diff --git a/crypto/asn1/internal.h b/crypto/asn1/internal.h
index 64e1e6b10..5dca7280c 100644
--- a/crypto/asn1/internal.h
+++ b/crypto/asn1/internal.h
@@ -56,8 +56,8 @@
  *
  */
 
-#ifndef OPENSSL_HEADER_ASN1_ASN1_LOCL_H
-#define OPENSSL_HEADER_ASN1_ASN1_LOCL_H
+#ifndef OPENSSL_HEADER_ASN1_INTERNAL_H
+#define OPENSSL_HEADER_ASN1_INTERNAL_H
 
 #include <time.h>
 
@@ -266,4 +266,4 @@ typedef struct ASN1_EXTERN_FUNCS_st {
 }  // extern C
 #endif
 
-#endif  // OPENSSL_HEADER_ASN1_ASN1_LOCL_H
+#endif  // OPENSSL_HEADER_ASN1_INTERNAL_H
diff --git a/crypto/asn1/tasn_dec.c b/crypto/asn1/tasn_dec.c
index 23c526e0f..622ed458a 100644
--- a/crypto/asn1/tasn_dec.c
+++ b/crypto/asn1/tasn_dec.c
@@ -85,7 +85,7 @@ static int asn1_template_ex_d2i(ASN1_VALUE **pval, const unsigned char **in,
 static int asn1_template_noexp_d2i(ASN1_VALUE **val, const unsigned char **in,
                                    long len, const ASN1_TEMPLATE *tt, char opt,
                                    CRYPTO_BUFFER *buf, int depth);
-static int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
+static int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, long len,
                        int utype, const ASN1_ITEM *it);
 static int asn1_d2i_ex_primitive(ASN1_VALUE **pval, const unsigned char **in,
                                  long len, const ASN1_ITEM *it, int tag,
@@ -749,7 +749,7 @@ err:
 
 // Translate ASN1 content octets into a structure
 
-static int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
+static int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, long len,
                        int utype, const ASN1_ITEM *it) {
   ASN1_VALUE **opval = NULL;
   ASN1_STRING *stmp;
diff --git a/crypto/bio/bio.c b/crypto/bio/bio.c
index 610c733b2..ca5cbff36 100644
--- a/crypto/bio/bio.c
+++ b/crypto/bio/bio.c
@@ -423,7 +423,7 @@ int BIO_indent(BIO *bio, unsigned indent, unsigned max_indent) {
 }
 
 static int print_bio(const char *str, size_t len, void *bio) {
-  return BIO_write((BIO *)bio, str, len);
+  return BIO_write_all((BIO *)bio, str, len);
 }
 
 void ERR_print_errors(BIO *bio) {
@@ -462,9 +462,11 @@ static int bio_read_all(BIO *bio, uint8_t **out, size_t *out_len,
       OPENSSL_free(*out);
       return 0;
     }
-    const size_t todo = len - done;
-    assert(todo < INT_MAX);
-    const int n = BIO_read(bio, *out + done, todo);
+    size_t todo = len - done;
+    if (todo > INT_MAX) {
+      todo = INT_MAX;
+    }
+    const int n = BIO_read(bio, *out + done, (int)todo);
     if (n == 0) {
       *out_len = done;
       return 1;
diff --git a/crypto/bio/fd.c b/crypto/bio/fd.c
index 9a2a65027..7775d7a75 100644
--- a/crypto/bio/fd.c
+++ b/crypto/bio/fd.c
@@ -257,7 +257,8 @@ static int fd_gets(BIO *bp, char *buf, int size) {
 
   ptr[0] = '\0';
 
-  return ptr - buf;
+  // The output length is bounded by |size|.
+  return (int)(ptr - buf);
 }
 
 static const BIO_METHOD methods_fdp = {
diff --git a/crypto/bio/file.c b/crypto/bio/file.c
index 0f2fffbd6..8ba9c544c 100644
--- a/crypto/bio/file.c
+++ b/crypto/bio/file.c
@@ -157,13 +157,11 @@ static int file_read(BIO *b, char *out, int outl) {
 }
 
 static int file_write(BIO *b, const char *in, int inl) {
-  int ret = 0;
-
   if (!b->init) {
     return 0;
   }
 
