I realise this isn't exactly what you're asking for, but there's no point in reinventing the wheel and writing a bash version. You can simply use the openssl command to generate the hash within your script. [me@home] echo -n "value" | openssl dgst -sha1 -hmac "key" 57443a4c052350a44638835d64fd66822f813319

Here is a clone of the hash_hmac function you can use in the event you need an HMAC generator and Hash is not available. It's only usable with MD5 and SHA1 encryption algorithms, but its output is identical to the official hash_hmac function (so far at least). compute HMAC using a specific key for certain OpenSSL-FIPS operations. file file or files to digest. If no files are specified then standard input is used. EXAMPLES To create a hex-encoded message digest of a file: openssl dgst -md5 -hex file.txt To sign a file using SHA-256 with binary file output: openssl dgst -sha256 -sign privatekey.pem Added openssl.digest and openssl.hmac modules. 2012-10-09. Added insanely comprehensive OpenSSL bindings in ext/, including Lua bindings for manipulating bignums, public keys, X.509 certificates (names, altnames, chains, stores, etc), and SSL_CTX objects. Create HMAC - SHA384 of a file using a specific key in bytes openssl dgst -SHA384 -mac HMAC -macopt hexkey:369bd7d655 file.data Create HMAC - SHA512 of some text The openssl package available in most linux distributions include a way of creating the HMAC-SHA1 string from the command line… echo - n "string to sign" | openssl dgst - sha1 - hmac "my secret key" OpenSSL is a cryptography toolkit implementing the Secure Sockets Layer ( SSL v2/v3) and Transport Layer Security ( TLS v1) network protocols and related cryptography standards required by them. The openssl program is a command line tool for using the various cryptography functions of OpenSSL's crypto library from the shell. It can be used for Examples. The following example shows how to sign a file by using the HMACSHA512 object and then how to verify the file.. using namespace System; using namespace System::IO; using namespace System::Security::Cryptography; // Computes a keyed hash for a source file, creates a target file with the keyed hash // prepended to the contents of the source file, then decrypts the file and compares

Short answer: 32 bytes of full-entropy key is enough. Assuming full-entropy key (that is, each bit of key is chosen independently of the others by an equivalent of fair coin toss), the security of HMAC-SHA-256 against brute force key search is defined by the key size up to 64 bytes (512 bits) of key, then abruptly drops to 32 bytes (256 bits) for larger keys; that's because in the later case

Jan 30, 2009 · OpenSSL command line HMAC. Hi, To generate an HMAC key using SHA-256, I can issue the following command: openssl dgst -sha256 -hmac -binary < message.bin > mac.bin I realised hmac = hash( (key xor opad) + hash((key xor ipad) xor message) ) So it's just some hash functions and xorring values together, nothing else. Block ciphers typically need a fixed-length key, but cryptographic hash functions "[map] data of arbitrary size to a bit string of a fixed size (a hash)". HMAC_CTX h; memcpy(h.key, KeyDataFromSomewhere, sizeof h.key) However, this is risky. It's far too easy to get the HMAC into an inconsistent state and ultimately get wrong results. Instead, when the object is declared as opaque: typedef struct hmac_ctx_st HMAC_CTX; The code above will now fail: % cat a.c #include "openssl/hmac.h" #include

EVP_PKEY_HMAC: An HMAC key for generating a Message Authentication Code; EVP_PKEY_CMAC: A CMAC key for generating a Message Authentication Code; Note: DSA handling changed for SSL/TLS cipher suites in OpenSSL 1.1.0. For details, see DSA with OpenSSL-1.1 on the mailing list.

OpenSSL is a cryptography toolkit implementing the Secure Sockets Layer ( SSL v2/v3) and Transport Layer Security ( TLS v1) network protocols and related cryptography standards required by them. The openssl program is a command line tool for using the various cryptography functions of OpenSSL's crypto library from the shell. It can be used for Examples. The following example shows how to sign a file by using the HMACSHA512 object and then how to verify the file.. using namespace System; using namespace System::IO; using namespace System::Security::Cryptography; // Computes a keyed hash for a source file, creates a target file with the keyed hash // prepended to the contents of the source file, then decrypts the file and compares Jan 30, 2009 · OpenSSL command line HMAC. Hi, To generate an HMAC key using SHA-256, I can issue the following command: openssl dgst -sha256 -hmac -binary < message.bin > mac.bin I realised hmac = hash( (key xor opad) + hash((key xor ipad) xor message) ) So it's just some hash functions and xorring values together, nothing else. Block ciphers typically need a fixed-length key, but cryptographic hash functions "[map] data of arbitrary size to a bit string of a fixed size (a hash)". HMAC_CTX h; memcpy(h.key, KeyDataFromSomewhere, sizeof h.key) However, this is risky. It's far too easy to get the HMAC into an inconsistent state and ultimately get wrong results. Instead, when the object is declared as opaque: typedef struct hmac_ctx_st HMAC_CTX; The code above will now fail: % cat a.c #include "openssl/hmac.h" #include openssl dgst -sha256 -mac hmac -macopt hexkey:$(cat mykey.txt) -out hmac.txt /bin/ps Since we're talking about cryptography, which is hard; and OpenSSL, which doesn't always have the most easy-to-use interfaces, I would suggest also verifying everything yourself, at least twice, instead of taking my word for it. If you encountered this compiling issue - "aggregate ‘HMAC_CTX ctx’ has incomplete type and cannot be defined" etc, basically, it means you're using a higher version of openssl (>=v1.1.0).