package funcs import ( "bytes" "compress/gzip" "encoding/base64" "fmt" "log" "net/url" "unicode/utf8" "github.com/zclconf/go-cty/cty" "github.com/zclconf/go-cty/cty/function" "golang.org/x/text/encoding/ianaindex" ) // Base64DecodeFunc constructs a function that decodes a string containing a base64 sequence. var Base64DecodeFunc = function.New(&function.Spec{ Params: []function.Parameter{ { Name: "str", Type: cty.String, }, }, Type: function.StaticReturnType(cty.String), Impl: func(args []cty.Value, retType cty.Type) (cty.Value, error) { s := args[0].AsString() sDec, err := base64.StdEncoding.DecodeString(s) if err != nil { return cty.UnknownVal(cty.String), fmt.Errorf("failed to decode base64 data '%s'", s) } if !utf8.Valid([]byte(sDec)) { log.Printf("[DEBUG] the result of decoding the provided string is not valid UTF-8: %s", sDec) return cty.UnknownVal(cty.String), fmt.Errorf("the result of decoding the provided string is not valid UTF-8") } return cty.StringVal(string(sDec)), nil }, }) // Base64EncodeFunc constructs a function that encodes a string to a base64 sequence. var Base64EncodeFunc = function.New(&function.Spec{ Params: []function.Parameter{ { Name: "str", Type: cty.String, }, }, Type: function.StaticReturnType(cty.String), Impl: func(args []cty.Value, retType cty.Type) (cty.Value, error) { return cty.StringVal(base64.StdEncoding.EncodeToString([]byte(args[0].AsString()))), nil }, }) // TextEncodeBase64Func constructs a function that encodes a string to a target encoding and then to a base64 sequence. var TextEncodeBase64Func = function.New(&function.Spec{ Params: []function.Parameter{ { Name: "string", Type: cty.String, }, { Name: "encoding", Type: cty.String, }, }, Type: function.StaticReturnType(cty.String), Impl: func(args []cty.Value, retType cty.Type) (cty.Value, error) { encoding, err := ianaindex.IANA.Encoding(args[1].AsString()) if err != nil || encoding == nil { return cty.UnknownVal(cty.String), function.NewArgErrorf(1, "%q is not a supported IANA encoding name or alias in this Terraform version", args[1].AsString()) } encName, err := ianaindex.IANA.Name(encoding) if err != nil { // would be weird, since we just read this encoding out encName = args[1].AsString() } encoder := encoding.NewEncoder() encodedInput, err := encoder.Bytes([]byte(args[0].AsString())) if err != nil { // The string representations of "err" disclose implementation // details of the underlying library, and the main error we might // like to return a special message for is unexported as // golang.org/x/text/encoding/internal.RepertoireError, so this // is just a generic error message for now. // // We also don't include the string itself in the message because // it can typically be very large, contain newline characters, // etc. return cty.UnknownVal(cty.String), function.NewArgErrorf(0, "the given string contains characters that cannot be represented in %s", encName) } return cty.StringVal(base64.StdEncoding.EncodeToString(encodedInput)), nil }, }) // TextDecodeBase64Func constructs a function that decodes a base64 sequence to a target encoding. var TextDecodeBase64Func = function.New(&function.Spec{ Params: []function.Parameter{ { Name: "source", Type: cty.String, }, { Name: "encoding", Type: cty.String, }, }, Type: function.StaticReturnType(cty.String), Impl: func(args []cty.Value, retType cty.Type) (cty.Value, error) { encoding, err := ianaindex.IANA.Encoding(args[1].AsString()) if err != nil || encoding == nil { return cty.UnknownVal(cty.String), function.NewArgErrorf(1, "%q is not a supported IANA encoding name or alias in this Terraform version", args[1].AsString()) } encName, err := ianaindex.IANA.Name(encoding) if err != nil { // would be weird, since we just read this encoding out encName = args[1].AsString() } s := args[0].AsString() sDec, err := base64.StdEncoding.DecodeString(s) if err != nil { switch err := err.