-  ret = fwrite(in, inl, 1, (FILE *)b->ptr);
+  int ret = (int)fwrite(in, inl, 1, (FILE *)b->ptr);
   if (ret > 0) {
     ret = inl;
   }
@@ -253,20 +251,18 @@ static long file_ctrl(BIO *b, int cmd, long num, void *ptr) {
 }
 
 static int file_gets(BIO *bp, char *buf, int size) {
-  int ret = 0;
-
   if (size == 0) {
     return 0;
   }
 
   if (!fgets(buf, size, (FILE *)bp->ptr)) {
     buf[0] = 0;
-    goto err;
+    // TODO(davidben): This doesn't distinguish error and EOF. This should check
+    // |ferror| as in |file_read|.
+    return 0;
   }
-  ret = strlen(buf);
 
-err:
-  return ret;
+  return (int)strlen(buf);
 }
 
 static const BIO_METHOD methods_filep = {
diff --git a/crypto/bio/pair.c b/crypto/bio/pair.c
index c4d09c14a..40711cdf9 100644
--- a/crypto/bio/pair.c
+++ b/crypto/bio/pair.c
@@ -221,7 +221,8 @@ static int bio_read(BIO *bio, char *buf, int size_) {
     rest -= chunk;
   } while (rest);
 
-  return size;
+  // |size| is bounded by the buffer size, which fits in |int|.
+  return (int)size;
 }
 
 static int bio_write(BIO *bio, const char *buf, int num_) {
@@ -293,7 +294,8 @@ static int bio_write(BIO *bio, const char *buf, int num_) {
     buf += chunk;
   } while (rest);
 
-  return num;
+  // |num| is bounded by the buffer size, which fits in |int|.
+  return (int)num;
 }
 
 static int bio_make_pair(BIO *bio1, BIO *bio2, size_t writebuf1_len,
diff --git a/crypto/cipher_extra/cipher_test.cc b/crypto/cipher_extra/cipher_test.cc
index 80146fe03..4c8c142cc 100644
--- a/crypto/cipher_extra/cipher_test.cc
+++ b/crypto/cipher_extra/cipher_test.cc
@@ -208,8 +208,9 @@ static void TestCipherAPI(const EVP_CIPHER *cipher, Operation op, bool padding,
   // pre-computed key schedule and a streaming operation.
   ASSERT_TRUE(MaybeCopyCipherContext(copy, &ctx));
   if (is_aead) {
-    ASSERT_TRUE(
-        EVP_CIPHER_CTX_ctrl(ctx.get(), EVP_CTRL_AEAD_SET_IVLEN, iv.size(), 0));
+    ASSERT_LE(iv.size(), size_t{INT_MAX});
+    ASSERT_TRUE(EVP_CIPHER_CTX_ctrl(ctx.get(), EVP_CTRL_AEAD_SET_IVLEN,
+                                    static_cast<int>(iv.size()), 0));
   } else {
     ASSERT_EQ(iv.size(), EVP_CIPHER_CTX_iv_length(ctx.get()));
   }
diff --git a/crypto/fipsmodule/ec/oct.c b/crypto/fipsmodule/ec/oct.c
index 3f0c0d65e..eb77643cf 100644
--- a/crypto/fipsmodule/ec/oct.c
+++ b/crypto/fipsmodule/ec/oct.c
@@ -320,8 +320,7 @@ int EC_POINT_set_compressed_coordinates_GFp(const EC_GROUP *group,
   }
 
   if (!BN_mod_sqrt(y, tmp1, &group->field, ctx)) {
-    unsigned long err = ERR_peek_last_error();
-
+    uint32_t err = ERR_peek_last_error();
     if (ERR_GET_LIB(err) == ERR_LIB_BN &&
         ERR_GET_REASON(err) == BN_R_NOT_A_SQUARE) {
       ERR_clear_error();
diff --git a/crypto/fipsmodule/ec/p256-nistz_test.cc b/crypto/fipsmodule/ec/p256-nistz_test.cc
index 6aa51e852..a53d94eeb 100644
--- a/crypto/fipsmodule/ec/p256-nistz_test.cc
+++ b/crypto/fipsmodule/ec/p256-nistz_test.cc
@@ -43,9 +43,11 @@ TEST(P256_NistzTest, SelectW5) {
   // Fill a table with some garbage input.
   alignas(64) P256_POINT table[16];
   for (size_t i = 0; i < 16; i++) {
-    OPENSSL_memset(table[i].X, 3 * i, sizeof(table[i].X));
-    OPENSSL_memset(table[i].Y, 3 * i + 1, sizeof(table[i].Y));
-    OPENSSL_memset(table[i].Z, 3 * i + 2, sizeof(table[i].Z));
+    OPENSSL_memset(table[i].X, static_cast<uint8_t>(3 * i), sizeof(table[i].X));
+    OPENSSL_memset(table[i].Y, static_cast<uint8_t>(3 * i + 1),
+                   sizeof(table[i].Y));
+    OPENSSL_memset(table[i].Z, static_cast<uint8_t>(3 * i + 2),
+                   sizeof(table[i].Z));
   }
 
