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plugins/auth/pam: expose sudo prompt to PAM via SUDO_PROMPT env - #539
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millert
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| debug_return_int(AUTH_ERROR); | ||
| } | ||
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| if (def_prompt && ctx->user.prompt) { |
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It's not possible for def_prompt to be NULL. I would change the conditional to be:
if (ctx->user.prompt || def_passprompt_override) {
...
}
That way SUDO_PROMPT will also be set if the "passprompt_override" sudoers option is enabled.
Some PAM implementations do not use PAM conversations and instead present their own native client UI. In those cases, modules cannot infer sudo's custom prompt text from the conversation callback path. Set SUDO_PROMPT in the PAM environment before pam_authenticate(), so modules that render their own UI can combine: - PAM service identity (from the PAM transaction) - sudo's resolved prompt string (SUDO_PROMPT) to display a consistent, context-aware prompt. To avoid stale state, clear SUDO_PROMPT before authentication starts and clear it again after pam_authenticate() returns. Allowing PAM modules in the stack to read (and potentially change) SUDO_PROMPT does not introduce a new trust boundary concern: PAM modules already control the conversation flow and can provide their own prompt text/messages through the standard PAM conversation mechanism.
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Some PAM modules implementations do not use PAM conversations and instead present their own native client when they have access to the terminal. In those cases, modules cannot infer sudo's custom prompt text from the conversation callback path.
Set SUDO_PROMPT in the PAM environment before pam_authenticate(), so modules that render their own UI can combine:
to display a consistent, context-aware prompt.
To avoid stale state, clear SUDO_PROMPT before authentication starts and clear it again after pam_authenticate() returns.
Allowing PAM modules in the stack to read (and potentially change) SUDO_PROMPT does not introduce a new trust boundary concern: PAM modules already control the conversation flow and can provide their own prompt text/messages through the standard PAM conversation mechanism.