data": "======C4",
+      "valid": false
+    },
+    {
+      "description": "Invalid - only padding",
+      "data": "========",
+      "valid": false
+    },
+    {
+      "description": "Invalid - mixed padding",
+      "data": "C=P=MU==",
+      "valid": false
+    },
+    {
+      "description": "Valid - digit 0",
+      "data": "00000000",
+      "valid": true
+    },
+    {
+      "description": "Valid - digit 1",
+      "data": "11111111",
+      "valid": true
+    },
+    {
+      "description": "Valid - digit 2",
+      "data": "22222222",
+      "valid": true
+    },
+    {
+      "description": "Valid - digit 3",
+      "data": "33333333",
+      "valid": true
+    },
+    {
+      "description": "Valid - digit 4",
+      "data": "44444444",
+      "valid": true
+    },
+    {
+      "description": "Valid - digit 5",
+      "data": "55555555",
+      "valid": true
+    },
+    {
+      "description": "Valid - digit 6",
+      "data": "66666666",
+      "valid": true
+    },
+    {
+      "description": "Valid - digit 7",
+      "data": "77777777",
+      "valid": true
+    },
+    {
+      "description": "Valid - digit 8",
+      "data": "88888888",
+      "valid": true
+    },
+    {
+      "description": "Valid - digit 9",
+      "data": "99999999",
+      "valid": true
+    },
+    {
+      "description": "Valid - letter A",
+      "data": "AAAAAAAA",
+      "valid": true
+    },
+    {
+      "description": "Valid - letter V",
+      "data": "VVVVVVVV",
+      "valid": true
+    },
+    {
+      "description": "Valid - repeating pattern",
+      "data": "0A0A0A0A",
+      "valid": true
+    },
+    {
+      "description": "Valid - very long valid base32hex",
+      "data": "91IMOR3F5GG5E33IDHIA====",
+      "valid": true
+    },
+    {
+      "description": "Invalid - 3 chars with 4 padding (should be 6 padding for 2 chars)",
+      "data": "C4P====",
+      "valid": false
+    },
+    {
+      "description": "Invalid - 6 chars with 3 padding (no valid padding for 6 chars)",
+      "data": "CPNMUO===",
+      "valid": false
+    }
+  ]
+}
diff --git a/test/ietf/encoding/base64.test.json b/test/ietf/encoding/base64.test.json
new file mode 100644
index 0000000..e36d75f
--- /dev/null
+++ b/test/ietf/encoding/base64.test.json
@@ -0,0 +1,526 @@
+{
+  "x-license": "https://github.com/sourcemeta/std/blob/main/LICENSE",
+  "target": "../../../schemas/ietf/encoding/base64.json",
+  "tests": [
+    {
+      "description": "Valid - empty string",
+      "data": "",
+      "valid": true
+    },
+    {
+      "description": "Valid - single char with padding",
+      "data": "YQ==",
+      "valid": true
+    },
+    {
+      "description": "Valid - two chars with padding",
+      "data": "YWI=",
+      "valid": true
+    },
+    {
+      "description": "Valid - three chars no padding",
+      "data": "YWJj",
+      "valid": true
+    },
+    {
+      "description": "Valid - four chars",
+      "data": "YWJjZA==",
+      "valid": true
+    },
+    {
+      "description": "Valid - Hello World",
+      "data": "SGVsbG8gV29ybGQh",
+      "valid": true
+    },
+    {
+      "description": "Invalid - insufficient chars in final group",
+      "data": "a+b/c==",
+      "valid": false
+    },
+    {
+      "description": "Valid - with plus sign",
+      "data": "a+b/cg==",
+      "valid": true
+    },
+    {
+      "description": "Valid - with slash",
+      "data": "abc/def=",
+      "valid": true
+    },
+    {
+      "description": "Valid - all uppercase",
+      "data": "QUJDRA==",
+      "valid": true
+    },
+    {
+      "description": "Valid - all lowercase",
+      "data": "cXdlcg==",
+      "valid": true
+    },
+    {
+      "description": "Valid - all digits",
+      "data": "MTIzNDU2Nzg5MA==",
+      "valid": true
+    },
+    {
+      "description": "Valid - GIF header",
+      "data": "R0lGODlhAQABAAAAACw=",
+      "valid": true
+    },
+    {
+      "description": "Valid - multiple of 4 chars",
+      "data": "YWJjZGVmZ2hpamtsbW5vcA==",
+      "valid": true
+    },
+    {
+      "description": "Valid - long string",
+      "data": "VGhpcyBpcyBhIGxvbmcgYmFzZTY0IGVuY29kZWQgc3RyaW5nIHRoYXQgc2hvdWxkIGJlIHZhbGlk",
+      "valid": true
+    },
+    {
+      "description": "Invalid - one equals padding only",