   for (int i = 0; i <= 16; i++) {
@@ -73,8 +75,9 @@ TEST(P256_NistzTest, SelectW7) {
   // Fill a table with some garbage input.
   alignas(64) P256_POINT_AFFINE table[64];
   for (size_t i = 0; i < 64; i++) {
-    OPENSSL_memset(table[i].X, 2 * i, sizeof(table[i].X));
-    OPENSSL_memset(table[i].Y, 2 * i + 1, sizeof(table[i].Y));
+    OPENSSL_memset(table[i].X, static_cast<uint8_t>(2 * i), sizeof(table[i].X));
+    OPENSSL_memset(table[i].Y, static_cast<uint8_t>(2 * i + 1),
+                   sizeof(table[i].Y));
   }
 
   for (int i = 0; i <= 64; i++) {
diff --git a/crypto/pem/pem_lib.c b/crypto/pem/pem_lib.c
index 28ed438b9..30ba387e4 100644
--- a/crypto/pem/pem_lib.c
+++ b/crypto/pem/pem_lib.c
@@ -78,7 +78,8 @@
 static int load_iv(char **fromp, unsigned char *to, size_t num);
 static int check_pem(const char *nm, const char *name);
 
-void PEM_proc_type(char *buf, int type) {
+// PEM_proc_type appends a Proc-Type header to |buf|, determined by |type|.
+static void PEM_proc_type(char buf[PEM_BUFSIZE], int type) {
   const char *str;
 
   if (type == PEM_TYPE_ENCRYPTED) {
@@ -96,24 +97,27 @@ void PEM_proc_type(char *buf, int type) {
   OPENSSL_strlcat(buf, "\n", PEM_BUFSIZE);
 }
 
-void PEM_dek_info(char *buf, const char *type, int len, char *str) {
+// PEM_dek_info appends a DEK-Info header to |buf|, with an algorithm of |type|
+// and a single parameter, specified by hex-encoding |len| bytes from |str|.
+static void PEM_dek_info(char buf[PEM_BUFSIZE], const char *type, size_t len,
+                         char *str) {
   static const unsigned char map[17] = "0123456789ABCDEF";
-  long i;
-  int j;
 
   OPENSSL_strlcat(buf, "DEK-Info: ", PEM_BUFSIZE);
   OPENSSL_strlcat(buf, type, PEM_BUFSIZE);
   OPENSSL_strlcat(buf, ",", PEM_BUFSIZE);
-  j = strlen(buf);
-  if (j + (len * 2) + 1 > PEM_BUFSIZE) {
+  size_t buf_len = strlen(buf);
+  // We must write an additional |2 * len + 2| bytes after |buf_len|, including
+  // the trailing newline and NUL.
+  if (len > (PEM_BUFSIZE - buf_len - 2) / 2) {
     return;
   }
-  for (i = 0; i < len; i++) {
-    buf[j + i * 2] = map[(str[i] >> 4) & 0x0f];
-    buf[j + i * 2 + 1] = map[(str[i]) & 0x0f];
+  for (size_t i = 0; i < len; i++) {
+    buf[buf_len + i * 2] = map[(str[i] >> 4) & 0x0f];
+    buf[buf_len + i * 2 + 1] = map[(str[i]) & 0x0f];
   }
-  buf[j + i * 2] = '\n';
-  buf[j + i * 2 + 1] = '\0';
+  buf[buf_len + len * 2] = '\n';
+  buf[buf_len + len * 2 + 1] = '\0';
 }
 
 void *PEM_ASN1_read(d2i_of_void *d2i, const char *name, FILE *fp, void **x,
@@ -318,7 +322,7 @@ int PEM_ASN1_write_bio(i2d_of_void *i2d, const char *name, BIO *bp, void *x,
       }
       kstr = (unsigned char *)buf;
     }
-    assert(iv_len <= (int)sizeof(iv));
+    assert(iv_len <= sizeof(iv));
     if (!RAND_bytes(iv, iv_len)) {  // Generate a salt
       goto err;
     }
@@ -332,7 +336,7 @@ int PEM_ASN1_write_bio(i2d_of_void *i2d, const char *name, BIO *bp, void *x,
       OPENSSL_cleanse(buf, PEM_BUFSIZE);
     }
 
