[PATCH v3] gpg-interface: trim CR from ssh-keygen
- From
Fabian Stelzer <fs@gigacodes.de>
- Date
- Jan 7, 2022, 09:07 UTC
- Message-ID
- <20220107090735.580225-1-fs@gigacodes.de>
- In-Reply-To
- <20220103095337.600536-1-fs@gigacodes.de>
We need to trim \r from the output of 'ssh-keygen -Y find-principals' on Windows, or we end up calling 'ssh-keygen -Y verify' with a bogus signer identity. ssh-keygen.c:2841 contains a call to puts(3), which confirms this hypothesis. Signature verification passes with the fix.
Helped-by: Pedro Martelletto <pedro@yubico.com> Signed-off-by: Fabian Stelzer <fs@gigacodes.de> --- gpg-interface.c | 34 ++++++++++++++++++++++++---------- 1 file changed, 24 insertions(+), 10 deletions(-)
diff --git a/gpg-interface.c b/gpg-interface.c index b52eb0e2e0..17b1e44baa 100644 --- a/gpg-interface.c +++ b/gpg-interface.c @@ -433,7 +433,6 @@ static int verify_ssh_signed_buffer(struct signature_check *sigc, struct tempfile *buffer_file; int ret = -1; const char *line; - size_t trust_size; char *principal; struct strbuf ssh_principals_out = STRBUF_INIT; struct strbuf ssh_principals_err = STRBUF_INIT; @@ -502,15 +501,30 @@ static int verify_ssh_signed_buffer(struct signature_check *sigc, ret = -1; } else { /* Check every principal we found (one per line) */ - for (line = ssh_principals_out.buf; *line; - line = strchrnul(line + 1, '\n')) { - while (*line == '\n') - line++; - if (!*line) - break; - - trust_size = strcspn(line, "\n"); - principal = xmemdupz(line, trust_size); + const char *next; + for (line = ssh_principals_out.buf; + *line; + line = next) { + const char *end_of_text; + + next = end_of_text = strchrnul(line, '\n'); + + /* Did we find a LF, and did we have CR before it? */ + if (*end_of_text && + line < end_of_text && + end_of_text[-1] == '\r') + end_of_text--; + + /* Unless we hit NUL, skip over the LF we found */ + if (*next) + next++; + + /* Not all lines are data. Skip empty ones */ + if (line == end_of_text) + continue; + + /* We now know we have an non-empty line. Process it */ + principal = xmemdupz(line, end_of_text - line); child_process_init(&ssh_keygen); strbuf_release(&ssh_keygen_out);
-- 2.33.1