+      "data": "YWI==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - three equals",
+      "data": "YQ===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - padding in middle",
+      "data": "YQ==YWI=",
+      "valid": false
+    },
+    {
+      "description": "Invalid - padding not at end",
+      "data": "Y=WI",
+      "valid": false
+    },
+    {
+      "description": "Invalid - single character without padding (insufficient data)",
+      "data": "Y",
+      "valid": false
+    },
+    {
+      "description": "Invalid - two characters without required padding",
+      "data": "YW",
+      "valid": false
+    },
+    {
+      "description": "Invalid - three characters without required padding",
+      "data": "YWJ",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains space",
+      "data": "YWJj ZA==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains dash",
+      "data": "YWJj-ZA==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains underscore",
+      "data": "YWJj_ZA==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains period",
+      "data": "YWJj.ZA==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains comma",
+      "data": "YWJj,ZA==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains special char",
+      "data": "YWJj@ZA==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - number type",
+      "data": 123,
+      "valid": false
+    },
+    {
+      "description": "Invalid - boolean type",
+      "data": true,
+      "valid": false
+    },
+    {
+      "description": "Invalid - null type",
+      "data": null,
+      "valid": false
+    },
+    {
+      "description": "Valid - only uppercase letters",
+      "data": "ABCDEFGH",
+      "valid": true
+    },
+    {
+      "description": "Valid - only lowercase letters",
+      "data": "abcdefgh",
+      "valid": true
+    },
+    {
+      "description": "Valid - only digits",
+      "data": "01234567",
+      "valid": true
+    },
+    {
+      "description": "Valid - plus at start",
+      "data": "+ABC",
+      "valid": true
+    },
+    {
+      "description": "Valid - slash at start",
+      "data": "/ABC",
+      "valid": true
+    },
+    {
+      "description": "Valid - plus at end",
+      "data": "ABC+",
+      "valid": true
+    },
+    {
+      "description": "Valid - slash at end",
+      "data": "ABC/",
+      "valid": true
+    },
+    {
+      "description": "Valid - multiple plus signs",
+      "data": "A+B+C+D+",
+      "valid": true
+    },
+    {
+      "description": "Valid - multiple slashes",
+      "data": "A/B/C/D/",
+      "valid": true
+    },
+    {
+      "description": "Valid - plus and slash mixed",
+      "data": "A+B/C+D/",
+      "valid": true
+    },
+    {
+      "description": "Valid - 8 chars no padding",
+      "data": "ABCDEFGH",
+      "valid": true
+    },
+    {
+      "description": "Valid - 12 chars no padding",
+      "data": "ABCDEFGHIJKL",
+      "valid": true
+    },
+    {
+      "description": "Valid - 16 chars no padding",
+      "data": "ABCDEFGHIJKLMNOP",
+      "valid": true
+    },
+    {
+      "description": "Invalid - 5 chars without required padding",
+      "data": "ABCDE",
+      "valid": false
+    },
+    {
+      "description": "Invalid - 6 chars without required padding",
+      "data": "ABCDEF",
+      "valid": false
+    },
+    {
+      "description": "Invalid - 7 chars without required padding",
+      "data": "ABCDEFG",
+      "valid": false
+    },
+    {
+      "description": "Invalid - 10 chars without required padding",
+      "data": "ABCDEFGHIJ",
+      "valid": false
+    },
+    {
+      "description": "Valid - padding with two equals at end of 4-char group",
+      "data": "AB==",
+      "valid": true
+    },
+    {
+      "description": "Valid - padding with one equal at end of 4-char group",
+      "data": "ABC=",
+      "valid": true
+    },
+    {
+      "description": "Valid - 8 chars then padding",
+      "data": "ABCDEFGH/w==",
+      "valid": true
+    },
+    {
+      "description": "Valid - all char types",
+      "data": "AZ09+/AB",
+      "valid": true
+    },
+    {
+      "description": "Valid - repeated patterns",
+      "data": "AAAABBBBCCCCDDDD",
+      "valid": true
+    },
+    {