-    assert(strlen(objstr) + 23 + 2 * iv_len + 13 <= sizeof buf);
+    assert(strlen(objstr) + 23 + 2 * iv_len + 13 <= sizeof(buf));
 
     buf[0] = '\0';
     PEM_proc_type(buf, PEM_TYPE_ENCRYPTED);
@@ -781,5 +785,5 @@ int PEM_def_callback(char *buf, int size, int rwflag, void *userdata) {
     return 0;
   }
   OPENSSL_strlcpy(buf, userdata, (size_t)size);
-  return len;
+  return (int)len;
 }
diff --git a/crypto/x509/a_sign.c b/crypto/x509/a_sign.c
index de89fabd7..8ee477988 100644
--- a/crypto/x509/a_sign.c
+++ b/crypto/x509/a_sign.c
@@ -62,6 +62,8 @@
 #include <openssl/obj.h>
 #include <openssl/x509.h>
 
+#include <limits.h>
+
 #include "internal.h"
 
 int ASN1_item_sign(const ASN1_ITEM *it, X509_ALGOR *algor1, X509_ALGOR *algor2,
@@ -83,17 +85,13 @@ int ASN1_item_sign(const ASN1_ITEM *it, X509_ALGOR *algor1, X509_ALGOR *algor2,
 int ASN1_item_sign_ctx(const ASN1_ITEM *it, X509_ALGOR *algor1,
                        X509_ALGOR *algor2, ASN1_BIT_STRING *signature,
                        void *asn, EVP_MD_CTX *ctx) {
-  EVP_PKEY *pkey;
-  unsigned char *buf_in = NULL, *buf_out = NULL;
-  size_t inl = 0, outl = 0;
-
+  int ret = 0;
+  uint8_t *in = NULL, *out = NULL;
   if (signature->type != V_ASN1_BIT_STRING) {
     OPENSSL_PUT_ERROR(ASN1, ASN1_R_WRONG_TYPE);
     goto err;
   }
 
-  pkey = EVP_PKEY_CTX_get0_pkey(ctx->pctx);
-
   // Write out the requested copies of the AlgorithmIdentifier.
   if (algor1 && !x509_digest_sign_algorithm(ctx, algor1)) {
     goto err;
@@ -102,26 +100,37 @@ int ASN1_item_sign_ctx(const ASN1_ITEM *it, X509_ALGOR *algor1,
     goto err;
   }
 
-  inl = ASN1_item_i2d(asn, &buf_in, it);
-  outl = EVP_PKEY_size(pkey);
-  buf_out = OPENSSL_malloc((unsigned int)outl);
-  if ((buf_in == NULL) || (buf_out == NULL)) {
-    outl = 0;
+  int in_len = ASN1_item_i2d(asn, &in, it);
+  if (in_len < 0) {
     goto err;
   }
 
