fix for issue 1118: check if iv is zero in gcm.
1) found by roberto in mbedtls forum
2) if iv_len is zero, return an error
3) add tests for invalid parameters
diff --git a/tests/suites/test_suite_gcm.aes192_en.data b/tests/suites/test_suite_gcm.aes192_en.data
index 18e56e7..5ea1101 100644
--- a/tests/suites/test_suite_gcm.aes192_en.data
+++ b/tests/suites/test_suite_gcm.aes192_en.data
@@ -670,6 +670,10 @@
depends_on:MBEDTLS_AES_C
gcm_encrypt_and_tag:MBEDTLS_CIPHER_ID_AES:"713358e746dd84ab27b8adb3b17ea59cd75fa6cb0c13d1a8":"35b8b655efdf2d09f5ed0233c9eeb0b6f85e513834848cd594dba3c6e64f78e7af4a7a6d53bba7b43764334d6373360ae3b73b1e765978dffa7dbd805fda7825b8e317e8d3f1314aa97f877be815439c5da845028d1686283735aefac79cdb9e02ec3590091cb507089b9174cd9a6111f446feead91f19b80fd222fc6299fd1c":"26ed909f5851961dd57fa950b437e17c":"c9469ad408764cb7d417f800d3d84f03080cee9bbd53f652763accde5fba13a53a12d990094d587345da2cdc99357b9afd63945ca07b760a2c2d4948dbadb1312670ccde87655a6a68edb5982d2fcf733bb4101d38cdb1a4942a5d410f4c45f5ddf00889bc1fe5ec69b40ae8aaee60ee97bea096eeef0ea71736efdb0d8a5ec9":"cc3f9983e1d673ec2c86ae4c1e1b04e30f9f395f67c36838e15ce825b05d37e9cd40041470224da345aa2da5dfb3e0c561dd05ba7984a1332541d58e8f9160e7e8457e717bab203de3161a72b7aedfa53616b16ca77fd28d566fbf7431be559caa1a129b2f29b9c5bbf3eaba594d6650c62907eb28e176f27c3be7a3aa24cef6":32:"5be7611b":0
+AES-GCM Bad IV (AES-192,128,0,0,32) #0
+depends_on:MBEDTLS_AES_C
+gcm_bad_parameters:MBEDTLS_CIPHER_ID_AES:MBEDTLS_GCM_ENCRYPT:"b10979797fb8f418a126120d45106e1779b4538751a19bf6":"":"":"":32:MBEDTLS_ERR_GCM_BAD_INPUT
+
AES-GCM Selftest
depends_on:MBEDTLS_AES_C
gcm_selftest: