rsa.md

Description

EOSIO-Taurus adds support to the RSA signature verification for easier integrations for enterprise applications using the RSA algorithm.

How to use it

A new intrinsic function verify_rsa_sha256_sig() is added.

When it is used in a smart contract, the declaration (see for example unittests/test-contracts/verify_rsa/verify_rsa.cpp) should be

extern "C" {
   __attribute__((eosio_wasm_import))
   int verify_rsa_sha256_sig(const char* message, uint32_t message_len,
                             const char* signature, uint32_t signature_len,
                             const char* exponent, uint32_t exponent_len,
                             const char* modulus, uint32_t modulus_len);
}

while the function signature in libraries/chain/apply_context.cpp is

bool verify_rsa_sha256_sig(const char* message, size_t message_len,
                           const char* signature, size_t signature_len,
                           const char* exponent, size_t exponent_len,
                           const char* modulus, size_t modulus_len);

For an example of using the verify_rsa_sha256_sig() function in a smart contract, please check unittests/test-contracts/verify_rsa/verify_rsa.cpp.

A protocol feature builtin_protocol_feature_t::verify_rsa_sha256_sig is added to enable the new intrinsic.