botan man page

botan — Botan command line util

Outline

The botan program is a command line tool for using a broad variety of functions of the Botan library in the shell.

All commands follow the syntax botan <command> <command-options>.

If botan is run with an unknown command, or without any command, or with the --help option, all available commands with their options will be printed.

Hash Function

hash --algo=SHA-256 --buf-size=4096 files

Compute the algo digest over the data in any number of files. If no files are listed on the command line, the input source defaults to standard input.

Password Hash

gen_bcrypt --work-factor=12 password

Calculate the bcrypt password digest of password. work-factor is an integer between 4 and 18.  A higher work-factor value results in a more expensive hash calculation.

check_bcrypt password hash

Checks if the bcrypt hash of the passed password equals the passed hash value.

Hmac

hmac --hash=SHA-256 --buf-size=4096 key files

Compute the HMAC tag with the cryptographic hash function hash using the key in file key over the data in files. files defaults to STDIN.

Public Key Cryptography

keygen --algo=RSA --params= --passphrase= --pbe= --pbe-millis=300 --der-out

Generate a PKCS #8 algo private key. If der-out is passed, the pair is BER encoded.  Otherwise, PEM encoding is used. To protect the PKCS #8 formatted key, it is recommended to encrypt it with a provided passphrase. pbe is the name of the desired encryption algorithm, which uses pbe-millis milliseconds to derive the encryption key from the passed passphrase. Algorithm specific parameters, as the desired bitlength of an RSA key, can be passed with params.

  • For RSA params specifies the bit length of the RSA modulus. It defaults to 3072.
  • For DH params specifies the DH parameters. It defaults to modp/ietf/2048.
  • For DSA params specifies the DSA parameters. It defaults to dsa/botan/2048.
  • For EC algorithms params specifies the elliptic curve. It defaults to secp256r1.
pkcs8 --pass-in= --pub-out --der-out --pass-out= --pbe= --pbe-millis=300 key

Open a PKCS #8 formatted key at key. If key is encrypted, the passphrase must be passed as pass-in. It is possible to (re)encrypt the read key with the passphrase passed as pass-out. The parameters pbe-millis and pbe work similarly to keygen.

sign --passphrase= --hash=SHA-256 --emsa= key file

Sign the data in file using the PKCS #8 private key key. If key is encrypted, the used passphrase must be passed as pass-in. emsa specifies the signature scheme and hash the cryptographic hash function used in the scheme.

  • For RSA signatures EMSA4 (RSA-PSS) is the default scheme.
  • For ECDSA and DSA emsa defaults to EMSA1 (signing the hash directly)
verify --hash=SHA-256 --emsa= pubkey file signature

Verify the authenticity of the data in file with the provided signature signature and the public key pubkey. Similarly to the signing process, emsa specifies the signature scheme and hash the cryptographic hash function used in the scheme.

gen_dl_group --pbits=1024 --qbits=0 --type=subgroup

Generate ANSI X9.42 encoded Diffie-Hellman group parameters.

  • If type=subgroup is passed, the size of the prime subgroup q is sampled as a prime of qbits length and p is pbits long. If qbits is not passed, its length is estimated from pbits as described in RFC 3766.
  • If type=strong is passed, p is sampled as a safe prime with length pbits and the prime subgroup has size q with pbits-1 length.
dl_group_info --pem name

Print raw Diffie-Hellman parameters (p,g) of the standarized DH group name. If pem is set, the X9.42 encoded group is printed.

ec_group_info --pem name

Print raw elliptic curve domain parameters of the standarized curve name. If pem is set, the encoded domain is printed.

X.509

gen_pkcs10 key CN --country= --organization= --email= --key-pass= --hash=SHA-256 --emsa=

Generate a PKCS #10 certificate signing request (CSR) using the passed PKCS #8 private key key. If the private key is encrypted, the decryption passphrase key-pass has to be passed.*emsa* specifies the padding scheme to be used when calculating the signature.

  • For RSA keys EMSA4 (RSA-PSS) is the default scheme.
  • For ECDSA, DSA, ECGDSA, ECKCDSA and GOST-34.10 keys emsa defaults to EMSA1.
gen_self_signed key CN --country= --dns= --organization= --email= --key-pass= --ca --hash=SHA-256 --emsa=

Generate a self signed X.509 certificate using the PKCS #8 private key key. If the private key is encrypted, the decryption passphrase key-pass has to be passed. If ca is passed, the certificate is marked for certificate authority (CA) usage. emsa specifies the padding scheme to be used when calculating the signature.

