feat: Assertion verification

cmd/dev.go

@@ -132,20 +132,6 @@ func readPipedStdin() []byte {
 	return nil
 }
 
-func readBytesFromFile(filePath string) []byte {
-	fileToEncrypt, err := os.Open(filePath)
-	if err != nil {
-		cli.ExitWithError(fmt.Sprintf("Failed to open file at path: %s", filePath), err)
-	}
-	defer fileToEncrypt.Close()
-
-	bytes, err := io.ReadAll(fileToEncrypt)
-	if err != nil {
-		cli.ExitWithError(fmt.Sprintf("Failed to read bytes from file at path: %s", filePath), err)
-	}
-	return bytes
-}
-
 func init() {
 	designCmd := man.Docs.GetCommand("dev/design-system",
 		man.WithRun(dev_designSystem),

cmd/tdf-decrypt.go

@@ -7,11 +7,16 @@ import (
 
 	"github.com/opentdf/otdfctl/pkg/cli"
 	"github.com/opentdf/otdfctl/pkg/man"
+	"github.com/opentdf/otdfctl/pkg/utils"
 	"github.com/spf13/cobra"
 )
 
 var TDF = "tdf"
 
+var assertionVerification string
+
+const TDF_MAX_FILE_SIZE = int64(10 * 1024 * 1024 * 1024) // 10 GB
+
 func dev_tdfDecryptCmd(cmd *cobra.Command, args []string) {
 	c := cli.New(cmd, args, cli.WithPrintJson())
 	h := NewHandler(c)
@@ -26,16 +31,20 @@ func dev_tdfDecryptCmd(cmd *cobra.Command, args []string) {
 	// Prefer file argument over piped input over default filename
 	bytesToDecrypt := piped
 	var tdfFile string
+	var err error
 	if len(args) > 0 {
 		tdfFile = args[0]
-		bytesToDecrypt = readBytesFromFile(tdfFile)
+		bytesToDecrypt, err = utils.ReadBytesFromFile(tdfFile, TDF_MAX_FILE_SIZE)
+		if err != nil {
+			cli.ExitWithError("Failed to read file:", err)
+		}
 	}
 
 	if len(bytesToDecrypt) == 0 {
 		cli.ExitWithError("Must provide ONE of the following to decrypt: [file argument, stdin input]", errors.New("no input provided"))
 	}
 
-	decrypted, err := h.DecryptBytes(bytesToDecrypt, disableAssertionVerification)
+	decrypted, err := h.DecryptBytes(bytesToDecrypt, assertionVerification, disableAssertionVerification)
 	if err != nil {
 		cli.ExitWithError("Failed to decrypt file", err)
 	}
@@ -74,6 +83,13 @@ func init() {
 		decryptCmd.GetDocFlag("tdf-type").Default,
 		decryptCmd.GetDocFlag("tdf-type").Description,
 	)
+	decryptCmd.Flags().StringVarP(
+		&assertionVerification,
+		decryptCmd.GetDocFlag("with-assertion-verification-keys").Name,
+		decryptCmd.GetDocFlag("with-assertion-verification-keys").Shorthand,
+		"",
+		decryptCmd.GetDocFlag("with-assertion-verification-keys").Description,
+	)
 	decryptCmd.Flags().Bool(
 		decryptCmd.GetDocFlag("no-verify-assertions").Name,
 		decryptCmd.GetDocFlag("no-verify-assertions").DefaultAsBool(),

cmd/tdf-encrypt.go

@@ -11,6 +11,7 @@ import (
 	"github.com/gabriel-vasile/mimetype"
 	"github.com/opentdf/otdfctl/pkg/cli"
 	"github.com/opentdf/otdfctl/pkg/man"
+	"github.com/opentdf/otdfctl/pkg/utils"
 	"github.com/spf13/cobra"
 )
 
@@ -24,6 +25,8 @@ const (
 var attrValues []string
 var assertions string
 
+const INPUT_MAX_FILE_SIZE = int64(10 * 1024 * 1024 * 1024) // 10 GB
+
 func dev_tdfEncryptCmd(cmd *cobra.Command, args []string) {
 	c := cli.New(cmd, args, cli.WithPrintJson())
 	h := NewHandler(c)
@@ -63,8 +66,12 @@ func dev_tdfEncryptCmd(cmd *cobra.Command, args []string) {
 
 	// prefer filepath argument over stdin input
 	bytesSlice := piped
+	var err error
 	if filePath != "" {
-		bytesSlice = readBytesFromFile(filePath)
+		bytesSlice, err = utils.ReadBytesFromFile(filePath, INPUT_MAX_FILE_SIZE)
+		if err != nil {
+			cli.ExitWithError("Failed to read file:", err)
+		}
 	}
 
