ssh/knownhosts: fix hashed hostname component count in error message

[kke]

Correct the component splitting in the nextWord function to omit the initial empty element when decoding the pipe-separated hostname hash.

Previously, the error message incorrectly counted this empty element, leading to misleading errors like:

knownhosts: got 3 components, want 3

This change makes the component split start from index 1.

Tests for the error messages were added.

[gopherbot]

This PR (HEAD: 59f185c6de4e34f276353e733b97e25e1720c02f) has been imported to Gerrit for code review.

Please visit Gerrit at https://go-review.googlesource.com/c/crypto/+/578435.

Important tips:

• Don't comment on this PR. All discussion takes place in Gerrit.
• You need a Gmail or other Google account to log in to Gerrit.
• To change your code in response to feedback:
  • Push a new commit to the branch used by your GitHub PR.
  • A new "patch set" will then appear in Gerrit.
  • Respond to each comment by marking as Done in Gerrit if implemented as suggested. You can alternatively write a reply.
  • Critical: you must click the blue Reply button near the top to publish your Gerrit responses.
  • Multiple commits in the PR will be squashed by GerritBot.
• The title and description of the GitHub PR are used to construct the final commit message.
  • Edit these as needed via the GitHub web interface (not via Gerrit or git).
  • You should word wrap the PR description at ~76 characters unless you need longer lines (e.g., for tables or URLs).
• See the Sending a change via GitHub and Reviews sections of the Contribution Guide as well as the FAQ for details.

[gopherbot]

Message from Gopher Robot:

Patch Set 1:

(1 comment)

---

Please don’t reply on this GitHub thread. Visit golang.org/cl/578435. After addressing review feedback, remember to publish your drafts!

[gopherbot]

Message from Gopher Robot:

Patch Set 1:

Congratulations on opening your first change. Thank you for your contribution!

Next steps: A maintainer will review your change and provide feedback. See https://go.dev/doc/contribute#review for more info and tips to get your patch through code review.

Most changes in the Go project go through a few rounds of revision. This can be surprising to people new to the project. The careful, iterative review process is our way of helping mentor contributors and ensuring that their contributions have a lasting impact.

During May-July and Nov-Jan the Go project is in a code freeze, during which little code gets reviewed or merged. If a reviewer responds with a comment like R=go1.11 or adds a tag like "wait-release", it means that this CL will be reviewed as part of the next development cycle. See https://go.dev/s/release for more details.

---

Please don’t reply on this GitHub thread. Visit golang.org/cl/578435. After addressing review feedback, remember to publish your drafts!

[gopherbot]

Message from Nicola Murino:

Patch Set 1:

(1 comment)

---

Please don’t reply on this GitHub thread. Visit golang.org/cl/578435. After addressing review feedback, remember to publish your drafts!

[gopherbot]

This PR (HEAD: 62fb541c0e8740055a98b633120876a4fd89d1d7) has been imported to Gerrit for code review.

Please visit Gerrit at https://go-review.googlesource.com/c/crypto/+/578435.

Important tips:

• Don't comment on this PR. All discussion takes place in Gerrit.
• You need a Gmail or other Google account to log in to Gerrit.
• To change your code in response to feedback:
  • Push a new commit to the branch used by your GitHub PR.
  • A new "patch set" will then appear in Gerrit.
  • Respond to each comment by marking as Done in Gerrit if implemented as suggested. You can alternatively write a reply.
  • Critical: you must click the blue Reply button near the top to publish your Gerrit responses.
  • Multiple commits in the PR will be squashed by GerritBot.
• The title and description of the GitHub PR are used to construct the final commit message.
  • Edit these as needed via the GitHub web interface (not via Gerrit or git).
  • You should word wrap the PR description at ~76 characters unless you need longer lines (e.g., for tables or URLs).
• See the Sending a change via GitHub and Reviews sections of the Contribution Guide as well as the FAQ for details.

[gopherbot]

This PR (HEAD: de728eaa8be3d473ca08254d3392b6a7d633c25b) has been imported to Gerrit for code review.

Please visit Gerrit at https://go-review.googlesource.com/c/crypto/+/578435.

Important tips:

• Don't comment on this PR. All discussion takes place in Gerrit.
• You need a Gmail or other Google account to log in to Gerrit.
• To change your code in response to feedback:
  • Push a new commit to the branch used by your GitHub PR.
  • A new "patch set" will then appear in Gerrit.
  • Respond to each comment by marking as Done in Gerrit if implemented as suggested. You can alternatively write a reply.
  • Critical: you must click the blue Reply button near the top to publish your Gerrit responses.
  • Multiple commits in the PR will be squashed by GerritBot.
• The title and description of the GitHub PR are used to construct the final commit message.
  • Edit these as needed via the GitHub web interface (not via Gerrit or git).
  • You should word wrap the PR description at ~76 characters unless you need longer lines (e.g., for tables or URLs).
• See the Sending a change via GitHub and Reviews sections of the Contribution Guide as well as the FAQ for details.

[gopherbot]

Message from Nicola Murino:

Patch Set 4:

(1 comment)

---

Please don’t reply on this GitHub thread. Visit golang.org/cl/578435. After addressing review feedback, remember to publish your drafts!

[gopherbot]

This PR (HEAD: 521524c99ae15119edba6df535c3b3271e6f4ff3) has been imported to Gerrit for code review.

Please visit Gerrit at https://go-review.googlesource.com/c/crypto/+/578435.

Important tips:

• Don't comment on this PR. All discussion takes place in Gerrit.
• You need a Gmail or other Google account to log in to Gerrit.
• To change your code in response to feedback:
  • Push a new commit to the branch used by your GitHub PR.
  • A new "patch set" will then appear in Gerrit.
  • Respond to each comment by marking as Done in Gerrit if implemented as suggested. You can alternatively write a reply.
  • Critical: you must click the blue Reply button near the top to publish your Gerrit responses.
  • Multiple commits in the PR will be squashed by GerritBot.
• The title and description of the GitHub PR are used to construct the final commit message.
  • Edit these as needed via the GitHub web interface (not via Gerrit or git).
  • You should word wrap the PR description at ~76 characters unless you need longer lines (e.g., for tables or URLs).
• See the Sending a change via GitHub and Reviews sections of the Contribution Guide as well as the FAQ for details.