(type) { case base64.CorruptInputError: return cty.UnknownVal(cty.String), function.NewArgErrorf(0, "the given value is has an invalid base64 symbol at offset %d", int(err)) default: return cty.UnknownVal(cty.String), function.NewArgErrorf(0, "invalid source string: %T", err) } } decoder := encoding.NewDecoder() decoded, err := decoder.Bytes(sDec) if err != nil || bytes.ContainsRune(decoded, '�') { return cty.UnknownVal(cty.String), function.NewArgErrorf(0, "the given string contains symbols that are not defined for %s", encName) } return cty.StringVal(string(decoded)), nil }, }) // Base64GzipFunc constructs a function that compresses a string with gzip and then encodes the result in // Base64 encoding. var Base64GzipFunc = function.New(&function.Spec{ Params: []function.Parameter{ { Name: "str", Type: cty.String, }, }, Type: function.StaticReturnType(cty.String), Impl: func(args []cty.Value, retType cty.Type) (cty.Value, error) { s := args[0].AsString() var b bytes.Buffer gz := gzip.NewWriter(&b) if _, err := gz.Write([]byte(s)); err != nil { return cty.UnknownVal(cty.String), fmt.Errorf("failed to write gzip raw data: '%s'", s) } if err := gz.Flush(); err != nil { return cty.UnknownVal(cty.String), fmt.Errorf("failed to flush gzip writer: '%s'", s) } if err := gz.Close(); err != nil { return cty.UnknownVal(cty.String), fmt.Errorf("failed to close gzip writer: '%s'", s) } return cty.StringVal(base64.StdEncoding.EncodeToString(b.Bytes())), nil }, }) // URLEncodeFunc constructs a function that applies URL encoding to a given string. var URLEncodeFunc = function.New(&function.Spec{ Params: []function.Parameter{ { Name: "str", Type: cty.String, }, }, Type: function.StaticReturnType(cty.String), Impl: func(args []cty.Value, retType cty.Type) (cty.Value, error) { return cty.StringVal(url.QueryEscape(args[0].AsString())), nil }, }) // Base64Decode decodes a string containing a base64 sequence. // // Terraform uses the "standard" Base64 alphabet as defined in RFC 4648 section 4. // // Strings in the Terraform language are sequences of unicode characters rather // than bytes, so this function will also interpret the resulting bytes as // UTF-8. If the bytes after Base64 decoding are _not_ valid UTF-8, this function // produces an error. func Base64Decode(str cty.Value) (cty.Value, error) { return Base64DecodeFunc.Call([]cty.Value{str}) } // Base64Encode applies Base64 encoding to a string. // // Terraform uses the "standard" Base64 alphabet as defined in RFC 4648 section 4. // // Strings in the Terraform language are sequences of unicode characters rather // than bytes, so this function will first encode the characters from the string // as UTF-8, and then apply Base64 encoding to the result. func Base64Encode(str cty.Value) (cty.Value, error) { return Base64EncodeFunc.Call([]cty.Value{str}) } // Base64Gzip compresses a string with gzip and then encodes the result in // Base64 encoding. // // Terraform uses the "standard" Base64 alphabet as defined in RFC 4648 section 4. // // Strings in the Terraform language are sequences of unicode characters rather // than bytes, so this function will first encode the characters from the string // as UTF-8, then apply gzip compression, and then finally apply Base64 encoding. func Base64Gzip(str cty.Value) (cty.Value, error) { return Base64GzipFunc.Call([]cty.Value{str}) } // URLEncode applies URL encoding to a given string. // // This function identifies characters in the given string that would have a // special meaning when included as a query string argument in a URL and // escapes them using RFC 3986 "percent encoding". // // If the given string contains non-ASCII characters, these are first encoded as // UTF-8 and then percent encoding is applied separately to each UTF-8 byte. func URLEncode(str cty.Value) (cty.Value, error) { return URLEncodeFunc.Call([]cty.Value{str}) } // TextEncodeBase64 applies Base64 encoding to a string that was encoded before with a target encoding. // // Terraform uses the "standard" Base64 alphabet as defined in RFC 4648 section 4. // // First step is to apply the target IANA encoding (e.g. UTF-16LE). // Strings in the Terraform language are sequences of unicode characters rather // than bytes, so this function will first encode the characters from the string // as UTF-8, and then apply Base64 encoding to the result. func TextEncodeBase64(str, enc cty.Value) (cty.Value, error) { return TextEncodeBase64Func.Call([]cty.Value{str, enc}) } // TextDecodeBase64 decodes a string containing a base64 sequence whereas a specific encoding of the string is expected. // // Terraform uses the "standard" Base64 alphabet as defined in RFC 4648 section 4. // // Strings in the Terraform language are sequences of unicode characters rather // than bytes, so this function will also interpret the resulting bytes as // the target encoding. func TextDecodeBase64(str, enc cty.Value) (cty.Value, error) { return TextDecodeBase64Func.Call([]cty.Value{str, enc}) }