 	// auto-detect mime type if not provided

docs/man/decrypt/_index.md

@@ -13,6 +13,9 @@ command:
     - name: no-verify-assertions
       description: disable verification of assertions
       default: false
+    - name: with-assertion-verification-keys
+      description: >
+        EXPERIMENTAL: path to JSON file of keys to verify signed assertions. See examples for more information.
 ---
 
 Decrypt a Trusted Data Format (TDF) file and output the contents to stdout or a file in the current working directory.
@@ -40,3 +43,16 @@ Advanced piping is supported
 $ echo "hello world" | otdfctl encrypt | otdfctl decrypt | cat
 hello world
 ```
+
+### ZTDF Assertion Verification (experimental)
+
+To verify the signed assertions (metadata bound to the TDF), you can provide verification keys. The supported assertion signing algorithms are HS256 and RS256 so the keys provided should either be an HS256 key or a public RS256 key.
+```shell
+# decrypt file and write to standard output
+otdfctl decrypt hello.txt.tdf --with-assertion-verification-keys my_assertion_verification_keys.json
+```
+Where my_assertion_verification_keys.json looks like:
+```json
+{"keys":{"assertion1":{ "alg":"HS256","key":"k0cn4xBcY+49z5gs4OHUs/kbQ3/T8p+uUW9pIQ/9aqE="},"assertion2":{ "alg":"RS256","key":"-----BEGIN PUBLIC KEY-----\nMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAmr0wRsdXN0O9NiltxoGy\nC6ZYwHbdiPVzvOnm9ven5g7Fpm3HOmygdi021WX1OlSua+OSrXGPjM2xbY3LTrFH\nQXQEITjraXQRp5vlKDbBnOrtjYDaKazBXgTYVdelE4AIAuQaGoTudMasHBGiLPEW\niTL4ySec0NzHn2s72Q4hn5/KJpIJOGqj0SlNViufdNylkjrJ3apoYFv1Mhwi3EF/\niFZQ5encDDJmcG/UYF3msbuHRzArJJQ733BNRvicWF/nqixKxprvm8Ts8a54tr8N\nZ7cEu1u5G6AY/pZFGk4ml8q3v5o1ja7xw2dgpJlS8Tl88tUzs+7GG8Ib8n7mHqeP\nTQIDAQAB\n-----END PUBLIC KEY-----\n"}}}
+```
+If no verification keys are provided, the SDK will default to verifying using the payload key. If the assertions were not signed with the payload key, the decrypt call will fail.

docs/man/encrypt/_index.md

@@ -27,7 +27,7 @@ command:
       default: /kas
     - name: with-assertions
       description: >
-        EXPERIMENTAL: JSON string of assertions to bind metadata to the TDF. See examples for more information.
+        EXPERIMENTAL: JSON string or path to a JSON file of assertions to bind metadata to the TDF. See examples for more information. WARNING: Providing keys in a JSON string is strongly discouraged. If including sensitive keys, instead provide a path to a JSON file containing that information.
 ---
 
 Build a Trusted Data Format (TDF) with encrypted content from a specified file or input from stdin utilizing OpenTDF platform.
@@ -86,12 +86,28 @@ otdfctl encrypt hello.txt --tdf-type nano --out hello.txt.tdf
 
 ## ZTDF Assertions (experimental)
 
-Assertions are a way to bind metadata to the TDF data object in a cryptographically secure way. 
+Assertions are a way to bind metadata to the TDF data object in a cryptographically secure way. The data is signed with the provided signing key, or if none is provided, the payload key. The signing key algorithms supported are HS256 and RS256. 
 
 ### STANAG 5636
 
-The following example demonstrates how to bind a STANAG 5636 metadata assertion to the TDF data object.
+The following example demonstrates how to bind a STANAG 5636 metadata assertion, to the TDF data object.
 
