[ncp] add support in spinel/NCP to generate PSKc from pass-phrase (#4294)

src/ncp/ncp_base.cpp

@@ -936,6 +936,9 @@ bool NcpBase::HandlePropertySetForSpecialProperties(uint8_t aHeader, spinel_prop
 #endif
 
 #if OPENTHREAD_FTD && OPENTHREAD_CONFIG_COMMISSIONER_ENABLE
+    case SPINEL_PROP_MESHCOP_COMMISSIONER_GENERATE_PSKC:
+        ExitNow(aError = HandlePropertySet_SPINEL_PROP_MESHCOP_COMMISSIONER_GENERATE_PSKC(aHeader));
+
     case SPINEL_PROP_THREAD_COMMISSIONER_ENABLED:
         ExitNow(aError = HandlePropertySet_SPINEL_PROP_THREAD_COMMISSIONER_ENABLED(aHeader));
 #endif

src/ncp/ncp_base.hpp

@@ -413,6 +413,7 @@ protected:
 #endif
 
 #if OPENTHREAD_FTD && OPENTHREAD_CONFIG_COMMISSIONER_ENABLE
+    otError HandlePropertySet_SPINEL_PROP_MESHCOP_COMMISSIONER_GENERATE_PSKC(uint8_t aHeader);
     otError HandlePropertySet_SPINEL_PROP_THREAD_COMMISSIONER_ENABLED(uint8_t aHeader);
 #endif // OPENTHREAD_FTD
 

src/ncp/ncp_base_ftd.cpp

@@ -759,6 +759,32 @@ exit:
     return error;
 }
 
+otError NcpBase::HandlePropertySet_SPINEL_PROP_MESHCOP_COMMISSIONER_GENERATE_PSKC(uint8_t aHeader)
+{
+    otError        error = OT_ERROR_NONE;
+    const char *   passPhrase;
+    const char *   networkName;
+    const uint8_t *extPanIdData;
+    uint16_t       length;
+    otPskc         pskc;
+
+    SuccessOrExit(error = mDecoder.ReadUtf8(passPhrase));
+    SuccessOrExit(error = mDecoder.ReadUtf8(networkName));
+    SuccessOrExit(error = mDecoder.ReadDataWithLen(extPanIdData, length));
+    VerifyOrExit(length == sizeof(spinel_net_xpanid_t), error = OT_ERROR_PARSE);
+
+    SuccessOrExit(error = otCommissionerGeneratePskc(passPhrase, networkName,
+                                                     reinterpret_cast<const otExtendedPanId *>(extPanIdData), &pskc));
+
+    SuccessOrExit(
+        error = mEncoder.BeginFrame(aHeader, SPINEL_CMD_PROP_VALUE_IS, SPINEL_PROP_MESHCOP_COMMISSIONER_GENERATE_PSKC));
+    SuccessOrExit(error = mEncoder.WriteData(pskc.m8, sizeof(pskc)));
+    SuccessOrExit(error = mEncoder.EndFrame());
+
+exit:
+    return error;
+}
+
 // SPINEL_PROP_THREAD_COMMISSIONER_ENABLED is replaced by SPINEL_PROP_MESHCOP_COMMISSIONER_STATE. Please use the new
 // property. The old property/implementation remains for backward compatibility.
 

src/ncp/spinel.c

@@ -1883,6 +1883,10 @@ const char *spinel_prop_key_to_cstr(spinel_prop_key_t prop_key)
         ret = "MESHCOP_COMMISSIONER_MGMT_SET";
         break;
 
+    case SPINEL_PROP_MESHCOP_COMMISSIONER_GENERATE_PSKC:
+        ret = "MESHCOP_COMMISSIONER_GENERATE_PSKC";
+        break;
+
     case SPINEL_PROP_CHANNEL_MANAGER_NEW_CHANNEL:
         ret = "CHANNEL_MANAGER_NEW_CHANNEL";
         break;

src/ncp/spinel.h

@@ -3208,6 +3208,29 @@ typedef enum
      */
     SPINEL_PROP_MESHCOP_COMMISSIONER_MGMT_SET = SPINEL_PROP_MESHCOP_EXT__BEGIN + 6,
 
+    // Thread Commissioner Generate PSKc
+    /** Format: `UUd` - Write only
+     *
+     * Required capability: SPINEL_CAP_THREAD_COMMISSIONER
+     *
+     * Writing to this property allows user to generate PSKc from a given commissioning pass-phrase, network name,
+     * extended PAN Id.
+     *
+     * Written value format is:
+     *
+     *   `U` : The commissioning pass-phrase.
+     *   `U` : Network Name.
+     *   `d` : Extended PAN ID.
+     *
+     * The response on success would be a `VALUE_IS` command with the PSKc with format below:
+     *
+     *   `D` : The PSKc
+     *
+     * On a failure a `LAST_STATUS` is emitted with the error status.
+     *
+     */
+    SPINEL_PROP_MESHCOP_COMMISSIONER_GENERATE_PSKC = SPINEL_PROP_MESHCOP_EXT__BEGIN + 7,
+
     SPINEL_PROP_MESHCOP_EXT__END = 0x1900,
 
     SPINEL_PROP_OPENTHREAD__BEGIN = 0x1900,