+      "description": "Valid - zeros encoded",
+      "data": "AAAA",
+      "valid": true
+    },
+    {
+      "description": "Valid - max values encoded",
+      "data": "////",
+      "valid": true
+    },
+    {
+      "description": "Valid - alternating chars",
+      "data": "AaAaAaAa",
+      "valid": true
+    },
+    {
+      "description": "Invalid - padding at beginning",
+      "data": "==ABCD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - padding in first position",
+      "data": "=ABC",
+      "valid": false
+    },
+    {
+      "description": "Invalid - only equals",
+      "data": "====",
+      "valid": false
+    },
+    {
+      "description": "Invalid - single equals",
+      "data": "=",
+      "valid": false
+    },
+    {
+      "description": "Invalid - double equals alone",
+      "data": "==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - four equals",
+      "data": "ABCD====",
+      "valid": false
+    },
+    {
+      "description": "Invalid - padding then more chars",
+      "data": "AB==CD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - padding then padding",
+      "data": "AB===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - mixed padding positions",
+      "data": "A=B=",
+      "valid": false
+    },
+    {
+      "description": "Invalid - three chars with two equals",
+      "data": "ABC==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - two chars with one equal",
+      "data": "AB=",
+      "valid": false
+    },
+    {
+      "description": "Invalid - five chars with padding",
+      "data": "ABCDE=",
+      "valid": false
+    },
+    {
+      "description": "Valid - uppercase G",
+      "data": "ABCG",
+      "valid": true
+    },
+    {
+      "description": "Valid - lowercase g",
+      "data": "ABCg",
+      "valid": true
+    },
+    {
+      "description": "Invalid - contains (",
+      "data": "ABC(",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains )",
+      "data": "ABC)",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains [",
+      "data": "ABC[",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains ]",
+      "data": "ABC]",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains {",
+      "data": "ABC{",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains }",
+      "data": "ABC}",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains !",
+      "data": "ABC!",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains ?",
+      "data": "ABC?",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains *",
+      "data": "ABC*",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains &",
+      "data": "ABC&",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains $",
+      "data": "ABC$",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains %",
+      "data": "ABC%",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains #",
+      "data": "ABC#",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains ^",
+      "data": "ABC^",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains ~",
+      "data": "ABC~",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains `",
+      "data": "ABC`",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains |",
+      "data": "ABC|",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains \\",
+      "data": "ABC\\",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains ;",
+      "data": "ABC;",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains :",
+      "data": "ABC:",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains '",
+      "data": "ABC'",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains \"",
+      "data": "ABC\"",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains <",
+      "data": "ABC<",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains >",
+      "data": "ABC>",
+      "valid": false
+    },
+    {
+      "description": "Invalid - leading tab",
+      "data": "\tABCD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - trailing tab",
+      "data": "ABCD\t",
+      "valid": false
+    },
+    {
+      "description": "Invalid - tab in middle",
+      "data": "AB\tCD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - leading space",
+      "data": " ABCD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - trailing space",