 ```shell
-otdfctl encrypt hello.txt --out hello.txt.tdf --with-assertions '[{"id":"assertion1","type":"handling","scope":"tdo","appliesToState":"encrypted","statement":{"format":"json+stanag5636","schema":"urn:nato:stanag:5636:A:1:elements:json","value":"{\"ocl\":\"2024-10-21T20:47:36Z\"}"}}]'
+otdfctl encrypt hello.txt --out hello.txt.tdf --with-assertions '[{"id":"assertion1","type":"handling","scope":"tdo","appliesToState":"encrypted","statement":{"format":"json+stanag5636","schema":"urn:nato:stanag:5636:A:1:elements:json","value":"{\"ocl\":\"2024-10-21T20:47:36Z\"}"}]'
 ```
+
+We also support providing an assertions json file. 
+You can optionally provide your own signing key. In this example, we provide an RS256 private key.
+```json
+[{"id":"assertion1","type":"handling","scope":"tdo","appliesToState":"encrypted","statement":{"format":"json+stanag5636","schema":"urn:nato:stanag:5636:A:1:elements:json","value":"{\"ocl\":\"2024-10-21T20:47:36Z\"}","signingKey":{"alg":"RS256","key":"-----BEGIN PRIVATE KEY-----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\nF267fElUPN4+pSOAhPI=\n-----END PRIVATE KEY-----\n"}}]
+```
+```shell
+otdfctl encrypt hello.txt --out hello.txt.tdf --with-assertions my_assertions_signed_rs256.json
+```
+Signing with HS256 is also available.
+```json
+[{"id":"assertion1","type":"handling","scope":"tdo","appliesToState":"encrypted","statement":{"format":"json+stanag5636","schema":"urn:nato:stanag:5636:A:1:elements:json","value":"{\"ocl\":\"2024-10-21T20:47:36Z\"}","signingKey":{"alg":"HS256","key":"k0cn4xBcY+49z5gs4OHUs/kbQ3/T8p+uUW9pIQ/9aqE="}}]
+```
+```shell
+otdfctl encrypt hello.txt --out hello.txt.tdf --with-assertions my_assertions_signed_hs256.json
+```

e2e/encrypt-decrypt.bats

@@ -22,7 +22,30 @@ setup_file() {
   VAL_ID=$(./otdfctl --host $HOST $WITH_CREDS $DEBUG_LEVEL policy attributes values create --attribute-id "$ATTR_ID" -v value1 --json | jq -r '.id')
   # entitles opentdf client id for client credentials CLI user
   SCS='[{"condition_groups":[{"conditions":[{"operator":1,"subject_external_values":["opentdf"],"subject_external_selector_value":".clientId"}],"boolean_operator":2}]}]'
-  ASSERTIONS='[{"id":"assertion1","type":"handling","scope":"tdo","appliesToState":"encrypted","statement":{"format":"json+stanag5636","schema":"urn:nato:stanag:5636:A:1:elements:json","value":"{\"ocl\":\"2024-10-21T20:47:36Z\"}"}}]'
+
+  # assertions setup
+  HS256_KEY=$(openssl rand -base64 32)
+  RS_PRIVATE_KEY=rs_private_key.pem
+  RS_PUBLIC_KEY=rs_public_key.pem
+  openssl genpkey -algorithm RSA -out $RS_PRIVATE_KEY -pkeyopt rsa_keygen_bits:2048
+  openssl rsa -pubout -in $RS_PRIVATE_KEY -out $RS_PUBLIC_KEY
+
+  export ASSERTIONS='[{"id":"assertion1","type":"handling","scope":"tdo","appliesToState":"encrypted","statement":{"format":"json+stanag5636","schema":"urn:nato:stanag:5636:A:1:elements:json","value":"{\"ocl\":\"2024-10-21T20:47:36Z\"}"}}]'
+
+  export SIGNED_ASSERTIONS_HS256=signed_assertions_hs256.json
+  export SIGNED_ASSERTION_VERIFICATON_HS256=assertion_verification_hs256.json
+  export SIGNED_ASSERTIONS_RS256=signed_assertion_rs256.json
+  export SIGNED_ASSERTION_VERIFICATON_RS256=assertion_verification_rs256.json
+  echo '[{"id":"assertion1","type":"handling","scope":"tdo","appliesToState":"encrypted","statement":{"format":"json+stanag5636","schema":"urn:nato:stanag:5636:A:1:elements:json","value":"{\"ocl\":\"2024-10-21T20:47:36Z\"}"},"signingKey":{"alg":"HS256","key":"replace"}}]' > $SIGNED_ASSERTIONS_HS256
