ctx->did_check_for_encdec2 is never set in src/lib/tpm.c

[niooss-ledger]

Hello,

https://github.com/tpm2-software/tpm2-pkcs11/blob/1.7.0/src/lib/tpm.c contains:

static TSS2_RC do_part_encrypt_decrypt(
        tpm_ctx *ctx, uint32_t handle,
        TPMI_ALG_SYM_MODE mode, TPMI_YES_NO is_decrypt,
        const TPM2B_MAX_BUFFER *data_in, const TPM2B_IV *iv_in,
        TPM2B_MAX_BUFFER **data_out, TPM2B_IV **iv_out) {

    TSS2_RC rval = TSS2_RC_SUCCESS;

    /* figure out what command to use */
    if (!ctx->did_check_for_encdec2) {
        /* do not free, value is cached */
        rval = tpm_supports_cc(ctx, TPM2_CC_EncryptDecrypt2,
                &ctx->use_encdec2);
        if (rval != TSS2_RC_SUCCESS) {
            return rval;
        }
    }
// ...

This code seems to implement some caching of ctx->use_encdec2 using a boolean ctx->did_check_for_encdec2. Nevertheless ctx->did_check_for_encdec2 is not set anywhere.

Is a ctx->did_check_for_encdec2 = true; statement missing, or should the caching mechanism around ctx->use_encdec2 be dropped?

[williamcroberts]

I think it needs the ctx->did_check_for_encdec2 = true; in that block.