-  if (!EVP_DigestSign(ctx, buf_out, &outl, buf_in, inl)) {
-    outl = 0;
+  EVP_PKEY *pkey = EVP_PKEY_CTX_get0_pkey(ctx->pctx);
+  size_t out_len = EVP_PKEY_size(pkey);
+  if (out_len > INT_MAX) {
+    OPENSSL_PUT_ERROR(X509, ERR_R_OVERFLOW);
+    goto err;
+  }
+
+  out = OPENSSL_malloc(out_len);
+  if (out == NULL) {
+    goto err;
+  }
+
+  if (!EVP_DigestSign(ctx, out, &out_len, in, in_len)) {
     OPENSSL_PUT_ERROR(X509, ERR_R_EVP_LIB);
     goto err;
   }
-  ASN1_STRING_set0(signature, buf_out, outl);
-  buf_out = NULL;
+
+  ASN1_STRING_set0(signature, out, (int)out_len);
+  out = NULL;
   signature->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07);
   signature->flags |= ASN1_STRING_FLAG_BITS_LEFT;
+  ret = 1;
+
 err:
   EVP_MD_CTX_cleanup(ctx);
-  OPENSSL_free(buf_in);
-  OPENSSL_free(buf_out);
-  return outl;
+  OPENSSL_free(in);
+  OPENSSL_free(out);
+  return ret;
 }
diff --git a/crypto/x509/asn1_gen.c b/crypto/x509/asn1_gen.c
index 937069e88..321f63bec 100644
--- a/crypto/x509/asn1_gen.c
+++ b/crypto/x509/asn1_gen.c
@@ -509,7 +509,7 @@ static int generate_v3(CBB *cbb, const char *str, const X509V3_CTX *cnf,
                CBB_flush(cbb);
       }
       if (format == ASN1_GEN_FORMAT_HEX) {
-        long len;
+        size_t len;
         uint8_t *data = x509v3_hex_to_bytes(value, &len);
         if (data == NULL) {
           OPENSSL_PUT_ERROR(ASN1, ASN1_R_ILLEGAL_HEX);
diff --git a/crypto/x509/x509spki.c b/crypto/x509/x509spki.c
index 8ff2053ae..2b9b904ee 100644
--- a/crypto/x509/x509spki.c
+++ b/crypto/x509/x509spki.c
@@ -77,7 +77,7 @@ EVP_PKEY *NETSCAPE_SPKI_get_pubkey(NETSCAPE_SPKI *x) {
 
 // Load a Netscape SPKI from a base64 encoded string
 
-NETSCAPE_SPKI *NETSCAPE_SPKI_b64_decode(const char *str, int len) {
+NETSCAPE_SPKI *NETSCAPE_SPKI_b64_decode(const char *str, ossl_ssize_t len) {
   unsigned char *spki_der;
   const unsigned char *p;
   size_t spki_len;
diff --git a/crypto/x509/x_x509a.c b/crypto/x509/x_x509a.c
index c473f93dd..4b34caaa7 100644
--- a/crypto/x509/x_x509a.c
+++ b/crypto/x509/x_x509a.c
@@ -90,7 +90,7 @@ static X509_CERT_AUX *aux_get(X509 *x) {
   return x->aux;
 }
 
-int X509_alias_set1(X509 *x, const unsigned char *name, int len) {
+int X509_alias_set1(X509 *x, const unsigned char *name, ossl_ssize_t len) {
   X509_CERT_AUX *aux;
   // TODO(davidben): Empty aliases are not meaningful in PKCS#12, and the
   // getters cannot quite represent them. Also erase the object if |len| is
@@ -112,7 +112,7 @@ int X509_alias_set1(X509 *x, const unsigned char *name, int len) {
   return ASN1_STRING_set(aux->alias, name, len);
 }
 
-int X509_keyid_set1(X509 *x, const unsigned char *id, int len) {
+int X509_keyid_set1(X509 *x, const unsigned char *id, ossl_ssize_t len) {
   X509_CERT_AUX *aux;
   // TODO(davidben): Empty key IDs are not meaningful in PKCS#12, and the
   // getters cannot quite represent them. Also erase the object if |len| is
diff --git a/crypto/x509v3/internal.h b/crypto/x509v3/internal.h
index e9d601ba3..315d9343d 100644
--- a/crypto/x509v3/internal.h
+++ b/crypto/x509v3/internal.h
@@ -90,7 +90,7 @@ OPENSSL_EXPORT char *x509v3_bytes_to_hex(const uint8_t *in, size_t len);
 //
 // This function was historically named |string_to_hex| in OpenSSL. Despite the
 // name, |string_to_hex| converted from hex.
-unsigned char *x509v3_hex_to_bytes(const char *str, long *len);
+unsigned char *x509v3_hex_to_bytes(const char *str, size_t *len);
 
 // x509v3_conf_name_matches returns one if |name| is equal to |cmp| or begins
 // with |cmp| followed by '.', and zero otherwise.
diff --git a/crypto/x509v3/v3_conf.c b/crypto/x509v3/v3_conf.c
index ebf33f182..8f71502f1 100644
--- a/crypto/x509v3/v3_conf.c
+++ b/crypto/x509v3/v3_conf.c
@@ -57,6 +57,7 @@
 // extension creation utilities
 