+      "data": "ABCD ",
+      "valid": false
+    },
+    {
+      "description": "Invalid - multiple spaces",
+      "data": "AB  CD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains carriage return",
+      "data": "AB\rCD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - non-ASCII character",
+      "data": "ABCé",
+      "valid": false
+    },
+    {
+      "description": "Invalid - emoji",
+      "data": "ABC😀",
+      "valid": false
+    },
+    {
+      "description": "Valid - very long valid base64",
+      "data": "VGhpcyBpcyBhIHZlcnkgbG9uZyBiYXNlNjQgZW5jb2RlZCBzdHJpbmcgdGhhdCB3ZSBhcmUgdXNpbmcgdG8gdGVzdCB0aGUgdmFsaWRhdGlvbiBvZiBsb25nZXIgaW5wdXRzIHRvIG1ha2Ugc3VyZSBvdXIgcGF0dGVybiB3b3JrcyBjb3JyZWN0bHk=",
+      "valid": true
+    }
+  ]
+}
diff --git a/test/ietf/encoding/base64url.test.json b/test/ietf/encoding/base64url.test.json
new file mode 100644
index 0000000..8bd4878
--- /dev/null
+++ b/test/ietf/encoding/base64url.test.json
@@ -0,0 +1,541 @@
+{
+  "x-license": "https://github.com/sourcemeta/std/blob/main/LICENSE",
+  "target": "../../../schemas/ietf/encoding/base64url.json",
+  "tests": [
+    {
+      "description": "Valid - empty string",
+      "data": "",
+      "valid": true
+    },
+    {
+      "description": "Valid - single char with padding",
+      "data": "YQ==",
+      "valid": true
+    },
+    {
+      "description": "Valid - two chars with padding",
+      "data": "YWI=",
+      "valid": true
+    },
+    {
+      "description": "Valid - three chars no padding",
+      "data": "YWJj",
+      "valid": true
+    },
+    {
+      "description": "Valid - four chars",
+      "data": "YWJjZA==",
+      "valid": true
+    },
+    {
+      "description": "Valid - Hello World",
+      "data": "SGVsbG8gV29ybGQh",
+      "valid": true
+    },
+    {
+      "description": "Invalid - insufficient chars in final group",
+      "data": "a-b_c==",
+      "valid": false
+    },
+    {
+      "description": "Valid - with hyphen",
+      "data": "a-b_cg==",
+      "valid": true
+    },
+    {
+      "description": "Valid - with underscore",
+      "data": "abc_def=",
+      "valid": true
+    },
+    {
+      "description": "Valid - all uppercase",
+      "data": "QUJDRA==",
+      "valid": true
+    },
+    {
+      "description": "Valid - all lowercase",
+      "data": "cXdlcg==",
+      "valid": true
+    },
+    {
+      "description": "Valid - all digits",
+      "data": "MTIzNDU2Nzg5MA==",
+      "valid": true
+    },
+    {
+      "description": "Valid - GIF header",
+      "data": "R0lGODlhAQABAAAAACw=",
+      "valid": true
+    },
+    {
+      "description": "Valid - multiple of 4 chars",
+      "data": "YWJjZGVmZ2hpamtsbW5vcA==",
+      "valid": true
+    },
+    {
+      "description": "Valid - long string",
+      "data": "VGhpcyBpcyBhIGxvbmcgYmFzZTY0IHVybCBlbmNvZGVkIHN0cmluZyB0aGF0IHNob3VsZCBiZSB2YWxpZA==",
+      "valid": true
+    },
+    {
+      "description": "Invalid - one equals padding only",
+      "data": "YWI==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - three equals",
+      "data": "YQ===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - padding in middle",
+      "data": "YQ==YWI=",
+      "valid": false
+    },
+    {
+      "description": "Invalid - padding not at end",
+      "data": "Y=WI",
+      "valid": false
+    },
+    {
+      "description": "Invalid - single character without padding (insufficient data)",
+      "data": "Y",
+      "valid": false
+    },
+    {
+      "description": "Invalid - two characters without required padding",
+      "data": "YW",
+      "valid": false
+    },
+    {
+      "description": "Invalid - three characters without required padding",
+      "data": "YWJ",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains space",
+      "data": "YWJj ZA==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains period",
+      "data": "YWJj.ZA==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains comma",
+      "data": "YWJj,ZA==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains special char",
+      "data": "YWJj@ZA==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - number type",
+      "data": 123,
+      "valid": false
+    },
+    {
+      "description": "Invalid - boolean type",
