Dear mbed TLS team,
Recently, while debugging my code, I encountered an issue when using the AES-GCM algorithm. I found that when calling the mbedtls_gcm_auth_decrypt interface in version 3.6.1, the calculated tag consistently does not match the input tag. However, when using the same interface in version 2.28.2, the tag is successfully calculated as expected. Below is the demo code we are using:

tstSecKeyList g_stPreInterKey = 
{   .u8KeyNum = 5U,
    .u8IsUse = 1U,
    .u16KeyLen = 16U,
    .u16IVLen = 12U,
    .u16AddLen = 16U,
    .enuSecType = SEC_AES_GCM,
    .au8Key =
    {
        0x68U, 0xffU, 0xb7U, 0xffU, 0x5eU, 0xffU, 0x10U, 0xffU, 0x9eU, 0xffU, 0xb8U, 0xffU, 0x01U, 0xffU, 
        0xb9U, 0xffU, 0xa0U, 0xffU, 0x1cU, 0xffU, 0xdfU, 0xffU, 0x0aU, 0xffU, 0xe6U, 0xffU, 0xc8U, 0xffU, 
        0xc5U, 0xffU, 0x39U, 0xffU
    },
    .au8Iv =
    {
        0x3, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x0, 0x1, 0x2, 0x3
    },
    .au8Add =
    {
        0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0
    }
    .u16AddLen = 0,
};

static uint8_t s_au8SecMemoryBuffer[6*1024];
mbedtls_gcm_context aesGcmContext;
uint8_t *pau8EncryptedPlain = inParam0;
(note: inParam0=434421d30c9abf31b96d2d28d00b5cb4e6fe84033999d53d3a50674b3aedd81f)
uint8_t *pau8AesTag = inParam0 + 16; (e6fe84033999d53d3a50674b3aedd81f)
uint8_t u8EncryptedPlainLen = 16;
uint8_t u8AesTagKeyLen = 16;

mbedtls_gcm_init(&aesGcmContext);
mbedtls_memory_buffer_alloc_init(s_au8SecMemoryBuffer, 6*1024);
vidPreInterKeyget(g_stPreInterKey.au8Key, au8preInterKey);
mbedtls_gcm_setkey(&aesGcmContext, MBEDTLS_CIPHER_ID_AES, au8preInterKey, 16*8);
s32Ret = mbedtls_gcm_auth_decrypt(&aesGcmContext, u8EncryptedPlainLen, g_stPreInterKey.au8Iv,
                     g_stPreInterKey.u16IVLen, g_stPreInterKey.au8Add, g_stPreInterKey.u16AddLen,
                     pau8AesTag, u8AesTagKeyLen, pau8EncryptedPlain, s_au8DecryptKey);

Best regards,
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