 #include <ctype.h>
+#include <limits.h>
 #include <stdio.h>
 #include <string.h>
 
@@ -81,7 +82,7 @@ static X509_EXTENSION *v3_generic_extension(const char *ext, const char *value,
 static X509_EXTENSION *do_ext_i2d(const X509V3_EXT_METHOD *method, int ext_nid,
                                   int crit, void *ext_struc);
 static unsigned char *generic_asn1(const char *value, const X509V3_CTX *ctx,
-                                   long *ext_len);
+                                   size_t *ext_len);
 
 X509_EXTENSION *X509V3_EXT_nconf(const CONF *conf, const X509V3_CTX *ctx,
                                  const char *name, const char *value) {
@@ -290,7 +291,7 @@ static X509_EXTENSION *v3_generic_extension(const char *ext, const char *value,
                                             int crit, int gen_type,
                                             const X509V3_CTX *ctx) {
   unsigned char *ext_der = NULL;
-  long ext_len = 0;
+  size_t ext_len = 0;
   ASN1_OBJECT *obj = NULL;
   ASN1_OCTET_STRING *oct = NULL;
   X509_EXTENSION *extension = NULL;
@@ -312,12 +313,17 @@ static X509_EXTENSION *v3_generic_extension(const char *ext, const char *value,
     goto err;
   }
 
-  if (!(oct = ASN1_OCTET_STRING_new())) {
+  if (ext_len > INT_MAX) {
+    OPENSSL_PUT_ERROR(X509V3, ERR_R_OVERFLOW);
     goto err;
   }
 
-  oct->data = ext_der;
-  oct->length = ext_len;
+  oct = ASN1_OCTET_STRING_new();
+  if (oct == NULL) {
+    goto err;
+  }
+
+  ASN1_STRING_set0(oct, ext_der, (int)ext_len);
   ext_der = NULL;
 
   extension = X509_EXTENSION_create_by_OBJ(NULL, obj, crit, oct);
@@ -330,15 +336,18 @@ err:
 }
 
 static unsigned char *generic_asn1(const char *value, const X509V3_CTX *ctx,
-                                   long *ext_len) {
-  ASN1_TYPE *typ;
-  unsigned char *ext_der = NULL;
-  typ = ASN1_generate_v3(value, ctx);
+                                   size_t *ext_len) {
+  ASN1_TYPE *typ = ASN1_generate_v3(value, ctx);
   if (typ == NULL) {
     return NULL;
   }
-  *ext_len = i2d_ASN1_TYPE(typ, &ext_der);
+  unsigned char *ext_der = NULL;
+  int len = i2d_ASN1_TYPE(typ, &ext_der);
   ASN1_TYPE_free(typ);
+  if (len < 0) {
+    return NULL;
+  }
+  *ext_len = len;
   return ext_der;
 }
 
diff --git a/crypto/x509v3/v3_info.c b/crypto/x509v3/v3_info.c
index 2ac92213f..5e14b7658 100644
--- a/crypto/x509v3/v3_info.c
+++ b/crypto/x509v3/v3_info.c
@@ -168,7 +168,6 @@ static void *v2i_AUTHORITY_INFO_ACCESS(const X509V3_EXT_METHOD *method,
                                        const STACK_OF(CONF_VALUE) *nval) {
   AUTHORITY_INFO_ACCESS *ainfo = NULL;
   ACCESS_DESCRIPTION *acc;
-  char *objtmp, *ptmp;
   if (!(ainfo = sk_ACCESS_DESCRIPTION_new_null())) {
     return NULL;
   }
@@ -178,22 +177,21 @@ static void *v2i_AUTHORITY_INFO_ACCESS(const X509V3_EXT_METHOD *method,
         !sk_ACCESS_DESCRIPTION_push(ainfo, acc)) {
       goto err;
     }
-    ptmp = strchr(cnf->name, ';');
+    char *ptmp = strchr(cnf->name, ';');
     if (!ptmp) {
       OPENSSL_PUT_ERROR(X509V3, X509V3_R_INVALID_SYNTAX);
       goto err;
     }
-    int objlen = ptmp - cnf->name;
     CONF_VALUE ctmp;
     ctmp.name = ptmp + 1;
     ctmp.value = cnf->value;
     if (!v2i_GENERAL_NAME_ex(acc->location, method, ctx, &ctmp, 0)) {
       goto err;
     }
-    if (!(objtmp = OPENSSL_malloc(objlen + 1))) {
+    char *objtmp = OPENSSL_strndup(cnf->name, ptmp - cnf->name);
+    if (objtmp == NULL) {
       goto err;
     }
-    OPENSSL_strlcpy(objtmp, cnf->name, objlen + 1);
     acc->method = OBJ_txt2obj(objtmp, 0);
     if (!acc->method) {
       OPENSSL_PUT_ERROR(X509V3, X509V3_R_BAD_OBJECT);
diff --git a/crypto/x509v3/v3_skey.c b/crypto/x509v3/v3_skey.c
index cae776f68..caa7fe50a 100644
--- a/crypto/x509v3/v3_skey.c
+++ b/crypto/x509v3/v3_skey.c
@@ -54,12 +54,14 @@
  * (eay@cryptsoft.com).  This product includes software written by Tim
  * Hudson (tjh@cryptsoft.com). */
 
