+static int aes_gcm_ctrl(EVP_CIPHER_CTX *c, int type, int arg, void *ptr)
+ {
+ EVP_AES_GCM_CTX *gctx = c->cipher_data;
+ switch (type)
+ {
+ case EVP_CTRL_INIT:
+ gctx->gcm = NULL;
+ gctx->key_set = 0;
+ gctx->iv_set = 0;
+ gctx->ivlen = c->cipher->iv_len;
+ gctx->iv = c->iv;
+ gctx->taglen = -1;
+ gctx->iv_gen = 0;
+ return 1;
+
+ case EVP_CTRL_GCM_SET_IVLEN:
+ if (arg <= 0)
+ return 0;
+#ifdef OPENSSL_FIPS
+ if (FIPS_mode() && !(c->flags & EVP_CIPH_FLAG_NON_FIPS_ALLOW)
+ && arg < 12)
+ return 0;
+#endif
+ /* Allocate memory for IV if needed */
+ if ((arg > EVP_MAX_IV_LENGTH) && (arg > gctx->ivlen))
+ {
+ if (gctx->iv != c->iv)
+ OPENSSL_free(gctx->iv);
+ gctx->iv = OPENSSL_malloc(arg);
+ if (!gctx->iv)
+ return 0;
+ }
+ gctx->ivlen = arg;
+ return 1;
+
+ case EVP_CTRL_GCM_SET_TAG:
+ if (arg <= 0 || arg > 16 || c->encrypt)
+ return 0;
+ memcpy(gctx->tag, ptr, arg);
+ gctx->taglen = arg;
+ return 1;
+
+ case EVP_CTRL_GCM_GET_TAG:
+ if (arg <= 0 || arg > 16 || !c->encrypt || gctx->taglen < 0)
+ return 0;
+ memcpy(ptr, gctx->tag, arg);
+ return 1;
+
+ case EVP_CTRL_GCM_SET_IV_FIXED:
+ /* Special case: -1 length restores whole IV */
+ if (arg == -1)
+ {
+ memcpy(gctx->iv, ptr, gctx->ivlen);
+ gctx->iv_gen = 1;
+ return 1;
+ }
+ /* Fixed field must be at least 4 bytes and invocation field
+ * at least 8.
+ */
+ if ((arg < 4) || (gctx->ivlen - arg) < 8)
+ return 0;
+ if (arg)
+ memcpy(gctx->iv, ptr, arg);
+ if (RAND_bytes(gctx->iv + arg, gctx->ivlen - arg) <= 0)
+ return 0;
+ gctx->iv_gen = 1;
+ return 1;
+
+ case EVP_CTRL_GCM_IV_GEN:
+ if (gctx->iv_gen == 0 || gctx->key_set == 0)
+ return 0;
+ CRYPTO_gcm128_setiv(gctx->gcm, gctx->iv, gctx->ivlen);
+ memcpy(ptr, gctx->iv, gctx->ivlen);
+ /* Invocation field will be at least 8 bytes in size and
+ * so no need to check wrap around or increment more than
+ * last 8 bytes.
+ */
+ ctr64_inc(gctx->iv + gctx->ivlen - 8);
+ gctx->iv_set = 1;
+ return 1;
+
+ default:
+ return -1;
+
+ }
+ }
+
+static int aes_gcm_init_key(EVP_CIPHER_CTX *ctx, const unsigned char *key,
+ const unsigned char *iv, int enc)
+ {
+ EVP_AES_GCM_CTX *gctx = ctx->cipher_data;
+ if (!iv && !key)
+ return 1;
+ if (key)
+ {
+ AES_set_encrypt_key(key, ctx->key_len * 8, &gctx->ks);
+ if (!gctx->gcm)
+ {
+ gctx->gcm =
+ CRYPTO_gcm128_new(&gctx->ks, (block128_f)AES_encrypt);
+ if (!gctx->gcm)
+ return 0;
+ }
+ else
+ CRYPTO_gcm128_init(gctx->gcm, &gctx->ks, (block128_f)AES_encrypt);
+ /* If we have an iv can set it directly, otherwise use
+ * saved IV.
