ECDSA verification + chain of trust on ARM Cortex M0

We are developing a small Bluetooth device including a Dialog Semiconductor DA14580 SoC. The DA14580 is based on a Cortex M0 with 42kB SRAM and a connected Flash with 512kB. Our server signs a short message with his Root-CA (ECDSA) certificate. Alternatively this message can be signed by a intermediate CA-certificate (ECDSA). We are now looking for somebody (preferably having experience with the DA14580) who can implement us a C-Code that 1. verifies the signature of the message 2. verifies the Chain of Trust up to the Root-CA certificate 3. runs on a Cortex M0 with as low as 42kB of RAM and 512kB of Flash The project also requires you to be able to generate a certificate, an intermediate certificate and sign a message which can be verified with the C-Code. The datasheet of the DA14580 can be found online.