  • For RSA keys EMSA4 (RSA-PSS) is the default scheme.
  • For ECDSA, DSA, ECGDSA, ECKCDSA and GOST-34.10 keys emsa defaults to EMSA1.
sign_cert --ca-key-pass= --hash=SHA-256 --duration=365 --emsa= ca_cert ca_key pkcs10_req

Create a CA signed X.509 certificate from the information contained in the PKCS #10 CSR pkcs10_req. The CA certificate is passed as ca_cert and the respective PKCS #8 private key as ca_key. If the private key is encrypted, the decryption passphrase ca-key-pass has to be passed. The created certificate has a validity period of duration days. emsa specifies the padding scheme to be used when calculating the signature. emsa defaults to the padding scheme used in the CA certificate.

ocsp_check subject issuer

Verify an X.509 certificate against the issuers OCSP responder. Pass the certificate to validate as subject and the CA certificate as issuer.

cert_info --fingerprint --ber file

Parse X.509 PEM certificate and display data fields. If --fingerprint is used, the certificate's fingerprint is also printed.

cert_verify subject *ca_certs

Verify if the provided X.509 certificate subject can be sucessfully validated. The list of trusted CA certificates is passed with ca_certs, which is a list of one or more certificates.

TLS Server/Client

tls_ciphers --policy=default --version=tls1.2

Prints the list of ciphersuites that will be offered under a particular policy/version. The policy can be any of the the strings "default", "suiteb", "strict", or "all" to denote built-in policies, or it can name a file from which a policy description will be read.

tls_client host --port=443 --print-certs --policy= --tls1.0 --tls1.1 --tls1.2 --session-db= --session-db-pass= --next-protocols= --type=tcp

Implements a testing TLS client, which connects to host via TCP or UDP on port port. The TLS version can be set with the flags tls1.0, tls1.1 and tls1.2 of which the lowest specified version is automatically chosen.  If none of the TLS version flags is set, the latest supported version is chosen. The client honors the TLS policy defined in the policy file and prints all certificates in the chain, if print-certs is passed. next-protocols is a comma seperated list and specifies the protocols to advertise with Application-Layer Protocol Negotiation (ALPN).

tls_server cert key --port=443 --type=tcp --policy=

Implements a testing TLS server, which allows TLS clients to connect. Binds to either TCP or UDP on port port. The server uses the certificate cert and the respective PKCS #8 private key key. The server honors the TLS policy defined in the policy file.

tls_http_server cert key --port=443 --policy= --session-db --session-db-pass=

Only available if Boost.Asio support was enabled. Provides a simple HTTP server which replies to all requests with an informational text output. The server honors the TLS policy defined in the policy file.

tls_proxy listen_port target_host target_port server_cert server_key

Only available if Boost.Asio support was enabled. Listens on a port and forwards all connects to a target server specified at target_host and target_port.

Number Theory

is_prime --prob=56 n

Test if the integer n is composite or prime with a Miller-Rabin primality test with (prob+2)/2 iterations.

factor n

Factor the integer n using a combination of trial division by small primes, and Pollard's Rho algorithm.

gen_prime --count=1 bits

Samples count primes with a length of bits bits.

PSK Database

Only available if sqlite3 support was compiled in.

psk_set db db_key name psk

Using the PSK database named db and encrypting under the (hex) key db_key, save the provided psk (also hex) under name:

$ botan psk_set psk.db deadba55 bunny f00fee
psk_get db db_key name

Get back a value saved with psk_set:

$ botan psk_get psk.db deadba55 bunny
f00fee
psk_list db db_key

List all values saved to the database under the given key:

$ botan psk_list psk.db deadba55
bunny

Data Encoding/Decoding

base64_dec file

Encode file to Base64.

base64_enc file

Decode Base64 encoded file.

hex_dec file

Encode file to Hex.

hex_enc file

Decode Hex encoded file.

Miscellaneous Commands

version --full

Print the version number. If option -full is provided additional details are printed.

config info_type

Prints build information, useful for applications which want to build against the library.  The info_type argument can be any of prefix, cflags, ldflags, or libs.

cpuid

List available processor flags (aes_ni, SIMD extensions, ...).

asn1print file

Decode and print file with ASN.1 Basic Encoding Rules (BER).

http_get url

Retrieve ressource from the passed http/https url.

speed --msec=100 --provider= --buf-size=4096 algos

Measures the speed of the passed algos. If no algos are passed all available speed tests are executed. msec (in milliseconds) sets the period of measurement for each algorithm.

rng --system --rdrand bytes

Sample bytes random bytes from the specified random number generator. If system is set, the Botan System_RNG is used. If system is unset and rdrand is set, the hardware rng RDRAND_RNG is used.  If both are unset, the Botan AutoSeeded_RNG is used.

cc_encrypt CC passphrase --tweak=

Encrypt the passed valid credit card number CC using FPE encryption and the passphrase passphrase. The key is derived from the passphrase using PBKDF2 with SHA256. Due to the nature of FPE, the ciphertext is also a credit card number with a valid checksum. tweak is public and parameterizes the encryption function.

cc_decrypt CC passphrase --tweak=

Decrypt the passed valid ciphertext CC using FPE decryption with the passphrase passphrase and the tweak tweak.