+ */
+ if (iv == NULL && gctx->iv_set)
+ iv = gctx->iv;
+ if (iv)
+ {
+ CRYPTO_gcm128_setiv(gctx->gcm, iv, gctx->ivlen);
+ gctx->iv_set = 1;
+ }
+ gctx->key_set = 1;
+ }
+ else
+ {
+ /* If key set use IV, otherwise copy */
+ if (gctx->key_set)
+ CRYPTO_gcm128_setiv(gctx->gcm, iv, gctx->ivlen);
+ else
+ memcpy(gctx->iv, iv, gctx->ivlen);
+ gctx->iv_set = 1;
+ gctx->iv_gen = 0;
+ }
+ return 1;
+ }
+
+static int aes_gcm(EVP_CIPHER_CTX *ctx, unsigned char *out,
+ const unsigned char *in, size_t len)
+ {
+ EVP_AES_GCM_CTX *gctx = ctx->cipher_data;
+ /* If not set up, return error */
+ if (!gctx->iv_set && !gctx->key_set)
+ return -1;
+ if (!ctx->encrypt && gctx->taglen < 0)
+ return -1;
+ if (in)
+ {
+ if (out == NULL)
+ {
+ if (CRYPTO_gcm128_aad(gctx->gcm, in, len))
+ return -1;
+ }
+ else if (ctx->encrypt)
+ {
+ if (CRYPTO_gcm128_encrypt(gctx->gcm, in, out, len))
+ return -1;
+ }
+ else
+ {
+ if (CRYPTO_gcm128_decrypt(gctx->gcm, in, out, len))
+ return -1;
+ }
+ return len;
+ }
+ else
+ {
+ if (!ctx->encrypt)
+ {
+ if (CRYPTO_gcm128_finish(gctx->gcm,
+ gctx->tag, gctx->taglen) != 0)
+ return -1;
+ gctx->iv_set = 0;
+ return 0;
+ }
+ CRYPTO_gcm128_tag(gctx->gcm, gctx->tag, 16);
+ gctx->taglen = 16;
+ /* Don't reuse the IV */
+ gctx->iv_set = 0;
+ return 0;
+ }
+
+ }
+
+static const EVP_CIPHER aes_128_gcm_cipher=
+ {
+ NID_aes_128_gcm,1,16,12,
+ EVP_CIPH_GCM_MODE|EVP_CIPH_FLAG_FIPS|EVP_CIPH_FLAG_DEFAULT_ASN1
+ | EVP_CIPH_CUSTOM_IV | EVP_CIPH_FLAG_CUSTOM_CIPHER
+ | EVP_CIPH_ALWAYS_CALL_INIT | EVP_CIPH_CTRL_INIT,
+ aes_gcm_init_key,
+ aes_gcm,
+ aes_gcm_cleanup,
+ sizeof(EVP_AES_GCM_CTX),
+ NULL,
+ NULL,
+ aes_gcm_ctrl,
+ NULL
+ };
+
+const EVP_CIPHER *EVP_aes_128_gcm (void)
+{ return &aes_128_gcm_cipher; }
+
+static const EVP_CIPHER aes_192_gcm_cipher=
+ {
+ NID_aes_128_gcm,1,24,12,
+ EVP_CIPH_GCM_MODE|EVP_CIPH_FLAG_FIPS|EVP_CIPH_FLAG_DEFAULT_ASN1
+ | EVP_CIPH_CUSTOM_IV | EVP_CIPH_FLAG_CUSTOM_CIPHER
+ | EVP_CIPH_ALWAYS_CALL_INIT | EVP_CIPH_CTRL_INIT,
+ aes_gcm_init_key,
+ aes_gcm,
+ aes_gcm_cleanup,
+ sizeof(EVP_AES_GCM_CTX),
+ NULL,
+ NULL,
+ aes_gcm_ctrl,
+ NULL
+ };
+
+const EVP_CIPHER *EVP_aes_192_gcm (void)
+{ return &aes_192_gcm_cipher; }
+
+static const EVP_CIPHER aes_256_gcm_cipher=
+ {
+ NID_aes_128_gcm,1,32,12,
+ EVP_CIPH_GCM_MODE|EVP_CIPH_FLAG_FIPS|EVP_CIPH_FLAG_DEFAULT_ASN1
+ | EVP_CIPH_CUSTOM_IV | EVP_CIPH_FLAG_CUSTOM_CIPHER
+ | EVP_CIPH_ALWAYS_CALL_INIT | EVP_CIPH_CTRL_INIT,
+ aes_gcm_init_key,
+ aes_gcm,
+ aes_gcm_cleanup,
+ sizeof(EVP_AES_GCM_CTX),
+ NULL,
+ NULL,
+ aes_gcm_ctrl,
+ NULL
+ };
+
+const EVP_CIPHER *EVP_aes_256_gcm (void)
+{ return &aes_256_gcm_cipher; }
+