+      "data": true,
+      "valid": false
+    },
+    {
+      "description": "Invalid - null type",
+      "data": null,
+      "valid": false
+    },
+    {
+      "description": "Valid - only uppercase letters",
+      "data": "ABCDEFGH",
+      "valid": true
+    },
+    {
+      "description": "Valid - only lowercase letters",
+      "data": "abcdefgh",
+      "valid": true
+    },
+    {
+      "description": "Valid - only digits",
+      "data": "01234567",
+      "valid": true
+    },
+    {
+      "description": "Valid - hyphen at start",
+      "data": "-ABC",
+      "valid": true
+    },
+    {
+      "description": "Valid - underscore at start",
+      "data": "_ABC",
+      "valid": true
+    },
+    {
+      "description": "Valid - hyphen at end",
+      "data": "ABC-",
+      "valid": true
+    },
+    {
+      "description": "Valid - underscore at end",
+      "data": "ABC_",
+      "valid": true
+    },
+    {
+      "description": "Valid - multiple hyphens",
+      "data": "A-B-C-D-",
+      "valid": true
+    },
+    {
+      "description": "Valid - multiple underscores",
+      "data": "A_B_C_D_",
+      "valid": true
+    },
+    {
+      "description": "Valid - hyphen and underscore mixed",
+      "data": "A-B_C-D_",
+      "valid": true
+    },
+    {
+      "description": "Valid - 8 chars no padding",
+      "data": "ABCDEFGH",
+      "valid": true
+    },
+    {
+      "description": "Valid - 12 chars no padding",
+      "data": "ABCDEFGHIJKL",
+      "valid": true
+    },
+    {
+      "description": "Valid - 16 chars no padding",
+      "data": "ABCDEFGHIJKLMNOP",
+      "valid": true
+    },
+    {
+      "description": "Invalid - 5 chars without required padding",
+      "data": "ABCDE",
+      "valid": false
+    },
+    {
+      "description": "Invalid - 6 chars without required padding",
+      "data": "ABCDEF",
+      "valid": false
+    },
+    {
+      "description": "Invalid - 7 chars without required padding",
+      "data": "ABCDEFG",
+      "valid": false
+    },
+    {
+      "description": "Invalid - 10 chars without required padding",
+      "data": "ABCDEFGHIJ",
+      "valid": false
+    },
+    {
+      "description": "Valid - padding with two equals at end of 4-char group",
+      "data": "AB==",
+      "valid": true
+    },
+    {
+      "description": "Valid - padding with one equal at end of 4-char group",
+      "data": "ABC=",
+      "valid": true
+    },
+    {
+      "description": "Valid - 8 chars then padding",
+      "data": "ABCDEFGH_w==",
+      "valid": true
+    },
+    {
+      "description": "Valid - all char types",
+      "data": "AZ09-_AB",
+      "valid": true
+    },
+    {
+      "description": "Valid - repeated patterns",
+      "data": "AAAABBBBCCCCDDDD",
+      "valid": true
+    },
+    {
+      "description": "Valid - zeros encoded",
+      "data": "AAAA",
+      "valid": true
+    },
+    {
+      "description": "Valid - alternating chars",
+      "data": "AaAaAaAa",
+      "valid": true
+    },
+    {
+      "description": "Invalid - padding at beginning",
+      "data": "==ABCD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - padding in first position",
+      "data": "=ABC",
+      "valid": false
+    },
+    {
+      "description": "Invalid - only equals",
+      "data": "====",
+      "valid": false
+    },
+    {
+      "description": "Invalid - single equals",
+      "data": "=",
+      "valid": false
+    },
+    {
+      "description": "Invalid - double equals alone",
+      "data": "==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - four equals",
+      "data": "ABCD====",
+      "valid": false
+    },
+    {
+      "description": "Invalid - padding then more chars",
+      "data": "AB==CD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - padding then padding",
+      "data": "AB===",
+      "valid": false
+    },
+    {
+      "description": "Invalid - mixed padding positions",
+      "data": "A=B=",
+      "valid": false
+    },
+    {
+      "description": "Invalid - three chars with two equals",
+      "data": "ABC==",
+      "valid": false
+    },
+    {
+      "description": "Invalid - two chars with one equal",
+      "data": "AB=",
+      "valid": false
+    },
+    {
