(SQL Server) Get ECC Public Key in JWK Format (JSON Web Key)

Demonstrates how to get an ECC public key in JWK (JSON Web Key) format.

Note: This example requires Chilkat v9.5.0.66 or later.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

-- Important: See this note about string length limitations for strings returned by sp_OAMethod calls.
--
CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    -- Important: Do not use nvarchar(max).  See the warning about using nvarchar(max).
    DECLARE @sTmp0 nvarchar(4000)
    -- Note: This example requires Chilkat v9.5.0.66 or later.

    -- Load a PEM file into memory.
    DECLARE @sbPem int
    -- Use "Chilkat_9_5_0.StringBuilder" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.StringBuilder', @sbPem OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    DECLARE @success int
    EXEC sp_OAMethod @sbPem, 'LoadFile', @success OUT, 'qa_data/pem/ecc_public.pem', 'utf-8'
    IF @success <> 1
      BEGIN

        PRINT 'Failed to load PEM file.'
        EXEC @hr = sp_OADestroy @sbPem
        RETURN
      END

    -- Load the PEM into a public key object.
    DECLARE @pubKey int
    -- Use "Chilkat_9_5_0.PublicKey" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.PublicKey', @pubKey OUT

    EXEC sp_OAMethod @sbPem, 'GetAsString', @sTmp0 OUT
    EXEC sp_OAMethod @pubKey, 'LoadFromString', @success OUT, @sTmp0
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @pubKey, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @sbPem
        EXEC @hr = sp_OADestroy @pubKey
        RETURN
      END

    -- Get the public key in JWK format:
    DECLARE @jwk nvarchar(4000)
    EXEC sp_OAMethod @pubKey, 'GetJwk', @jwk OUT

    -- The GetJwk method will return the JWK in the most compact JSON format possible,
    -- as a single line with no extra whitespace.  To get a more human-readable JWK (for this example),
    -- load into a Chilkat JSON object and emit non-compact:

    DECLARE @json int
    -- Use "Chilkat_9_5_0.JsonObject" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.JsonObject', @json OUT

    EXEC sp_OAMethod @json, 'Load', @success OUT, @jwk
    EXEC sp_OASetProperty @json, 'EmitCompact', 0

    PRINT 'ECC Public Key in JWK format:'
    EXEC sp_OAMethod @json, 'Emit', @sTmp0 OUT
    PRINT @sTmp0

    -- Sample output:
    -- { 
    --   "kty": "EC",
    --   "crv": "P-256",
    --   "x": "oBUyo8CQAFPeYPvv78ylh5MwFZjTCLQeb042TjiMJxE",
    --   "y": "vvQyxZkUjJQUPU_0bCy3Pj5qQdfu8jwEfqEeYGZ95CU"
    -- }
    -- 
    -- Additional information can be added like this:
    EXEC sp_OAMethod @json, 'AppendString', @success OUT, 'use', 'enc'
    EXEC sp_OAMethod @json, 'AppendString', @success OUT, 'kid', '123ABC'

    -- Now examine the JSON:
    EXEC sp_OAMethod @json, 'Emit', @sTmp0 OUT
    PRINT @sTmp0

    -- { 
    --   "kty": "EC",
    --   "crv": "P-256",
    --   "x": "oBUyo8CQAFPeYPvv78ylh5MwFZjTCLQeb042TjiMJxE",
    --   "y": "vvQyxZkUjJQUPU_0bCy3Pj5qQdfu8jwEfqEeYGZ95CU",
    --   "use": "enc",
    --   "kid": "123ABC"
    -- }

    EXEC @hr = sp_OADestroy @sbPem
    EXEC @hr = sp_OADestroy @pubKey
    EXEC @hr = sp_OADestroy @json


END
GO