implemented pkcs1_encrypt()

diff --git a/src/libstrongswan/crypto/rsa/rsa_public_key.c b/src/libstrongswan/crypto/rsa/rsa_public_key.c
index 2105d8ffe32ff9dfeb86575ae513cb00f60bf849..16ac3bbbdc2ab0800b991465e4a25ed6b93e6ed1 100644 (file)
--- a/src/libstrongswan/crypto/rsa/rsa_public_key.c
+++ b/src/libstrongswan/crypto/rsa/rsa_public_key.c
@@ -34,6 +34,7 @@
 #include "rsa_public_key.h"
 
 #include <debug.h>
+#include <utils/randomizer.h>
 #include <crypto/hashers/hasher.h>
 #include <asn1/asn1.h>
 #include <asn1/pem.h>
@@ -136,6 +137,55 @@ static chunk_t rsaep(const private_rsa_public_key_t *this, chunk_t data)
        return encrypted;
 }
 
+/**
+ * Implementation of rsa_public_key_t.eme_pkcs1_encrypt.
+ */
+static status_t pkcs1_encrypt(private_rsa_public_key_t *this,
+                                                         chunk_t in, chunk_t *out)
+{
+       chunk_t em;
+       u_char *pos;
+       int padding = this->k - in.len - 3;
+
+       if (padding < 8)
+       {
+               DBG1("rsa padding of %d bytes is too small", padding);
+               return FAILED;
+       }
+       em.len = this->k;
+       em.ptr = pos = malloc(em.len);
+       
+       /* add padding according to PKCS#1 7.2.1 1.+2. */
+       *pos++ = 0x00;
+    *pos++ = 0x02;
+
+    /* pad with pseudo random bytes unequal to zero */
+       {
+               randomizer_t *randomizer = randomizer_create();
+
+           /* pad with pseudo random bytes unequal to zero */
+               while (padding--)
+               {
+                       randomizer->get_pseudo_random_bytes(randomizer, 1, pos);
+                       while (!*pos)
+                       {
+                               randomizer->get_pseudo_random_bytes(randomizer, 1, pos);
+                       }
+                       pos++;
+               }
+               randomizer->destroy(randomizer);
+       }
+
+       /* append the padding terminator */
+       *pos++ = 0x00;
+
+       /* now add the data */
+       memcpy(pos, in.ptr, in.len);
+       *out = this->rsaep(this, em);
+       free(em.ptr);
+       return SUCCESS;
+}
+
 /**
  * Implementation of rsa_public_key.verify_emsa_pkcs1_signature.
  */
@@ -376,6 +426,7 @@ private_rsa_public_key_t *rsa_public_key_create_empty(void)
        private_rsa_public_key_t *this = malloc_thing(private_rsa_public_key_t);
        
        /* public functions */
+       this->public.pkcs1_encrypt = (status_t (*) (rsa_public_key_t*,chunk_t,chunk_t*))pkcs1_encrypt;
        this->public.verify_emsa_pkcs1_signature = (status_t (*) (const rsa_public_key_t*,hash_algorithm_t,chunk_t,chunk_t))verify_emsa_pkcs1_signature;
        this->public.get_modulus = (mpz_t *(*) (const rsa_public_key_t*))get_modulus;
        this->public.get_keysize = (size_t (*) (const rsa_public_key_t*))get_keysize;