Fix expected failing value for WFSEEK()

[rlm2002]

Adds on to #1139. Adds WFSEEK_SUCCESS() to wolfssh/port.h, fixes issue where checking the return value of WFSEEK() against 0 may fail erroneously due to Nucleus (NU_Seek()) and MPLAB Harmony (SYS_FS_FileSeek()) returning the new file position and only signaling failure with a negative value.

Fixed existing checks that misread the return value (already tested the result, but with != 0 or != -1):

• src/ssh.c — wolfSSH_ReadKey_file()
• src/wolfsftp.c — resume seek in wolfSSH_SFTP_Put()
• src/port.c — wPwrite() / wPread() (Harmony)
• apps/wolfssh/common.c, examples/client/common.c — load_der_file()

Added checks where the result was discarded

• src/wolfscp.c — _GetFileSize()
• apps/wolfsshd/wolfsshd.c — getBufferFromFile()
• examples/echoserver/echoserver.c and the ESP-IDF copy — load_file(), LoadTpmSshKey()
• examples/client/common.c — readKeyBlob()
• examples/tpmcertserver/tpmcertclient.c — TpmCcLoadFile()
• tests/auth.c, tests/regress.c — file loaders

WFTELL() negative-return guards - can return -1, and several callers cast straight to word32, turning an error into a 4 GB size

[wolfSSL-Fenrir-bot]

Fenrir Automated Review — PR #1145

Scan targets checked: wolfssh-bugs, wolfssh-src

Findings: 1
1 finding(s) posted as inline comments (see file-level comments below)

This review was generated automatically by Fenrir. Findings are non-blocking.

[Copilot]

Pull request overview

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Adds a portable way to interpret WFSEEK() results across platforms where seek returns a new file position (negative on failure), and updates call sites to use that check instead of comparing against 0.

Changes:

• Introduces WFSEEK_SUCCESS() in wolfssh/port.h with port-specific overrides plus a default fallback.
• Updates WFSEEK() result checks across core SSH/SFTP/SCP code and several examples/apps to use WFSEEK_SUCCESS().
• Adds/adjusts error handling paths when seek fails (close file / return error).

Reviewed changes

Copilot reviewed 11 out of 11 changed files in this pull request and generated 7 comments.

Show a summary per file

File	Description
wolfssh/port.h	Adds WFSEEK_SUCCESS() and default definition to standardize seek success checks across ports.
src/wolfsftp.c	Uses WFSEEK_SUCCESS() when seeking for resumed uploads.
src/wolfscp.c	Uses WFSEEK_SUCCESS() for _GetFileSize() and returns an error on seek failure.
src/ssh.c	Uses WFSEEK_SUCCESS() when seeking key files to determine size.
src/port.c	Uses WFSEEK_SUCCESS() for Harmony seek checks in wfopen().
ide/Espressif/ESP-IDF/examples/wolfssh_echoserver/main/echoserver.c	Adds seek failure handling using WFSEEK_SUCCESS() when loading files/keys.
examples/tpmcertserver/tpmcertclient.c	Adds seek failure handling using WFSEEK_SUCCESS() when loading files.
examples/echoserver/echoserver.c	Adds seek failure handling using WFSEEK_SUCCESS() when loading files/keys.
examples/client/common.c	Updates DER/key blob loaders to use WFSEEK_SUCCESS() and handle seek failure.
apps/wolfsshd/wolfsshd.c	Adds seek failure handling using WFSEEK_SUCCESS() when reading files to buffers.
apps/wolfssh/common.c	Updates DER loader to use WFSEEK_SUCCESS() when seeking to end.

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[Copilot]

Pull request overview

Copilot reviewed 13 out of 13 changed files in this pull request and generated 3 comments.

Suppressed comments (3)

wolfssh/port.h:127

• Casting the seek result to int can truncate large positive file positions (e.g., long/off_t), potentially turning a successful seek into a negative value and falsely reporting failure. Prefer comparing in the native type (e.g., (r) >= 0) or casting to a sufficiently wide signed type used by the port’s seek API.

    #define WFSEEK_SUCCESS(r)   ((int)(r) >= 0)

wolfssh/port.h:444

• Casting the seek result to int can truncate large positive file positions (e.g., long/off_t), potentially turning a successful seek into a negative value and falsely reporting failure. Prefer comparing in the native type (e.g., (r) >= 0) or casting to a sufficiently wide signed type used by the port’s seek API.

    #define WFSEEK_SUCCESS(r)   ((int)(r) >= 0)

src/wolfscp.c:2707

• On the tmpSz < 0 error path, the file position is left at EOF (after a successful seek), whereas the success path rewinds. To keep _GetFileSize() behavior consistent and reduce caller surprises, consider rewinding (or restoring the prior position) before returning WS_BAD_FILE_E when WFTELL() fails.

    if (WFSEEK_SUCCESS(WFSEEK(fs, fp, 0, WSEEK_END))) {
        tmpSz = WFTELL(fs, fp);
        if (tmpSz < 0) {
            return WS_BAD_FILE_E;
        }
        *fileSz = (word32)tmpSz;
        WREWIND(fs, fp);

        return WS_SUCCESS;
    }
    return WS_BAD_FILE_E;