Merge pull request #126 from skx/115-hash

Add md5/sha1/sha256 digest functions.

PRIMITIVES.md

@@ -192,6 +192,8 @@ Things you'll find here include:
   * Create a new list.
 * `match`
   * Perform a regular expression test.
+* `md5`
+  * Return the MD5 digest of the given string.
 * `ms`
   * Return the time, in milliseconds.
 * `nil?`
@@ -215,6 +217,10 @@ Things you'll find here include:
   * Output the specified string, or format string + values.
 * `set`
   * Update the value of the specified hash-key.
+* `sha1`
+  * Return the SHA1 digest of the given string.
+* `sha256`
+  * Return the SHA256 digest of the given string.
 * `shell`
   * Run a command via the shell, and return STDOUT and STDERR it generated.
 * `sin`

builtins/builtins.go

@@ -8,6 +8,9 @@ package builtins
 import (
 	"bufio"
 	"bytes"
+	"crypto/md5"
+	"crypto/sha1"
+	"crypto/sha256"
 	"fmt"
 	"math"
 	"math/rand"
@@ -135,6 +138,7 @@ func PopulateEnvironment(env *env.Environment) {
 	env.Set("keys", &primitive.Procedure{F: keysFn, Help: helpMap["keys"], Args: []primitive.Symbol{primitive.Symbol("hash")}})
 	env.Set("list", &primitive.Procedure{F: listFn, Help: helpMap["list"], Args: []primitive.Symbol{primitive.Symbol("arg1"), primitive.Symbol("arg...")}})
 	env.Set("match", &primitive.Procedure{F: matchFn, Help: helpMap["match"], Args: []primitive.Symbol{primitive.Symbol("regexp"), primitive.Symbol("str")}})
+	env.Set("md5", &primitive.Procedure{F: md5Fn, Help: helpMap["md5"], Args: []primitive.Symbol{primitive.Symbol("string")}})
 	env.Set("ms", &primitive.Procedure{F: msFn, Help: helpMap["ms"]})
 	env.Set("nil?", &primitive.Procedure{F: nilFn, Help: helpMap["nil?"], Args: []primitive.Symbol{primitive.Symbol("object")}})
 	env.Set("now", &primitive.Procedure{F: nowFn, Help: helpMap["now"]})
@@ -145,6 +149,8 @@ func PopulateEnvironment(env *env.Environment) {
 	env.Set("print", &primitive.Procedure{F: printFn, Help: helpMap["print"], Args: []primitive.Symbol{primitive.Symbol("arg1..argN")}})
 	env.Set("random", &primitive.Procedure{F: randomFn, Help: helpMap["random"], Args: []primitive.Symbol{primitive.Symbol("max")}})
 	env.Set("set", &primitive.Procedure{F: setFn, Help: helpMap["set"], Args: []primitive.Symbol{primitive.Symbol("hash"), primitive.Symbol("key"), primitive.Symbol("val")}})
+	env.Set("sha1", &primitive.Procedure{F: sha1Fn, Help: helpMap["sha1"], Args: []primitive.Symbol{primitive.Symbol("string")}})
+	env.Set("sha256", &primitive.Procedure{F: sha256Fn, Help: helpMap["sha256"], Args: []primitive.Symbol{primitive.Symbol("string")}})
 	env.Set("shell", &primitive.Procedure{F: shellFn, Help: helpMap["shell"], Args: []primitive.Symbol{primitive.Symbol("list")}})
 	env.Set("sin", &primitive.Procedure{F: sinFn, Help: helpMap["sin"], Args: []primitive.Symbol{primitive.Symbol("n")}})
 	env.Set("sinh", &primitive.Procedure{F: sinhFn, Help: helpMap["sinh"], Args: []primitive.Symbol{primitive.Symbol("n")}})
@@ -1277,6 +1283,20 @@ func modFn(env *env.Environment, args []primitive.Primitive) primitive.Primitive
 	return primitive.Number(a % b)
 }
 
+// md5Fn is the implementation of `(md5)`
+func md5Fn(env *env.Environment, args []primitive.Primitive) primitive.Primitive {
+	// We need one argument
+	if len(args) != 1 {
+		return primitive.ArityError()
+	}
+
+	// The argument must be a string
+	str := args[0].ToString()
+
+	// Get the output
+	return primitive.String(fmt.Sprintf("%X", md5.Sum([]byte(str))))
+}
+
 // msFn is the implementation of `(ms)`
 func msFn(env *env.Environment, args []primitive.Primitive) primitive.Primitive {
 	return primitive.Number(time.Now().UnixNano() / int64(time.Millisecond))
@@ -1545,6 +1565,34 @@ func setFn(env *env.Environment, args []primitive.Primitive) primitive.Primitive
 	return args[2]
 }
 
