SI_IMAGE_JPEG
SI_IMAGE_JPEG
Constant for rendering captcha as a JPEG image
Securimage CAPTCHA Class.
A class for creating and validating secure CAPTCHA images and audio.
The class contains many options regarding appearance, security, storage of captcha data and image/audio generation options.
$image_bg_color : \Securimage_Color
The background color of the captcha
$text_color : \Securimage_Color
The color of the captcha text
$line_color : \Securimage_Color
The color of the lines over the captcha
$noise_color : \Securimage_Color
The color of the noise that is drawn
$signature_color : \Securimage_Color
The color of the signature text
$skip_table_check : bool
Whether or not to skip checking if Securimage tables exist when using a database.
Turn this to true once database functionality is working to improve performance.
$database_file : string
Fully qualified path to the database file when using SQLite3.
This value is only used when $database_driver == sqlite and does not apply when no database is used, or when using MySQL or PostgreSQL.
On *nix, file must have permissions of 0666.
Make sure the directory containing this file is NOT web accessible
$namespace : string
The captcha namespace used for having multiple captchas on a page or to separate captchas from differen forms on your site.
Example:
<?php
// use <img src="securimage_show.php?namespace=contact_form">
// or manually in securimage_show.php
$img->setNamespace('contact_form');
// in form validator
$img->setNamespace('contact_form');
if ($img->check($code) == true) {
echo "Valid!";
}$audio_mix_normalization : float
The method and threshold (or gain factor) used to normalize the mixing with background noise.
See http://www.voegler.eu/pub/audio/ for more information.
Default: 0.6
Valid:
>= 1
Normalize by multiplying by the threshold (boost - positive gain).
A value of 1 in effect means no normalization (and results in clipping).
<= -1
Normalize by dividing by the the absolute value of threshold (attenuate - negative gain).
A factor of 2 (-2) is about 6dB reduction in volume.
[0, 1) (open inverval - not including 1)
The threshold above which amplitudes are comressed logarithmically.
e.g. 0.6 to leave amplitudes up to 60% "as is" and compressabove.
(-1, 0) (open inverval - not including -1 and 0)
The threshold above which amplitudes are comressed linearly.
e.g. -0.6 to leave amplitudes up to 60% "as is" and compress above.$display_value : string
Alternate text to draw as the captcha image text
A value that can be passed to the constructor that can be used to generate a captcha image with a given value.
This value does not get stored in the session or database and is only used when calling Securimage::show().
If a display_value was passed to the constructor and the captcha image is generated, the display_value will be used as the string to draw on the captcha image.
Used only if captcha codes are generated and managed by a 3rd party app/library
__construct(array $options)
Create a new securimage object, pass options to set in the constructor.
The object can then be used to display a captcha, play an audible captcha, or validate a submission.
| array | $options | Options to initialize the class. May be any class property. |
getCaptchaId(bool $new, array $options) : null|string
Generate a new captcha ID or retrieve the current ID (if exists).
| bool | $new | If true, generates a new challenge and returns and ID. If false, the existing captcha ID is returned, or null if none exists. |
| array | $options | Additional options to be passed to Securimage. $options must include database settings if they are not set directly in securimage.php |
Returns null if no captcha id set and new was false, or the captcha ID
checkByCaptchaId(string $id, string $value, array $options) : bool
Validate a captcha code input against a captcha ID
| string | $id | The captcha ID to check |
| string | $value | The captcha value supplied by the user |
| array | $options | Array of options to construct Securimage with. Options must include database options if they are not set in securimage.php |
true if the code was valid for the given captcha ID, false if not or if database failed to open
show(string $background_image)
Generates a new challenge and serves a captcha image.
Appropriate headers will be sent to the browser unless the send_headers option is false.
| string | $background_image | The absolute or relative path to the background image to use as the background of the captcha image. |
check(string $code) : bool
Checks a given code against the correct value from the session and/or database.
| string | $code | The captcha code to check |
true if the given code was correct, false if not.
getCaptchaHtml(array $options) : string
Returns HTML code for displaying the captcha image, audio button, and form text input.
