Revise comments for x509write_csr_der_internal

Address remaining PR comments for #2118
- Add ChangeLog.d/x509write_csr_heap_alloc.txt.
- Fix parameter alignment per Gille's recommendation.
- Update comments to more explicitly describe the manipulation of buf.
- Replace use of `MBEDTLS_MPI_MAX_SIZE` as `sig` buffer size for
  call to `x509write_csr_der_internal()` with more intuitive
  `MBEDTLS_PK_SIGNATURE_MAX_SIZE`.
- Update `mbedtls_x509write_csr_der()` to return
  `MBEDTLS_ERR_X509_ALLOC_FAILED` on mbedtls_calloc error.

Signed-off-by: Simon Leet <simon.leet@microsoft.com>
This commit is contained in:
Simon Leet 2020-06-26 21:23:32 +00:00
parent afc2717e84
commit 1535a43149
2 changed files with 58 additions and 30 deletions

View file

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Changes
* Reduce the stack consumption of mbedtls_x509write_csr_der() which
previously could lead to stack overflow on constrained devices.
Contributed by Doru Gucea and Simon Leet in #3464.