+// sha1Fn runs a SHA1 hash
+func sha1Fn(env *env.Environment, args []primitive.Primitive) primitive.Primitive {
+	// We need one argument
+	if len(args) != 1 {
+		return primitive.ArityError()
+	}
+
+	// The argument must be a string
+	str := args[0].ToString()
+
+	// Get the output
+	return primitive.String(fmt.Sprintf("%X", sha1.Sum([]byte(str))))
+}
+
+// sha256Fn runs a SHA256 hash
+func sha256Fn(env *env.Environment, args []primitive.Primitive) primitive.Primitive {
+	// We need one argument
+	if len(args) != 1 {
+		return primitive.ArityError()
+	}
+
+	// The argument must be a string
+	str := args[0].ToString()
+
+	// Get the output
+	return primitive.String(fmt.Sprintf("%X", sha256.Sum256([]byte(str))))
+}
+
 // shellFn runs a command via the shell
 func shellFn(env *env.Environment, args []primitive.Primitive) primitive.Primitive {
 

builtins/builtins_test.go

@@ -1907,6 +1907,47 @@ func TestGlob(t *testing.T) {
 
 }
 
+// TestHash tests our hash functions
+func TestHash(t *testing.T) {
+
+	funs := []primitive.GolangPrimitiveFn{
+		md5Fn,
+		sha1Fn,
+		sha256Fn,
+	}
+
+	for _, fn := range funs {
+
+		// No eargs
+		out := fn(nil, []primitive.Primitive{})
+
+		// Will lead to an error
+		e, ok := out.(primitive.Error)
+		if !ok {
+			t.Fatalf("expected error, got %v", out)
+		}
+		if e != primitive.ArityError() {
+			t.Fatalf("got error, but wrong one")
+
+		}
+
+		// Hash a string
+		out = fn(ENV, []primitive.Primitive{
+			primitive.String("foo"),
+		})
+
+		// Will lead to an error
+		r, ok2 := out.(primitive.String)
+		if !ok2 {
+			t.Fatalf("expected string, got %v", r)
+		}
+
+		if len(r) < 15 {
+			t.Fatalf("result '%s' was the wrong length", r)
+		}
+	}
+}
+
 // TestHelp tests help
 func TestHelp(t *testing.T) {
 	// no arguments

builtins/help.txt

@@ -250,6 +250,14 @@ Any matches found will be returned as a list, with nil being returned on no matc
 
 Example: (print (match "c.ke$" "cake"))
 %%
+md5
+
+md5 returns the calculated MD5 digest of the provived string
+
+See also: sha1, sha256
+
+Example: (print (md5 "steve"))
+%%
 ms
 
 ms returns the current time as a number of milliseconds, it is useful for benchmarking.
@@ -331,6 +339,22 @@ See also: get
 Example: (set! person {:name "Steve"})
          (set person :name "Bobby")
 %%
+sha1
+
+sha1 returns the calculated SHA1 digest of the provived string
+
+See also: md5sum, sha256
+
+Example: (print (sha1 "steve"))
+%%
+sha256
+
+sha256 returns the calculated SHA256 digest of the provived string
+
+See also: md5sum, sha1
+
+Example: (print (sha256 "steve"))
+%%
 shell
 
 shell allows you to run a command, via the shell.

main.go

@@ -9,13 +9,11 @@ import (
 	"bufio"
 	"flag"
 	"fmt"
-	"math/rand"
 	"os"
 	"path"
 	"regexp"
 	"sort"
 	"strings"
-	"time"
 
 	"github.com/skx/yal/builtins"
 	"github.com/skx/yal/config"
@@ -197,9 +195,6 @@ func help(show []string) {
 
 func main() {
 
-	// (gensym) needs a decent random seed, as does (random).
-	rand.Seed(time.Now().UnixNano())
-
 	// Parse our command-line flags
 	exp := flag.String("e", "", "A string to evaluate.")
 	hlp := flag.Bool("h", false, "Show help information and exit.")
@@ -230,7 +225,6 @@ func main() {
 	//
 	create()
 
-
 	//
 	// By default we have no STDERR handler wired up, but if we set the
 	// debug flag we'll send that to the actual console's STDERR stream
@@ -240,13 +234,12 @@ func main() {
 		iohelper := ENV.GetIOConfig()
 
 		// Setup a destination for STDERR
-		iohelper.STDERR =os.Stderr
+		iohelper.STDERR = os.Stderr
 
 		// Update
 		ENV.SetIOConfig(iohelper)
 	}
 
-
 	// LSP?
 	if *lsp {
 		lspStart()