Options can be specified to modify the output of the HTML. Accepted options:
'securimage_path':
Optional: The URI to where securimage is installed (e.g. /securimage)
'image_id':
A string that sets the "id" attribute of the captcha image (default: captcha_image)
'image_alt_text':
The alt text of the captcha image (default: CAPTCHA Image)
'show_audio_button':
true/false Whether or not to show the audio button (default: true)
'show_refresh_button':
true/false Whether or not to show a button to refresh the image (default: true)
'show_text_input':
true/false Whether or not to show the text input for the captcha (default: true)
'refresh_alt_text':
Alt text for the refresh image (default: Refresh Image)
'refresh_title_text':
Title text for the refresh image link (default: Refresh Image)
'input_id':
A string that sets the "id" attribute of the captcha text input (default: captcha_code)
'input_name':
A string that sets the "name" attribute of the captcha text input (default: same as input_id)
'input_text':
A string that sets the text of the label for the captcha text input (default: Type the text:)
'input_attributes':
An array of additional HTML tag attributes to pass to the text input tag (default: empty)
'image_attributes':
An array of additional HTML tag attributes to pass to the captcha image tag (default: empty)
'error_html':
Optional HTML markup to be shown above the text input field
'namespace':
The optional captcha namespace to use for showing the image and playing back the audio. Namespaces are for using multiple captchas on the same page.| array | $options | Array of options for modifying the HTML code. |
The generated HTML code for displaying the captcha
getCode(bool $array, bool $returnExisting) : array|string
Return the code from the session or database (if configured). If none exists or was found, an empty string is returned.
| bool | $array | true to receive an array containing the code and properties, false to receive just the code. |
| bool | $returnExisting | If true, and the class property code is set, it will be returned instead of getting the code from the session or database. |
Return is an array if $array = true, otherwise a string containing the code
errorHandler(int $errno, string $errstr, string $errfile, int $errline, array $errcontext) : boolean
The error handling function used when outputting captcha image or audio.
This error handler helps determine if any errors raised would prevent captcha image or audio from displaying. If they have no effect on the output buffer or headers, true is returned so the script can continue processing.
See https://github.com/dapphp/securimage/issues/15
| int | $errno | PHP error number |
| string | $errstr | String description of the error |
| string | $errfile | File error occurred in |
| int | $errline | Line the error occurred on in file |
| array | $errcontext | Additional context information |
true if the error was handled, false if PHP should handle the error
readCodeFromFile(int $numWords) : string|array
Gets a captcha code from a file containing a list of words.
Seek to a random offset in the file and reads a block of data and returns a line from the file.
| int | $numWords | Number of words (lines) to read from the file |
Returns a string if only one word is to be read, or an array of words
validate()
Validate a code supplied by the user
Checks the entered code against the value stored in the session and/or database (if configured). Handles case sensitivity. Also removes the code from session/database if the code was entered correctly to prevent re-use attack.
This function does not return a value.
getSoxEffectChain(int $numEffects) : string
Get a random effect or chain of effects to apply to a segment of the audio file.
These effects should increase the randomness of the audio for a particular letter/number by modulating the signal. The SoX effects used are bend, chorus, overdrive, pitch, reverb, tempo, and tremolo.
For each effect selected, random parameters are supplied to the effect.
| int | $numEffects | How many effects to chain together |
A string of valid SoX effects and their respective options.
getSoxNoiseData(float $duration, int $numChannels, int $sampleRate, int $bitRate) : string
This function is not yet used.
Generate random background noise from sweeping oscillators
| float | $duration | How long in seconds the generated sound will be |
| int | $numChannels | Number of channels in output wav |
| int | $sampleRate | Sample rate of output wav |
| int | $bitRate | Bits per sample (8, 16, 24) |
Audio data in wav format
initColor(string $color, \Securimage_Color $default)
Convert an html color code to a Securimage_Color
| string | $color | |
| \Securimage_Color | $default | The defalt color to use if $color is invalid |