crypto: add oaepLabel option

The label acts as the "L" input to the RSA-OAEP algorithm.

PR-URL: https://github.com/nodejs/node/pull/29489
Reviewed-By: David Carlier <devnexen@gmail.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Minwoo Jung <minwoo@nodesource.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

2 files changed, 22 insertions, 0 deletions

diff --git a/src/node_crypto.cc b/src/node_crypto.cc
index b1d8145e6d..40dad6827b 100644
--- a/src/node_crypto.cc
+++ b/src/node_crypto.cc
@@ -5204,6 +5204,8 @@ bool PublicKeyCipher::Cipher(Environment* env,
                              const ManagedEVPPKey& pkey,
                              int padding,
                              const EVP_MD* digest,
+                             const void* oaep_label,
+                             size_t oaep_label_len,
                              const unsigned char* data,
                              int len,
                              AllocatedBuffer* out) {
@@ -5220,6 +5222,16 @@ bool PublicKeyCipher::Cipher(Environment* env,
       return false;
   }
 
+  if (oaep_label_len != 0) {
+    // OpenSSL takes ownership of the label, so we need to create a copy.
+    void* label = OPENSSL_memdup(oaep_label, oaep_label_len);
+    CHECK_NOT_NULL(label);
+    if (!EVP_PKEY_CTX_set0_rsa_oaep_label(ctx.get(), label, oaep_label_len)) {
+      OPENSSL_free(label);
+      return false;
+    }
+  }
+
   size_t out_len = 0;
   if (EVP_PKEY_cipher(ctx.get(), nullptr, &out_len, data, len) <= 0)
     return false;
@@ -5265,6 +5277,12 @@ void PublicKeyCipher::Cipher(const FunctionCallbackInfo<Value>& args) {
       return THROW_ERR_OSSL_EVP_INVALID_DIGEST(env);
   }
 
+  ArrayBufferViewContents<unsigned char> oaep_label;
+  if (!args[offset + 3]->IsUndefined()) {
+    CHECK(args[offset + 3]->IsArrayBufferView());
+    oaep_label.Read(args[offset + 3].As<ArrayBufferView>());
+  }
+
   AllocatedBuffer out;
 
   ClearErrorOnReturn clear_error_on_return;
@@ -5274,6 +5292,8 @@ void PublicKeyCipher::Cipher(const FunctionCallbackInfo<Value>& args) {
       pkey,
       padding,
       digest,
+      oaep_label.data(),
+      oaep_label.length(),
       buf.data(),
       buf.length(),
       &out);
diff --git a/src/node_crypto.h b/src/node_crypto.h
index 99e6c48117..e335491612 100644
--- a/src/node_crypto.h
+++ b/src/node_crypto.h
@@ -714,6 +714,8 @@ class PublicKeyCipher {
                      const ManagedEVPPKey& pkey,
                      int padding,
                      const EVP_MD* digest,
+                     const void* oaep_label,
+                     size_t oaep_label_size,
                      const unsigned char* data,
                      int len,
                      AllocatedBuffer* out);