README
¶
randchars
Fast random ASCII character generation. There are both PRNG and CSPRNG based implementations. For convenience, package level globals are provided. These package globals are safe for concurrent use.
PRNG
To use the PRNG based random character generation:
import "github.com/mohae/randchars"
The PRNGs are seeded using a random value obtained from crypto/rand. The PRNGs can be re-seeded, either using a user supplied value or with a value obtained from crypto/rand.
Generator
Generator quickly generates random characters of an arbitrary length with the following character set options: a-zA-Z0-9, a-zA-Z, a-z0-9, a-z, A-Z0-9, A-Z, and Base64.
Generator uses a RNG that implements PCG written by Damian Gryski: go-pcgr
This fulfills the Generatorer interface.
Base64Generator
The Base64Generator generates random characters of an arbitrary length using the base 64 alphabet as shown in Table 1 of RFC 4648 and uses a PRNG that implements XORoShiRo128+ written by Damian Gryski: go-xoroshiro. This generator is slightly faster than using Generator.Base64() and existed before Generator had a Base64 method, which was added to Generator so it could fulfill the Generatorer interface.
CSPRNG
For use-cases that require a CSPRNG, a CSPRNG based implementation is provided.
To use the CSPRNG based random character generation:
import "github.com/mohae/randchars/crandchars"
This version uses the stdlib's crypto/rand package. The Generator caches a number of random bytes. The cache is refilled whenever it is exhausted. This speeds up the process of generating random characters. If a local Generator is being used, the cache size can be specified by using the NewGenerator() func.
For convenience, a thread-safe package level Generator is provided.
The CSPRNG Generator implements the randchars.Generatorer interface.
License
MIT Licensed. See the LICENSE file.
Documentation
¶
Overview ¶
Package randchars quickly generates a chunk of random ASCII characters using a PRNG. Two different generators are provide: Generator and Base64.
Generator provides more flexibility in the set of characters used: a-zA-Z0-9, a-z0-9, A-Z0-9, a-zA-Z, a-z, A-Z, Base64, as defined in Table 1 of RFC 4648, and Base64URL, as defined in Table 2 of RFC 4648.
Base64 generates a chunk of Base 64 random characters. The character set used is from Table 1 of RFC 4648.
Calls to the package functions using the package global genarator are threadsafe.
Index ¶
- func Alpha(n int) []byte
- func AlphaNum(n int) []byte
- func Base64(n int) []byte
- func Base64Bytes(n int) []byte
- func Base64URL(n int) []byte
- func Base64URLBytes(n int) []byte
- func Int64() int64
- func LowerAlpha(n int) []byte
- func LowerAlphaNum(n int) []byte
- func ReSeed()
- func ReseedBase64()
- func ReseedBase64URL()
- func Seed(n int64)
- func SeedBase64(n int64)
- func SeedBase64URL(n int64)
- func SeedWithState(seed, state int64)
- func UpperAlpha(n int) []byte
- func UpperAlphaNum(n int) []byte
- type Base64Generator
- type Base64URLGenerator
- type Generator
- func (g *Generator) Alpha(n int) []byte
- func (g *Generator) AlphaNum(n int) []byte
- func (g *Generator) Base64(n int) []byte
- func (g *Generator) Base64URL(n int) []byte
- func (g *Generator) LowerAlpha(n int) []byte
- func (g *Generator) LowerAlphaNum(n int) []byte
- func (g *Generator) ReSeed()
- func (g *Generator) Seed(n int64)
- func (g *Generator) SeedWithState(seed, state int64)
- func (g *Generator) UpperAlpha(n int) []byte
- func (g *Generator) UpperAlphaNum(n int) []byte
- type Generatorer
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func Alpha ¶
Alpha returns a randomly generated []byte of length n using a-zA-Z. This will panic if n < 0.
func AlphaNum ¶
AlphaNum returns a randomly generated []byte of length n using a-zA-Z0-9. This will panic if n < 0.
func Base64 ¶
Base64 returns a randomly generated []byte of length n using base64, as defined in Table 1 of RFC 4648. This will panic if n < 0.
func Base64Bytes ¶
Base64Bytes returns n randomly generated Base 64 bytes.
func Base64URL ¶
Base64URL returns a randomly generated []byte of length n using base64url, as defined in Table 2 of RFC 4648 filename safe base64. This will panic if n < 0.
func Base64URLBytes ¶
Base64URLBytes returns n randomly generated Base64URL bytes.
func LowerAlpha ¶
LowerAlpha returns a randomly generated []byte of length n using a-z. This will panic if n < 0.
func LowerAlphaNum ¶
LowerAlphaNum returns a randomly generated []byte of length n using a-z0-9. This will panic if n < 0.
func ReseedBase64 ¶
func ReseedBase64()
ReseedBase64 seeds Base64Generator's prng using a value obtained from a CSPRNG.
func ReseedBase64URL ¶
func ReseedBase64URL()
ReseedBase64URL seeds Base64URLGenerator's prng using a value obtained from a CSPRNG.
func SeedBase64 ¶
func SeedBase64(n int64)
SeedBase64 seeds Base64Generator's prng using the provided value.
func SeedBase64URL ¶
func SeedBase64URL(n int64)
SeedBase64URL seeds Base64URLGenerator's prng using the provided value.
func SeedWithState ¶
func SeedWithState(seed, state int64)
SeedWithState seeds the Generator's prng and set's its state.
func UpperAlpha ¶
UpperAlpha returns a randomly generated []byte of length n using A-Z. This will panic if n < 0.
func UpperAlphaNum ¶
UpperAlphaNum returns a randomly generated []byte of length n using A-Z0-9. This will panic if n < 0.
