ref: a1c3c34c70431447a89fbe08c3475dbfaee7b672
dir: /sys/src/cmd/auth/rsa2jwk.c/
#include <u.h> #include <libc.h> #include <auth.h> #include <mp.h> #include <libsec.h> #include "rsa2any.h" #define between(x,min,max) (((min-1-x) & (x-max-1))>>8) int encurl64chr(int o) { int c; c = between(o, 0, 25) & ('A'+o); c |= between(o, 26, 51) & ('a'+(o-26)); c |= between(o, 52, 61) & ('0'+(o-52)); c |= between(o, 62, 62) & ('-'); c |= between(o, 63, 63) & ('_'); return c; } char* encurl64(void *in, int n) { int lim; char *out, *p; lim = 4*n/3 + 5; if((out = malloc(lim)) == nil) sysfatal("malloc: %r"); enc64x(out, lim, in, n, encurl64chr); if((p = strchr(out, '=')) != nil) *p = 0; return out; } void usage(void) { fprint(2, "usage: auth/rsa2pub [file]\n"); exits("usage"); } void main(int argc, char **argv) { uchar nbuf[8192], ebuf[512]; char *nstr, *estr; RSApriv *k; int nlen, elen; fmtinstall('[', encodefmt); quotefmtinstall(); ARGBEGIN{ default: usage(); }ARGEND if(argc > 1) usage(); if((k = getrsakey(argc, argv, 0, nil)) == nil) sysfatal("%r"); nlen = (mpsignif(k->pub.n)+7)/8; if(nlen >= sizeof(nbuf)) sysfatal("key too big"); mptobe(k->pub.n, nbuf, nlen, nil); nstr = encurl64(nbuf, nlen); elen = (mpsignif(k->pub.ek)+7)/8; if(elen >= sizeof(ebuf)) sysfatal("key too big"); mptobe(k->pub.ek, ebuf, elen, nil); estr = encurl64(ebuf, elen); print( "{" "\"kty\": \"RSA\"," "\"n\": \"%s\"," "\"e\": \"%s\"" "}\n", nstr, estr); exits(nil); }