+      "description": "Invalid - five chars with padding",
+      "data": "ABCDE=",
+      "valid": false
+    },
+    {
+      "description": "Valid - uppercase G",
+      "data": "ABCG",
+      "valid": true
+    },
+    {
+      "description": "Valid - lowercase g",
+      "data": "ABCg",
+      "valid": true
+    },
+    {
+      "description": "Invalid - contains plus (base64 char, not base64url)",
+      "data": "ABC+",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains slash (base64 char, not base64url)",
+      "data": "ABC/",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains (",
+      "data": "ABC(",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains )",
+      "data": "ABC)",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains [",
+      "data": "ABC[",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains ]",
+      "data": "ABC]",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains {",
+      "data": "ABC{",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains }",
+      "data": "ABC}",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains !",
+      "data": "ABC!",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains ?",
+      "data": "ABC?",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains *",
+      "data": "ABC*",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains &",
+      "data": "ABC&",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains $",
+      "data": "ABC$",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains %",
+      "data": "ABC%",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains #",
+      "data": "ABC#",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains ^",
+      "data": "ABC^",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains ~",
+      "data": "ABC~",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains `",
+      "data": "ABC`",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains |",
+      "data": "ABC|",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains \\",
+      "data": "ABC\\",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains ;",
+      "data": "ABC;",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains :",
+      "data": "ABC:",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains '",
+      "data": "ABC'",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains \"",
+      "data": "ABC\"",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains <",
+      "data": "ABC<",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains >",
+      "data": "ABC>",
+      "valid": false
+    },
+    {
+      "description": "Invalid - leading tab",
+      "data": "\tABCD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - trailing tab",
+      "data": "ABCD\t",
+      "valid": false
+    },
+    {
+      "description": "Invalid - tab in middle",
+      "data": "AB\tCD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - leading space",
+      "data": " ABCD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - trailing space",
+      "data": "ABCD ",
+      "valid": false
+    },
+    {
+      "description": "Invalid - multiple spaces",
+      "data": "AB  CD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains newline",
+      "data": "AB\nCD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - contains carriage return",
+      "data": "AB\rCD",
+      "valid": false
+    },
+    {
+      "description": "Invalid - non-ASCII character",
+      "data": "ABCé",
+      "valid": false
+    },
+    {
+      "description": "Invalid - emoji",
+      "data": "ABC😀",
+      "valid": false
+    },
+    {
+      "description": "Valid - very long valid base64url",
+      "data": "VGhpcyBpcyBhIHZlcnkgbG9uZyBiYXNlNjQgdXJsIGVuY29kZWQgc3RyaW5nIHRoYXQgd2UgYXJlIHVzaW5nIHRvIHRlc3QgdGhlIHZhbGlkYXRpb24gb2YgbG9uZ2VyIGlucHV0cyB0byBtYWtlIHN1cmUgb3VyIHBhdHRlcm4gd29ya3MgY29ycmVjdGx5",
+      "valid": true
+    },
+    {
+      "description": "Valid - URL-safe chars only",
+      "data": "A-Z_09ab",
+      "valid": true
+    },
+    {
+      "description": "Invalid - base64 plus in base64url context",
+      "data": "SGVs+G8h",
+      "valid": false
+    },
+    {
+      "description": "Invalid - base64 slash in base64url context",
+      "data": "SGVs/G8h",
+      "valid": false
+    }
+  ]
+}