Types ¶
type Base64Generator ¶
type Base64Generator struct {
// contains filtered or unexported fields
}
Base64 supports the Base 64 Alphabet as shown in Table 1 of RFC 4248. This uses an implementation of the XORoShiRo128+ PRNG: http://xoroshiro.di.unimi.it/.
This is more performant than using Generator for base64.
func NewBase64Generator ¶
func NewBase64Generator() *Base64Generator
NewBase64 returns an initialized Base64Generator that is ready to use. The seed value used is an int64 obtained from a CSPRNG.
func NewBase64GeneratorWithSeed ¶
func NewBase64GeneratorWithSeed(seed int64) *Base64Generator
NewBase64GeneratorWithSeed a Base64Generator using the received value as its seed.
func (*Base64Generator) Bytes ¶
func (g *Base64Generator) Bytes(n int) []byte
Bytes returns n randomly generated Base 64 bytes.
func (*Base64Generator) Reseed ¶
func (g *Base64Generator) Reseed()
Reseed seeds Base64Generator's prng using a value obtained from a CSPRNG.
func (*Base64Generator) Seed ¶
func (g *Base64Generator) Seed(n int64)
Seed seeds Base64Generator's prng using the provided value.
type Base64URLGenerator ¶
type Base64URLGenerator struct {
// contains filtered or unexported fields
}
Base64URL supports the Base64URL Alphabet as shown in Table 2 of RFC 4248. This uses an implementation of the XORoShiRo128+ PRNG: http://xoroshiro.di.unimi.it/.
This is more performant than using Generator for base64url.
func NewBase64URLGenerator ¶
func NewBase64URLGenerator() *Base64URLGenerator
NewBase64URL returns an initialized Base64GeneratorURL that is ready to use. The seed value used is an int64 obtained from a CSPRNG.
func NewBase64URLGeneratorWithSeed ¶
func NewBase64URLGeneratorWithSeed(seed int64) *Base64URLGenerator
NewBase64URLGeneratorWithSeed a Base64GeneratorURL using the received value as its seed.
func (*Base64URLGenerator) Bytes ¶
func (g *Base64URLGenerator) Bytes(n int) []byte
Bytes returns n randomly generated Base64URL bytes.
func (*Base64URLGenerator) Reseed ¶
func (g *Base64URLGenerator) Reseed()
Reseed seeds Base64URLGenerator's prng using a value obtained from a CSPRNG.
func (*Base64URLGenerator) Seed ¶
func (g *Base64URLGenerator) Seed(n int64)
Seed seeds Base64URLGenerator's prng using the provided value.
type Generator ¶
type Generator struct {
// contains filtered or unexported fields
}
Generator generates the random ASCII characters. It relies on a PRNG that implements PCG: www.pcg-random.org.
func NewGeneratorSeedWithState ¶
NewGeneratorSeedWithState a Generator using the received values as its seed and state.
func NewGeneratorWithSeed ¶
NewGeneratorWithSeed a Generator using the received value as its seed.
func (*Generator) Alpha ¶
Alpha returns a randomly generated []byte of length n using a-zA-Z. This will panic if n < 0.
func (*Generator) AlphaNum ¶
AlphaNum returns a randomly generated []byte of length n using a-zA-Z0-9. This will panic if n < 0.
func (*Generator) Base64 ¶
Base64 returns a randomly generated []byte of length n using Base64, as defined in Table 1 of RFC 4648. This will panic if n < 0.
func (*Generator) Base64URL ¶
Base64URL returns a randomly generated []byte of length n using Base64URL, as defined in Table 2 of RFC 4648. This will panic if n < 0.
func (*Generator) LowerAlpha ¶
LowerAlpha returns a randomly generated []byte of length n using a-z. This will panic if n < 0.
func (*Generator) LowerAlphaNum ¶
LowerAlphaNum returns a randomly generated []byte of length n using a-z0-9. This will panic if n < 0.
func (*Generator) ReSeed ¶
func (g *Generator) ReSeed()
ReSeed seeds the Generator's prng using a value obtained from a CSPRNG.
func (*Generator) SeedWithState ¶
SeedWithState seeds the Generator's prng and set's its state.
func (*Generator) UpperAlpha ¶
UpperAlpha returns a randomly generated []byte of length n using A-Z. This will panic if n < 0.
func (*Generator) UpperAlphaNum ¶
UpperAlphaNum returns a randomly generated []byte of length n using A-Z0-9. This will panic if n < 0.
Source Files
Directories
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cmd
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randchars
randchars is a cli app that generates random characters.
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randchars is a cli app that generates random characters. |
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Package crandchars generates a chunk of random ASCII characters using a CSPRNG.
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Package crandchars generates a chunk of random ASCII characters using a CSPRNG. |