a5_encrypt_string()

[gaby_h]

I am trying to figure out how to use this function to encrypt a field. I figured that A5_encrypt_string(fieldname) would do it, but it's obviously not the case; A5 keeps saying wrong expression. Tried encrypt_string(), same thing. Could some on please tell me how to refer to a field instead of a text string?

[csda1]

Re: a5_encrypt_string()

Hi Gaby,

I am trying to figure out how to use this function to encrypt a field. I figured that A5_encrypt_string(fieldname) would do it, but it's obviously not the case; A5 keeps saying wrong expression. Tried encrypt_string(), same thing. Could some on please tell me how to refer to a field instead of a text string?

Context is everything. If you are using it in a calculated field of a layout, Alpha will use the table's fieldname as you have it. Anywhere else, e.g. an event or function, you need to give it a pointer to the table's field. One way would be to use the format

<TBL>. Field_Name.VALUE_GET()

e.g.

A5_encrypt_string(table.current().fieldname.value_get())

[gaby_h]

Re: a5_encrypt_string()

Thanks Ira; it works now.
Would you be so kind to help me understand the Key parameter. The help file gives the following expl: a5_encrypt_string("alpha software", "abc") and I am using "abc" as key without understanding what it is for, what it does. All the help file says is it's used to encode the SourceString.
Thanks

[Stan Mathews]

Re: a5_encrypt_string()

One common usage of such encryption is to transmit data that "cannot" be unencrypted by someone else. If the recipient does not know the key....

dim ec as C
ec = a5_encrypt_string("alpha software", "abc")
? a5_decrypt_string(ec)
ERROR: Not an executable file
? a5_decrypt_string(ec, "def")
Error decrypting string.  Is your pass phrase correct?
OpenSSL Description: error:06065064:digital envelope routines:EVP_DecryptFinal_ex:bad decrypt

they can't see the contents.

A three letter key wouldn't be to hard to break by trying multiple permutations. Longer keys are progressively more difficult to break.

[gaby_h]

Re: a5_encrypt_string()

Thanks Stan.
Sorry for being a pain but I' m having problem with A5_Decrypt_String() now. I have 3 fields: Name, EncName, DecrName and 2 buttons:
Encrypt button that sets the vale in EncName = to the encrypted value in Name - A5_encrypt_string(Name, "test") - this works well.
Decr button where I'm trying to set the value in DecrName = to the decrypted value in EncName: A5_Decrypt_string(EncName, "test") but A5 keeps saying Invalid Expression. I don't understand why; I am using the same principle as Encrypt button.

[Scott Emerick]

Re: a5_encrypt_string()

Gaby,

Does this help?

name = "Alpha Five"

EncName = A5_encrypt_string(Name, "test")

?EncName
= "lut0S8EPNbbN+SBZErS+lw=="

DecrName = a5_decrypt_string(EncName,"test")

?DecrName
= "Alpha Five"

Scott

[gaby_h]

Re: a5_encrypt_string()

Hi Scott:
Thanks for trying to help. I am not much of a coder, that's why i use almost exclusively AS. My buttons use Set Field values in AS. The strange thing is
A5_encrypt_string(Name, "test") works in AS
A5_decrypt_string(EncName,"test") works in the interactive window, but A5 won't accept it in the expression builder in AS.

[Stan Mathews]

Re: a5_encrypt_string()

Agreed. Action scripting does not like A5_decrypt_string() or the plain decrypt_string() which it will try to autocomplete.

Here's an example using xbasic.

[Peter.Greulich]

Re: a5_encrypt_string()

A5_decrypt_string(EncName,"test") works in the interactive window, but A5 won't accept it in the expression builder in AS.

Insert the code into Action scripting using: "Inline Xbasic".

[Scott Emerick]

Re: a5_encrypt_string()

Yup Stan,

I was just doing that myself. A5 crashed big time when I tried to just enter the expression in AS with out using the expression builder.

I would call that a bug ...

Scott

[gaby_h]

Re: a5_encrypt_string()

Hi Peter:
I tried that. When I click on the button A5 returns a long error message starting with SSL....

[Peter.Greulich]

Re: a5_encrypt_string()

Hi Peter:
I tried that. When I click on the button A5 returns a long error message starting with SSL....

Hhhmmm...

Use Stan's xbasic method. Just change the field names, etc. as needed.

[gaby_h]

Re: a5_encrypt_string()

Here's an example using xbasic.

Stan, sorry but I could not open the db, some files are missing.

[Stan Mathews]

Re: a5_encrypt_string()

Stan, sorry but I could not open the db, some files are missing.

Not a db, just a table. Unzip to a new/temp directory. Open Alpha, add the table to your control panel, tables/sets tab, examine the form.

[gaby_h]

Re: a5_encrypt_string()

Works perfectly. Thanks Stan, you are the man