static gchar *twitter_oauth_sign(const gchar * txt, const gchar * key)
{
PurpleCipher *cipher;
PurpleCipherContext *ctx;
static guchar output[20];
size_t output_size;
cipher = purple_ciphers_find_cipher("hmac");
if (!cipher) {
purple_debug_error(GENERIC_PROTOCOL_ID, "%s: Could not find cipher\n", G_STRFUNC);
return NULL;
}
ctx = purple_cipher_context_new(cipher, NULL);
if (!ctx) {
purple_debug_error(GENERIC_PROTOCOL_ID, "%s: Could not create cipher context\n", G_STRFUNC);
return NULL;
}
purple_cipher_context_set_option(ctx, "hash", "sha1");
purple_cipher_context_set_key(ctx, (guchar *) key);
purple_cipher_context_append(ctx, (guchar *) txt, strlen(txt));
if (!purple_cipher_context_digest(ctx, 20, output, &output_size)) {
purple_debug_error(GENERIC_PROTOCOL_ID, "%s: Could not sign text\n", G_STRFUNC);
purple_cipher_context_destroy(ctx);
return NULL;
}
purple_cipher_context_destroy(ctx);
return purple_base64_encode(output, output_size);
}
/**
* @return A null-terminated base64 encoded version of the HMAC
* calculated using the given key and data.
*/
static gchar *hmac_sha256(const char *key, const char *message)
{
PurpleCipherContext *context;
guchar digest[32];
context = purple_cipher_context_new_by_name("hmac", NULL);
purple_cipher_context_set_option(context, "hash", "sha256");
purple_cipher_context_set_key(context, (guchar *)key);
purple_cipher_context_append(context, (guchar *)message, strlen(message));
purple_cipher_context_digest(context, sizeof(digest), digest, NULL);
purple_cipher_context_destroy(context);
return purple_base64_encode(digest, sizeof(digest));
}
static char *
des3_cbc(const char *key, const char *iv, const char *data, int len, gboolean decrypt)
{
PurpleCipherContext *des3;
char *out;
size_t outlen;
des3 = purple_cipher_context_new_by_name("des3", NULL);
purple_cipher_context_set_key(des3, (guchar *)key);
purple_cipher_context_set_batch_mode(des3, PURPLE_CIPHER_BATCH_MODE_CBC);
purple_cipher_context_set_iv(des3, (guchar *)iv, 8);
out = g_malloc(len);
if (decrypt)
purple_cipher_context_decrypt(des3, (guchar *)data, len, (guchar *)out, &outlen);
else
purple_cipher_context_encrypt(des3, (guchar *)data, len, (guchar *)out, &outlen);
purple_cipher_context_destroy(des3);
return out;
}
