crypto builtins (#57)

Signed-off-by: Anand Krishnamoorthi <anakrish@microsoft.com>

src/builtins/crypto.rs

@@ -0,0 +1,148 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+use crate::ast::{Expr, Ref};
+use crate::builtins;
+use crate::builtins::utils::{ensure_args_count, ensure_string};
+use crate::lexer::Span;
+use crate::value::Value;
+
+use std::collections::HashMap;
+
+use anyhow::{bail, Result};
+use constant_time_eq::constant_time_eq;
+use hmac::{Hmac, Mac};
+use md5::{Digest, Md5};
+use sha1::Sha1;
+use sha2::{Sha256, Sha512};
+
+pub fn register(m: &mut HashMap<&'static str, builtins::BuiltinFcn>) {
+    m.insert("crypto.hmac.equal", (hmac_equal_fixed_time, 2));
+    m.insert("crypto.hmac.md5", (hmac_md5, 2));
+    m.insert("crypto.hmac.sha1", (hmac_sha1, 2));
+    m.insert("crypto.hmac.sha256", (hmac_sha256, 2));
+    m.insert("crypto.hmac.sha512", (hmac_sha512, 2));
+
+    m.insert("crypto.md5", (crypto_md5, 1));
+    m.insert("crypto.sha1", (crypto_sha1, 1));
+    m.insert("crypto.sha256", (crypto_sha256, 1));
+}
+
+fn hmac_equal_fixed_time(span: &Span, params: &[Ref<Expr>], args: &[Value]) -> Result<Value> {
+    let name = "crypto.hmac.equal";
+    ensure_args_count(span, name, params, args, 2)?;
+
+    let hmac1 = ensure_string(name, &params[0], &args[0])?;
+    let hmac2 = ensure_string(name, &params[1], &args[1])?;
+
+    Ok(Value::Bool(constant_time_eq(
+        hmac1.as_bytes(),
+        hmac2.as_bytes(),
+    )))
+}
+
+fn hmac_md5(span: &Span, params: &[Ref<Expr>], args: &[Value]) -> Result<Value> {
+    let name = "crypto.hmac.md5";
+    ensure_args_count(span, name, params, args, 2)?;
+
+    let x = ensure_string(name, &params[0], &args[0])?;
+    let key = ensure_string(name, &params[1], &args[1])?;
+
+    let mut hmac = Hmac::<Md5>::new_from_slice(key.as_bytes())
+        .or_else(|_| bail!(span.error("failed to create hmac instance")))?;
+
+    hmac.update(x.as_bytes());
+    let result = hmac.finalize();
+
+    Ok(Value::String(hex::encode(result.into_bytes()).into()))
+}
+
+fn hmac_sha1(span: &Span, params: &[Ref<Expr>], args: &[Value]) -> Result<Value> {
+    let name = "crypto.hmac.sha1";
+    ensure_args_count(span, name, params, args, 2)?;
+
+    let x = ensure_string(name, &params[0], &args[0])?;
+    let key = ensure_string(name, &params[1], &args[1])?;
+
+    let mut hmac = Hmac::<Sha1>::new_from_slice(key.as_bytes())
+        .or_else(|_| bail!(span.error("failed to create hmac instance")))?;
+
+    hmac.update(x.as_bytes());
+    let result = hmac.finalize();
+
+    Ok(Value::String(hex::encode(result.into_bytes()).into()))
+}
+
+fn hmac_sha256(span: &Span, params: &[Ref<Expr>], args: &[Value]) -> Result<Value> {
+    let name = "crypto.hmac.sha256";
+    ensure_args_count(span, name, params, args, 2)?;
+
+    let x = ensure_string(name, &params[0], &args[0])?;
+    let key = ensure_string(name, &params[1], &args[1])?;
+
+    let mut hmac = Hmac::<Sha256>::new_from_slice(key.as_bytes())
+        .or_else(|_| bail!(span.error("failed to create hmac instance")))?;
+
+    hmac.update(x.as_bytes());
+    let result = hmac.finalize();
+
+    Ok(Value::String(hex::encode(result.into_bytes()).into()))
+}
+
+fn hmac_sha512(span: &Span, params: &[Ref<Expr>], args: &[Value]) -> Result<Value> {
+    let name = "crypto.hmac.sha512";
+    ensure_args_count(span, name, params, args, 2)?;
+
+    let x = ensure_string(name, &params[0], &args[0])?;
+    let key = ensure_string(name, &params[1], &args[1])?;
+
+    let mut hmac = Hmac::<Sha512>::new_from_slice(key.as_bytes())
+        .or_else(|_| bail!(span.error("failed to create hmac instance")))?;
+
+    hmac.update(x.as_bytes());
+    let result = hmac.finalize();
+
+    Ok(Value::String(hex::encode(result.into_bytes()).into()))
+}
+
+fn crypto_md5(span: &Span, params: &[Ref<Expr>], args: &[Value]) -> Result<Value> {
+    let name = "crypto.md5";
+    ensure_args_count(span, name, params, args, 1)?;
+
+    let x = ensure_string(name, &params[0], &args[0])?;
+
+    let mut h = Md5::new();
+
+    h.update(x.as_bytes());
+    let result = h.finalize();
+
+    Ok(Value::String(hex::encode(result).into()))
+}
+
+fn crypto_sha1(span: &Span, params: &[Ref<Expr>], args: &[Value]) -> Result<Value> {
+    let name = "crypto.sha1";
+    ensure_args_count(span, name, params, args, 1)?;
+
+    let x = ensure_string(name, &params[0], &args[0])?;
+
+    let mut h = Sha1::new();
+
+    h.update(x.as_bytes());
+    let result = h.finalize();
+
+    Ok(Value::String(hex::encode(result).into()))
+}
+
+fn crypto_sha256(span: &Span, params: &[Ref<Expr>], args: &[Value]) -> Result<Value> {
+    let name = "crypto.sha256";
+    ensure_args_count(span, name, params, args, 1)?;
+
+    let x = ensure_string(name, &params[0], &args[0])?;
+
+    let mut h = Sha256::new();
+
+    h.update(x.as_bytes());
+    let result = h.finalize();
+
+    Ok(Value::String(hex::encode(result).into()))
+}