Add RS256 sign support

invisal · Aug 20, 2020 · dd78423 · dd78423
1 parent 1bbae3e
commit dd78423
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Showing 6 changed files with 107 additions and 3 deletions.
diff --git a/src/binary.ts b/src/binary.ts
@@ -11,6 +11,13 @@ export class RawBinary extends Uint8Array {
     return btoa(String.fromCharCode.apply(null, [...this]));
   }
 
+  base64url(): string {
+    let a = btoa(String.fromCharCode.apply(null, [...this])).replace(/=/g, "");
+    a = a.replace(/\+/g, "-");
+    a = a.replace(/\//g, "_");
+    return a;
+  }
+
   base32(): string {
     const lookup = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567";
     const trim = [0x0, 0x1, 0x3, 0x7, 0xf, 0x1f, 0x3f, 0x7f, 0xff];

diff --git a/src/rsa/common.ts b/src/rsa/common.ts
@@ -16,6 +16,6 @@ export interface RSAOption {
 }
 
 export interface RSASignOption {
-  hash: "sha1" | "sha256";
+  hash: "sha256";
   algorithm: "rsassa-pkcs1-v1_5";
 }
diff --git a/src/rsa/mod.ts b/src/rsa/mod.ts
@@ -75,6 +75,23 @@ export class RSA {
     );
   }
 
+  async sign(
+    message: Uint8Array | string,
+    options?: Partial<RSASignOption>,
+  ): Promise<RawBinary> {
+    const computedOption: RSASignOption = {
+      ...options,
+      algorithm: "rsassa-pkcs1-v1_5",
+      hash: "sha256",
+    };
+
+    return await PureRSA.sign(
+      this.key,
+      computeMessage(message),
+      computedOption,
+    );
+  }
+
   static parseKey(key: string): RSAKey {
     if (key.indexOf("-----BEGIN RSA PRIVATE KEY-----") === 0) {
       const trimmedKey = key.substr(31, key.length - 61);

diff --git a/src/rsa/rsa_internal.ts b/src/rsa/rsa_internal.ts
@@ -3,6 +3,7 @@ import { eme_oaep_encode, eme_oaep_decode } from "./eme_oaep.ts";
 import { os2ip, i2osp } from "./primitives.ts";
 import { concat, random_bytes } from "./../helper.ts";
 import { ber_decode, ber_simple } from "./basic_encoding_rule.ts";
+import { RawBinary } from "../binary.ts";
 
 /**
  * @param n public key modulus
@@ -120,5 +121,27 @@ export function rsa_pkcs1_verify(
   return true;
 }
 
-// 3031300d0609608648016503040201050004208041fb8cba9e4f8cc1483790b05262841f27fdcb211bc039ddf8864374db5f53
-//                                       8041fb8cba9e4f8cc1483790b05262841f27fdcb211bc039ddf8864374db5f53
+export function rsa_pkcs1_sign(
+  bytes: number,
+  n: bigint,
+  d: bigint,
+  message: Uint8Array,
+): RawBinary {
+  // deno-fmt-ignore
+  const oid = [0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01, 0x05, 0x00]
+  const der = [
+    0x30,
+    message.length + 2 + oid.length,
+    ...oid,
+    0x04,
+    message.length,
+    ...message,
+  ];
+
+  const ps = new Array(bytes - 3 - der.length).fill(0xff);
+  const em = new Uint8Array([0x00, 0x01, ...ps, 0x00, ...der]);
+
+  const msg = os2ip(em);
+  const c = rsaep(n, d, msg);
+  return new RawBinary(i2osp(c, bytes));
+}
diff --git a/src/rsa/rsa_js.ts b/src/rsa/rsa_js.ts
@@ -4,6 +4,7 @@ import {
   rsa_oaep_decrypt,
   rsa_pkcs1_decrypt,
   rsa_pkcs1_verify,
+  rsa_pkcs1_sign,
 } from "./rsa_internal.ts";
 import { RawBinary } from "./../binary.ts";
 import { RSAKey, RSAOption, RSASignOption } from "./common.ts";
@@ -66,4 +67,15 @@ export class PureRSA {
       createHash(options.hash).update(message).digest(),
     );
   }
+
+  static async sign(key: RSAKey, message: Uint8Array, options: RSASignOption) {
+    if (!key.d) throw "You need private key to sign the message";
+
+    return rsa_pkcs1_sign(
+      key.length,
+      key.n,
+      key.d,
+      createHash(options.hash).update(message).digest(),
+    );
+  }
 }
diff --git a/tests/rsa/rsa.verify.test.ts b/tests/rsa/rsa.verify.test.ts
@@ -29,3 +29,48 @@ Deno.test("Verify RSASSA-PKSC1-v1_5", async () => {
 
