openssl.scm

;;;; openssl.scm
;;;; Bindings to the OpenSSL SSL/TLS library

(module openssl
  (
   ssl-connect
   ssl-make-client-context
   ssl-client-context?
   ssl-listen
   ssl-close
   ssl-port?
   ssl-port->tcp-port
   ssl-listener?
   ssl-listener?
   ssl-listener-port
   ssl-listener-fileno
   ssl-accept-ready?
   ssl-accept
   ssl-handshake-timeout
   ssl-shutdown-timeout
   ssl-load-certificate-chain!
   ssl-load-private-key!
   ssl-set-verify!
   ssl-load-verify-root-certificates!
   ssl-load-suggested-certificate-authorities!
   ssl-peer-verified?
   ssl-peer-subject-name ssl-peer-issuer-name
   ssl-make-i/o-ports
   net-unwrap-tcp-ports
   ssl-signature-verify)

(import scheme chicken foreign ports)

(declare
 (usual-integrations)
 (no-procedure-checks-for-usual-bindings)
 (bound-to-procedure
   ##sys#update-errno
   ##sys#signal-hook
   ##sys#string-append
   ##sys#tcp-port->fileno
   ##sys#current-thread
   ##sys#size
   ##sys#setslot
   ##sys#check-string
   ##sys#expand-home-path))

(use srfi-18 tcp)

#>
#include <errno.h>
#ifdef _WIN32
  #ifdef _MSC_VER
    #include <winsock2.h>
  #else
    #include <ws2tcpip.h>
  #endif

  #include <openssl/rand.h>
#else
  #define closesocket     close
#endif

#ifdef ECOS
  #include <sys/sockio.h>
#else
  #include <unistd.h>
#endif

#include <openssl/err.h>
#include <openssl/ssl.h>
#include <openssl/rsa.h>

<#

(foreign-code #<<EOF
ERR_load_crypto_strings();
SSL_load_error_strings();
SSL_library_init();

#ifdef _WIN32
  RAND_screen();
#endif

EOF
)

;;
;;  ......
;;

;; verify a signature, given a public key file
(define (ssl-signature-verify certfile signature)
  ((foreign-lambda*
     c-string* ((c-string pathname) (c-string signature))
     "unsigned char *pad = RSA_PKCS1_PADDING;\n"
     "EVP_PKEY *pkey = load_pubkey(NULL, pathname, str2fmt(\"PEM\"), 0, NULL, NULL, \"Public Key\");\n"
     "RSA *rsa = EVP_PKEY_get1_RSA(pkey);\n"
     "EVP_PKEY_free(pkey);\n"
     "int keysize = RSA_size(rsa);\n"
     "unsigned char *rsa_out = malloc(keysize);\n"
     "int rsa_outlen = RSA_public_decrypt(strlen(signature), signature, rsa_out, rsa, pad);\n"
     "C_return(rsa_out);\n")
   (certfile signature)))
)