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Add support for askpass program for reading answers from the user.

This commit is contained in:
Maarten Billemont 2017-08-31 13:37:28 -04:00
parent eef82f7ed4
commit 019cefd3fb

View File

@ -117,36 +117,103 @@ static const char *mpw_getenv(const char *variableName) {
return envBuf? strdup( envBuf ): NULL; return envBuf? strdup( envBuf ): NULL;
} }
char *mpw_read_fd(int fd);
char *mpw_read_file(FILE *file);
/** Use the askpass program to prompt the user.
* @return A newly allocated string or NULL if askpass is not supported or an error occurred. */
static char *mpw_askpass(const char *prompt) {
const char *askpass = mpw_getenv( "MPW_ASKPASS" );
if (!askpass)
return NULL;
int pipes[2];
if (pipe( pipes ) == ERR) {
wrn( "Couldn't pipe: %s\n", strerror( errno ) );
return NULL;
}
pid_t pid = fork();
if (pid == ERR) {
wrn( "Couldn't fork for askpass:\n %s: %s\n", askpass, strerror( errno ) );
return NULL;
}
if (!pid) {
// askpass fork
close( pipes[0] );
if (dup2( pipes[1], STDOUT_FILENO ) == ERR)
ftl( "Couldn't connect pipe to process: %s\n", strerror( errno ) );
else if (execl( askpass, askpass, prompt, NULL ) == ERR)
ftl( "Couldn't execute askpass:\n %s: %s\n", askpass, strerror( errno ) );
exit( EX_SOFTWARE );
}
close( pipes[1] );
char *answer = mpw_read_fd( pipes[0] );
close( pipes[0] );
int status;
if (waitpid( pid, &status, 0 ) == ERR) {
wrn( "Couldn't wait for askpass: %s\n", strerror( errno ) );
mpw_free_string( &answer );
return NULL;
}
if (WIFEXITED( status ) && WEXITSTATUS( status ) == EXIT_SUCCESS && answer && strlen( answer )) {
// Remove trailing newline.
if (answer[strlen( answer ) - 1] == '\n')
answer[strlen( answer ) - 1] = '\0';
return answer;
}
mpw_free_string( &answer );
return NULL;
}
/** Ask the user a question. /** Ask the user a question.
* @return A newly allocated string or NULL if an error occurred trying to read from the user. */ * @return A newly allocated string or NULL if an error occurred trying to read from the user. */
static const char *mpw_getline(const char *prompt) { static const char *mpw_getline(const char *prompt) {
// Get answer from askpass.
char *answer = mpw_askpass( prompt );
if (answer)
return answer;
// Get password from terminal.
fprintf( stderr, "%s ", prompt ); fprintf( stderr, "%s ", prompt );
char *buf = NULL;
size_t bufSize = 0; size_t bufSize = 0;
ssize_t lineSize = getline( &buf, &bufSize, stdin ); ssize_t lineSize = getline( &answer, &bufSize, stdin );
if (lineSize <= 1) { if (lineSize <= 1) {
free( buf ); mpw_free_string( &answer );
return NULL; return NULL;
} }
// Remove the newline. // Remove trailing newline.
buf[lineSize - 1] = '\0'; answer[lineSize - 1] = '\0';
return buf; return answer;
} }
/** Ask the user for a password. /** Ask the user for a password.
* @return A newly allocated string or NULL if an error occurred trying to read from the user. */ * @return A newly allocated string or NULL if an error occurred trying to read from the user. */
static const char *mpw_getpass(const char *prompt) { static const char *mpw_getpass(const char *prompt) {
char *passBuf = getpass( prompt ); // Get password from askpass.
if (!passBuf) const char *password = mpw_askpass( prompt );
if (password)
return password;
// Get password from terminal.
char *answer = getpass( prompt );
if (!answer)
return NULL; return NULL;
char *buf = strdup( passBuf ); password = strdup( answer );
bzero( passBuf, strlen( passBuf ) ); bzero( answer, strlen( answer ) );
return buf; return password;
} }
/** Get the absolute path to the mpw configuration file with the given prefix name and file extension. /** Get the absolute path to the mpw configuration file with the given prefix name and file extension.
@ -230,9 +297,27 @@ static bool mpw_mkdirs(const char *filePath) {
return success; return success;
} }
/** Read until EOF from the given file descriptor.
* @return A newly allocated string or NULL the read buffer couldn't be allocated. */
char *mpw_read_fd(int fd) {
char *buf = NULL;
size_t blockSize = 4096, bufSize = 0, bufOffset = 0;
ssize_t readSize = 0;
while ((mpw_realloc( &buf, &bufSize, blockSize )) &&
((readSize = read( fd, buf + bufOffset, blockSize )) > 0));
if (readSize == ERR)
dbg( "While reading: %s\n", strerror( errno ) );
return buf;
}
/** Read the file contents of a given file. /** Read the file contents of a given file.
* @return A newly allocated string or NULL the read buffer couldn't be allocated. */ * @return A newly allocated string or NULL the read buffer couldn't be allocated. */
static char *mpw_read_file(FILE *file) { char *mpw_read_file(FILE *file) {
if (!file)
return NULL;
char *buf = NULL; char *buf = NULL;
size_t blockSize = 4096, bufSize = 0, bufOffset = 0, readSize = 0; size_t blockSize = 4096, bufSize = 0, bufOffset = 0, readSize = 0;