+#include <limits.h>
 #include <stdio.h>
 #include <string.h>
 
 #include <openssl/digest.h>
 #include <openssl/err.h>
 #include <openssl/obj.h>
+#include <openssl/mem.h>
 #include <openssl/x509v3.h>
 
 #include "../x509/internal.h"
@@ -74,21 +76,26 @@ char *i2s_ASN1_OCTET_STRING(const X509V3_EXT_METHOD *method,
 ASN1_OCTET_STRING *s2i_ASN1_OCTET_STRING(const X509V3_EXT_METHOD *method,
                                          const X509V3_CTX *ctx,
                                          const char *str) {
-  ASN1_OCTET_STRING *oct;
-  long length;
-
-  if (!(oct = ASN1_OCTET_STRING_new())) {
+  size_t len;
+  uint8_t *data = x509v3_hex_to_bytes(str, &len);
+  if (data == NULL) {
     return NULL;
   }
-
-  if (!(oct->data = x509v3_hex_to_bytes(str, &length))) {
-    ASN1_OCTET_STRING_free(oct);
-    return NULL;
+  if (len > INT_MAX) {
+    OPENSSL_PUT_ERROR(X509V3, ERR_R_OVERFLOW);
+    goto err;
   }
 
-  oct->length = length;
-
+  ASN1_OCTET_STRING *oct = ASN1_OCTET_STRING_new();
+  if (oct == NULL) {
+    goto err;
+  }
+  ASN1_STRING_set0(oct, data, (int)len);
   return oct;
+
+err:
+  OPENSSL_free(data);
+  return NULL;
 }
 
 static char *i2s_ASN1_OCTET_STRING_cb(const X509V3_EXT_METHOD *method,
diff --git a/crypto/x509v3/v3_utl.c b/crypto/x509v3/v3_utl.c
index 183cf6ab7..bbc82e283 100644
--- a/crypto/x509v3/v3_utl.c
+++ b/crypto/x509v3/v3_utl.c
@@ -494,7 +494,7 @@ err:
   return NULL;
 }
 
-unsigned char *x509v3_hex_to_bytes(const char *str, long *len) {
+unsigned char *x509v3_hex_to_bytes(const char *str, size_t *len) {
   unsigned char *hexbuf, *q;
   unsigned char ch, cl, *p;
   uint8_t high, low;
diff --git a/include/openssl/pem.h b/include/openssl/pem.h
index 9319ac80b..21885ba39 100644
--- a/include/openssl/pem.h
+++ b/include/openssl/pem.h
@@ -372,9 +372,6 @@ OPENSSL_EXPORT STACK_OF(X509_INFO) *PEM_X509_INFO_read(FILE *fp,
 // password.
 OPENSSL_EXPORT int PEM_def_callback(char *buf, int size, int rwflag,
                                     void *userdata);
-OPENSSL_EXPORT void PEM_proc_type(char *buf, int type);
-OPENSSL_EXPORT void PEM_dek_info(char *buf, const char *type, int len,
-                                 char *str);
 
 
 DECLARE_PEM_rw(X509, X509)
diff --git a/include/openssl/x509.h b/include/openssl/x509.h
index 9e9e5b179..19d647d33 100644
--- a/include/openssl/x509.h
+++ b/include/openssl/x509.h
@@ -413,13 +413,13 @@ OPENSSL_EXPORT X509 *d2i_X509_AUX(X509 **x509, const unsigned char **inp,
 // NULL, the alias is cleared instead. Aliases are not part of the certificate
 // itself and will not be serialized by |i2d_X509|.
 OPENSSL_EXPORT int X509_alias_set1(X509 *x509, const unsigned char *name,
-                                   int len);
+                                   ossl_ssize_t len);
 
