terraform/lang/funcs/encoding.go

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package funcs
import (
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"bytes"
"compress/gzip"
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"encoding/base64"
"fmt"
"log"
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"net/url"
"unicode/utf8"
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"github.com/zclconf/go-cty/cty"
"github.com/zclconf/go-cty/cty/function"
)
// 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 the provided string is not valid UTF-8: %s", sDec)
return cty.UnknownVal(cty.String), fmt.Errorf("the result of decoding the the provided string is not valid UTF-8")
}
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return cty.StringVal(string(sDec)), nil
},
})
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// 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
},
})
// 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
},
})
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// Base64Decode decodes a string containing a base64 sequence.
//
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// Terraform uses the "standard" Base64 alphabet as defined in RFC 4648 section 4.
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//
// 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})
}
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// Base64Encode applies Base64 encoding to a string.
//
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// Terraform uses the "standard" Base64 alphabet as defined in RFC 4648 section 4.
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//
// 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})
}
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// Base64Gzip compresses a string with gzip and then encodes the result in
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// Base64 encoding.
//
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// Terraform uses the "standard" Base64 alphabet as defined in RFC 4648 section 4.
//
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// 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})
}
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// URLEncode applies URL encoding to a given string.
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//
// 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
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// escapes them using RFC 3986 "percent encoding".
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//
// 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})
}