+  jq --arg pem "$(echo $HS256_KEY)" '.[0].signingKey.key = $pem' $SIGNED_ASSERTIONS_HS256 > tmp.json && mv tmp.json $SIGNED_ASSERTIONS_HS256
+  echo '{"keys":{"assertion1":{"alg":"HS256","key":"replace"}}}' > $SIGNED_ASSERTION_VERIFICATON_HS256
+  jq --arg pem "$(echo $HS256_KEY)" '.keys.assertion1.key = $pem' $SIGNED_ASSERTION_VERIFICATON_HS256 > tmp.json && mv tmp.json $SIGNED_ASSERTION_VERIFICATON_HS256
+  echo '[{"id":"assertion1","type":"handling","scope":"tdo","appliesToState":"encrypted","statement":{"format":"json+stanag5636","schema":"urn:nato:stanag:5636:A:1:elements:json","value":"{\"ocl\":\"2024-10-21T20:47:36Z\"}"},"signingKey":{"alg":"RS256","key":"replace"}}]' > $SIGNED_ASSERTIONS_RS256
+  jq --arg pem "$(<$RS_PRIVATE_KEY)" '.[0].signingKey.key = $pem' $SIGNED_ASSERTIONS_RS256 > tmp.json && mv tmp.json $SIGNED_ASSERTIONS_RS256
+  echo '{"keys":{"assertion1":{"alg":"RS256","key":"replace"}}}' > $SIGNED_ASSERTION_VERIFICATON_RS256
+  jq --arg pem "$(<$RS_PUBLIC_KEY)" '.keys.assertion1.key = $pem' $SIGNED_ASSERTION_VERIFICATON_RS256 > tmp.json && mv tmp.json $SIGNED_ASSERTION_VERIFICATON_RS256
+
+
   SM=$(./otdfctl --host $HOST $WITH_CREDS $DEBUG_LEVEL policy subject-mappings create --action-standard DECRYPT -a "$VAL_ID" --subject-condition-set-new "$SCS")
   export FQN="https://testing-enc-dec.io/attr/attr1/value/value1"
   export MIXED_CASE_FQN="https://Testing-Enc-Dec.io/attr/Attr1/value/VALUE1"
@@ -34,6 +57,7 @@ teardown() {
 
 teardown_file(){
     ./otdfctl --host "$HOST" $WITH_CREDS policy attributes namespaces unsafe delete --id "$NS_ID" --force
+    rm -f $SIGNED_ASSERTIONS_HS256 $SIGNED_ASSERTION_VERIFICATON_HS256 $SIGNED_ASSERTIONS_RS256 $SIGNED_ASSERTION_VERIFICATON_RS256
 }
 
 @test "roundtrip TDF3, no attributes, file" {
@@ -57,6 +81,18 @@ teardown_file(){
   ./otdfctl decrypt --host $HOST --tls-no-verify $DEBUG_LEVEL $WITH_CREDS $OUTFILE_TXT | grep "$SECRET_TEXT"
 }
 
+@test "roundtrip TDF3, assertions with HS265 keys and verificaion, file" {
+  ./otdfctl encrypt -o $OUTFILE_GO_MOD --host $HOST --tls-no-verify $DEBUG_LEVEL $WITH_CREDS -a $FQN --with-assertions $SIGNED_ASSERTIONS_HS256 --tdf-type tdf3 $INFILE_GO_MOD
+  ./otdfctl decrypt -o $RESULTFILE_GO_MOD --host $HOST --tls-no-verify $DEBUG_LEVEL $WITH_CREDS --with-assertion-verification-keys $SIGNED_ASSERTION_VERIFICATON_HS256 --tdf-type tdf3 $OUTFILE_GO_MOD
+  diff $INFILE_GO_MOD $RESULTFILE_GO_MOD
+}
+
+@test "roundtrip TDF3, assertions with RS256 keys and verificaion, file" {
+  ./otdfctl encrypt -o $OUTFILE_GO_MOD --host $HOST --tls-no-verify $DEBUG_LEVEL $WITH_CREDS -a $FQN --with-assertions $SIGNED_ASSERTIONS_RS256 --tdf-type tdf3 $INFILE_GO_MOD
+  ./otdfctl decrypt -o $RESULTFILE_GO_MOD --host $HOST --tls-no-verify $DEBUG_LEVEL $WITH_CREDS --with-assertion-verification-keys $SIGNED_ASSERTION_VERIFICATON_RS256 --tdf-type tdf3 $OUTFILE_GO_MOD
+  diff $INFILE_GO_MOD $RESULTFILE_GO_MOD
+}
+
 @test "roundtrip NANO, no attributes, file" {
   ./otdfctl encrypt -o $OUTFILE_GO_MOD --host $HOST --tls-no-verify $DEBUG_LEVEL $WITH_CREDS --tdf-type nano $INFILE_GO_MOD
   ./otdfctl decrypt -o $RESULTFILE_GO_MOD --host $HOST --tls-no-verify $DEBUG_LEVEL $WITH_CREDS --tdf-type nano $OUTFILE_GO_MOD