 // X509_keyid_set1 sets |x509|'s key ID to |len| bytes from |id|. If |id| is
 // NULL, the key ID is cleared instead. Key IDs are not part of the certificate
 // itself and will not be serialized by |i2d_X509|.
 OPENSSL_EXPORT int X509_keyid_set1(X509 *x509, const unsigned char *id,
-                                   int len);
+                                   ossl_ssize_t len);
 
 // X509_alias_get0 looks up |x509|'s alias. If found, it sets |*out_len| to the
 // alias's length and returns a pointer to a buffer containing the contents. If
@@ -1792,7 +1792,7 @@ OPENSSL_EXPORT int NETSCAPE_SPKI_verify(NETSCAPE_SPKI *spki, EVP_PKEY *pkey);
 // If |len| is 0 or negative, the length is calculated with |strlen| and |str|
 // must be a NUL-terminated C string.
 OPENSSL_EXPORT NETSCAPE_SPKI *NETSCAPE_SPKI_b64_decode(const char *str,
-                                                       int len);
+                                                       ossl_ssize_t len);
 
 // NETSCAPE_SPKI_b64_encode encodes |spki| as a base64-encoded Netscape signed
 // public key and challenge (SPKAC) structure. It returns a newly-allocated
diff --git a/ssl/ssl_test.cc b/ssl/ssl_test.cc
index a731e41d6..85c06a508 100644
--- a/ssl/ssl_test.cc
+++ b/ssl/ssl_test.cc
@@ -12,6 +12,7 @@
  * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
  * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
 
+#include <limits.h>
 #include <stdio.h>
 #include <string.h>
 #include <time.h>
@@ -3431,8 +3432,10 @@ static bool GetServerTicketTime(long *out, const SSL_SESSION *session) {
   const uint8_t *iv = ticket + 16;
   bssl::ScopedEVP_CIPHER_CTX ctx;
   int len1, len2;
-  if (!EVP_DecryptInit_ex(ctx.get(), EVP_aes_128_cbc(), nullptr, kZeros, iv) ||
-      !EVP_DecryptUpdate(ctx.get(), plaintext.get(), &len1, ciphertext, len) ||
+  if (len > INT_MAX ||
+      !EVP_DecryptInit_ex(ctx.get(), EVP_aes_128_cbc(), nullptr, kZeros, iv) ||
+      !EVP_DecryptUpdate(ctx.get(), plaintext.get(), &len1, ciphertext,
+                         static_cast<int>(len)) ||
       !EVP_DecryptFinal_ex(ctx.get(), plaintext.get() + len1, &len2)) {
     return false;
   }
@@ -7751,8 +7754,8 @@ TEST(SSLTest, BIO) {
     // |BIO_should_write|.
     int ret;
     for (int i = 0; i < 1024; i++) {
-      std::vector<uint8_t> buffer(1024);
-      ret = BIO_write(client_bio.get(), buffer.data(), buffer.size());
+      const uint8_t kZeros[1024] = {0};
+      ret = BIO_write(client_bio.get(), kZeros, sizeof(kZeros));
       if (ret <= 0) {
         break;
       }
diff --git a/ssl/test/test_config.cc b/ssl/test/test_config.cc
index 94828c6f6..109c69ef4 100644
--- a/ssl/test/test_config.cc
+++ b/ssl/test/test_config.cc
@@ -17,6 +17,7 @@
 #include <assert.h>
 #include <ctype.h>
 #include <errno.h>
+#include <limits.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -572,8 +573,13 @@ static int NextProtosAdvertisedCallback(SSL *ssl, const uint8_t **out,
     return SSL_TLSEXT_ERR_NOACK;
   }
 
-  *out = (const uint8_t *)config->advertise_npn.data();
-  *out_len = config->advertise_npn.size();
+  if (config->advertise_npn.size() > UINT_MAX) {
+    fprintf(stderr, "NPN value too large.\n");
+    return SSL_TLSEXT_ERR_ALERT_FATAL;
+  }
+
+  *out = reinterpret_cast<const uint8_t *>(config->advertise_npn.data());
+  *out_len = static_cast<unsigned>(config->advertise_npn.size());
   return SSL_TLSEXT_ERR_OK;
 }