Convert R vectors to/from the Base64 format
Convert R vectors of any type to and from the Base64 format for encrypting any binary data as string using alphanumeric subset of ASCII character set.
base64encode(x, size=NA, endian=.Platform$endian) base64decode(z, what, size=NA, signed = TRUE, endian=.Platform$endian)
x |
vector or any structure that can be converted to a vector by
|
z |
String with Base64 code, using [A-Z,a-z,0-9,+,/,=] subset of characters |
what |
Either an object whose mode will give the mode of the vector
to be created, or a character vector of length one describing
the mode: one of '"numeric", "double", "integer", "int",
"logical", "complex", "character", "raw".
Same as variable |
size |
integer. The number of bytes per element in the byte stream
stored in |
signed |
logical. Only used for integers of sizes 1 and 2, when it
determines if the quantity stored as raw should be regarded as a
signed or unsigned integer.
Same as variable |
endian |
If provided, can be used to swap endian-ness. Using '"swap"'
will force swapping of byte order. Use '"big"' (big-endian, aka IEEE,
aka "network") or '"little"' (little-endian, format used on PC/Intel
machines) to indicate type of data encoded in "raw" format.
Same as variable |
The Base64 encoding is designed to encode arbitrary binary information for transmission by electronic mail. It is defined by MIME (Multipurpose Internet Mail Extensions) specification RFC 1341, RFC 1421, RFC 2045 and others. Triplets of 8-bit octets are encoded as groups of four characters, each representing 6 bits of the source 24 bits. Only a 65-character subset ([A-Z,a-z,0-9,+,/,=]) present in all variants of ASCII and EBCDIC is used, enabling 6 bits to be represented per printable character.
Default sizes for different types of what: logical - 4,
integer - 4, double - 8 , complex - 16,
character - 2, raw - 1.
Function base64encode returns a string with Base64 code.
Function base64decode returns vector of appropriate mode
and length (see x above).
Jarek Tuszynski (SAIC) jaroslaw.w.tuszynski@saic.com
Base64 description in Connected: An Internet Encyclopedia https://www.freesoft.org/CIE/RFC/1521/7.htm
MIME RFC 1341 http://www.faqs.org/rfcs/rfc1341.html
MIME RFC 1421 http://www.faqs.org/rfcs/rfc1421.html
MIME RFC 2045 http://www.faqs.org/rfcs/rfc2045.html
Portions of the code are based on Matlab code by Peter Acklam
xmlValue from XML package reads XML code
which sometimes is encoded in Base64 format.
x = (10*runif(10)>5) # logical
for (i in c(NA, 1, 2, 4)) {
y = base64encode(x, size=i)
z = base64decode(y, typeof(x), size=i)
stopifnot(x==z)
}
print("Checked base64 for encode/decode logical type")
x = as.integer(1:10) # integer
for (i in c(NA, 1, 2, 4)) {
y = base64encode(x, size=i)
z = base64decode(y, typeof(x), size=i)
stopifnot(x==z)
}
print("Checked base64 encode/decode for integer type")
x = (1:10)*pi # double
for (i in c(NA, 4, 8)) {
y = base64encode(x, size=i)
z = base64decode(y, typeof(x), size=i)
stopifnot(mean(abs(x-z))<1e-5)
}
print("Checked base64 for encode/decode double type")
x = log(as.complex(-(1:10)*pi)) # complex
y = base64encode(x)
z = base64decode(y, typeof(x))
stopifnot(x==z)
print("Checked base64 for encode/decode complex type")
x = "Chance favors the prepared mind" # character
y = base64encode(x)
z = base64decode(y, typeof(x))
stopifnot(x==z)
print("Checked base64 for encode/decode character type")Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.