   assertEquals(verified, true);
 });
+
+Deno.test("Sign RSASSA-PKSC1-v1_5", async () => {
+  const privateKey = `-----BEGIN RSA PRIVATE KEY-----
+    MIIEogIBAAKCAQEAnzyis1ZjfNB0bBgKFMSvvkTtwlvBsaJq7S5wA+kzeVOVpVWw
+    kWdVha4s38XM/pa/yr47av7+z3VTmvDRyAHcaT92whREFpLv9cj5lTeJSibyr/Mr
+    m/YtjCZVWgaOYIhwrXwKLqPr/11inWsAkfIytvHWTxZYEcXLgAXFuUuaS3uF9gEi
+    NQwzGTU1v0FqkqTBr4B8nW3HCN47XUu0t8Y0e+lf4s4OxQawWD79J9/5d3Ry0vbV
+    3Am1FtGJiJvOwRsIfVChDpYStTcHTCMqtvWbV6L11BWkpzGXSW4Hv43qa+GSYOD2
+    QU68Mb59oSk2OB+BtOLpJofmbGEGgvmwyCI9MwIDAQABAoIBACiARq2wkltjtcjs
+    kFvZ7w1JAORHbEufEO1Eu27zOIlqbgyAcAl7q+/1bip4Z/x1IVES84/yTaM8p0go
+    amMhvgry/mS8vNi1BN2SAZEnb/7xSxbflb70bX9RHLJqKnp5GZe2jexw+wyXlwaM
+    +bclUCrh9e1ltH7IvUrRrQnFJfh+is1fRon9Co9Li0GwoN0x0byrrngU8Ak3Y6D9
+    D8GjQA4Elm94ST3izJv8iCOLSDBmzsPsXfcCUZfmTfZ5DbUDMbMxRnSo3nQeoKGC
+    0Lj9FkWcfmLcpGlSXTO+Ww1L7EGq+PT3NtRae1FZPwjddQ1/4V905kyQFLamAA5Y
+    lSpE2wkCgYEAy1OPLQcZt4NQnQzPz2SBJqQN2P5u3vXl+zNVKP8w4eBv0vWuJJF+
+    hkGNnSxXQrTkvDOIUddSKOzHHgSg4nY6K02ecyT0PPm/UZvtRpWrnBjcEVtHEJNp
+    bU9pLD5iZ0J9sbzPU/LxPmuAP2Bs8JmTn6aFRspFrP7W0s1Nmk2jsm0CgYEAyH0X
+    +jpoqxj4efZfkUrg5GbSEhf+dZglf0tTOA5bVg8IYwtmNk/pniLG/zI7c+GlTc9B
+    BwfMr59EzBq/eFMI7+LgXaVUsM/sS4Ry+yeK6SJx/otIMWtDfqxsLD8CPMCRvecC
+    2Pip4uSgrl0MOebl9XKp57GoaUWRWRHqwV4Y6h8CgYAZhI4mh4qZtnhKjY4TKDjx
+    QYufXSdLAi9v3FxmvchDwOgn4L+PRVdMwDNms2bsL0m5uPn104EzM6w1vzz1zwKz
+    5pTpPI0OjgWN13Tq8+PKvm/4Ga2MjgOgPWQkslulO/oMcXbPwWC3hcRdr9tcQtn9
+    Imf9n2spL/6EDFId+Hp/7QKBgAqlWdiXsWckdE1Fn91/NGHsc8syKvjjk1onDcw0
+    NvVi5vcba9oGdElJX3e9mxqUKMrw7msJJv1MX8LWyMQC5L6YNYHDfbPF1q5L4i8j
+    8mRex97UVokJQRRA452V2vCO6S5ETgpnad36de3MUxHgCOX3qL382Qx9/THVmbma
+    3YfRAoGAUxL/Eu5yvMK8SAt/dJK6FedngcM3JEFNplmtLYVLWhkIlNRGDwkg3I5K
+    y18Ae9n7dHVueyslrb6weq7dTkYDi3iOYRW8HRkIQh06wEdbxt0shTzAJvvCQfrB
+    jg/3747WSsf/zBTcHihTRBdAv6OmdhV4/dD5YBfLAkLrd+mX7iE=
+    -----END RSA PRIVATE KEY-----`;
+
+  const key = RSA.parseKey(privateKey);
+  const rsa = new RSA(key);
+  let expectedSignature =
+    "POstGetfAytaZS82wHcjoTyoqhMyxXiWdR7Nn7A29DNSl0EiXLdwJ6xC6AfgZWF1bOsS_TuYI3OG85AmiExREkrS6" +
+    "tDfTQ2B3WXlrr-wp5AokiRbz3_oB4OxG-W9KcEEbDRcZc0nH3L7LzYptiy1PtAylQGxHTWZXtGz4ht0bAecBgmpdg" +
+    "XMguEIcoqPJ1n3pIWk_dUZegpqx0Lka21H6XxUTxiy8OcaarA8zdnPUnV6AmNP3ecFawIFYdvJB_cm-GvpCSbr8G8" +
+    "y_Mllj8f4x9nBH8pQux89_6gUY618iYv7tuPWBFfEbLxtF2pZS6YC1aSfLQxeNe8djT9YjpvRZA";
+
+  const signature = await rsa.sign(
+    "eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiYWRtaW4iOnRydWUsImlhdCI6MTUxNjIzOTAyMn0",
+    { algorithm: "rsassa-pkcs1-v1_5", hash: "sha256" },
+  );
+
+  assertEquals(signature.base64url(), expectedSignature);
+});